title: Notch4 Signaling Induces a Mesenchymal-Epithelial-like Transition in Melanoma Cells to Suppress Malignant Behaviors.
abstract: The effects of Notch signaling are context-dependent and both oncogenic and tumor-suppressive functions have been described. Notch signaling in melanoma is considered oncogenic, but clinical trials testing Notch inhibition in this malignancy have not proved successful. Here, we report that expression of the constitutively active intracellular domain of Notch4 (N4ICD) in melanoma cells triggered a switch from a mesenchymal-like parental phenotype to an epithelial-like phenotype. The epithelial-like morphology was accompanied by strongly reduced invasive, migratory, and proliferative properties concomitant with the downregulation of epithelial-mesenchymal transition markers Snail2 (SNAI2), Twist1, vimentin (VIM), and MMP2 and the reexpression of E-cadherin (CDH1). The N4ICD-induced phenotypic switch also resulted in significantly reduced tumor growth in vivo Immunohistochemical analysis of primary human melanomas and cutaneous metastases revealed a significant correlation between Notch4 and E-cadherin expression. Mechanistically, we demonstrate that N4ICD induced the expression of the transcription factors Hey1 and Hey2, which bound directly to the promoter regions of Snail2 and Twist1 and repressed gene transcription, as determined by EMSA and luciferase assays. Taken together, our findings indicate a role for Notch4 as a tumor suppressor in melanoma, uncovering a potential explanation for the poor clinical efficacy of Notch inhibitors observed in this setting. Cancer Res; 76(7); 1690-7. ©2016 AACR.
authors.affiliation: Cancer Biology Unit, Department of Dermatology, Medical University Graz, Graz, Austria. Department of Orthopedics and Orthopedic Surgery, Medical University Graz, Graz, Austria. Center for Medical Research (ZMF), Medical University Graz, Graz, Austria.
authors.forename: Ehsan
authors.initials: E
authors.lastname: Bonyadi Rad
authors.affiliation: Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, University of Graz, Graz, Austria. Dermatology Research Centre, The University of Queensland, School of Medicine, Translational Research Institute, Brisbane, Queensland, Australia.
authors.forename: Heinz
authors.initials: H
authors.lastname: Hammerlindl
authors.affiliation: Cancer Biology Unit, Department of Dermatology, Medical University Graz, Graz, Austria. Center for Medical Research (ZMF), Medical University Graz, Graz, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Wels
authors.affiliation: Cancer Biology Unit, Department of Dermatology, Medical University Graz, Graz, Austria. Center for Medical Research (ZMF), Medical University Graz, Graz, Austria.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Popper
authors.affiliation: Cancer Biology Unit, Department of Dermatology, Medical University Graz, Graz, Austria. Center for Medical Research (ZMF), Medical University Graz, Graz, Austria. Dermatology Research Centre, The University of Queensland, School of Medicine, Translational Research Institute, Brisbane, Queensland, Australia.
authors.forename: Dinoop
authors.initials: D
authors.lastname: Ravindran Menon
authors.affiliation: Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology & Immunology, Medical University of Vienna, Vienna, Austria.
authors.forename: Heimo
authors.initials: H
authors.lastname: Breiteneder
authors.affiliation: Department of Pathology, University Hospital St. Poelten, Karl Landsteiner University of Health Sciences, St. Poelten, Austria.
authors.forename: Melitta
authors.initials: M
authors.lastname: Kitzwoegerer
authors.affiliation: Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology & Immunology, Medical University of Vienna, Vienna, Austria. Department of Dermatology, University Hospital St. Poelten, Karl Landsteiner University of Health Sciences, St. Poelten, Austria.
authors.forename: Christine
authors.initials: C
authors.lastname: Hafner
authors.affiliation: The Wistar Institute, Philadelphia, Pennsylvania.
authors.forename: Meenhard
authors.initials: M
authors.lastname: Herlyn
authors.affiliation: Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, University of Graz, Graz, Austria.
authors.forename: Helmut
authors.initials: H
authors.lastname: Bergler
authors.affiliation: Cancer Biology Unit, Department of Dermatology, Medical University Graz, Graz, Austria. Center for Medical Research (ZMF), Medical University Graz, Graz, Austria. Dermatology Research Centre, The University of Queensland, School of Medicine, Translational Research Institute, Brisbane, Queensland, Australia. Translational Research Institute, University of Queensland Diamantina Institute, Brisbane, Queensland, Australia. h.schaider@uq.edu.au.
authors.forename: Helmut
authors.initials: H
authors.lastname: Schaider
mesh_terms: D058750:Epithelial-Mesenchymal Transition / Q000502:physiology*; D006801:Humans; D008545:Melanoma / Q000235:genetics*; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D000074562:Receptor, Notch4; D051880:Receptors, Notch / Q000235:genetics*; D015398:Signal Transduction; D012878:Skin Neoplasms / Q000235:genetics*
chemical_list: C106075:NOTCH4 protein, human; D011518:Proto-Oncogene Proteins; D000074562:Receptor, Notch4; D051880:Receptors, Notch