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  • 1.
    Bellomo, Claudia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Caja, Laia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Fabregat, Isabel
    Bellvitge Biomedical Research Institute (IDIBELL), L’Hospitalet, and Department of Physiological Sciences, School of Medicine, University of Barcelona, ES-08908, Barcelona, Spain.
    Mikulits, Wolfgang
    Department of Medicine I, Division: Institute of Cancer Research, Comprehensive Cancer Center Vienna, Medical University of Vienna, A-1090, Vienna, Austria.
    Kardassis, Dimitris
    Division of Basic Medical Sciences, University of Crete Medical School and Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology of Hellas, GR-71003, Heraklion, Greece.
    Heldin, Carl-Henrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Moustakas, Aristidis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Snail mediates crosstalk between TGFβ and LXRα in hepatocellular carcinoma2018In: Cell Death and Differentiation, ISSN 1350-9047, E-ISSN 1476-5403, Vol. 25, no 5, p. 885-903Article in journal (Refereed)
    Abstract [en]

    Understanding the complexity of changes in differentiation and cell survival in hepatocellular carcinoma (HCC) is essential for the design of new diagnostic tools and therapeutic modalities. In this context, we have analyzed the crosstalk between transforming growth factor β (TGFβ) and liver X receptor α (LXRα) pathways. TGFβ is known to promote cytostatic and pro-apoptotic responses in HCC, and to facilitate mesenchymal differentiation. We here demonstrate that stimulation of the nuclear LXRα receptor system by physiological and clinically useful agonists controls the HCC response to TGFβ. Specifically, LXRα activation antagonizes the mesenchymal, reactive oxygen species and pro-apoptotic responses to TGFβ and the mesenchymal transcription factor Snail mediates this crosstalk. In contrast, LXRα activation and TGFβ cooperate in enforcing cytostasis in HCC, which preserves their epithelial features. LXRα influences Snail expression transcriptionally, acting on the Snail promoter. These findings propose that clinically used LXR agonists may find further application to the treatment of aggressive, mesenchymal HCCs, whose progression is chronically dependent on autocrine or paracrine TGFβ.

  • 2.
    Bellomo, Claudia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Caja, Laia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research.
    Moustakas, Aristidis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Transforming growth factor beta as regulator of cancer stemness and metastasis2016In: British Journal of Cancer, ISSN 0007-0920, E-ISSN 1532-1827, Vol. 115, no 7, p. 761-769Article, review/survey (Refereed)
    Abstract [en]

    Key elements of cancer progression towards metastasis are the biological actions of cancer stem cells and stromal cells in the tumour microenvironment. Cross-communication between tumour and stromal cells is mediated by secreted cytokines, one of which, the transforming growth factor beta (TGF beta), regulates essentially every cell within the malignant tissue. In this article, we focus on the actions of TGF beta on cancer stem cells, cancer-associated fibroblasts and immune cells that assist the overall process of metastatic dissemination. We aim at illustrating intricate connections made by various cells in the tumour tissue and which depend on the action of TGF beta.

  • 3.
    Bertran, Esther
    et al.
    (IDIBELL), Barcelona, Spain.
    Caja, Laia
    (IDIBELL), Barcelona, Spain.
    Navarro, Estanis
    (IDIBELL), Barcelona, Spain.
    Sancho, Patricia
    (IDIBELL), Barcelona, Spain.
    Mainez, Jèssica
    (IDIBELL), Barcelona, Spain.
    Murillo, Miguel M
    (IDIBELL), Barcelona, Spain.
    Vinyals, Antonia
    (IDIBELL), Barcelona, Spain.
    Fabra, Angels
    (IDIBELL), Barcelona, Spain.
    Fabregat, Isabel
    (IDIBELL), Barcelona, Spain.
    Role of CXCR4/SDF-1 alpha in the migratory phenotype of hepatoma cells that have undergone epithelial-mesenchymal transition in response to the transforming growth factor-beta.2009In: Cellular Signalling, ISSN 0898-6568, E-ISSN 1873-3913, Vol. 21, no 11, p. 1595-1606Article in journal (Refereed)
    Abstract [en]

    Treatment of FaO rat hepatoma cells with TGF-beta selects cells that survive to its apoptotic effect and undergo epithelial-mesenchymal transitions (EMT). We have established a cell line (T beta T-FaO, from TGF-beta-treated FaO) that shows a mesenchymal, de-differentiated, phenotype in the presence of TGF-beta and is refractory to its suppressor effects. In the absence of this cytokine, cells revert to an epithelial phenotype in 3-4 weeks and recover the response to TGF-beta. T beta T-FaO show higher capacity to migrate than that observed in the parental FaO cells. We found that FaO cells express low levels of CXCR4 and do not respond to SDF-1 alpha. However, TGF-beta up-regulates CXCR4, through a NF kappaB-dependent mechanism, and T beta T-FaO cells show elevated levels of CXCR4, which is located in the presumptive migration front. A specific CXCR4 antagonist (AMD3100) attenuates the migratory capacity of T beta T-FaO cells on collagen gels. Extracellular SDF-1 alpha activates the ERKs pathway in T beta T-FaO, but not in FaO cells, increasing cell scattering and protecting cells from apoptosis induced by serum deprivation. Targeted knock-down of CXCR4 with specific siRNA blocks the T beta T-FaO response to SDF-1 alpha. Thus, the SDF-1/CXCR4 axis might play an important role in mediating cell migration and survival after a TGF-beta-induced EMT in hepatoma cells.

  • 4. Bertran, Esther
    et al.
    Crosas-Molist, Eva
    Sancho, Patricia
    Caja, Laia
    Bellvitge Biomedical Research Institute (IDIBELL), L’Hospitalet de Llobregat, Barcelona, Spain.
    Lopez-Luque, Judit
    Navarro, Estanislao
    Egea, Gustavo
    Lastra, Raquel
    Serrano, Teresa
    Ramos, Emilio
    Fabregat, Isabel
    Overactivation of the TGF-β pathway confers a mesenchymal-like phenotype and CXCR4-dependent migratory properties to liver tumor cells2013In: Hepatology, ISSN 0270-9139, E-ISSN 1527-3350, Vol. 58, no 6, p. 2032-44Article in journal (Refereed)
    Abstract [en]

    UNLABELLED: Transforming growth factor-beta (TGF-β) is an important regulatory suppressor factor in hepatocytes. However, liver tumor cells develop mechanisms to overcome its suppressor effects and respond to this cytokine by inducing other processes, such as the epithelial-mesenchymal transition (EMT), which contributes to tumor progression and dissemination. Recent studies have placed chemokines and their receptors at the center not only of physiological cell migration but also of pathological processes, such as metastasis in cancer. In particular, CXCR4 and its ligand, stromal cell-derived factor 1α (SDF-1α) / chemokine (C-X-C motif) ligand 12 (CXCL12) have been revealed as regulatory molecules involved in the spreading and progression of a variety of tumors. Here we show that autocrine stimulation of TGF-β in human liver tumor cells correlates with a mesenchymal-like phenotype, resistance to TGF-β-induced suppressor effects, and high expression of CXCR4, which is required for TGF-β-induced cell migration. Silencing of the TGF-β receptor1 (TGFBR1), or its specific inhibition, recovered the epithelial phenotype and attenuated CXCR4 expression, inhibiting cell migratory capacity. In an experimental mouse model of hepatocarcinogenesis (diethylnitrosamine-induced), tumors showed increased activation of the TGF-β pathway and enhanced CXCR4 levels. In human hepatocellular carcinoma tumors, high levels of CXCR4 always correlated with activation of the TGF-β pathway, a less differentiated phenotype, and a cirrhotic background. CXCR4 concentrated at the tumor border and perivascular areas, suggesting its potential involvement in tumor cell dissemination.

