title: Structure and regulation of the versican promoter: the versican promoter is regulated by AP-1 and TCF transcription factors in invasive human melanoma cells.
abstract: Versican is a large chondroitin sulfate proteoglycan of the extracellular matrix that is involved in a variety of cellular processes. We showed previously that versican, which is overexpressed in cutaneous melanomas as well as in premalignant lesions, contributes to melanoma progression, favoring the detachment of cells and the metastatic dissemination. Here, we investigated the transcriptional regulation of the versican promoter in melanoma cell lines with different levels of biological aggressiveness and stages of differentiation. We show that versican promoter up-regulation accounts for the differential expression levels of mRNA and protein detected in the invasive SK-mel-131 human melanoma cells. The activity of the versican promoter increased 5-fold in these cells in comparison with that measured in non-invasive MeWo melanoma cells. Several transcriptional regulatory elements were identified in the proximal promoter, including AP-1, Sp1, AP-2, and two TCF-4 sites. We show that promoter activation is mediated by the ERK/MAPK and JNK signaling pathways acting on the AP-1 site, suggesting that BRAF mutation present in SK-mel-131 cells impinge upon the up-regulation of the versican gene through signaling elicited by the ERK/MAPK pathway. This is the first time the AP-1 transcription factor family has been shown to be related to the regulation of versican expression. Furthermore, deletion of the TCF-4 binding sites caused a 60% decrease in the promoter activity in SK-mel-131 cells. These results showing that AP-1 and TCF-4 binding sites are the main regulatory regions directing versican production provide new insights into versican promoter regulation during melanoma progression.
authors.affiliation: Departament de Bioquímica i Biologia Molecular, Facultat de Veterinària, Universitat Autònoma de Barcelona, 08193 Barcelona, Spain.
authors.forename: Clelia
authors.initials: C
authors.lastname: Domenzain-Reyna
authors.forename: Daniel
authors.initials: D
authors.lastname: Hernández
authors.forename: Laia
authors.initials: L
authors.lastname: Miquel-Serra
authors.forename: María José
authors.initials: MJ
authors.lastname: Docampo
authors.forename: Celia
authors.initials: C
authors.lastname: Badenas
authors.forename: Angels
authors.initials: A
authors.lastname: Fabra
authors.forename: Anna
authors.initials: A
authors.lastname: Bassols
mesh_terms: D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D048670:MAP Kinase Kinase 4 / Q000235:genetics / Q000378:metabolism; D020935:MAP Kinase Signaling System; D008545:Melanoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012334:RNA, Neoplasm / Q000096:biosynthesis / Q000235:genetics; D020218:Response Elements; D016329:Sp1 Transcription Factor / Q000235:genetics / Q000378:metabolism; D000073940:Transcription Factor 4; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism*; D050656:Transcription Factor AP-2 / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation; D053675:Versicans / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D016329:Sp1 Transcription Factor; C532096:TCF4 protein, human; D000073940:Transcription Factor 4; D018808:Transcription Factor AP-1; D050656:Transcription Factor AP-2; D014157:Transcription Factors; C508322:VCAN protein, human; D053675:Versicans; D048049:Extracellular Signal-Regulated MAP Kinases; D048670:MAP Kinase Kinase 4