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  • 1.
    Ahlgren, Sara
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Andersson, Kristofer
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Kit formulation for 99mTc-labeling of recombinant anti-HER2 Affibody molecules with a C-terminally engineered cysteine2010In: Nuclear Medicine and Biology, ISSN 0969-8051, E-ISSN 1872-9614, Vol. 37, no 5, p. 539-546Article in journal (Refereed)
    Abstract [en]

    Introduction: Molecular imaging of HER2-expression in malignant tumors provides potentially important information for patient management. Affibody molecules have shown to be suitable tracers for imaging applications using SPECT or PET. Results from an earlier evaluation of the application of site specific 99mTc-labeling on the Affibody molecule, ZHER2:2395-C, were favorable.

    Methods: As a preparation for clinical application of this tracer we have developed and evaluated a robust single-vial freeze-dried kit, allowing labeling of the Affibody molecule, ZHER2:2395-C, with 99mTc.

    Results: The composition of the kit (containing glucoheptonate, EDTA and tin(II)-chloride), as well as the protein amount and the pertechnetate volume were optimized for a high labeling yield (> 90 %) and minimal presence of reduced hydrolyzed technetium colloids (< 1 %). The specificity to HER2 receptors, the binding competence and the stability in PBS and murine serum were verified in vitro. The shelf-life was also evaluated in vitro, showing no reduction in labeling yield or binding capacity to HER2-expressing cells after over 400 days of storage of the single-vial freeze-dried kit.

    Conclusions: ZHER2:2395-C labeled with 99mTc using the lyophilized kit was stable and resulted in a favorable biodistribution in an in vivo evaluation in normal NMRI mice.

  • 2.
    Ahlgren, Sara
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Rosik, Daniel
    Affibody AB, Stockholm, Sweden.
    Sandström, Mattias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Sjöberg, Anna
    Affibody AB, Stockholm, Sweden.
    Baastrup, Barbro
    Affibody AB, Stockholm, Sweden.
    Widmark, Olof
    Affibody AB, Stockholm, Sweden.
    Fant, Gunilla
    Affibody AB, Stockholm, Sweden.
    Feldwisch, Joachim
    Affibody AB, Stockholm, Sweden.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Evaluation of maleimide derivative of DOTA for site-specific labeling of recombinant affibody molecules2008In: Bioconjugate chemistry, ISSN 1043-1802, E-ISSN 1520-4812, Vol. 19, no 1, p. 235-243Article in journal (Refereed)
    Abstract [en]

    Affibody molecules are a new class of small (7 kDa) scaffold affinity proteins, which demonstrate promising properties as agents for in vivo radionuclide targeting. The Affibody scaffold is cysteine-free and therefore independent of disulfide bonds. Thus, a single thiol group can be engineered into the protein by introduction of one cysteine. Coupling of thiol-reactive bifunctional chelators can enable site-specific labeling of recombinantly produced Affibody molecules. In this study, the use of 1,4,7,10-tetraazacyclododecane-1,4,7-tris-acetic acid-10-maleimidoethylacetamide (MMA-DOTA) for 111 In-labeling of anti-HER2 Affibody molecules His 6-Z HER2:342-Cys and Z HER2:2395-Cys has been evaluated. The introduction of a cysteine residue did not affect the affinity of the proteins, which was 29 pM for His 6-Z HER2:342-Cys and 27 pM for Z HER2:2395-Cys, comparable with 22 pM for the parental Z HER2:342. MMA-DOTA was conjugated to DTT-reduced Affibody molecules with a coupling efficiency of 93% using a 1:1 molar ratio of chelator to protein. The conjugates were labeled with 111 In to a specific radioactivity of up to 7 GBq/mmol, with preserved binding for the target HER2. In vivo, the non-His-tagged variant 111 In-[MMA-DOTA-Cys61]-Z HER2:2395-Cys demonstrated appreciably lower liver uptake than its His-tag-containing counterpart. In mice bearing HER2-expressing LS174T xenografts, 111 In-[MMA-DOTA-Cys61]-Z HER2:2395-Cys showed specific and rapid tumor localization, and rapid clearance from blood and nonspecific compartments, leading to a tumor-to-blood-ratio of 18 +/- 8 already 1 h p.i. Four hours p.i., the tumor-to-blood ratio was 138 +/- 8. Xenografts were clearly visualized already 1 h p.i.

  • 3.
    Ahlgren, Sara
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science.
    Wållberg, Helena
    Affibody AB, Stockholm, Sweden.
    Hansson, Monika
    Affibody AB, Stockholm, Sweden.
    Sandström, Mattias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Oncology.
    Lewsley, Richard
    Department of Metabolism, Covance Laboratories Ltd, Harrogate, UK.
    Wennborg, Anders
    Affibody AB, Stockholm, Sweden.
    Abrahmsén, Lars
    Affibody AB, Stockholm, Sweden.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science.
    Feldwisch, Joachim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science.
    Targeting of HER2-Expressing Tumors Using 111In-ABY-025, a Second-Generation Affibody Molecule with a Fundamentally Reengineered Scaffold2010In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 51, no 7, p. 1131-1138Article in journal (Refereed)
    Abstract [en]

    Overexpression of HER2 in breast carcinomas predicts response to trastuzumab therapy. Affibody molecules based on a non-immunoglobulin scaffold have demon-strated high potential for in vivo molecular imaging of HER2-expressing tumors. Re-engineering of the molecular scaffold has led to a second generation of optimized Affibody molecules, having a surface distinctly different from the parental protein domain from staphylococcal protein A. The new tracer showed further increased melting point, stability and overall hydrophilicity compared to the parental molecule, and was shown to be more amenable for chemical peptide synthesis. The goal of this study was to assess potential effects of this extensive re-engineering on HER2 targeting, using ABY-025, a DOTA conjugated variant of the novel tracer.

    Methods: 111In-ABY-025 was compared with previously evaluated parent HER2-binding Affibody tracers in vitro and in vivo. The in vivo behavior was further evaluated in mice bearing SKOV-3 xenografts, in rats and in cynomolgus macaques.

    Results: 111In-ABY-025 bound specifically to HER2 in vitro and in vivo. Direct comparison with the previous generation of HER2-binding tracers showed that ABY-025 retained excellent targeting properties. Rapid blood clearance was shown in mice, rats and macaques. A highly specific tumor uptake of 16.7 ± 2.5 %IA/g was seen at 4 h after injection. The tumor-to-blood ratio was 6.3 at 0.5 h, 88 at 4 h, and increased up to 3 days after injection. Gamma camera imaging of tumors was already possible 0.5 h after injection. Furthermore, repeated i.v. administration of ABY-025 did not induce antibody formation in rats.

    Conclusions: The biodistribution of 111In-ABY-025 was in remarkably good agreement with the parent tracers, despite profound re-engineering of the non-binding surface. The molecule displayed rapid blood clearance in all species investigated and excellent targeting capacity in tumor bearing mice, leading to high tumor-to-organ-ratios and high contrast imaging shortly after injection.

  • 4.
    Ahlgren, Sara
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Wållberg, Helena
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Tran, Thuy A.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Widström, Charles
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Section of Medical Physics.
    Hjertman, Magnus
    Affibody AB, Stockholm, Sweden.
    Abrahmsén, Lars
    Affibody AB, Stockholm, Sweden.
    Berndorff, Dietmar
    Global Drug Discovery, Bayer Schering Pharma AG, Berlin, Germany.
    Dinkelborg, Ludger M.
    Global Drug Discovery, Bayer Schering Pharma AG, Berlin, Germany.
    Cyr, John E.
    Global Drug Discovery, Bayer Schering Pharma AG, Berlin, Germany.
    Feldwisch, Joachim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Targeting of HER2-expressing tumors with a site-specifically 99mTc-labeled recombinant affibody molecule, ZHER2:2395, with C-terminally engineered cysteine2009In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 50, no 5, p. 781-789Article in journal (Refereed)
    Abstract [en]

    The detection of human epidermal growth factor receptor type 2 (HER2) expression in malignant tumors provides important information influencing patient management. Radionuclide in vivo imaging of HER2 may permit the detection of HER2 in both primary tumors and metastases by a single noninvasive procedure. Small (7 kDa) high-affinity anti-HER2 Affibody molecules may be suitable tracers for SPECT visualization of HER2-expressing tumors. The use of generator-produced (99m)Tc as a label would facilitate the prompt translation of anti-HER2 Affibody molecules into use in clinics. METHODS: A C-terminal cysteine was introduced into the Affibody molecule Z(HER2:342) to enable site-specific labeling with (99m)Tc. Two recombinant variants, His(6)-Z(HER2:342)-Cys (dissociation constant [K(D)], 29 pM) and Z(HER2:2395)-Cys, lacking a His tag (K(D), 27 pM), were labeled with (99m)Tc in yields exceeding 90%. The binding specificity and the cellular processing of Affibody molecules were studied in vitro. Biodistribution and gamma-camera imaging studies were performed in mice bearing HER2-expressing xenografts. RESULTS: (99m)Tc-His(6)-Z(HER2:342)-Cys was capable of targeting HER2-expressing SKOV-3 xenografts in SCID mice, but the liver radioactivity uptake was high. A series of comparative biodistribution experiments indicated that the presence of the His tag caused elevated accumulation in the liver. (99m)Tc-Z(HER2:2395)-Cys, not containing a His tag, showed low uptake in the liver and high and specific uptake in HER2-expressing xenografts. Four hours after injection, the radioactivity uptake values (percentage of injected activity per gram of tissue [%IA/g]) were 6.9 +/- 2.5 (mean +/- SD) %IA/g in LS174T xenografts (moderate level of HER2 expression) and 15 +/- 3 %IA/g in SKOV-3 xenografts (high level of HER2 expression). The corresponding tumor-to-blood ratios were 88 +/- 24 and 121 +/- 24, respectively. Both LS174T and SKOV-3 xenografts were clearly visualized with a clinical gamma-camera 1 h after injection of (99m)Tc-Z(HER2:2395)-Cys. CONCLUSION: The Affibody molecule (99m)Tc-Z(HER2:2395)-Cys is a promising tracer for SPECT visualization of HER2-expressing tumors.