    CONCLUSION: A crosstalk exists among the TGF-β and CXCR4 pathways in liver tumors, reflecting a novel molecular mechanism that explains the protumorigenic effects of TGF-β and opens new perspectives for tumor therapy.

  • 5.
    Caja, Laia
    et al.
    L’Hospitalet de Llobregat, Barcelona, Spain.
    Bertran, Esther
    (IDIBELL), Barcelona, Spain.
    Campbell, Jean
    University of Washington, Washington, Seattle.
    Fausto, Nelson
    University of Washington, Washington, Seattle.
    Fabregat, Isabel
    (IDIBELL), Barcelona, Spain.
    The transforming growth factor-beta (TGF-β) mediates acquisition of a mesenchymal stem cell-like phenotype in human liver cells.2011In: Journal of Cellular Physiology, ISSN 0021-9541, E-ISSN 1097-4652, Vol. 226, no 5, p. 1214-1223Article in journal (Refereed)
    Abstract [en]

    Transforming growth factor-beta (TGF-β) mediates several and sometime opposite effects in epithelial cells, inducing growth inhibition, and apoptosis but also promoting an epithelial to mesenchymal transition (EMT) process, which enhances cell migration and invasion. TGF-β plays relevant roles in different liver pathologies; however, very few is known about its specific signaling and cellular effects in human primary hepatocytes. Here we show that TGF-β inhibits proliferation and induces pro-apoptotic genes (such as BMF or BIM) in primary cultures of human fetal hepatocytes (HFH), but also up-regulates anti-apoptotic genes, such as BCL-XL and XIAP. Inhibition of the epidermal growth factor receptor (EGFR), using gefitinib, abrogates the increase in the expression of the anti-apoptotic genes and significantly enhances cell death. Simultaneously, TGF-β is able to induce an EMT process in HFH, coincident with Snail up-regulation and a decrease in E-cadherin levels, cells showing mesenchymal proteins and reorganization of the actin cytoskeleton in stress fibers. Interestingly, these cells show loss of expression of specific hepatic genes and increased expression of stem cell markers. Chronic treatment with TGF-β allows selection of a population of mesenchymal cells with a de-differentiated phenotype, reminiscent of progenitor-like cells. Process is reversible and the mesenchymal stem-like cells re-differentiate to hepatocytes under controlled experimental conditions. In summary, we show for the first time that human hepatocytes may respond to TGF-β inducing different signals, some of them might contribute to tumor suppression (growth inhibition and apoptosis), but others should mediate liver tumor progression and invasion (EMT and acquisition of a stem-like phenotype).

  • 6.
    Caja, Laia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Kahata, Kaoru
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research.
    Moustakas, Aristidis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research.
    Context-dependent action of transforming growth factor β family members on normal and cancer stem cells2012In: Current pharmaceutical design, ISSN 1873-4286, Vol. 18, no 27, p. 4072-4086Article in journal (Refereed)
    Abstract [en]

    The transforming growth factor β (TGFβ) family embraces many growth factors including the Activins and bone morphogenetic proteins (BMPs). The pathways mediated by these growth factors are implicated in many fundamental biological processes such as early embryonic development, organ morphogenesis and adult tissue homeostasis and in a large number of pathologies including cancer. The action of these pathways is often contextual, which means that different cell types present different physiological responses to these ligands or that the response of one cell type to a certain ligand differs depending on the presence of other signaling proteins that stimulate the target cell together with TGFβ/BMP. The latter usually reflects developmental stage or progression to a specific pathological stage. Not only diverse growth factors and cytokines can influence the response of tissues to TGFβ/BMP, but a single cell type may also show drastically different physiological outcomes to TGFβ or Activin signaling as compared to BMP signaling. This review describes differential physiological outcomes of TGFβ and BMP signaling in normal embryonic or adult stem cells and eventually in cancer stem cells and the process of epithelial-mesenchymal transition. We also summarize evidence on the mechanistic antagonism between TGFβ and BMP signaling as established in vascular differentiation and the progression of tissue fibrosis and cancer. The article ends by discussing possible advantages that the acquired knowledge of these signaling mechanisms offers to new regimes of cancer therapy and the ever-lasting problem of drug resistance elicited by tumor initiating cells.

  • 7.
    Caja, Laia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Ortiz, Conrad
    Bertran, Esther
    Murillo, Miguel M
    Miró-Obradors, M Jesús
    Palacios, Evangelina
    Fabregat, Isabel
    Differential intracellular signalling induced by TGF-beta in rat adult hepatocytes and hepatoma cells: implications in liver carcinogenesis.2007In: Cellular Signalling, ISSN 0898-6568, E-ISSN 1873-3913, Vol. 19, no 4, p. 683-94Article in journal (Refereed)
    Abstract [en]

    The transforming growth factor-beta (TGF-beta) regulates hepatocyte growth, inhibiting proliferation and inducing apoptosis. Indeed, escaping from the TGF-beta suppressor actions might be a prerequisite for liver tumour progression. In this work we show that TGF-beta plays a dual role in regulating apoptosis in FaO rat hepatoma cells, since, in addition to its pro-apoptotic effect, TGF-beta also activates survival signals, such as AKT, the epidermal growth factor receptor (EGFR) being required for its activation. TGF-beta induces the expression of the EGFR ligands transforming growth factor-alpha (TGF-alpha) and heparin-binding EGF-like growth factor (HB-EGF) and induces intracellular re-localization of the EGFR. Cells that overcome the apoptotic effects of TGF-beta undergo morphological changes reminiscent of an epithelial-mesenchymal transition (EMT) process. In contrast, TGF-beta does not activate AKT in adult hepatocytes, which correlates with lack of EGFR transactivation and no response to EGFR inhibitors. Although TGF-beta induces TGF-alpha and HB-EGF in adult hepatocytes, these cells show very low expression of TACE/ADAM 17 (TNF-alpha converting enzyme), which is required for EGFR ligand proteolysis and activation. Furthermore, adult hepatocytes do not undergo EMT processes in response to TGF-beta, which might be due, at least in part, to the fact that F-actin re-organization induced by TGF-beta in FaO cells require the EGFR pathway. Finally, results indicate that EGFR transactivation does not block TGF-beta-induced cell cycle arrest in FaO cells, but must be interfering with the pro-apoptotic signalling. In conclusion, TGF-beta is a suppressor factor for adult quiescent hepatocytes, but not for hepatoma cells, where it plays a dual role, both suppressing and promoting carcinogenesis.

