Volume 37, Number 10, 684-690, DOI: 10.1290/1071-2690(2001)037<0684:TROTTG>2.0.CO;2

Transcriptional regulation of the transforming growth factor-β2 gene in glioblastoma cells

Michelle Kingsley-Kallesen, Troy A. Luster and Angie Rizzino

View Related Documents

Abstract

The expression of transforming growth factor-β2 (TGF-β2) appears to play a strong role in the establishment and progression of glial tumors. In particular, elevated expression of TGF-β2 appears to be responsible for the impaired cellmediated immunity often observed in patients with a glioblastoma. This study examined the regulation of the TGF-β2 at the transcriptional level in the U87MG glioblastoma cell line. We demonstrate that a cAMP response element/activating transcription factor (CRE/ATF) site and an E-box motif located just upstream of the transcription start site are essential for the transcription of the TGF-β2 gene in U87MG cells Gel mobility analysis determined that activating transcription factor-1, and possibly cAMP-responsive element binding protein binds to the CRE/ATF site, and upsteam stimulatory factor (USF) 1 and USF2 bind to the E-box motif. Interestingly, expression of a dominant negative USF protein down-regulates TGF-β2 activity by 80–95% in glioblastoma cells. We conclude that the binding of transcription factors, in particular the USF proteins, to the TGF-β2 promoter is essential for its expression and possibly its up-regulation in glioblastomas.

Key words  U87MG - CRE/ATF - E-box - ATF-1 - CREB - USF

Fulltext Preview

Image of the first page of the fulltext document