  • 5.
    Almqvist, Ylva
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Sjöström, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Jensen, Holger J.
    Danmark.
    Lundqvist, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Sundin, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    In vitro characterization of 211 At-labeled antibody A33: a potential therapeutic agent against metastatic colorectal carcinoma2005In: Cancer Biotherapy and Radiopharmaceuticals, ISSN 1084-9785, E-ISSN 1557-8852, Vol. 20, no 5, p. 514-523Article in journal (Refereed)
    Abstract [en]

    The humanized antibody A33 binds to the A33 antigen, expressed in 95% of primary and metastatic colorectal carcinomas. The restricted pattern of expression in normal tissue makes this antigen a possible target for radioimmunotherapy of colorectal micrometastases. In this study, the A33 antibody was labeled with the therapeutic nuclide 211At using N-succinimidyl para-(tri-methylstannyl)benzoate (SPMB). The in vitro characteristics of the 211At-benzoate-A33 conjugate (211At-A33) were investigated and found to be similar to those of 125I-benzoate-A33 (125I-A33) in different assays. Both conjugates bound with high affinity to SW1222 cells (Kd = 1.7 ± 0.2 nM, and 1.8 ± 0.1 nM for 211At-A33 and 125I-A33, respectively), and both showed good intracellular retention (70% of the radioactivity was still cell associated after 20 hours). The cytotoxic effect of 211At-A33 was also confirmed. After incubation with 211At-A33, SW1222 cells had a survival of approximately 0.3% when exposed to some 150 decays per cell (DPC). The cytotoxic effect was found to be dose-dependent, as cells exposed to only 56 DPC had a survival of approximately 5%. The 211At-A33 conjugate shows promise as a potential radioimmunotherapy agent for treatment of micrometastases originating from colorectal carcinoma.

  • 6.
    Almqvist, Ylva
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Steffen, Ann-Charlott
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Divgi, Chaitanya R.
    Sundin, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    In vitro and in vivo characterization of 177Lu‑huA33: A radioimmunoconjugate against colorectal cancer2006In: Nuclear Medicine and Biology, ISSN 0969-8051, E-ISSN 1872-9614, Vol. 33, no 8, p. 991-998Article in journal (Refereed)
    Abstract [en]

    INTRODUCTION: The humanized monoclonal antibody A33 (huA33) is a potential targeting agent against colorectal carcinoma since the A33 antigen is highly and homogenously expressed in >95% of all colorectal cancers, both primary tumors and metastases. The aim of this study was to determine the biodistribution and tumor-targeting ability of (177)Lu-labeled huA33. METHODS: huA33 was labeled with the beta-emitting therapeutic nuclide (177)Lu using the chelator CHX-A"-DTPA, and the properties of the (177)Lu-CHX-A"-huA33 ((177)Lu-huA33) conjugate was determined both in vitro and in vivo in a biodistribution study in nude mice xenografted with colorectal SW1222 tumor cells. RESULTS: The (177)Lu-huA33 conjugate bound specifically to colorectal cancer cells in vitro (with a K(D) value of 2.3+/-0.3 nM, determined by a saturation assay) and in vivo. The tumor uptake of (177)Lu-huA33 was very high, peaking at 134+/-21%ID/g 72 h postinjection (pi). Normal tissue uptake was low; radioactivity concentration in blood (which had the second highest radioactivity concentration) was lower than in tumor at all time points studied (8 h to 10 days). The tumor-to-blood ratio increased with time, reaching 70+/-30, 10 days pi. Throughout the study, the uptake of (177)Lu in bone (known to accumulate free (177)Lu) was low, and the fraction of protein-bound (177)Lu in plasma samples was high (95% to 99%). This indicates high stability of the (177)Lu-huA33 conjugate in vivo. CONCLUSION: The (177)Lu-huA33 conjugate shows a very favorable biodistribution, with an impressively high tumor uptake and high tumor-to-organ ratios, indicating that the conjugate may be suitable for radioimmunotherapy of colorectal cancer.

  • 7.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Honarvar, Hadis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Wållberg, Helena
    Strand, Joanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Varasteh, Zohreh
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Dunås, Finn
    Sandström, Mattias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science.
    Rosestedt, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Löfblom, John
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Ståhl, Stefan
    Selection of an optimal cysteine-containing peptide-based chelator for labeling of Affibody molecules with 188-Re2013In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 40, no Suppl. 2, p. S219-S220Article in journal (Other academic)
    Abstract [en]

    Affibody molecules constitute a class of small (7 kDa) scaffold proteins that can be engineered to have excellent tumor targeting properties. High reabsorption in kidneys complicates development of affibody molecules for radionuclide therapy. In this study, we evaluated the influence of the composition of cysteine-containing C-terminal peptide-based chelators on the biodistribution and renal retention of 188Re-labeled anti-HER2 affibody molecules. Biodistribution of affibody molecules containing GGXC or GXGC peptide chelators (where X is G, S, E or K) was compared with biodistribution of a parental affibody molecule ZHER2:2395 having a KVDC peptide chelator. All constructs retained low picomolar affinity to HER2-expressing cells after labeling. The biodistribution of all 188Re-labeled affibody molecules was in general comparable, with the main observed difference found in the uptake and retention of radioactivity in excretory organs. The 188Re-ZHER2:V2 affibody molecule with a GGGC chelator provided the lowest uptake in all organs and tissues. The renal retention of 188Re-ZHER2:V2 (3.1±0.5 %ID/g at 4 h after injection) was 55-fold lower than retention of the parental 188Re-ZHER2:2395 (172±32 %ID/g). We show that engineering of cysteine-containing peptide-based chelators can be used for significant improvement of biodistribution of 188Re-labeled scaffold proteins, particularly reduction of their uptake in excretory organs.

  • 8.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Honarvar, Hadis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Wållberg, Helena
    Strand, Joanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Varasteh, Zohreh
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Rosestedt, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Dunås, Finn
    Sandström, Mattias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Medical Radiation Sciences.
    Löfblom, John
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Ståhl, Stefan
    Selection of an optimal cysteine-containing peptide-based chelator for labeling of affibody molecules with 188Re2014In: European Journal of Medicinal Chemistry, ISSN 0223-5234, E-ISSN 1768-3254, Vol. 87, p. 519-528Article in journal (Refereed)
    Abstract [en]

    Affibody molecules constitute a class of small (7 kDa) scaffold proteins that can be engineered to have excellent tumor targeting properties. High reabsorption in kidneys complicates development of affibody molecules for radionuclide therapy. In this study, we evaluated the influence of the composition of cysteine-containing C-terminal peptide-based chelators on the biodistribution and renal retention of 188Re-labeled anti-HER2 affibody molecules. Biodistribution of affibody molecules containing GGXC or GXGC peptide chelators (where X is G, S, E or K) was compared with biodistribution of a parental affibody molecule ZHER2:2395 having a KVDC peptide chelator. All constructs retained low picomolar affinity to HER2-expressing cells after labeling. The biodistribution of all 188Re-labeled affibody molecules was in general comparable, with the main observed difference found in the uptake and retention of radioactivity in excretory organs. The 188Re-ZHER2:V2 affibody molecule with a GGGC chelator provided the lowest uptake in all organs and tissues. The renal retention of 188Re-ZHER2:V2 (3.1 ± 0.5 %ID/g at 4 h after injection) was 55-fold lower than retention of the parental 188Re-ZHER2:2395 (172 ± 32 %ID/g). We show that engineering of cysteine-containing peptide-based chelators can be used for significant improvement of biodistribution of 188Re-labeled scaffold proteins, particularly reduction of their uptake in excretory organs.

  • 9.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Liu, H.
    KTH, Div Prot Technol, Stockholm, Sweden..
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Gräslund, T.
    KTH, Div Prot Technol, Stockholm, Sweden..
    Improving of molecular design of a novel Affibody-fused HER2-recognising anticancer toxin using radionuclide-based techniques2016In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 43, p. S178-S178Article in journal (Refereed)
  • 10.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Membreno, Rosemery
    CUNY Hunter Coll, Dept Chem, New York, NY 10021 USA.;CUNY, Grad Ctr, PhD Program Chem, New York, NY USA.;Mem Sloan Kettering Canc Ctr, Dept Radiol, 1275 York Ave, New York, NY 10021 USA..
    Cook, Brendon
    CUNY Hunter Coll, Dept Chem, New York, NY 10021 USA.;CUNY, Grad Ctr, PhD Program Chem, New York, NY USA.;Mem Sloan Kettering Canc Ctr, Dept Radiol, 1275 York Ave, New York, NY 10021 USA..
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Zeglis, Brian M.
    CUNY Hunter Coll, Dept Chem, New York, NY 10021 USA.;CUNY, Grad Ctr, PhD Program Chem, New York, NY USA.;Mem Sloan Kettering Canc Ctr, Dept Radiol, 1275 York Ave, New York, NY 10021 USA..
    Pretargeted Imaging and Therapy2017In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 58, no 10, p. 1553-1559Article in journal (Refereed)
    Abstract [en]

    In vivo pretargeting stands as a promising approach to harnessing the exquisite tumor-targeting properties of antibodies for nuclear imaging and therapy while simultaneously skirting their pharmacokinetic limitations. The core premise of pretargeting lies in administering the targeting vector and radioisotope separately and having the 2 components combine within the body. In this manner, pretargeting strategies decrease the circulation time of the radioactivity, reduce the uptake of the radionuclide in healthy nontarget tissues, and facilitate the use of short-lived radionuclides that would otherwise be incompatible with antibody-based vectors. In this short review, we seek to provide a brief yet informative survey of the 4 preeminent mechanistic approaches to pretargeting, strategies predicated on streptavidin and biotin, bispecific antibodies, complementary oligonucleotides, and bioorthogonal click chemistry.

  • 11.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Radiolabeled Probes Targeting Tyrosine-Kinase Receptors For Personalized Medicine2014In: Current pharmaceutical design, ISSN 1381-6128, E-ISSN 1873-4286, Vol. 20, no 14, p. 2275-2292Article in journal (Refereed)
    Abstract [en]

    Receptor tyrosine kinases (RTK) are transmembrane receptors regulating cellular proliferation, differentiation, apoptosis, motility and recruitment of the vasculature. Aberrant expression and/or function of RTK have been detected in many malignant tumors and are considered to be a part of the transformed phenotype. The action of several classes of anti-cancer drugs is based on specific recognition of RTK. Monoclonal antibodies target extracellular binding domains, while tyrosine kinase inhibitors (TKI) bind to intracellular kinase domains to suppress RTK signaling. The issues regarding the efficient use of RTK targeting are the inter- and intra-patient heterogeneity of RTK expression and the changes of expression levels during the course of disease and in response to therapy. Radionuclide molecular imaging of RTK expression may aid in selecting patients who would benefit from RTK-targeting therapy and in identifying non-responders. Therefore, the therapy would be more personalized. Currently, radiolabeled proteins (monoclonal antibodies and their fragments, natural peptides ligands to RTK and de novo selected affinity proteins) and TKI and their analogues are under development for the visualization of RTK. In this review, we discuss the advantages and disadvantages of these approaches.