  • 8.
    Caja, Laia Puigsubira
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Bellomo, Claudia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Moustakas, Aristidis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Transforming growth factor beta and bone morphogenetic protein actions in brain tumors2015In: FEBS Letters, ISSN 0014-5793, E-ISSN 1873-3468, Vol. 589, no 14, p. 1588-1597Article, review/survey (Refereed)
    Abstract [en]

    Members of the transforming growth factor beta (TGF-beta) family are implicated in the biology of several cancers. Here we focus on malignancies of the brain and examine the TGF beta and the bone morphogenetic protein (BMP) signaling branches of the family. These pathways exhibit context-dependent actions during tumorigenesis, acting either as tumor suppressors or as pro-tumorigenic agents. In the brain, the TGF-beta s associate with oncogenic development and progression to the more malignant state. Inversely, the BMPs suppress tumorigenic potential by acting as agents that induce tumor cell differentiation. The latter has been best demonstrated in grade IV astrocytomas, otherwise known as glioblastoma multiforme. We discuss how the actions of TGF-beta s and BMPs on cancer stem cells may explain their effects on tumor progression, and try to highlight intricate mechanisms that may link tumor cell differentiation to invasion. The focus on TGF-beta and BMP and their actions in brain malignancies provides a rich territory for mechanistic understanding of tumor heterogeneity and suggests ways for improved therapeutic intervention, currently being addressed by clinical trials.

  • 9. Caja, Laia
    et al.
    Sancho, Patricia
    L’Hospitalet de Llobregat, Barcelona, Spain.
    Bertran, Esther
    L’Hospitalet de Llobregat, Barcelona, Spain.
    Fabregat, Isabel
    L’Hospitalet de Llobregat, Barcelona, Spain.
    Dissecting the effect of targeting the epidermal growth factor receptor on TGF-β-induced-apoptosis in human hepatocellular carcinoma cells.2011In: Journal of Hepatology, ISSN 0168-8278, E-ISSN 1600-0641, Vol. 55, no 2, p. 351-358Article in journal (Refereed)
    Abstract [en]

    BACKGROUND & AIMS: Transforming growth factor-beta (TGF-β) induces apoptosis in hepatocytes, a process that is inhibited by the epidermal growth factor receptor (EGFR) pathway. The aim of this work was to ablate EGFR in hepatocellular carcinoma (HCC) cells to understand its role in impairing TGF-β-induced cell death.

    METHODS: Response to TGF-β in terms of apoptosis was analyzed in different HCC cell lines and the effect of canceling EGFR expression was evaluated.

    RESULTS: TGF-β induces apoptosis in some HCC cells (such as Hep3B, PLC/PRF/5, Huh7, or SNU449), but it also mediates survival signals, coincident with the up-regulation of EGFR ligands. Inhibition of the EGFR, either by targeted knock-down with specific siRNA or by pharmacological inhibition, significantly enhances apoptotic response. TGF-β treatment in EGFR targeted knock-down cells correlates with higher levels of the NADPH oxidase NOX4 and changes in the expression profile of BCL-2 and IAP families. However, other HCC cells, such as HepG2, which show over activation of the Ras/ERKs pathway, SK-Hep1, with an endothelial phenotype, or SNU398, where the TGF-β-Smad signaling is altered, show apoptosis resistance that is not restored through EGFR blockade.

    CONCLUSIONS: The inhibition of EGFR in HCC may enhance TGF-β-induced pro-apoptotic signaling. However, this effect may only concern those tumors with an epithelial phenotype which do not bear alterations in TGF-β signaling nor exhibit an over-activation of the survival pathways downstream of the EGFR.

  • 10. Caja, Laia
    et al.
    Sancho, Patricia
    Univ Barcelona, Barcelona, Spain.
    Bertran, Esther
    Univ Barcelona, Barcelona, Spain.
    Iglesias-Serret, Daniel
    Univ Barcelona, Barcelona, Spain.
    Gil, Joan
    Univ Barcelona, Barcelona, Spain.
    Fabregat, Isabel
    Univ Barcelona, Barcelona, Spain.
    Overactivation of the MEK/ERK pathway in liver tumor cells confers resistance to TGF-{beta}-induced cell death through impairing up-regulation of the NADPH oxidase NOX4.2009In: Cancer Research, ISSN 0008-5472, E-ISSN 1538-7445, Vol. 69, no 19, p. 7595-7602Article in journal (Refereed)
    Abstract [en]

    Transforming growth factor-beta (TGF-beta) induces apoptosis in hepatocytes, being considered a liver tumor suppressor. However, many human hepatocellular carcinoma (HCC) cells escape from its proapoptotic effects, gaining response to this cytokine in terms of malignancy. We have recently reported that the apoptosis induced by TGF-beta in hepatocytes requires up-regulation of the NADPH oxidase NOX4, which mediates reactive oxygen species (ROS) production. TGF-beta-induced NOX4 expression is inhibited by antiapoptotic signals, such as the phosphatydilinositol-3-phosphate kinase or the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathways. The aim of the present work was to analyze whether resistance to TGF-beta-induced apoptosis in HCC cells is related to the impairment of NOX4 up-regulation due to overactivation of survival signals. Results indicate that inhibition of the MAPK/ERK kinase (MEK)/ERK pathway in HepG2 cells, which are refractory to the proapoptotic effects of TGF-beta, sensitizes them to cell death through a mitochondrial-dependent mechanism, coincident with increased levels of BIM and BMF, decreased levels of BCL-XL and MCL1, and BAX/BAK activation. Regulation of BMF, BCL-XL, and MCL1 occurs at the mRNA level, whereas BIM regulation occurs post-transcriptionally. ROS production and glutathione depletion are only observed in cells treated with TGF-beta and PD98059, which correlates with NOX4 up-regulation. Targeting knockdown of NOX4 impairs ROS increase and all the mitochondrial-dependent apoptotic features by a mechanism that is upstream from the regulation of BIM, BMF, BCL-XL, and MCL1 levels. In conclusion, overactivation of the MEK/ERK pathway in liver tumor cells confers resistance to TGF-beta-induced cell death through impairing NOX4 up-regulation, which is required for an efficient mitochondrial-dependent apoptosis.

