title: PlexinD1 Is a Novel Transcriptional Target and Effector of Notch Signaling in Cancer Cells.
abstract: The secreted semaphorin Sema3E controls cell migration and invasiveness in cancer cells. Sema3E-receptor, PlexinD1, is frequently upregulated in melanoma, breast, colon, ovarian and prostate cancers; however, the mechanisms underlying PlexinD1 upregulation and the downstream events elicited in tumor cells are still unclear. Here we show that the canonical RBPjk-dependent Notch signaling cascade controls PlexinD1 expression in primary endothelial and cancer cells. Transcriptional activation was studied by quantitative PCR and promoter activity reporter assays. We found that Notch ligands and constitutively activated intracellular forms of Notch receptors upregulated PlexinD1 expression; conversely RNAi-based knock-down, or pharmacological inhibition of Notch signaling by gamma-secretase inhibitors, downregulated PlexinD1 levels. Notably, both Notch1 and Notch3 expression positively correlates with PlexinD1 levels in prostate cancer, as well as in other tumor types. In prostate cancer cells, Sema3E-PlexinD1 axis was previously reported to regulate migration; however, implicated mechanisms were not elucidated. Here we show that in these cells PlexinD1 activity induces the expression of the transcription factor Slug, downregulates E-cadherin levels and enhances cell migration. Moreover, our mechanistic data identify PlexinD1 as a pivotal mediator of this signaling axis downstream of Notch in prostate cancer cells. In fact, on one hand, PlexinD1 is required to mediate cell migration and E-cadherin regulation elicited by Notch. On the other hand, PlexinD1 upregulation is sufficient to induce prostate cancer cell migration and metastatic potential in mice, leading to functional rescue in the absence of Notch. In sum, our work identifies PlexinD1 as a novel transcriptional target induced by Notch signaling, and reveals its role promoting prostate cancer cell migration and downregulating E-cadherin levels in Slug-dependent manner. Collectively, these findings suggest that Notch-PlexinD1 signaling axis may be targeted to impair prostate cancer cell invasiveness and metastasis.
authors.affiliation: Cancer Cell Biology Laboratory, Candiolo Cancer Institute-FPO, IRCCS, Candiolo, Italy.|Department of Oncology, University of Torino, Torino, Italy.
authors.forename: Michael
authors.initials: M
authors.lastname: Rehman
authors.affiliation: Cancer Cell Biology Laboratory, Candiolo Cancer Institute-FPO, IRCCS, Candiolo, Italy.|Department of Oncology, University of Torino, Torino, Italy.
authors.forename: Sreeharsha
authors.initials: S
authors.lastname: Gurrapu
authors.affiliation: Cancer Cell Biology Laboratory, Candiolo Cancer Institute-FPO, IRCCS, Candiolo, Italy.|Department of Oncology, University of Torino, Torino, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Cagnoni
authors.affiliation: Cancer Cell Biology Laboratory, Candiolo Cancer Institute-FPO, IRCCS, Candiolo, Italy.|Department of Oncology, University of Torino, Torino, Italy.
authors.forename: Lorena
authors.initials: L
authors.lastname: Capparuccia
authors.affiliation: Cancer Cell Biology Laboratory, Candiolo Cancer Institute-FPO, IRCCS, Candiolo, Italy.|Department of Oncology, University of Torino, Torino, Italy.
authors.forename: Luca
authors.identifier: http://orcid.org/0000-0002-2884-7946
authors.initials: L
authors.lastname: Tamagnone
mesh_terms: D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D015816:Cell Adhesion Molecules, Neuronal / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D003959:Diamines / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D057809:HEK293 Cells; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D000072100:Jagged-1 Protein / Q000494:pharmacology; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology; D008562:Membrane Glycoproteins; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D008856:Microscopy, Fluorescence; D011401:Promoter Regions, Genetic; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D051880:Receptors, Notch / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D000071250:Snail Family Transcription Factors / Q000235:genetics / Q000378:metabolism; D013844:Thiazoles / Q000494:pharmacology; D014183:Transplantation, Heterologous; D015854:Up-Regulation / Q000187:drug effects; D005466:Fluorocarbons
chemical_list: D001552:Benzazepines; D015820:Cadherins; D015816:Cell Adhesion Molecules, Neuronal; D003959:Diamines; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D000072100:Jagged-1 Protein; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D051880:Receptors, Notch; D000071250:Snail Family Transcription Factors; D013844:Thiazoles; C000612000:24-diamino-5-phenylthiazole; C000606273:JAG1 protein, human; C493082:PLXND1 protein, human; C000604407:SNAI1 protein, human; C545185:2,2-dimethyl-N-(6-oxo-6,7-dihydro-5H-dibenzo(b,d)azepin-7-yl)-N'-(2,2,3,3,3-pentafluoropropyl)malonamide; D005466:Fluorocarbons