  • 12.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Perols, Anna
    Eriksson Karlström, Amelie
    Sandström, Mattias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Medical Physics.
    Boschetti, Frederic
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Preclinical evaluation of anti-HER2 Affibody molecules site-specifically labeled with 111In using a maleimido derivative of NODAGA2012In: Nuclear Medicine and Biology, ISSN 0969-8051, E-ISSN 1872-9614, Vol. 39, no 4, p. 518-529Article in journal (Refereed)
    Abstract [en]

    Introduction

    Affibody molecules have demonstrated potential for radionuclide molecular imaging. The aim of this study was to synthesize and evaluate a maleimido derivative of the 1,4,7-triazacyclononane-1-glutaric acid-4,7-diacetic acid (NODAGA) for site-specific labeling of anti-HER2 Affibody molecule.

    Methods

    The maleimidoethylmonoamide NODAGA (MMA-NODAGA) was synthesized and conjugated to ZHER2:2395 Affibody molecule having a C-terminal cysteine. Labeling efficiency, binding specificity to and cell internalization by HER2-expressing cells of [111In-MMA-NODAGA-Cys61]-ZHER2:2395 were studied. Biodistribution of [111In-MMA-NODAGA-Cys61]-ZHER2:2395 and [111In-MMA-DOTA-Cys61]-ZHER2:2395 was compared in mice.

    Results

    The affinity of [MMA-NODAGA-Cys61]-ZHER2:2395 binding to HER2 was 67 pM. The 111In-labeling yield was 99.6%±0.5% after 30 min at 60°C. [111In-MMA-NODAGA-Cys61]-ZHER2:2395 bound specifically to HER2-expressing cells in vitro and in vivo. Tumor uptake of [111In-MMA-NODAGA-Cys61]-ZHER2:2395 in mice bearing DU-145 xenografts (4.7%±0.8% ID/g) was lower than uptake of [111In-MMA-DOTA-Cys61]-ZHER2:2395 (7.5%±1.6% ID/g). However, tumor-to-organ ratios were higher for [111In-MMA-NODAGA-Cys61]-ZHER2:2395 due to higher clearance rate from normal tissues.

    Conclusions

    MMA-NODAGA is a promising chelator for site-specific labeling of targeting proteins containing unpaired cysteine. Appreciable influence of chelators on targeting properties of Affibody molecules was demonstrated.

  • 13.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Perols, Anna
    Tsourma, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Mitran, Bogdan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Honarvar, Hadis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Robillard, Marc
    Rossin, Raffaella
    Ten Hoeve, Wolter
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Eriksson Karlström, Amelie
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Feasibility of affibody-based bioorthogonal chemistry-mediated radionuclide pretargeting2016In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 57, no 3, p. 431-436Article in journal (Refereed)
    Abstract [en]

    Affibody molecules constitute a new class of probes for radionuclide tumor targeting. The small size of affibody molecules is favorable for rapid localization in tumors and clearance from circulation. However, high renal re-absorption of affibody molecules prevents the use of residualizing radiometals, including a number of promising low energy beta- and alpha-emitters, for radionuclide therapy. We tested a hypothesis that affibody-based pretargeting mediated by a bioorthogonal interaction between trans-cyclooctene (TCO) and tetrazine would provide higher accumulation of radiometals in tumor xenografts than in the kidneys.

    Methods:

    TCO was conjugated to the anti-HER2 affibody molecule Z2395. DOTA-tetrazine was labeled with indium-111 and lutetium-177. In vitro pretargeting was studied in HER2-expressing SKOV-3 and BT474 cell lines. In vivo studies were performed on BALB/C nu/nu mice bearing SKOV-3 xenografts.

    Results:

    125I-Z2395-TCO bound specifically to HER2-expressing cells in vitro with an affinity of 45±16 pM. 111In-tetrazine bound specifically and selectively to Z2395-TCO pre-treated cells. In vivo studies demonstrated HER2-specific 125I-Z2395-TCO accumulation in xenografts. TCO-mediated 111In-tetrazine localization was shown in tumors, when the radiolabeled tracer was injected 4 h after an injection of Z2395-TCO. At 1 h post injection, the tumor uptake of 111In-tetrazine and 177Lu-tetrazine was ca. 2-fold higher than the renal uptake. Pretargeting provided more than a 56-fold reduction of renal uptake of 111In in comparison with direct targeting.

    Conclusion:

    The feasibility of affibody-based bioorthogonal chemistry-mediated pretargeting was demonstrated. The use of pretargeting provides a substantial reduction of radiometal accumulation in kidneys, creating preconditions for palliative radionuclide therapy.

  • 14.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Strand, Joanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Rosik, D.
    Selvaraju, Ram Kumar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Karlstrom, A. Eriksson
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Comparative evaluation of anti-HER2 affibody molecules labeled with 68Ga and 111In using maleimido derivatives of DOTA and NODAGA2012In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 39, no S2, p. S299-S299Article in journal (Other academic)
  • 15.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Strand, Joanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Rosik, Daniel
    Selvaraju, Ram Kumar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Eriksson Karlström, Amelie
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Influence of Nuclides and Chelators on Imaging Using Affibody Molecules: Comparative Evaluation of Recombinant Affibody Molecules Site-Specifically Labeled with 68Ga and 111In via Maleimido Derivatives of DOTA and NODAGA2013In: Bioconjugate chemistry, ISSN 1043-1802, E-ISSN 1520-4812, Vol. 24, no 6, p. 1102-1109Article in journal (Refereed)
    Abstract [en]

    Accurate detection of cancer-associated molecular abnormalities in tumors could make cancer treatment more personalized. Affibody molecules enable high contrast imaging of tumor-associated protein expression shortly after injection. The use of the generator-produced positron-emitting radionuclide 68Ga should increase sensitivity of HER2 imaging. The chemical nature of radionuclides and chelators influences the biodistribution of Affibody molecules, providing an opportunity to further increase the imaging contrast. The aim of the study was to compare maleimido derivatives of DOTA and NODAGA for site-specific labeling of a recombinant ZHER2:2395 HER2-binding Affibody molecule with 68Ga. DOTA and NODAGA were site-specifically conjugated to the ZHER2:2395 Affibody molecule having a C-terminal cysteine and labeled with 68Ga and 111In. All labeled conjugates retained specificity to HER2 in vitro. Most of the cell-associated activity was membrane-bound with a minor difference in internalization rate. All variants demonstrated specific targeting of xenografts and a high tumor uptake. The xenografts were clearly visualized using all conjugates. The influence of chelator on the biodistribution and targeting properties was much less pronounced for 68Ga than for 111In. The tumor uptake of 68Ga-NODAGA-ZHER2:2395 and 68Ga-DOTA-ZHER2:2395 and tumor-to-blood ratios at 2 h p.i. did not differ significantly. However, the tumor-to-liver ratio was significantly higher for 68Ga-NODAGA- ZHER2:2395 (8 ± 2 vs 5.0 ± 0.3) offering the advantage of better liver metastases visualization. In conclusion, influence of chelators on biodistribution of Affibody molecules depends on the radionuclides and reoptimization of labeling chemistry is required when a radionuclide label is changed.

  • 16.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Tsourma, M.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology. Dept Immunol Genet & Pathol, Uppsala, Sweden..
    Mitran, Bogdan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform. Preclin PET Platform, Uppsala, Sweden..
    Honarvar, Hadis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science. Dept Immunol Genet & Pathol, Uppsala, Sweden..
    Perols, A.
    KTH, Div Prot Technol, Stockholm, Sweden..
    Robillard, M.
    Tagworks Pharmaceut, Eindhoven, Netherlands..
    Rossin, R.
    Tagworks Pharmaceut, Eindhoven, Netherlands..
    ten Hoeve, W.
    Syncom BV, Groningen, Netherlands..
    Sandström, Mattias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Karlstrom, A. Eriksson
    KTH, Div Prot Technol, Stockholm, Sweden..
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Affibody-based bioorthogonal chemistry-mediated radionuclide pretargeting: proof-of-principle2015In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 42, no S1, p. S246-S246Article in journal (Other academic)
  • 17.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Westerlund, K.
    KTH, Div Prot Technol, Stockholm, Sweden..
    Velletta, J.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Honarvar, Hadis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Eriksson-Karlström, A.
    KTH, Div Prot Technol, Stockholm, Sweden..
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Comparative evaluation of Lu-177-HP2 and In-111-HP2, secondary agents for affibody-based PNA-mediated radionuclide pretargeting2016In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 43, p. S237-S237Article in journal (Refereed)
  • 18.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Wållberg, Helena
    Honarvar, Hadis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Strand, Joanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Varasteh, Zohreh
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Sandström, Mattias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Medical Radiation Sciences. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Löfblom, John
    Larsson, Erik
    Strand, Sven-Erik
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Medical Physics.
    Ståhl, Stefan
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    188Re-ZHER2:V2, a promising affibody-based targeting agent against HER2-expressing tumors: preclinical assessment2014In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 55, no 11, p. 1842-1848Article in journal (Refereed)
    Abstract [en]

    Affibody molecules are small (7 kDa) nonimmunoglobulin scaffold proteins with favorable tumor-targeting properties. Studies concerning the influence of chelators on biodistribution of 99mTc-labeled Affibody molecules demonstrated that the variant with a C-terminal glycyl-glycyl-glycyl-cysteine peptide–based chelator (designated ZHER2:V2) has the best biodistribution profile in vivo and the lowest renal retention of radioactivity. The aim of this study was to evaluate 188Re-ZHER2:V2 as a potential candidate for radionuclide therapy of human epidermal growth factor receptor type 2 (HER2)–expressing tumors.

    Methods:

    ZHER2:V2 was labeled with 188Re using a gluconate-containing kit. Targeting of HER2-overexpressing SKOV-3 ovarian carcinoma xenografts in nude mice was studied for a dosimetry assessment.

    Results:

    Binding of 188Re-ZHER2:V2 to living SKOV-3 cells was demonstrated to be specific, with an affinity of 6.4 ± 0.4 pM. The biodistribution study showed a rapid blood clearance (1.4 ± 0.1 percentage injected activity per gram [%ID/g] at 1 h after injection). The tumor uptake was 14 ± 2, 12 ± 2, 5 ± 2, and 1.8 ± 0.5 %IA/g at 1, 4, 24, and 48 h after injection, respectively. The in vivo targeting of HER2-expressing xenografts was specific. Already at 4 h after injection, tumor uptake exceeded kidney uptake (2.1 ± 0.2 %IA/g). Scintillation-camera imaging showed that tumor xenografts were the only sites with prominent accumulation of radioactivity at 4 h after injection. Based on the biokinetics, a dosimetry evaluation for humans suggests that 188Re-ZHER2:V2 would provide an absorbed dose to tumor of 79 Gy without exceeding absorbed doses of 23 Gy to kidneys and 2 Gy to bone marrow. This indicates that future human radiotherapy studies may be feasible.