  • 11.
    Caja, Laia
    et al.
    (IDIBELL), L’Hospitalet de Llobregat, Barcelona, Spain.
    Sancho, Patricia
    (IDIBELL), L’Hospitalet de Llobregat, Barcelona, Spain.
    Bertran, Esther
    (IDIBELL), L’Hospitalet de Llobregat, Barcelona, Spain.
    Ortiz, Conrad
    (IDIBELL), L’Hospitalet de Llobregat, Barcelona, Spain.
    Campbell, Jean S
    University of Washington, Seattle, USA.
    Fausto, Nelson
    University of Washington, Seattle, USA.
    Fabregat, Isabel
    L’Hospitalet de Llobregat, Barcelona, Spain.
    The tyrphostin AG1478 inhibits proliferation and induces death of liver tumor cells through EGF receptor-dependent and independent mechanisms.2011In: Biochemical pharmacology, ISSN 1873-2968, Vol. 82, no 11, p. 1583-1592Article in journal (Refereed)
    Abstract [en]

    Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related death. Different signaling pathways are de-regulated in this pathogenesis, among them the epidermal growth factor receptor one (EGFR/Erb1). Here we show that blockage of this pathway by the tyrphostin 4-(3-chloroanilino)-6,7-dimethoxyquinazoline (AG1478) in different liver tumor cell lines promotes both inhibition of cell proliferation and induction of cell death, which are coincident with arrest in the G1 phase of the cell cycle, caspase-3 activation and DNA fragmentation. AG1478 up-regulates the expression of the pro-apoptotic member of the BCL-2 family BIM and down-regulates the expression of the anti-apoptotic BCL-XL and MCL1. Furthermore, it also decreases the levels of the caspase inhibitors HIAP2 and XIAP. The treatment of HCC cells with AG1478 enhanced the apoptosis induced by other pro-apoptotic stimuli, such as the physiological cytokine, TGF-β, highly expressed in liver tumors, or the chemotherapeutic drug doxorubicin. The effects observed by AG1478 were broader than the ones seen by silencing of the EGFR with siRNA, which indicates that this drug might act on other targets different from the EGFR. In this same line of evidence, AG1478 retained some cytotoxic effects in cells where EGFR has been targeted knock-down with shRNA. Interestingly, AG1478 preferentially acts on liver tumor cells, being untransformed cells much less responsive to its cytotoxic effects. In conclusion, AG1478 could be a potential therapeutic drug to be used in HCC.

  • 12.
    Caja, Laia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research.
    Tzavlaki, Kalliopi
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research.
    Dadras, Mahsa Shahidi
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Tan, E-Jean
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Hatem, Gad
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research.
    Maturi, Naga Prathyusha
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Neuro-Oncology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Morén, Anita
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research.
    Wik, Lotta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Molecular tools. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Watanabe, Yukihide
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Univ Tsukuba, Dept Expt Pathol, Fac Med, Tsukuba, Ibaraki, Japan.
    Savary, Katia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Science for Life Laboratory, SciLifeLab. Univ Reims, UMR CNRS MEDyC 7369, Reims, France.
    Kamali-Moghaddam, Masood
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Molecular tools. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Uhrbom, Lene
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Neuro-Oncology.
    Heldin, Carl-Henrik
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research.
    Moustakas, Aristidis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Snail regulates BMP and TGF beta pathways to control the differentiation status of glioma-initiating cells2018In: Oncogene, ISSN 0950-9232, E-ISSN 1476-5594, Vol. 37, no 19, p. 2515-2531Article in journal (Refereed)
    Abstract [en]

    Glioblastoma multiforme is a brain malignancy characterized by high heterogeneity, invasiveness, and resistance to current therapies, attributes related to the occurrence of glioma stem cells (GSCs). Transforming growth factor beta (TGF beta) promotes self-renewal and bone morphogenetic protein (BMP) induces differentiation of GSCs. BMP7 induces the transcription factor Snail to promote astrocytic differentiation in GSCs and suppress tumor growth in vivo. We demonstrate that Snail represses stemness in GSCs. Snail interacts with SMAD signaling mediators, generates a positive feedback loop of BMP signaling and transcriptionally represses the TGFB1 gene, decreasing TGF beta 1 signaling activity. Exogenous TGF beta 1 counteracts Snail function in vitro, and in vivo promotes proliferation and re-expression of Nestin, confirming the importance of TGFB1 gene repression by Snail. In conclusion, novel insight highlights mechanisms whereby Snail differentially regulates the activity of the opposing BMP and TGF beta pathways, thus promoting an astrocytic fate switch and repressing stemness in GSCs.

  • 13. Carmona-Cuenca, Irene
    et al.
    Roncero, César
    Sancho, Patricia
    Caja, Laia
    Centre d’Oncologia Molecular, IDIBELL-Institut d’Investigació Biomèdica de Bellvitge, Hospital Duran i Reynals, Barcelona, Spain.
    Fausto, Nelson
    Fernández, Margarita
    Fabregat, Isabel
    Upregulation of the NADPH oxidase NOX4 by TGF-beta in hepatocytes is required for its pro-apoptotic activity2008In: Journal of Hepatology, ISSN 0168-8278, E-ISSN 1600-0641, Vol. 49, no 6, p. 965-76Article in journal (Refereed)
    Abstract [en]

    BACKGROUND/AIMS: The transforming growth factor-beta (TGF-beta) induces apoptosis in hepatocytes through an oxidative stress process. Here, we have analyzed the role of different NADPH oxidase isoforms in the intracellular signalling induced by TGF-beta in hepatocytes, to later explore whether this mechanism is altered in liver tumor cells.

    METHODS: Primary cultures of rat and human hepatocytes, HepG2 and Hep3B cells were used in in vitro studies to analyze the TGF-beta response.

    RESULTS: TGF-beta-induced apoptosis in rat hepatocytes does not require Rac-dependent NADPH oxidases. TGF-beta upregulates the Rac-independent Nox4, which correlates with its pro-apoptotic activity. Regulation of Nox4 occurs at the transcriptional level and is counteracted by intracellular survival signals. siRNA targeted knock-down of Nox4 attenuates NADPH oxidase activity, caspase activation and cell death in rat hepatocytes. NOX4 upregulation by TGF-beta is also observed in human hepatocytes, coincident with apoptosis. In human hepatocellular carcinoma (HCC) cell lines, NOX4 upregulation by TGF-beta is only observed in cells that are sensitive to its cytotoxic effect, such as Hep3B cells. siRNA targeted knock-down of NOX4 in these cells impairs TGF-beta-induced apoptosis.

    CONCLUSIONS: Upregulation of NOX4 by TGF-beta is required for its pro-apoptotic activity in hepatocytes. Impairment of this TGF-beta-induced response might confer apoptosis resistance in HCC cells.

