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Nordberg, Erika
Publications (2 of 2) Show all publications
Nordberg, E., Friedman, M., Göstring, L., Adams, G., Brismar, H., Nilsson, F., . . . Carlsson, J. (2007). Cellular studies of binding, internalization and retention of a radiolabeled EGFR-binding affibody molecule. Nuclear Medicine and Biology, 34(6), 609-618
Open this publication in new window or tab >>Cellular studies of binding, internalization and retention of a radiolabeled EGFR-binding affibody molecule
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2007 (English)In: Nuclear Medicine and Biology, ISSN 0969-8051, E-ISSN 1872-9614, Vol. 34, no 6, p. 609-618Article in journal (Refereed) Published
Abstract [en]

INTRODUCTION: The cellular binding and processing of an epidermal growth factor receptor (EGFR) targeting affibody molecule, (Z(EGFR:955))(2), was studied. This new and small molecule is aimed for applications in nuclear medicine. The natural ligand epidermal growth factor (EGF) and the antibody cetuximab were studied for comparison. METHODS: All experiments were made with cultured A431 squamous carcinoma cells. Receptor specificity, binding time patterns, retention and preliminary receptor binding site localization studies were all made after (125)I labeling. Internalization was studied using Oregon Green 488, Alexa Fluor 488 and CypHer5E markers. RESULTS: [(125)I](Z(EGFR:955))(2) and [(125)I]cetuximab gave a maximum cellular uptake of (125)I within 4 to 8 h of incubation, while [(125)I]EGF gave a maximum uptake already after 2 h. The retention studies showed that the cell-associated fraction of (125)I after 48 h of incubation was approximately 20% when delivered as [(125)I](Z(EGFR:955))(2) and approximately 25% when delivered as [(125)I]cetuximab. [(125)I]EGF-mediated delivery gave a faster (125)I release, where almost all cell-associated radioactivity had disappeared within 24 h. All three substances were internalized as demonstrated with confocal microscopy. Competitive binding studies showed that both EGF and cetuximab inhibited binding of (Z(EGFR:955))(2) and indicated that the three substances competed for an overlapping binding site. CONCLUSION: The results gave information on cellular processing of radionuclides when delivered with (Z(EGFR:955))(2) in comparison to delivery with EGF and cetuximab. Competition assays suggested that [(125)I](Z(EGFR:955))(2) bind to Domain III of EGFR. The affibody molecule (Z(EGFR:955))(2) can be a candidate for EGFR imaging applications in nuclear medicine.

Keywords
A431, Affibody molecule, EGFR, Internalization, Radionuclide, Retention
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-97199 (URN)10.1016/j.nucmedbio.2007.05.010 (DOI)000249157300003 ()17707800 (PubMedID)
Available from: 2008-04-29 Created: 2008-04-29 Last updated: 2017-12-14Bibliographically approved
Nordberg, E., Steffen, A.-C., Persson, M., Sundberg, Å. L., Carlsson, J. & Glimelius, B. (2005). Cellular uptake of radioiodine delivered by trastuzumab can be modified by the addition of epidermal growth factor.. European Journal of Nuclear Medicine and Molecular Imaging, 32(7), 771-7
Open this publication in new window or tab >>Cellular uptake of radioiodine delivered by trastuzumab can be modified by the addition of epidermal growth factor.
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2005 (English)In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 32, no 7, p. 771-7Article in journal (Refereed) Published
Abstract [en]

PURPOSE: The purpose of this study was to analyse whether non-radiolabelled epidermal growth factor (EGF) can modify the cellular uptake of 125I when delivered as [125I]trastuzumab. 125I was used as a marker for the diagnostically and therapeutically more interesting isotopes 123I (SPECT), 124I (PET) and 131I (therapy). METHODS: The cell-associated radioactivity was measured in squamous carcinoma A431 cells following addition of [125I]trastuzumab. Different concentrations of [125I]trastuzumab and unlabelled EGF were used, and the total, membrane-bound and internalised radioactivity was measured. We also analysed how EGF and trastuzumab affected the cell growth. RESULTS: It was generally found that the cellular 125I uptake was decreased by the addition of EGF when [125I]trastuzumab was added for short incubation times. However, if the incubation times were longer, EGF increased the 125I uptake. This shift came earlier when higher [125I]trastuzumab concentrations were applied. The addition of EGF also influenced cell proliferation, and concentrations above 10 ng/ml reduced cell growth by approximately 20% after 24 h of incubation. CONCLUSION: By adding unlabelled EGF, it was possible to modify the cellular uptake of [125I]trastuzumab. This points towards new approaches for the modification of radionuclide uptake in EGFR- and HER2-positive tumours.

Keywords
Antibodies; Monoclonal/*administration & dosage/chemistry, Antineoplastic Agents/*administration & dosage, Cell Line; Tumor, Cell Membrane/metabolism, Cell Proliferation, Dose-Response Relationship; Drug, Epidermal Growth Factor/*administration & dosage/metabolism, Humans, Iodine Radioisotopes/*pharmacokinetics, Ligands, Positron-Emission Tomography, Receptor; Epidermal Growth Factor/metabolism, Receptor; erbB-2/metabolism, Time Factors, Tomography; Emission-Computed; Single-Photon, Tumor Markers; Biological
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:uu:diva-80492 (URN)10.1007/s00259-005-1761-8 (DOI)15765233 (PubMedID)
Available from: 2007-02-12 Created: 2007-02-12 Last updated: 2017-12-14Bibliographically approved
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