    Conclusion:

    188Re-ZHER2:V2 can deliver high absorbed doses to tumors without exceeding kidney and bone marrow toxicity limits.

  • 19.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Wållberg, Helena
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Rosestedt, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Hosseinimehr, Seyed Jalal
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Ståhl, Stefan
    Order of amino acids in C-terminal cysteine-containing peptide-based chelators influences cellular processing and biodistribution of (99m)Tc-labeled recombinant Affibody molecules2012In: Amino Acids, ISSN 0939-4451, E-ISSN 1438-2199, Vol. 42, no 5, p. 1975-1985Article in journal (Refereed)
    Abstract [en]

    Affibody molecules constitute a novel class of molecular display selected affinity proteins based on non-immunoglobulin scaffold. Preclinical investigations and pilot clinical data have demonstrated that Affibody molecules provide high contrast imaging of tumor-associated molecular targets shortly after injection. The use of cysteine-containing peptide-based chelators at the C-terminus of recombinant Affibody molecules enabled site-specific labeling with the radionuclide (99m)Tc. Earlier studies have demonstrated that position, composition and the order of amino acids in peptide-based chelators influence labeling stability, cellular processing and biodistribution of Affibody molecules. To investigate the influence of the amino acid order, a series of anti-HER2 Affibody molecules, containing GSGC, GEGC and GKGC chelators have been prepared and characterized. The affinity to HER2, cellular processing of (99m)Tc-labeled Affibody molecules and their biodistribution were investigated. These properties were compared with that of the previously studied (99m)Tc-labeled Affibody molecules containing GGSC, GGEC and GGKC chelators. All variants displayed picomolar affinities to HER2. The substitution of a single amino acid in the chelator had an appreciable influence on the cellular processing of (99m)Tc. The biodistribution of all (99m)Tc-labeled Affibody molecules was in general comparable, with the main difference in uptake and retention of radioactivity in excretory organs. The hepatic accumulation of radioactivity was higher for the lysine-containing chelators and the renal retention of (99m)Tc was significantly affected by the amino acid composition of chelators. The order of amino acids influenced renal uptake of some conjugates at 1 h after injection, but the difference decreased at later time points. Such information can be helpful for the development of other scaffold protein-based imaging and therapeutic radiolabeled conjugates.

  • 20. Andersson, K. G.
    et al.
    Varasteh, Zohreh
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Rosestedt, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Malm, M.
    Sandström, Mattias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Medical Radiation Sciences.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Lofblom, J.
    Stahl, S.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    111In-labeled NOTA-conjugated Affibody molecules for visualization of HER3 expression in malignant tumors2014In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 41, no S2, p. S311-S311, article id OP681Article in journal (Other academic)
  • 21.
    Andersson, Ken G.
    et al.
    KTH Royal Inst Technol, Div Prot Technol, SE-10691 Stockholm, Sweden.
    Oroujeni, Maryam
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Garousi, Javad
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Mitran, Bogdan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Ståhl, Stefan
    KTH Royal Inst Technol, Div Prot Technol, SE-10691 Stockholm, Sweden.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Löfblom, John
    KTH Royal Inst Technol, Div Prot Technol, SE-10691 Stockholm, Sweden.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Feasibility of imaging of epidermal growth factor receptor expression with ZEGFR: 2377 affibody molecule labeled with 99mTc using a peptide-based cysteine-containing chelator2016In: International journal of oncology, ISSN 1791-2423, Vol. 49, no 6, p. 2285-2293Article in journal (Refereed)
    Abstract [en]

    The epidermal growth factor receptor (EGFR) is overexpressed in a number of malignant tumors and is a molecular target for several specific anticancer antibodies and tyrosine kinase inhibitors. The overexpression of EGFR is a predictive biomarker for response to several therapy regimens. Radionuclide molecular imaging might enable detection of EGFR overexpression by a non-invasive procedure and could be used repeatedly. Affibody molecules are engineered scaffold proteins, which could be selected to have a high affinity and selectivity to predetermined targets. The anti-EGFR ZEGFR:2377 affibody molecule is a potential imaging probe for EGFR detection. The use of the generator-produced radionuclide 99mTc should facilitate clinical translation of an imaging probe due to its low price, availability and favorable dosimetry of the radionuclide. In the present study, we evaluated feasibility of ZEGFR:2377 labeling with 99mTc using a peptide-based cysteine-containing chelator expressed at the C-terminus of ZEGFR:2377. The label was stable in vitro under cysteine challenge. In addition, 99mTc-ZEGFR:2377 was capable of specific binding to EGFR-expressing cells with high affinity (274 pM). Studies in BALB/C nu/nu mice bearing A431 xenografts demonstrated that 99mTc-ZEGFR:2377 accumulates in tumors in an EGFR-specific manner. The tumor uptake values were 3.6±1 and 2.5±0.4% ID/g at 3 and 24 h after injection, respectively. The corresponding tumor-to-blood ratios were 1.8±0.4 and 8±3. The xenografts were clearly visualized at both time-points. This study demonstrated the potential of 99mTc-labeled ZEGFR:2377 for imaging of EGFR in vivo.

  • 22. Andersson, Ken G.
    et al.
    Rosestedt, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Varasteh, Zohreh
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Malm, Magdalena
    Sandström, Mattias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Lofblom, John
    Stahl, Stefan
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Comparative evaluation of 111In-labeled NOTA‑conjugated affibody molecules for visualization of HER3 expression in malignant tumors2015In: Oncology Reports, ISSN 1021-335X, E-ISSN 1791-2431, Vol. 34, no 2, p. 1042-1048Article in journal (Refereed)
    Abstract [en]

    Expression of human epidermal growth factor receptor type 3 (HER3) in malignant tumors has been associated with resistance to a variety of anticancer therapies. Several anti-HER3 monoclonal antibodies are currently under pre-clinical and clinical development aiming to overcome HER3-mediated resistance. Radionuclide molecular imaging of HER3 expression may improve treatment by allowing the selection of suitable patients for HER3-targeted therapy. Affibody molecules are a class of small (7 kDa) high-affinity targeting proteins with appreciable potential as molecular imaging probes. In a recent study, we selected affibody molecules with affinity to HER3 at a low picomolar range. The aim of the present study was to develop an anti-HER3 affibody molecule suitable for labeling with radiometals. The HEHEHE-Z08698-NOTA and HEHEHE-Z08699-NOTA HER3-specific affibody molecules were labeled with indium-111 (In-111) and assessed in vitro and in vivo for imaging properties using single photon emission computed tomography (SPECT). Labeling of HEHEHE-Z08698-NOTA and HEHEHE-Z08699-NOTA with In-111 provided stable conjugates. In vitro cell tests demonstrated specific binding of the two conjugates to HER3-expressing BT-474 breast carcinoma cells. In mice bearing BT-474 xenografts, the tumor uptake of the two conjugates was receptor-specific. Direct in vivo comparison of In-111-HEHEHE-Z08698-NOTA and In-111-HEHEHE-Z08699-NOTA demonstrated that the two conjugates provided equal radioactivity uptake in tumors, although the tumor-to-blood ratio was improved for In-111-HEHEHE-Z08698-NOTA [12 +/- 3 vs. 8 +/- 1,4 h post injection (p.i)] due to more efficient blood clearance. In-111-HEHEHE-Z08698-NOTA is a promising candidate for imaging of HER3-expression in malignant tumors using SPECT. Results of the present study indicate that this conjugate could be used for patient stratification for anti-HER3 therapy.

  • 23. Babaei, Mohammad Hossein
    et al.
    Almqvist, Ylva
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Shafii, Mohammad
    Kairemo, Kalevi
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    [99mTc] HYNIC-hEGF, a potential agent for imaging of EGF receptors in vivo: preparation and pre-clinical evaluation2005In: Oncology Reports, ISSN 1021-335X, E-ISSN 1791-2431, Vol. 13, no 6, p. 1169-75Article in journal (Refereed)
    Abstract [en]

    Expression of epidermal growth factor receptors (EGFR) has prognostic and predictive value in many kinds of tumors. Imaging of expression of EGFR in vivo may give valuable diagnostic information. The epidermal growth factor (EGF), a natural ligand, is a possible candidate for the targeting of EGFR. The present study describes a method for preparation of (99m)Tc-EGF via the hydrazinopyridine-3-carboxylic acid (HYNIC) conjugation using tricine and ethylenediamine-N,N'-diacetic acid (EDDA) as co-ligands. Both conjugates bound EGFR expressing cells with nanomolar affinity, and demonstrated good intracellular retention. The complex with EDDA demonstrated much higher stability in blood serum and during cysteine challenge. Biodistribution of (99m)Tc-EDDA-HYNIC-EGF in normal mice demonstrated fast blood clearance of conjugate, and its ability to bind EGFR in vivo. (99m)Tc-EDDA-HYNIC-EGF is a promising candidate for visualization of EGFR expression in vivo.

  • 24. Barta, Pavel
    et al.
    Malmberg, Jennie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Melicharova, Ludmila
    Strandgård, John
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Laznicek, Milan
    Andersson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Protein interactions with HER-family receptors can have different characteristics depending on the hosting cell line2012In: International Journal of Oncology, ISSN 1019-6439, Vol. 40, no 5, p. 1677-1682Article in journal (Refereed)
    Abstract [en]

    Cell lines are common model systems in the development of therapeutic proteins and in the research on cellular functions and dysfunctions. In this field, the protein interaction assay is a frequently used tool for assessing the adequacy of a protein for diagnostic and therapeutic purposes. In this study, we investigated the extent to which the interaction characteristics depend on the choice of cell line for HER-family receptors. The interaction characteristics of two therapeutic antibodies (trastuzumab and cetuximab) and one Affibody molecule (ZHER2:342), interacting with the intended receptor were characterized with high precision using an automated real-time interaction method, in different cell lines (HaCaT, A431, HEP-G2, SKOV3, PC3, DU-145). Clear differences in binding affinity and kinetics, up to one order of magnitude, were found for the interaction of the same protein binding to the same receptor on different cells for all three proteins. For HER-family receptors, it is therefore important to refer to the measured affinity for a protein-receptor interaction together with the hosting cell line. The ability to accurately measure affinity and kinetics of a protein-receptor interaction on cell lines of different origins may increase the understanding of underlying receptor biology, and impact the selection of candidates in the development of therapeutic or diagnostic agents.