  • 14.
    Chisari, Andrea N
    et al.
    Research Institut (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain.
    Sancho, Patricia
    Research Institut (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain.
    Caja, Laia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Bertran, Esther
    Research Institut (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain.
    Fabregat, Isabel
    Research Institut (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain.
    Lack of amino acids in mouse hepatocytes in culture induces the selection of preneoplastic cells.2012In: Cellular Signalling, ISSN 0898-6568, E-ISSN 1873-3913, Vol. 24, no 1, p. 325-32Article in journal (Refereed)
    Abstract [en]

    Protein malnutrition occurs when there is insufficient protein to meet metabolic demands. Previous works have indicated that cycles of protein fasting/refeeding enhance the incidence of early lesions during chemical carcinogenesis in rat liver. The general objective of this work was to study the effect of aminoacids (Aa) deprivation on the proliferation and survival of hepatocytes, to understand its possible involvement in the generation of pre-neoplastic stages in the liver. Lack of Aa in the culture medium of an immortalized mice hepatocyte cell line induced loss in cell viability, correlating with apoptosis. However, a subpopulation of cells was able to survive, which showed a more proliferative phenotype and resistance to apoptotic stimuli. Escaping to Aa deprivation-induced death is coincident with an activated mTOR signaling and higher levels of phospho-AKT and phospho-ERKs, which correlated with increased activation of EGFR/SRC pathway and overexpression of EGFR ligands, such as TGF-α and HB-EGF. Lack of Aa induced a rapid increase in reactive oxygen species (ROS) production. However, cells that survived showed an enhancement in the levels of reduced glutathione and a higher expression of γ-GCS, the regulatory enzyme of glutathione synthesis, which can be interpreted as an adaptation of the cells to counteract the oxidative stress. In conclusion, results presented in this paper indicate that it is possible to isolate a subpopulation of hepatocytes that are able to grow in the absence of Aa, showing higher capacity to proliferate and survive, reminiscent of a preneoplastic phenotype.

  • 15.
    Coppotelli, Giuseppe
    et al.
    Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden.
    Mughal, Nouman
    Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden.
    Callegari, Simone
    Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden.
    Sompallae, Ramakrishna
    Department of Biostatistics, Harvard School of Public Health, Boston, MA 02115, USA.
    Caja Puigsubira, Laia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Luijsterburg, Martijn S
    Department of Toxicogenetics, Leiden University Medical Center, 2333 ZC Leiden, The Netherlands .
    Dantuma, Nico P
    Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden.
    Moustakas, Aristidis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research.
    Masucci, Maria G
    Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden.
    The Epstein-Barr virus nuclear antigen-1 reprograms transcription by mimicry of high mobility group A proteins2013In: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 41, no 5, p. 2950-2962Article in journal (Refereed)
    Abstract [en]

    Viral proteins reprogram their host cells by hijacking regulatory components of protein networks. Here we describe a novel property of the Epstein-Barr virus (EBV) nuclear antigen-1 (EBNA1) that may underlie the capacity of the virus to promote a global remodeling of chromatin architecture and cellular transcription. We found that the expression of EBNA1 in transfected human and mouse cells is associated with decreased prevalence of heterochromatin foci, enhanced accessibility of cellular DNA to micrococcal nuclease digestion and decreased average length of nucleosome repeats, suggesting de-protection of the nucleosome linker regions. This is a direct effect of EBNA1 because targeting the viral protein to heterochromatin promotes large-scale chromatin decondensation with slow kinetics and independent of the recruitment of adenosine triphosphate-dependent chromatin remodelers. The remodeling function is mediated by a bipartite Gly-Arg rich domain of EBNA1 that resembles the AT-hook of High Mobility Group A (HMGA) architectural transcription factors. Similar to HMGAs, EBNA1 is highly mobile in interphase nuclei and promotes the mobility of linker histone H1, which counteracts chromatin condensation and alters the transcription of numerous cellular genes. Thus, by regulating chromatin compaction, EBNA1 may reset cellular transcription during infection and prime the infected cells for malignant transformation.

  • 16. Crosas-Molist, Eva
    et al.
    Meirelles, Thayna
    López-Luque, Judit
    Serra-Peinado, Carla
    Selva, Javier
    Caja, Laia
    Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), L’Hospitalet de Llobregat, Barcelona, Spain.
    Gorbenko Del Blanco, Darya
    Uriarte, Juan José
    Bertran, Esther
    Mendizábal, Yolanda
    Hernández, Vanessa
    García-Calero, Carolina
    Busnadiego, Oscar
    Condom, Enric
    Toral, David
    Castellà, Manel
    Forteza, Alberto
    Navajas, Daniel
    Sarri, Elisabet
    Rodríguez-Pascual, Fernando
    Dietz, Harry C
    Fabregat, Isabel
    Egea, Gustavo
    Vascular smooth muscle cell phenotypic changes in patients with Marfan syndrome2015In: Arteriosclerosis, Thrombosis and Vascular Biology, ISSN 1079-5642, E-ISSN 1524-4636, Vol. 35, no 4, p. 960-972Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: Marfan's syndrome is characterized by the formation of ascending aortic aneurysms resulting from altered assembly of extracellular matrix microfibrils and chronic tissue growth factor (TGF)-β signaling. TGF-β is a potent regulator of the vascular smooth muscle cell (VSMC) phenotype. We hypothesized that as a result of the chronic TGF-β signaling, VSMC would alter their basal differentiation phenotype, which could facilitate the formation of aneurysms. This study explores whether Marfan's syndrome entails phenotypic alterations of VSMC and possible mechanisms at the subcellular level.

    APPROACH AND RESULTS: Immunohistochemical and Western blotting analyses of dilated aortas from Marfan patients showed overexpression of contractile protein markers (α-smooth muscle actin, smoothelin, smooth muscle protein 22 alpha, and calponin-1) and collagen I in comparison with healthy aortas. VSMC explanted from Marfan aortic aneurysms showed increased in vitro expression of these phenotypic markers and also of myocardin, a transcription factor essential for VSMC-specific differentiation. These alterations were generally reduced after pharmacological inhibition of the TGF-β pathway. Marfan VSMC in culture showed more robust actin stress fibers and enhanced RhoA-GTP levels, which was accompanied by increased focal adhesion components and higher nuclear localization of myosin-related transcription factor A. Marfan VSMC and extracellular matrix measured by atomic force microscopy were both stiffer than their respective controls.

    CONCLUSIONS: In Marfan VSMC, both in tissue and in culture, there are variable TGF-β-dependent phenotypic changes affecting contractile proteins and collagen I, leading to greater cellular and extracellular matrix stiffness. Altogether, these alterations may contribute to the known aortic rigidity that precedes or accompanies Marfan's syndrome aneurysm formation.

