RESUMO
Human lymphoid cells were found to synthesize predominantly antisense, and not sense, fibroblast growth factor-2 (FGF-2) mRNA. Two cDNAs corresponding to human 1069- and 1173-nucleotide antisense FGF-2 mRNAs were cloned from Jurkat T cells. The two cDNAs each possess a unique exon 1 and common exon 2, 3, 4, and 5 sequences. Exon 4 and 5 sequences overlap in the 3' untranslated region of FGF-2 cDNA, but not in the FGF-2 open reading frame. This is unlike the Xenopus antisense FGF-2 homologue, which overlaps with parts of both the FGF-2 3' untranslated region and its open reading frame. To investigate the regulation of human antisense FGF-2 gene expression, a 2.5-kilobase (kb) promoter region was isolated and characterized. Transient transfection of promoter-luciferase constructs demonstrated the antisense FGF-2 promoter to be active in Jurkat cells. Using transient transfection and in vitro binding assays, specific mutations within the promoter sequence have implicated that Ets-like transcription factors are significant in regulating the human antisense FGF-2 gene in Jurkat cells.