  • 25.
    Bass, Tarek Z.
    et al.
    KTH Royal Inst Technol, Sch Biotechnol, Div Prot Technol, SE-10691 Stockholm, Sweden..
    Rosestedt, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Mitran, Bogdan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Frejd, Fredrik Y.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science. Affibody AB, SE-17163 Solna, Sweden.
    Löfblom, John
    KTH Royal Inst Technol, Sch Biotechnol, Div Prot Technol, SE-10691 Stockholm, Sweden..
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Ståhl, Stefan
    KTH Royal Inst Technol, Sch Biotechnol, Div Prot Technol, SE-10691 Stockholm, Sweden..
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    In vivo evaluation of a novel format of a bivalent HER3-targeting and albumin- binding therapeutic affibody construct2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 43118Article in journal (Refereed)
    Abstract [en]

    Overexpression of human epidermal growth factor receptor 3 (HER3) is involved in resistance to several therapies for malignant tumours. Currently, several anti-HER3 monoclonal antibodies are under clinical development. We introduce an alternative approach to HER3-targeted therapy based on engineered scaffold proteins, i.e. affibody molecules. We designed a small construct (22.5 kDa, denoted 3A3), consisting of two high-affinity anti-HER3 affibody molecules flanking an albumin-binding domain ABD, which was introduced for prolonged residence in circulation. In vitro, 3A3 efficiently inhibited growth of HER3-expressing BxPC-3 cells. Biodistribution in mice was measured using 3A3 that was site-specifically labelled with In-111 via a DOTA chelator. The residence time of In-111-DOTA-3A3 in blood was extended when compared with the monomeric affibody molecule. In-111-DOTA-3A3 accumulated specifically in HER3-expressing BxPC-3 xenografts in mice. However, In-111-DOTA-3A3 cleared more rapidly from blood than a size-matched control construct In-111-DOTA-TAT, most likely due to sequestering of 3A3 by mErbB3, the murine counterpart of HER3. Repeated dosing and increase of injected protein dose decreased uptake of In-111-DOTA-3A3 in mErbB3-expressing tissues. Encouragingly, growth of BxPC-3 xenografts in mice was delayed in an experimental (pilot-scale) therapy study using 3A3. We conclude that the 3A3 affibody format seems promising for treatment of HER3-overexpressing tumours.

  • 26. Bergström, Mats
    et al.
    Lu, Li
    Fasth, Karl-Johan
    Wu, Feng
    Bergström-Pettermann, Erzebet
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Hedberg, Elisabeth
    Cheng, Aiping
    Långström, Bengt
    In vitro and animal validation of bromine-76-bromodeoxyuridine as a proliferation marker1998In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 39, no 7, p. 1273-9Article in journal (Refereed)
    Abstract [en]

    The potential of 76Br-bromodeoxyuridine as a PET tracer for characterizing proliferation potential was investigated in multicellular tumor aggregates and in healthy rats and pigs. METHODS: Bromine-76-bromide was produced by proton irradiation of a 76Se-enriched target using a 17-MeV cyclotron and recovered by thermal diffusion. Bromine-76-BrdU was prepared from the corresponding trimethylstannate by an oxidative bromination. Multicellular aggregates from a carcinoid cell line and two bladder cancer cell lines were co-incubated with 76Br-BrdU and 3H-thymidine and the uptake and DNA incorporation analyzed. About 0.5 MBq 76Br-BrdU were injected in the tail vein of unanaesthetised Sprague-Dawley rats. Two to 36 hr later they were decapitated and the radioactivity concentration and fraction of radioactivity incorporated into DNA determined in five different organs and the blood. Parallel studies were performed in animals pretreated with hydroxyurea. In separate experiments, rats were given an injection of 76Br-bromide and organ uptake was evaluated after 20 hr. PET studies were performed in two pigs and the uptake in different organs was investigated after injection of 76Br-BrdU. In these studies, diuresis was induced by furosemide and mannitol and radioactivity in blood and organs was followed during 10 hr. RESULTS: In the cell aggregates, 30%-90% of the radioactivity was extracted in the DNA fraction. A good correlation was found between 76Br-BrdU and 3H-thymidine with respect to total uptake and DNA fraction. The DNA fraction increased from 2-10 hr after incubation. With in vivo injection in the rat, relatively high uptake of radioactivity was found in all organs, unrelated to the degree of DNA synthesis. However, inhibition by hydroxyurea occurred only in the spleen and intestines, organs which also showed a high degree of incorporation of 76Br-BrdU into DNA. In the pig, the highest in vivo uptake was observed in the red bone marrow and the intestines. In these organs, 70%-80% of the radioactivity was recovered in the DNA fraction. The concentration of radioactivity in the heart, liver and kidney was 3-10 times lower, and here the DNA fraction accounted for 10%-20% of the radioactivity. The decay-corrected radioactivity in blood and nonproliferating organs decreased with diuresis with a half-life of 13 and 16 hr, respectively. CONCLUSION: It is suggested that the radioactivity uptake as seen after the administration of 76Br-BrdU, is constituted by two parts: one relating to incorporation into DNA and one existing as free 76Br- or metabolites of 76Br-BrdU. If sufficient time has passed, 76Br- dominates other metabolites. A correct assessment of DNA-incorporated radioactivity using PET with 76Br-BrdU is not trivial and can only be made with due correction for 76Br-, using either a complementary investigation after hydroxyurea pretreatment (in animal studies) or a separate 76Br-bromide investigation. Alternatively, the free bromide can be eliminated partially through forced diuresis.

  • 27.
    Beshara, Soheir
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Lundqvist, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Sundin, Johanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Valind, Sven
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Antoni, Gunnar
    Långström, Bengt
    Danielson, Bo G.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Kinetic analysis of 52Fe-labelled iron(III) hydroxide-sucrose complex following bolus administration using positron emission tomography1999In: British Journal of Haematology, ISSN 0007-1048, E-ISSN 1365-2141, Vol. 104, no 2, p. 288-295Article in journal (Refereed)
    Abstract [en]

    Kinetic analysis of a single intravenous injection of 100 mg iron(III) hydroxide-sucrose complex (Venofer) mixed with 52Fe(III) hydroxide-sucrose as a tracer was followed for 3-6 h in four generally anaesthetized, artificially ventilated minipigs using positron emission tomography (PET). The amount of injected radioactivity ranged from 30 to 200 MBq. Blood radioactivity, measured by PET in the left ventricle of the heart, displayed a fast clearance phase followed by a slow one. In the liver and bone marrow a fast radioactivity uptake occurred during the first 30 min, followed by a slower steady increase. In the liver a slight decrease in radioactivity uptake was noted by the end of the study. A kinetic analysis using a three-compartment (namely blood pool, reversible and irreversible tissue pools) model showed a fairly high distribution volume in the liver as compared with the bone marrow. In conclusion, the pharmacokinetics of the injected complex was clearly visualized with the PET technique. The organs of particular interest, namely the heart (for blood kinetics), liver and bone marrow could all be viewed by a single setting of a PET tomograph with an axial field of view of 10 cm. The half-life (T1/2) of 52Fe (8.3 h) enables a detailed kinetic study up to 24 h. A novel method was introduced to verify the actual 52Fe contribution to the PET images by removing the interfering radioactive daughter 52mMn positron emissions. The kinetic data fitted the three-compartment model, from which rate constants could be obtained for iron transfer from the blood to a pool of iron in bone marrow or liver to which it was bound during the study period. In addition, there was a reversible tissue pool of iron, which in the liver slowly equilibrated with the blood, to give a net efflux from the liver some hours after i.v. administration. The liver uptake showed a relatively long distribution phase, whereas the injected iron was immediately incorporated into the bone marrow. Various transport mechanisms seem to be involved in the handling of the injected iron complex.

  • 28.
    Beshara, Soheir
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Lundqvist, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Sundin, Johanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Valind, Sven
    Antoni, Gunnar
    Långström, Bengt
    Danielson, Bo G.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Pharmacokinetics and red cell utilization of iron(III) hydroxide- sucrose complex in anaemic patients: a study using positron emission tomography1999In: British Journal of Haematology, ISSN 0007-1048, E-ISSN 1365-2141, Vol. 104, no 2, p. 296-302Article in journal (Refereed)
    Abstract [en]

    The pharmacokinetics of a single intravenous injection of 100 mg iron hydroxide-sucrose complex labelled with a tracer in the form of 52Fe/59Fe was followed in six anaemic patients for a period ranging from 6 to 8 3 h using positron emission tomography (PET). Red cell utilization of the labelled iron was followed for 4 weeks. PET data showed radioactive uptake by the liver, spleen and bone marrow. The uptake by the macrophage-rich spleen demonstrated the reticuloendothelial uptake of this iron preparation, with subsequent effective release of that iron for marrow utilization. Red cell utilization, followed for 4 weeks, ranged from 59% to 97%. The bone marrow influx rate constant was independent of blood iron concentration, indicating non-saturation of the transport system in bone marrow. This implied that higher doses of the iron complex can probably be used in the same setting. A higher influx rate into the marrow compared with the liver seemed to be consistent with higher red cell utilization. This would indicate that early distribution of the injected iron complex may predict the long-term utilization.

  • 29.
    Beshara, Soheir
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Långström, Bengt
    Uppsala University.
    Antoni, Gunnar
    Uppsala University.
    Danielson, Bo G.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Lundqvist, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Pharmacokinetics and red cell utilization of 52Fe/59Fe-labelled iron polymaltose in anaemic patients using positron emission tomography2003In: British Journal of Haematology, ISSN 0007-1048, E-ISSN 1365-2141, Vol. 120, no 5, p. 853-859Article in journal (Refereed)
    Abstract [en]

    Parenteral iron-polysaccharide complexes are increasingly applied. The pharmacokinetics of iron sucrose have been assessed by our group using positron emission tomography (PET). A single intravenous injection of 100 mg iron as iron (III) hydroxide-polymaltose complex, labelled with a tracer in the form of 52Fe/59Fe, was similarly assessed in six patients using PET for about 8 h. Red cell utilization was followed for 4 weeks. Iron polymaltose was similarly distributed to the liver, spleen and bone marrow. However, a larger proportion of this complex was rapidly distributed to the bone marrow. The shorter equilibration phase for the liver, about 25 min, indicates the minimal role of the liver for direct distribution. Splenic uptake also reflected the reticuloendothelial handling of this complex. Red cell utilization ranged from 61% to 99%. Despite the relatively higher uptake by the bone marrow, there was no saturation of marrow transport systems at this dose level. In conclusion, high red cell utilization of iron polymaltose occurred in anaemic patients. The major portion of the injected dose was rapidly distributed to the bone marrow. In addition, the reticuloendothelial uptake of this complex may reflect the safety of polysaccharide complexes. Non-saturation of transport systems to the bone marrow indicated the presence of a large interstitial transport pool, which might possibly be transferrin.