  • 17.
    Fernando, Joan
    et al.
    L'Hospitalet de Llobregat, Barcelona, Spain.
    Sancho, Patricia
    L'Hospitalet de Llobregat, Barcelona, Spain.
    Fernández-Rodriguez, Conrado M
    Hospital Universitario Fundación Alcorcón, Madrid, Spain.
    Lledó, José L
    Hospital Universitario Fundación Alcorcón, Madrid, Spain.
    Caja, Laia
    L'Hospitalet de Llobregat, Barcelona, Spain.
    Campbell, Jean S
    University of Washington, Seattle, Washington.
    Fausto, Nelson
    University of Washington, Seattle, Washington.
    Fabregat, Isabel
    L'Hospitalet de Llobregat, Barcelona, Spain.
    Sorafenib sensitizes hepatocellular carcinoma cells to physiological apoptotic stimuli.2012In: Journal of Cellular Physiology, ISSN 0021-9541, E-ISSN 1097-4652, Vol. 227, no 4, p. 1319-25Article in journal (Refereed)
    Abstract [en]

    Sorafenib increases survival rate of patients with advanced hepatocellular carcinoma (HCC). The mechanism underlying this effect is not completely understood. In this work we have analyzed the effects of sorafenib on autocrine proliferation and survival of different human HCC cell lines. Our results indicate that sorafenib in vitro counteracts autocrine growth of different tumor cells (Hep3B, HepG2, PLC-PRF-5, SK-Hep1). Arrest in S/G2/M cell cycle phases were observed coincident with cyclin D1 down-regulation. However, sorafenib's main anti-tumor activity seems to occur through cell death induction which correlated with caspase activation, increase in the percentage of hypodiploid cells, activation of BAX and BAK and cytochrome c release from mitochondria to cytosol. In addition, we observed a rise in mRNA and protein levels of the pro-apoptotic "BH3-domain only" PUMA and BIM, as well as decreased protein levels of the anti-apoptotic MCL1 and survivin. PUMA targeting knock-down, by using specific siRNAs, inhibited sorafenib-induced apoptotic features. Moreover, we obtained evidence suggesting that sorafenib also sensitizes HCC cells to the apoptotic activity of transforming growth factor-β (TGF-β) through the intrinsic pathway and to tumor necrosis factor-α (TNF) through the extrinsic pathway. Interestingly, sensitization to sorafenib-induced apoptosis is characteristic of liver tumor cells, since untransformed hepatocytes did not respond to sorafenib inducing apoptosis, either alone or in combination with TGF-β or TNF. Indeed, sorafenib effectiveness in delaying HCC late progression might be partly related to a selectively sensitization of HCC cells to apoptosis by disrupting autocrine signals that protect them from adverse conditions and pro-apoptotic physiological cytokines.

  • 18. Moreno-Càceres, J
    et al.
    Caja, Laia
    Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain.
    Mainez, J
    Mayoral, R
    Martín-Sanz, P
    Moreno-Vicente, R
    Del Pozo, M Á
    Dooley, S
    Egea, G
    Fabregat, I
    Caveolin-1 is required for TGF-β-induced transactivation of the EGF receptor pathway in hepatocytes through the activation of the metalloprotease TACE/ADAM172014In: Cell Death and Disease, ISSN 2041-4889, E-ISSN 2041-4889, Vol. 5, article id e1326Article in journal (Refereed)
    Abstract [en]

    Transforming growth factor-beta (TGF-β) plays a dual role in hepatocytes, inducing both pro- and anti-apoptotic responses, whose balance decides cell fate. Survival signals are mediated by the epidermal growth factor receptor (EGFR) pathway, which is activated by TGF-β in these cells. Caveolin-1 (Cav1) is a structural protein of caveolae linked to TGF-β receptors trafficking and signaling. Previous results have indicated that in hepatocytes, Cav1 is required for TGF-β-induced anti-apoptotic signals, but the molecular mechanism is not fully understood yet. In this work, we show that immortalized Cav1(-/-) hepatocytes were more sensitive to the pro-apoptotic effects induced by TGF-β, showing a higher activation of caspase-3, higher decrease in cell viability and prolonged increase through time of intracellular reactive oxygen species (ROS). These results were coincident with attenuation of TGF-β-induced survival signals in Cav1(-/-) hepatocytes, such as AKT and ERK1/2 phosphorylation and NFκ-B activation. Transactivation of the EGFR pathway by TGF-β was impaired in Cav1(-/-) hepatocytes, which correlated with lack of activation of TACE/ADAM17, the metalloprotease responsible for the shedding of EGFR ligands. Reconstitution of Cav1 in Cav1(-/-) hepatocytes rescued wild-type phenotype features, both in terms of EGFR transactivation and TACE/ADAM17 activation. TACE/ADAM17 was localized in detergent-resistant membrane (DRM) fractions in Cav1(+/+) cells, which was not the case in Cav1(-/-) cells. Disorganization of lipid rafts after treatment with cholesterol-binding agents caused loss of TACE/ADAM17 activation after TGF-β treatment. In conclusion, in hepatocytes, Cav1 is required for TGF-β-mediated activation of the metalloprotease TACE/ADAM17 that is responsible for shedding of EGFR ligands and activation of the EGFR pathway, which counteracts the TGF-β pro-apoptotic effects. Therefore, Cav1 contributes to the pro-tumorigenic effects of TGF-β in liver cancer cells.

  • 19.
    Ortiz, Conrad
    et al.
    Bellvitge Biomed Res Inst IDIBEL, Barcelona, Spain.
    Caja, Laia
    Bertran, Esther
    Bellvitge Biomed Res Inst IDIBEL, Barcelona, Spain.
    Gonzalez-Rodriguez, Águeda
    Univ Autonoma Madrid, CSIC, Inst Invest Biomed Alberto Sols, Madrid, Spain.
    Valverde, Ángela M
    Univ Autonoma Madrid, CSIC, Inst Invest Biomed Alberto Sols, Madrid, Spain.
    Fabregat, Isabel
    Bellvitge Biomed Res Inst IDIBELL, Biol Clues Invas & Metastat Phenotype Grp, Barcelona, Spain.
    Sancho, Patricia
    Bellvitge Biomed Res Inst IDIBELL, Biol Clues Invas & Metastat Phenotype Grp, Barcelona, Spain.
    Protein-tyrosine phosphatase 1B (PTP1B) deficiency confers resistance to transforming growth factor-β (TGF-β)-induced suppressor effects in hepatocytes.2012In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 287, no 19, p. 15263-74Article in journal (Refereed)
    Abstract [en]

    Transforming growth factor-β (TGF-β) plays a dual role in hepatocytes, mediating both tumor suppressor and promoter effects. The suppressor effects of the cytokine can be negatively regulated by activation of survival signals, mostly dependent on tyrosine kinase activity. The aim of our work was to study the role of the protein-tyrosine phosphatase 1B (PTP1B) on the cellular responses to TGF-β, using for this purpose immortalized neonatal hepatocytes isolated from both PTP1B(+/+) and PTP1B(-/-) mice. We have found that PTP1B deficiency conferred resistance to TGF-β suppressor effects, such as apoptosis and growth inhibition, correlating with lower Smad2/Smad3 activation. Both responses were recovered in the presence of the general tyrosine kinase inhibitor genistein. PTP1B(-/-) cells showed elevated NF-κB activation in response to TGF-β. Knockdown of the NF-κB p65 subunit increased cell response in terms of Smads phosphorylation and apoptosis. Interestingly, these effects were accompanied by inhibition of Smad7 up-regulation. In addition, lack of PTP1B promoted an altered NADPH oxidase (NOX) expression pattern in response to TGF-β, strongly increasing the NOX1/NOX4 ratio, which was reverted by genistein and p65 knockdown. Importantly, NOX1 knockdown inhibited nuclear translocation of p65, promoted Smad phosphorylation, and decreased Smad7 levels. In summary, our results suggest that PTP1B deficiency confers resistance to TGF-β through Smad inhibition, an effect that is mediated by NOX1-dependent NF-κB activation, which in turn, increases the level of the Smad inhibitor Smad7 and participates in a positive feedback loop on NOX1 up-regulation.

