Structure and Regulation of the Versican Promoter

doi:10.1074/jbc.M807108200

Structure and Regulation of the Versican Promoter

THE VERSICAN PROMOTER IS REGULATED BY AP-1 AND TCF TRANSCRIPTION FACTORS IN INVASIVE HUMAN MELANOMA CELLS^*

^‡Departament de Bioquímica i Biologia Molecular, Facultat de Veterinària, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, ^§Unitat de Genètica, Hospital de Barcelona, 08036 Barcelona, and ^¶Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907 L'Hospitalet de Llobregat, Spain

4 To whom correspondence should be addressed: Edifici V, 08193-Cerdanyola del Vallès, Spain. Fax: 34-93-581-20-06; E-mail: anna.bassols{at}uab.cat.

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.

Footnotes

↵5 The abbreviations used are: ERK, extracellular signal-regulated kinase; JNK, c-Jun NH₂-terminal kinase; MAPK, mitogen-activated protein kinase; EMSA, electrophoretic mobility shift assay; GFP, green fluorescent protein; MMP, matrix metalloproteinase; RT, reverse transcription; DN, dominant negative; DP, dominant positive; TCF, T cell factor.
↵* This work was supported by Grants SAF2003-08750 from the Ministerio de Educación y Ciencia (to A. B.), FIS-PI-06194 from the Ministerio de Sanidad y Consumo (to A. F.), and 2005SGR00542 from the Generalitat de Catalunya (to A. B.). This work was also supported in part by the FEDER program of the European Union.
↵ The on-line version of this article (available at http://www.jbc.org) contains supplemental Fig. 1 and Table 1.
↵1 Present address: Dept. de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, P. O. Box 70-228, 04510 México, D.F., México.
↵2 Supported by a fellowship from the Generalitat de Catalunya.
↵3 Supported by a fellowship from the Spanish Ministerio de Educación.
- Received September 15, 2008.
- Revision received March 6, 2009.
The American Society for Biochemistry and Molecular Biology, Inc.