  • 30.
    Beshara, Soheir
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Chemistry.
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Physiology.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Långström, Bengt
    PET Centre, University Hospital, Uppsala, Sweden.
    Antoni, Gunnar
    PET Centre, University Hospital, Uppsala, Sweden.
    Danielsson, Bo G.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Internal Medicine.
    Lundqvist, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Pharmacokinetics and red cell utilization of 52Fe/59Fe-labelled iron polymaltose in anaemic patients using positron emission tomography2003In: British Journal of Haematology, ISSN 0007-1048, E-ISSN 1365-2141, Vol. 120, no 5, p. 853-859Article in journal (Other academic)
    Abstract [en]

    Parenteral iron-polysaccharide complexes are increasingly applied. The pharmacokinetics of iron sucrose have been assessed by our group using positron emission tomography (PET). A single intravenous injection of 100 mg iron as iron (III) hydroxide-polymaltose complex, labelled with a tracer in the form of 52Fe/59Fe, was similarly assessed in six patients using PET for about 8 h. Red cell utilization was followed for 4 weeks. Iron polymaltose was similarly distributed to the liver, spleen and bone marrow. However, a larger proportion of this complex was rapidly distributed to the bone marrow. The shorter equilibration phase for the liver, about 25 min, indicates the minimal role of the liver for direct distribution. Splenic uptake also reflected the reticuloendothelial handling of this complex. Red cell utilization ranged from 61% to 99%. Despite the relatively higher uptake by the bone marrow, there was no saturation of marrow transport systems at this dose level. In conclusion, high red cell utilization of iron polymaltose occurred in anaemic patients. The major portion of the injected dose was rapidly distributed to the bone marrow. In addition, the reticuloendothelial uptake of this complex may reflect the safety of polysaccharide complexes. Non-saturation of transport systems to the bone marrow indicated the presence of a large interstitial transport pool, which might possibly be transferrin.

  • 31.
    Bruskin, Alexander
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Lundqvist, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Westlin, Jan-Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Arnberg, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    A search for the optimal positron emitting label for DTPA-octreotide1995In: Journal of labelled compounds & radiopharmaceuticals, ISSN 0362-4803, E-ISSN 1099-1344, Vol. 37, p. 506-509Article in journal (Refereed)
  • 32.
    Bruskin, Alexander
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry II. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Sivaev, Igor
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry II.
    Persson, Mikael
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry II. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Lundqvist, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry II. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Carlsson, Jörgen
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry II. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Sjöberg, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry II.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry II. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Radiobromination of monoclonal antibody using potassium [76Br] (4 isothiocyanatobenzyl-ammonio)-bromo-decahydro-closo-dodecaborate (Bromo-DABI)2004In: Nuclear Medicine and Biology, ISSN 0969-8051, E-ISSN 1872-9614, Vol. 31, no 2, p. 205-11Article in journal (Refereed)
    Abstract [en]

    The use of charged linkers in attaching radiohalogens to tumor-seeking biomolecules may improve intracellular retention of the radioactive label after internalization and degradation of targeting proteins. Derivatives of polyhedral boron clusters, such as closo-dodecaborate (2-) anion, might be possible charged linkers. In this study, a bifunctional derivative of closo-dodecaborate, (4-isothiocyanatobenzyl-ammonio)-undecahydro-closo-dodecaborate (DABI) was labeled with positron-emitting nuclide (76)Br (T 1/2 = 16.2 h) and coupled to anti-HER2/neu humanized antibody Trastuzumab. The overall labeling yield at optimized conditions was 80.7 +/- 0.6%. The label was proven to be stable in vitro in physiological and a set of denaturing conditions. The labeled antibody retained its capacity to bind to HER-2/neu antigen expressing cells. The results of the study demonstrated feasibility for using derivatives of closo-dodecaborate in indirect labeling of antibodies for radioimmunoPET.

  • 33. Bruskin, Alexander
    et al.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Westlin, J-E
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Lundqvist, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Separation of two labeled components of [111In] -OctreoScan by HPLC2001In: Journal of Radioanalytical and Nuclear Chemistry, ISSN 0236-5731, E-ISSN 1588-2780, Vol. 247, no 1, p. 95-99Article in journal (Refereed)
    Abstract [en]

    [111In]-DTPA-D-Phe1-octreotide (OctreoScan®, Mallinkrodt) is widely used for detection of neuroendocrine tumors and has lately been proposed for radionuclide therapy. We found, using HPLC and a GF-250 column (Zorbax®, Hewlett Packard), that OctreoScan® can be separated in two radiolabeled components of about equal amount. The analytical conditions for a quantitative isolation indicate that the two-peptide components of OctreoScan®have different lipophilicity. The isolated components are stable and do not transform into each other at room temperature during 6 hours (shelf-life of OctreoScan®).

  • 34.
    Carlsson, Jörgen
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Blomquist, Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Oncology.
    Gedda, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Liljegren, Åsa
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Malmström, Per-Uno
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Urology.
    Sjöström, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Sundin, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Westlin, Jan-Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Oncology.
    Zhao, Qinghai
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Lundqvist, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Conjugate chemistry and cellular processing of EGF-dextran1999In: Acta Oncologica, ISSN 0284-186X, E-ISSN 1651-226X, Vol. 38, no 3, p. 313-321Article in journal (Refereed)
    Abstract [en]

    Conjugates with specific binding to the epidermal growth factor receptor, EGFR, of interest for radionuclide based imaging and therapy were prepared using mouse epidermal growth factor, mEGF, and dextran. In one type of conjugate, mEGF was coupled to dextran by reductive amination in which the free amino group on the mEGF N-terminal reacted with the aldehyde group on the reductive end of dextran. The end-end coupled conjugate could be further activated by the cyanopyridinium agent CDAP, thereby introducing tyrosines to the dextran part. In the other type of conjugate, the cyanylating procedure using CDAP was applied, first to activate dextran and then allowing for the amino terminus of mEGF to randomly attach to the dextran. In the latter case, radionuclide-labelled tyrosines or glycines could be added in the same conjugation step. All types of mEGF-dextran conjugates had EGFR-specific binding since the binding could be displaced by an excess of non-radioactive mEGF. The conjugates were to a large extent internalized in the test cells and the associated radioactivity was retained intracellularly for different times depending on both the type of cells and conjugate applied. Different intracellular 'traffic routes' for the radionuclides are discussed as well as applications for both imaging and therapy.

  • 35.
    Carlsson, Jörgen
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Ren, Z. P.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Genetics and Pathology.
    Wester, K.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Sundberg, A. L.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Heldin, Nils-Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Genetics and Pathology.
    Hesselager, G.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Genetics and Pathology.
    Persson, M.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Gedda, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Lundqvist, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Blomquist, Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Oncology.
    Nistér, M.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Genetics and Pathology.
    Planning for intracavitary anti-EGFR radionuclide therapy of gliomas: Literature review and data on EGFR expression2006In: Journal of Neuro-Oncology, ISSN 0167-594X, E-ISSN 1573-7373, Vol. 77, no 1, p. 33-45Article in journal (Refereed)
    Abstract [en]

    Targeting with radionuclide labelled substances that bind specifically to the epidermal growth factor receptor, EGFR, is considered for intracavitary therapy of EGFR-positive glioblastoma multiforme, GBM. Relevant literature is reviewed and examples of EGFR expression in GBM are given. The therapeutical efforts made so far using intracavitary anti-tenascin radionuclide therapy of GBM have given limited effects, probably due to low radiation doses to the migrating glioma cells in the brain. Low radiation doses might be due to limited penetration of the targeting agents or heterogeneity in the expression of the target structure. In this article we focus on the possibilities to target EGFR on the tumour cells instead of an extracellular matrix component. There seems to be a lack of knowledge on the degree of intratumoral variation of EGFR expression in GBM, although the expression seemed rather homogeneous over large areas in most of the examples (n=16) presented from our laboratory. The observed homogeneity was surprising considering the genomic instability and heterogeneity that generally characterises highly malignant tumours. However, overexpression of EGFR is, at least in primary GBMs, one of the steps in the development of malignancy, and tumour cells that lose or downregulate EGFR will probably be outgrown in an expanding tumour cell population. Thus, loss of EGFR expression might not be the critical factor for successful intracavitary radionuclide therapy. Instead, it is likely that the penetration properties of the targeting agents are critical, and detailed studies on this are urgent.

  • 36.
    Carlsson, Jörgen
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Steffen, Ann-Charlott
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Sundberg, Åsa L.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Vikström, Mikael
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Gedda, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Stenerlöw, Bo
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Lundqvist, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Targeting EGFR and HER2 with 211At-labeled molecules: unexpected and expected dose-effect relations in cultured tumor cells2008In: Current radiopharmaceuticals, ISSN 1874-4710, Vol. 1, no 3, p. 225-233Article in journal (Refereed)
  • 37.
    Cheng, Junping
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Ekberg, Tomas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Engström, Mats
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Nestor, Marika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Jensen, Holger J.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Anniko, Matti
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Radioimmunotherapy with astatine-211 using chimeric monoclonal antibody U36 in head and neck squamous cell carcinoma2007In: The Laryngoscope, ISSN 0023-852X, E-ISSN 1531-4995, Vol. 117, no 6, p. 1013-1018Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: In advanced head and neck squamous cell carcinoma (HNSCC), there is a need for an adjuvant treatment. We aim to evaluate the biodistribution and therapeutic effect of radioimmunotherapy using the alpha emitting, astatine-211-labeled, chimeric monoclonal antibody U36 (U36) on the HNSCC cell line UT-SCC7 in vivo. STUDY DESIGN: Xenograft tumors were inoculated subcutaneously in nude mice. Astatine-211-labeled U36 was injected intravenously with or without blocking of target with nonlabeled U36. METHODS: In the biodistribution experiments, radioactivity was measured in tumors and various organs at set time points. In the therapeutic experiments, two groups (with or without blocking) received therapy, and the tumor growth was compared with that of controls. In addition, one group received nonlabeled U36 only. RESULTS: The biodistribution experiments demonstrated that astatine-211-labeled U36 could target UT-SCC7 xenografts in nude mice. With time, uptake increased in tumors and decreased in normal organs. Nonlabeled U36 did not influence tumor growth. In the two therapy groups, 18 of 20 tumors responded to therapy by decreasing or stabilizing their volumes. Significant difference was seen between the treated groups and the controls (P < .05). CONCLUSION: The study illustrates the specific binding of astatine-211-labeled U36 to HNSCC and suggests radioimmunotherapy with the alpha emitting radionuclide to be a useful treatment modality.