  • 20. Ortiz, Conrad
    et al.
    Caja, Laia
    Fundacio Inst Invest Biomed Bellvitge IDIBELL, Barcelona, Spain.
    Sancho, Patricia
    Bertran, Esther
    Fabregat, Isabel
    Inhibition of the EGF receptor blocks autocrine growth and increases the cytotoxic effects of doxorubicin in rat hepatoma cells: role of reactive oxygen species production and glutathione depletion2008In: Biochemical pharmacology, ISSN 1873-2968, Vol. 75, no 10, p. 1935-1945Article in journal (Refereed)
    Abstract [en]

    FaO rat hepatoma cells show increased levels of the epidermal growth factor receptor (EGFR) ligands, when compared with adult normal hepatocytes, and higher activity of the TNF-alpha converting enzyme (TACE/ADAM17), which is required for EGFR ligand proteolysis and activation. In this work we have analysed the consequences of inhibiting the EGFR in FaO rat hepatoma cells, focusing the attention on autocrine growth and protection from apoptosis. Results have indicated that FaO cells show overactivation of the EGFR pathway, which induces basal growth (in the absence of serum) and protection from pro-apoptotic agents, such as doxorubicin, generating drug resistance. Treatment of cells with the combination of doxorubicin and the tyrphostin 4-(3-chloroanilino)-6,7-dimethoxyquinazoline (AG1478, a potent and specific inhibitor of EGFR tyrosine kinase) potently inhibits autocrine growth and induces apoptosis. The apoptotic effect correlates with high expression and activation of the pro-apoptotic Bax and decreased transcript and protein levels of the anti-apoptotic Mcl-1 and Bcl-x(L). Furthermore, the combination of AG1478 and doxorubicin induces reactive oxygen species (ROS) production and glutathione depletion in FaO cells, coincident with up-regulation of the NADPH oxidase NOX4 and down-regulation of the gamma-glutamylcysteine synthetase (gamma-GCS), a key regulatory enzyme of the glutathione synthesis. Incubation of cells with glutathione ethyl ester attenuates the apoptosis induced by the combination of doxorubicin and AG1478, which indicates that glutathione depletion is required for an efficient cell death. In conclusion, targeting EGFR combined with other conventional pro-apoptotic drugs should potentially be effective in antineoplastic therapy towards liver cancer.

  • 21.
    Papoutsoglou, Panagiotis
    et al.
    Uppsala University, Science for Life Laboratory, SciLifeLab.
    Caja, Laia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Ameur, Adam
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Heldin, Carl-Henrik
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Moustakas, Aristidis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    TGFβ signaling down-regulates LINC00707 to inhibit inflammatory responsesManuscript (preprint) (Other academic)
    Abstract [en]

    The class of long non-coding RNAs (lncRNAs) consists of RNA molecules, which lack protein coding potential and regulate a wide variety of cellular processes. At the molecular level, lncRNAs act as regulators of gene expression by interacting with chromatin, other types of RNA or proteins. Transforming growth factor β (TGFβ) plays pivotal roles in diverse biological processes, such as cell growth arrest, embryonic development and regulation of the immune system. In this study, we describe the long intergenic non-protein coding RNA 707 (LINC00707) as a TGFβ responsive gene. By combining transcriptomic data from human keratinocytes and glioblastoma cancer stem cells, we observed that TGFβ signaling down-regulates the expression of LINC00707. RNA sequencing revealed that in keratinocytes knockdown of LINC00707 or stimulation by TGFβ, affected expression of genes involved in inflammatory responses and interferon-γ-mediated signaling. In summary, we suggest that the immune suppressive actions of TGFβ involve suppression of the pro-inflammatory LINC00707.

  • 22.
    Papoutsoglou, Panagiotis
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Tsubakihara, Yutaro
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research.
    Caja, Laia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Pallis, Paris
    Ameur, Adam
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, The Linnaeus Centre for Bioinformatics. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Genetics and Pathology, Genomics. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Heldin, Carl-Henrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Moustakas, Aristidis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    The TGFB2-AS1 lncRNA regulates TGFβ signaling by modulating corepressor activity2018Article in journal (Refereed)
    Abstract [en]

    LncRNAs regulate cell function through many physiological processes. We have identified lncRNAs whose expression is regulated by transforming growth factor β (TGFβ), by a transcriptomic screen. We focused on TGFB2-antisense RNA1 (TGFB2-AS1), which was induced by TGFβ through Smad and protein kinase pathways, and exhibited predominantly nuclear localization. Depleting TGFB2-AS1 enhanced TGFβ/Smad-mediated transcription and expression of the TGFβ-target genes FN1 and SERPINE1. Overexpression of TGFB2-AS1 reduced expression of these genes, attenuated TGFβ-induced cell growth arrest, and altered BMP and Wnt pathway gene profiles. Mechanistically, TGFB2-AS1 mainly via its 3’ terminal region, bound to EED, an adaptor of the Polycomb repressor complex 2 (PRC2), promoting repressive histone H3K27me3 modifications at TGFβ-target gene promoters. Silencing EED or inhibiting PRC2 methylation activity, partially rescued TGFB2-AS1 mediated gene repression. Our observations support the notion that TGFB2-AS1 is a TGFβ-induced lncRNA with inhibitory functions on TGFβ and BMP pathways output, constituting an auto-regulatory negative feedback mechanism that balances TGFβ- and BMP-mediated responses.

