Different fibroblast growth factor 1 (FGF-1) transcripts in neural tissues, glioblastomas and kidney carcinoma cell lines.
We have previously reported the tissue specific distribution of four different FGF-1 transcripts containing alternative 5' untranslated exons spliced to the first protein coding exon. The predominant transcript in brain is FGF-1.B and in kidney FGF-1.A. Others have shown, by in situ hybridization and immunohistochemical analysis, that expression of FGF-1 in the brain is exclusively in neural cells but not in glial cells. Here we have examined the distribution of FGF-1.B and FGF-1.A transcripts in glioblastoma and retinal tissues and in kidney carcinoma cell lines. Our results show that FGF-1.B is the predominant transcript in neural derived tissues including both the diabetic retina and normal retina tissues. Surprisingly, FGF-1.B transcript is highly expressed in glioblastoma tissues. In contrast, a normal brain glial cell line, CHII, expresses very low levels of FGF-1 mRNA. These results strongly implicate the role of FGF-1 in the etiology of glioblastoma. We also examined several kidney carcinoma derived cell lines for the expression of FGF-1 mRNA. Most of these kidney cell lines do not express any FGF-1 transcripts. An interpretation by deduction is that kidney adenocarcinomas are derived from cortex but medulla has been reported as the site of FGF-1 synthesis. Of the kidney derived cell lines which are positive for FGF-1 message, only one expressed FGF-1.A transcript. The data may suggest that the establishment of kidney cell lines results in a switch of promoter usage from the 1.A seen in kidney tissue. Similarly, culturing of glioma cell lines may result in a switch from FGF-1.B seen in glioma tissues to FGF-1.D seen in most glioma cell lines. Continued studies of the FGF-1 transcripts, their functional promoters and their tissues distribution will provide insight into the potential role of FGF-1 in cell growth, tissue differentiation and malignant transformation.
Myers
R L
RL
Department of Internal Medicine, Ohio State University, Columbus 43210, USA.
Chedid
M
M
Tronick
S R
SR
Chiu
I M
IM
D017398:Alternative Splicing; D015152:Blotting, Northern; D001921:Brain / Q000378:metabolism*; D001932:Brain Neoplasms / Q000378:metabolism*; D002460:Cell Line; D005091:Exons; D016220:Fibroblast Growth Factor 1 / Q000096:biosynthesis*; D015870:Gene Expression / Q000187:drug effects; D005909:Glioblastoma / Q000378:metabolism*; D006801:Humans; D007680:Kidney Neoplasms / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D012016:Reference Values; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D012333:RNA, Messenger; D016220:Fibroblast Growth Factor 1; D013755:Tetradecanoylphorbol Acetate