  • 38.
    Cheng, Junping
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Engström, Mats
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Ekberg, Tomas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Nestor, Marika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Anniko, Matti
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    The use of closo-dodecaborate-containing linker improves targeting of HNSCC xenografts with radioiodinated chimeric monoclonal antibody U362010In: Molecular Medicine Reports, ISSN 1791-2997, Vol. 3, no 1, p. 155-160Article in journal (Refereed)
    Abstract [en]

    Radionuclide imaging of head and neck squamous cell carcinoma (HNSCC) using monoclonal antibodies (MAbs) has the potential to contribute to improved diagnosis and staging, thereby making more effective treatment possible. Chimeric monoclonal antibody U36 (cMAb U36), specific to CD44v6 antigen. is a candidate for the targeting of HNSCC. The aim of this study was to compare the influence of indirect iodination via closo-dodecaborate-based linker (DABI) with the influence of direct radioiodination on the biodistribution of the chimeric anti-CD44v6 antibody U36. The study was performed using nude mice bearing UT-SCC7 HNSCC xenografts using the paired-label method. The biodistribution of cMAb U36 labelled directly with I-131 and using DABI with I-125 was compared in the same animals. The influence of DABI on the tumour-to-organ ratio was evaluated. For both conjugates, radioactivity uptake in blood and organs decreased with time, except in tumours and the thyroid. DABI-labelled cMAb U36 was characterised by fast blood clearance and an elevated uptake in the liver and spleen. The use of DABI enabled a 1.5 to 2-fold improvement in the tumour-to-blood and tumour-to-organ ratios in comparison with direct radioiodination, with the exception of the liver and spleen. These results indicate that DABI is a promising linker for the coupling of radioiodine to HNSCC-targeting antibodies.

  • 39.
    Cheng, Junping
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Persson, Mikael
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Siavaev, Igor
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Kairemo, Kalevi
    Anniko, Matti
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Targeting of a head and neck squamous cell carcinoma xenograft model using the chimeric monoclonal antibody U36 radioiodinated with a closo-dodecaborate-containing linker2004In: Acta Oto-Laryngologica, ISSN 0001-6489, E-ISSN 1651-2251, Vol. 124, no 9, p. 1078-85Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: High rates of local recurrence and distant metastases following surgery of high-grade head and neck squamous cell carcinoma (HNSCC) necessitate the use of adjuvant systemic treatment. Radioimmunotargeting might be a possible treatment modality in this case. The nuclear properties of 131I make it a suitable isotope for treatment of minimal residual disease and small metastases, but the conventional radioiodine label has poor cellular retention and its radiocatabolites accumulate in the thyroid. We attempted to overcome these problems by using closo-dodecaborate derivatives for attachment of radioiodine. MATERIAL AND METHODS: We investigated the feasibility of targeting an SCC25 HNSCC xenograft in vivo using a benzylisothiocyanate derivative of closo-dodecaborate (DABI) as radioiodine linker and the chimeric anti-CD44v6 antibody U36. 125I was used in biodistribution studies. RESULTS: The use of DABI enabled tumor targeting and decreased the radioactivity uptake of the thyroid. CONCLUSION: Tumor localization of DABI-labeled U36 was similar to its para-iodobenzoate-labeled counterpart, presumably due to the strong dependence of targeting efficiency on tumor size.

  • 40.
    Chiotellis, A.
    et al.
    Univ Nottingham, Nottingham, England..
    Sladojevich, F.
    Swiss Fed Inst Technol, Zurich, Switzerland..
    Mu, L.
    Swiss Fed Inst Technol, Zurich, Switzerland..
    Mueller-Herde, A.
    Swiss Fed Inst Technol, Zurich, Switzerland..
    Valverde, I. E.
    Univ Basel Hosp, Basel, Switzerland..
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Schibli, R.
    Swiss Fed Inst Technol, Zurich, Switzerland..
    Ametamey, S. M.
    Swiss Fed Inst Technol, Zurich, Switzerland..
    Mindt, T. L.
    Swiss Fed Inst Technol, Zurich, Switzerland..
    Novel Chemoselective [F-18]-Radiolabeling of Thiol-Containing Biomolecules under Mild Aqueous Conditions2016In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 43, p. S123-S123Article in journal (Refereed)
  • 41. Chiotellis, Aristeidis
    et al.
    Sladojevich, Filippo
    Mu, Linjing
    Müller Herde, Adrienne
    Valverde, Ibai E
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Schibli, Roger
    Ametamey, Simon M
    Mindt, Thomas L
    Novel chemoselective (18)F-radiolabeling of thiol-containing biomolecules under mild aqueous conditions2016In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 52, no 36, p. 6083-6086Article in journal (Refereed)
    Abstract [en]

    We report a novel prosthetic group based on a heterocyclic methylsulfone derivative for the rapid, stable, and chemoselective (18)F-labeling of thiol-containing (bio)molecules under mild aqueous reaction conditions. Compared to established maleimide approaches, the new methodology displays some clear advantages for imaging probe development.

  • 42. Ekblad, Torun
    et al.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Feldwisch, Joachim
    Wennborg, Anders
    Karlström, Amelie Eriksson
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Positioning of Tc-99m-chelators influences radiolabeling, stability and biodistribution of Affibody molecules2009In: Bioorganic & Medicinal Chemistry Letters, ISSN 0960-894X, E-ISSN 1090-2120, Vol. 19, no 14, p. 3912-3914Article in journal (Refereed)
    Abstract [en]

    Affibody molecules represent a novel class of affinity proteins with a high potential as tracers for radio-nuclide molecular imaging. In this comparative structure-property study, a series of Affibody molecules with the Tc-99m-chelators maGGG, maSSS, or maESE attached to the e-amine of the internally positioned K49 was prepared by peptide synthesis, for comparison to molecules with similar chelators positioned at the N-terminus. The conjugates were labeled with Tc-99m and evaluated in vitro and in vivo. It was found that both composition and position of the chelating moiety influence the label stability, biodistribution and targeting properties of HER2-binding Affibody molecules. (C) 2009 Elsevier Ltd. All rights reserved.

  • 43.
    Ekblad, Torun
    et al.
    School of Biotechnology, Royal Institute of Technology, Stockholm, Sweden.
    Tran, Thuy
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Widström, Charles
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Oncology.
    Feldwisch, Joachim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Abrahmsén, Lars
    Wennborg, Anders
    Karlström, Amelie Eriksson
    School of Biotechnology, Royal Institute of Technology, Stockholm, Sweden.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Development and preclinical characterisation of 99mTc-labelled Affibody molecules with reduced renal uptake2008In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 35, no 12, p. 2245-2255Article in journal (Refereed)
    Abstract [en]

    Purpose  Affibody molecules are low molecular weight proteins (7 kDa), which can be selected to bind to tumour-associated target proteins with subnanomolar affinity. Because of rapid tumour localisation and clearance from nonspecific compartments, Affibody molecules are promising tracers for molecular imaging. Earlier, 99mTc-labelled Affibody molecules demonstrated specific targeting of tumour xenografts. However, the biodistribution was suboptimal either because of hepatobiliary excretion or high renal uptake of the radioactivity. The goal of this study was to optimise the biodistribution of Affibody molecules by chelator engineering.

    Materials and methods  Anti-HER2 ZHER2:342 Affibody molecules, carrying the mercaptoacetyl-glutamyl-seryl-glutamyl (maESE), mercaptoacetyl-glutamyl-glutamyl-seryl (maEES) and mercaptoacetyl-seryl-glutamyl-glutamyl (maSEE) chelators, were prepared by peptide synthesis and labelled with 99mTc. The tumour-targeting capacity of these conjugates was compared with each other and with the best previously available conjugate, 99mTc-maEEE-ZHER2:342, in nude mice bearing SKOV-3 xenografts. The tumour-targeting capacity of the most promising conjugate, 99mTc-maESE-ZHER2:342, was compared with radioiodinated ZHER2:342. Results  All novel conjugates demonstrated successful tumour targeting and a low degree of hepatobiliary excretion. The renal uptakes of serine-containing conjugates, 33 ± 5, 68 ± 21 and 71 ± 10%IA/g, for99mTc-maESE-ZHER2:342, 99mTc-maEES-ZHER2:342 and 99mTc-maSEE-ZHER2:342, respectively, were significantly reduced in comparison with 99mTc-maEEE-ZHER2:342 (102 ± 13%IA/g). For 99mTc-maESE-ZHER2:342, a tumour uptake of 9.6 ± 1.8%IA/g and a tumour-to-blood ratio of 58 ± 6 were reached at 4 h p.i. Conclusions  A combination of serine and glutamic acid residues in the chelator sequence confers increased renal excretion and relatively low renal uptake of 99mTc-labelled Affibody molecules. In combination with preserved targeting capacity, this improved imaging of targets in abdominal area.

  • 44. Engfeldt, Torun
    et al.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Tran, Thuy
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Bruskin, Alexander
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Widström, Charles
    Department of Hospital Physics, Uppsala University Hospital.
    Karlström, Amelie Eriksson
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Imaging of HER2-expressing tumours using a synthetic Affibody molecule containing the 99mTc-chelating mercaptoacetyl-glycyl-glycyl-glycyl (MAG3) sequence2007In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 34, no 5, p. 722-733Article in journal (Refereed)
    Abstract [en]

    PURPOSE: Expression of human epidermal growth factor receptor type 2 (HER2) in malignant tumours possesses well-documented prognostic and predictive value. Non-invasive imaging of expression can provide valuable diagnostic information, thereby influencing patient management. Previously, we reported a phage display selection of a small (about 7 kDa) protein, the Affibody molecule Z(HER2:342), which binds HER2 with subnanomolar affinity, and demonstrated the feasibility of targeting of HER2-expressing xenografts using radioiodinated Z(HER2:342). The goal of this study was to develop a method for (99m)Tc labelling of Z(HER2:342) using the MAG3 chelator, which was incorporated into Z(HER2:342) using peptide synthesis, and evaluate the targeting properties of the labelled conjugate. METHODS: MAG3-Z(HER2:342) was assembled using Fmoc/tBu solid phase peptide synthesis. Biochemical characterisation of the agent was performed using RP-HPLC, ESI-MS, biosensor studies and circular dichroism. A procedure for (99m)Tc labelling in the presence of sodium/potassium tartrate was established. Tumour targeting was evaluated by biodistribution study and gamma camera imaging in xenograft-bearing mice. Biodistribution of (99m)Tc-MAG3-Z(HER2:342) and (125)I-para-iodobenzoate -Z(HER2:342) was compared 6 h p.i. RESULTS: Synthetic MAG3-Z(HER2:342) possessed an affinity of 0.2 nM for HER2 receptors. The peptide was labelled with (99m)Tc with an efficiency of about 75-80%. Labelled (99m)Tc-MAG3-Z(HER2:342) retained capacity to bind specifically HER2-expressing SKOV-3 cells in vitro. (99m)Tc-MAG3-Z(HER2:342) showed specific tumour targeting with a contrast similar to a radioiodinated analogue in mice bearing LS174T xenografts. Gamma camera imaging demonstrated clear and specific visualisation of HER2 expression. CONCLUSION: Incorporation of a mercaptoacetyl-containing chelating sequence during chemical synthesis enabled site-specific (99m)Tc labelling of the Z(HER2:342) Affibody molecule with preserved targeting capacity.