  • 23. Pérez-Perarnau, Alba
    et al.
    Preciado, Sara
    Palmeri, Claudia Mariela
    Moncunill-Massaguer, Cristina
    Iglesias-Serret, Daniel
    González-Gironès, Diana M
    Miguel, Miriam
    Karasawa, Satoki
    Sakamoto, Satoshi
    Cosialls, Ana M
    Rubio-Patiño, Camila
    Saura-Esteller, José
    Ramón, Rosario
    Caja, Laia
    Institut d’Investigacio Biomedica de Bellvitge (IDIBELL) L’Hospitalet de Llobregat, Spain.
    Fabregat, Isabel
    Pons, Gabriel
    Handa, Hiroshi
    Albericio, Fernando
    Gil, Joan
    Lavilla, Rodolfo
    A trifluorinated thiazoline scaffold leading to pro-apoptotic agents targeting prohibitins2014In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 53, no 38, p. 10150-10154Article in journal (Refereed)
    Abstract [en]

    A new class of small molecules, with an unprecedented trifluorothiazoline scaffold, were synthesized and their pro-apoptotic activity was evaluated. With an EC50 in the low micromolar range, these compounds proved to be potent inducers of apoptosis in a broad spectrum of tumor cell lines, regardless of the functional status of p53. Fast structure-activity relationship studies allowed the preparation of the strongest apoptosis-inducing candidate. Using a high performance affinity purification approach, we identified prohibitins 1 and 2, key proteins involved in the maintenance of cell viability, as the targets for these compounds.

  • 24.
    Sancho, Patricia
    et al.
    L'Hospitalet, Barcelona, Spain.
    Bertran, Esther
    L'Hospitalet, Barcelona, Spain.
    Caja, Laia
    L'Hospitalet, Barcelona, Spain.
    Carmona-Cuenca, Irene
    Universidad Complutense, Madrid, Spain.
    Murillo, Miguel M
    Universidad Complutense, Madrid, Spain.
    Fabregat, Isabel
    L'Hospitalet, Barcelona, Spain.
    The inhibition of the epidermal growth factor (EGF) pathway enhances TGF-beta-induced apoptosis in rat hepatoma cells through inducing oxidative stress coincident with a change in the expression pattern of the NADPH oxidases (NOX) isoforms.2009In: Biochimica et Biophysica Acta, ISSN 0006-3002, E-ISSN 1878-2434, Vol. 1793, no 2, p. 253-263Article in journal (Refereed)
    Abstract [en]

    Transforming growth factor-beta (TGF-beta) induces apoptosis in hepatocytes, through a mechanism mediated by reactive oxygen species (ROS) production. Numerous tumoral cells develop mechanisms to escape from the TGF-beta-induced tumor suppressor effects. In this work we show that in FaO rat hepatoma cells inhibition of the epidermal growth factor receptor (EGFR) with the tyrphostin AG1478 enhances TGF-beta-induced cell death, coincident with an elevated increase in ROS production and GSH depletion. These events correlate with down-regulation of genes involved in the maintenance of redox homeostasis, such as gamma-GCS and MnSOD, and elevated mitochondrial ROS. Nonetheless, not all the ROS proceed from the mitochondria. Emerging evidences indicate that ROS production by TGF-beta is also mediated by the NADPH oxidase (NOX) system. TGF-beta-treated FaO cells induce nox1 expression. However, the treatment with TGF-beta and AG1478 greatly enhanced the expression of another family member: nox4. NOX1 and NOX4 targeted knock-down by siRNA experiments suggest that they play opposite roles, because NOX1 knockdown increases caspase-3 activity and cell death, whilst NOX4 knock-down attenuates the apoptotic process. This attenuation correlates with maintenance of GSH and antioxidant enzymes levels. In summary, EGFR inhibition enhances apoptosis induced by TGF-beta in FaO rat hepatoma cells through an increased oxidative stress coincident with a change in the expression pattern of NOX enzymes.

  • 25.
    Savary, Katia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Caglayan, Demet
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Cancer and Vascular Biology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Caja, Laia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Tzavlaki, Kalliopi
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Bin Nayeem, Sarmah
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Bergström, Tobias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Cancer and Vascular Biology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Jiang, Yiwen
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Cancer and Vascular Biology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Uhrbom, Lene
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Cancer and Vascular Biology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Forsberg-Nillson, Karin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Cancer and Vascular Biology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Westermark, Bengt
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Cancer and Vascular Biology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Heldin, Carl-Henrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Ferletta, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Moustakas, Aristidis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Snail depletes the tumorigenic potential of glioblastoma2013In: Oncogene, ISSN 0950-9232, E-ISSN 1476-5594, Vol. 32, no 47, p. 5409-5420Article in journal (Refereed)
    Abstract [en]

    Glioblastoma multiforme (GBM) is an aggressive brain malignancy characterized by high heterogeneity and invasiveness. It is increasingly accepted that the refractory feature of GBM to current therapies stems from the existence of few tumorigenic cells that sustain tumor growth and spreading, the so-called glioma-initiating cells (GICs). Previous studies showed that cytokines of the bone morphogenetic protein (BMP) family induce differentiation of the GICs, and thus act as tumor suppressors. Molecular pathways that explain this behavior of BMP cytokines remain largely elusive. Here, we show that BMP signaling induces Smad-dependent expression of the transcriptional regulator Snail in a rapid and sustained manner. Consistent with its already established promigratory function in other cell types, we report that Snail silencing decreases GBM cell migration. Consequently, overexpression of Snail increases GBM invasiveness in a mouse xenograft model. Surprisingly, we found that Snail depletes the GBM capacity to form gliomaspheres in vitro and to grow tumors in vivo, both of which are important features shared by GICs. Thus Snail, acting downstream of BMP signaling, dissociates the invasive capacity of GBM cells from their tumorigenic potential.

  • 26.
    Tan, E-Jean
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research.
    Thuault, Sylvie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research.
    Caja, Laia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research.
    Carletti, Tea
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research.
    Heldin, Carl-Henrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research.
    Moustakas, Aristidis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Ludwig Institute for Cancer Research. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Regulation of transcription factor Twist expression by the DNA architectural protein high mobility group A2 during epithelial-to-mesenchymal transition2012In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 287, no 10, p. 7134-7145Article in journal (Refereed)
    Abstract [en]

    Deciphering molecular mechanisms that control epithelial-to-mesenchymal transition (EMT) contributes to our understanding of how tumor cells become invasive and competent for intravasation. We have established that transforming growth factor β activates Smad proteins, which induce expression of the embryonic factor high mobility group A2 (HMGA2), which causes mesenchymal transition. HMGA2 associates with Smad complexes and induces expression of an established regulator of EMT, the zinc finger transcription factor Snail. We now show that HMGA2 can also induce expression of a second regulator of EMT, the basic helix-loop-helix transcription factor Twist. Silencing of endogenous Twist demonstrated that this protein acts in a partially redundant manner together with Snail. Double silencing of Snail and Twist reverts mesenchymal HMGA2-expressing cells to a more epithelial phenotype when compared with single silencing of Snail or Twist. Furthermore, HMGA2 can directly associate with A:T-rich sequences and promote transcription from the Twist promoter. The new evidence proposes a model whereby HMGA2 directly induces multiple transcriptional regulators of the EMT program and, thus, is a potential biomarker for carcinomas displaying EMT during progression to more advanced stages of malignancy.

1 - 26 of 26
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