Sequence analysis of the promoter region of the glioblastoma derived T cell suppressor factor/transforming growth factor (TGF)-beta 2 gene reveals striking differences to the TGF-beta 1 and -beta 3 genes

Human glioblastoma cells secrete a factor termed glioblastoma derived T cell suppressor factor (G-TsF) or transforming growth factor beta 2 (TGF-beta 2) which inhibits the response of T cells to mitogenic or antigenic stimulation. In the present study we isolated the promoter region of the G-TsF/TGF-beta 2 gene. The promoter region shares no homology to the promoter of the TGF-beta 1 or the 5' region of the TGF-beta 3 gene and harbours several familiar DNA motifs, including the cytokine-1 region, an octamer-like sequence, Sp1- and AP-2-like elements and a putative NF-kappa B site. In contrast to the TGF-beta 1 gene, the G-TsF/TGF-beta 2 gene contains three TATA-like sequences but lacks an AP-1 site. To understand the cell type specificity of expression of G-TsF/TGF-beta 2, the individual contribution of the DNA elements detected in the promoter has to be analysed in further studies.