  • 45. Engfeldt, Torun
    et al.
    Tran, Thuy
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Widström, Charles
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Section of Medical Physics.
    Feldwisch, Joachim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Abrahmsen, Lars
    Wennborg, Anders
    Karlström, Amelie Eriksson
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    99mTc-chelator engineering to improve tumour targeting properties of a HER2-specific Affibody molecule2007In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 34, no 11, p. 1843-1853Article in journal (Refereed)
    Abstract [en]

    PURPOSE: Monitoring HER2 expression is crucial for selection of breast cancer patients amenable to HER2-targeting therapy. The Affibody molecule Z(HER2:342) binds to HER2 with picomolar affinity and enables specific imaging of HER2 expression. Previously, Z(HER2:342) with the additional N-terminal mercaptoacetyl-glycyl-glycyl-glycyl (maGGG) sequence was labelled with (99m)Tc and demonstrated specific targeting of HER2-expressing xenografts. However, hepatobiliary excretion caused high radioactivity accumulation in the abdomen. We investigated whether the biodistribution of Z(HER2:342) can be improved by substituting glycyl residues in the chelating sequence with more hydrophilic seryl residues. METHODS: The Affibody molecule Z(HER2:342), carrying the chelators mercaptoacetyl-glycyl-seryl-glycyl (maGSG), mercaptoacetyl-glycyl-D: -seryl-glycyl [maG(D-S)G] and mercaptoacetyl-seryl-seryl-seryl (maSSS), were prepared by peptide synthesis and labelled with (99m)Tc. The differences in the excretion pathways were evaluated in normal mice. The tumour targeting capacity of (99m)Tc-maSSS-Z(HER2:342) was studied in nude mice bearing SKOV-3 xenografts and compared with the capacity of radioiodinated Z(HER2:342). RESULTS: A shift towards renal excretion was obtained when glycine was substituted with serine in the chelating sequence. The radioactivity in the gastrointestinal tract was reduced threefold for the maSSS conjugate in comparison with the maGGG conjugate 4 h post injection (p.i.). The tumour uptake of (99m)Tc-maSSS-Z(HER2:342) was 11.5 +/- 0.5% IA/g 4 h p.i., and the tumour-to-blood ratio was 76. The pharmacokinetics and uptake characteristics of technetium-labelled Z(HER2:342) were better than those of radioiodinated Z(HER2:342). CONCLUSION: The introduction of serine residues in the chelator results in better tumour imaging properties of the Affibody molecule Z(HER2:342) compared with glycyl-containing chelators and is favourable for imaging of tumours and metastases in the abdominal area.

  • 46. Eriksson, Ludvig
    et al.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Sjöberg, Stefan
    Feasibility of palladium catalysed isotopic exchange between [125I]iodide and 2-iodo-para-carborane2003In: Journal of labelled compounds & radiopharmaceuticals, ISSN 0362-4803, E-ISSN 1099-1344, Vol. 46, no 7, p. 623-631Article in journal (Refereed)
    Abstract [en]

    Many ortho-/meta-/para-closo-carborane derivatives have been proposed for boron neutron capture therapy. However, it is difficult to follow their pharmacokinetics in patients, which creates a risk of suboptimal treatment. Adding a radioactive label to closo-carboranes may simplify pharmacokinetic studies. This paper reports on a study of the feasibility of palladium-catalyzed isotopic exchange of iodinated closo-carborane with radioisotopes of iodine. 2-iodo-para-carborane was selected as a model compound. It was shown that such isotopic exchange is possible and provides a high yield (83±4.2%) after 40 min of reaction time. The reaction conditions were optimized, and it was demonstrated that the presence of tetra n-butylammonium hydrogensulfate is important in order to stabilize the catalyst and to give reproducibility of the labeling.

  • 47. Evans-Axelsson, Susan
    et al.
    Ulmert, David
    Orbom, Anders
    Peterson, Pernilla
    Nilsson, Olle
    Wennerberg, Johan
    Strand, Joanna
    Wingårdh, Karin
    Olsson, Tomas
    Hagman, Zandra
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Bjartell, Anders
    Lilja, Hans
    Strand, Sven-Erik
    Targeting free prostate-specific antigen for in vivo imaging of prostate cancer using a monoclonal antibody specific for unique epitopes accessible on free prostate-specific antigen alone2012In: Cancer Biotherapy and Radiopharmaceuticals, ISSN 1084-9785, E-ISSN 1557-8852, Vol. 27, no 4, p. 243-251Article in journal (Refereed)
    Abstract [en]

    This study investigated the feasibility of targeting the free, unbound forms of prostate-specific antigen (fPSA) for in vivo imaging of prostate adenocarcinomas (PCa), as PSA is produced and secreted at abundance during every clinical stage and grade of PCa, including castration-resistant disease. We injected 125I-labeled monoclonal antibody PSA30 (specific for an epitope uniquely accessible on fPSA alone) intravenously in male nude mice carrying subcutaneous xenografts of LNCaP tumors (n=36). Mice were sacrificed over a time course from 4 hours to 13 days after injecting 125I-labeled PSA30. Tissue uptake of 125I-PSA30 at 48 and 168 hours after intravenous injection was compared with two clinically used positron emission tomography radiopharmaceuticals, 18F-fluoro-deoxy-glucose (18F-FDG) or 18F-choline, in cryosections using Digital AutoRadiography (DAR) and also compared with immunohistochemical staining of PSA and histopathology. On DAR, the areas with high 125I-PSA30 uptake corresponded mainly to morphologically intact and PSA-producing LNCaP cells, but did not associate with the areas of high uptake of either 18F-FDG or 18F-choline. Biodistribution of 125I-PSA30 measured in dissected organs ex vivo during 4 to 312 hours after intravenous injection demonstrated maximum selective tumor uptake 24–48 hours after antibody injection. Our data showed selective uptake in vivo of a monoclonal antibody highly specific for fPSA in LNCaP cells. Hence, in vivo imaging of fPSA may be feasible with putative usefulness in disseminated PCa.

  • 48.
    Fast, K J
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Bergström, M
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Hedberg, E
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Cheng, A
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Organic Chemistry.
    Lu, L
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Wu, F
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Bergström, E
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Tolmachev, Vladimir
    Långström, Bengt
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Organic Chemistry.
    76-Br-bromodeoxyuridine marker with PET-preclinical validation studies1997In: Journal of labelled compounds & radiopharmaceuticals, ISSN 0362-4803, E-ISSN 1099-1344, Vol. 40, no 5, p. 391-393Article in journal (Refereed)
  • 49.
    Feldwisch, Joachim
    et al.
    Affibody AB, Solna, Sweden.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Engineering of affibody molecules for therapy and diagnostics2012In: Methods in molecular biology, ISSN 1940-6029, Vol. 899, p. 103-126Article in journal (Refereed)
    Abstract [en]

    Affibody molecules are small and robust non-immunoglobulin affinity ligands capable of binding to a wide range of protein targets. They are selected from combinatorial libraries based on a 58 amino acid, three-alpha-helical Z-domain scaffold. They share no sequence or structural homologies to antibodies and in contrast to antibodies they can be functionally produced both by peptide synthesis and by recombinant expression in Escherichia coli. Protein engineering is used to adapt Affibody molecules binding to a target of interest to the specific demands imposed by the intended application. Obviously, the optimal molecule for molecular imaging will be different from the optimal molecule for therapy. Here, we describe general strategies to optimize Affibody molecules for diagnostic imaging and therapy applications.

  • 50.
    Fortin, Marc-André
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Malmström, Per-Uno
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Urology.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Labelling chemistry and characterization of [90Y/177Lu]-DOTA-ZHER2:342-3 Affibody molecule, a candidate agent for locoregional treatment of urinary bladder carcinoma2007In: International Journal of Molecular Medicine, ISSN 1107-3756, E-ISSN 1791-244X, Vol. 19, no 2, p. 285-291Article in journal (Refereed)
    Abstract [en]

    The direct instillation of radiolabelled conjugates in the urinary bladder is a promising path for the treatment of bladder carcinoma. The targeting of HER2/neu receptors expressed on the surface of many bladder carcinoma cells shows potential to be developed as a therapeutic strategy, and patients identified with a high risk of progression may benefit from adjuvant targeted radionuclide therapy. A phage-display selected Affibody molecule (Z(HER2:342)) which binds to HER2/neu with picomolar affinity, can be used for targeting HER2/neu-expressing bladder carcinomas. A DOTA-derivative of Z(HER2:342), designated as DOTA-Z(HER2:342)-3, is considered as a suitable targeting agent for therapy. The DOTA chelator provides stable labelling with radiometals, and the low molecular weight (7.2 kDa) of the DOTA-Z(HER2:342)-3 compound is expected to enable efficient tumor penetration. DOTA-Z(HER2:342)-3 was radiolabelled with 90Y and 177Lu in 1 M ammonium acetate buffer, at pH 5.5, and in the presence of ascorbic acid. Nearly quantitative labelling yields were achieved for both nuclides after 15 min of incubation at 60 degrees C. After chelation, the conjugates retained their capacity to specifically bind to HER2/neu-expressing SKOV-3 cells. The radiolabelled affibody conjugate (DOTA-Z(HER2:342)-3) demonstrated high antigen-binding capacity and good cellular retention. Biodistribution in normal mice demonstrated low uptake in all organs and tissues except for kidneys.

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