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Differential expression of mRNA coding for heparin‐binding growth factor type 2 in human cells
Author(s) -
Sternfeld Mark D.,
Hendrickson Jill E.,
Keeble Winifred W.,
Rosenbaum James T.,
Robertson Joseph E.,
Pittelkow Mark R.,
Shipley Gary D.
Publication year - 1988
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041360212
Subject(s) - basic fibroblast growth factor , biology , cycloheximide , growth factor , paracrine signalling , cell culture , microbiology and biotechnology , epidermal growth factor , gene expression , fibroblast growth factor , fetal bovine serum , fibroblast , messenger rna , cell type , stromal cell , cell , gene , protein biosynthesis , cancer research , biochemistry , genetics , receptor
The proliferation of normal human fibroblasts, keratinocytes, and melanocytes in vitro can be controlled by purified polypeptide growth factors and serum. We have studied the cellular expression of the heparin‐binding growth factor type 2/basic fibroblast growth factor (HBGF‐2/bFGF) gene to determine whether these cell types synthesize mRNA for this mitogen. Our results indicate that normal human fibroblasts synthesize four distinct mRNAs of 7.0, 3.7, 2.2, and 1.5 kilobases, which hybridize to a specific HBGF‐2/bFGF cDNA probe. In fibroblasts, the level of all four of these transcripts increases dramatically (more than tenfold) within 4 hours of treatment of quiescent cells with fresh fetal bovine serum. Of the purified growth factors tested, transforming growth factor type‐beta also increased HBGF‐2/bFGF mRNA abundance, but not to the levels attained by serum treatment. Treatment of fibroblasts with cycloheximide before and during serum treatment blocked the ability of serum to induce the expression of the HBGF‐2/bFGF gene. The gene is expressed at low levels in human fibroblasts rapidly growing in serum‐free medium and at higher levels in cells rapidly growing in serum‐containing medium. In contrast to fibroblasts, mRNA coding for HBGF‐2/bFGF is undetectable in proliferating normal human keratinocytes, melanocytes, or mammary epithelial cells. Because keratinocytes and melanocytes proliferate in response to purified HBGF‐2/bFGF, our results suggest that HBGF‐2/bFGF may mediate the proliferation of epidermal cells through paracrine mechanisms involving stromal fibroblasts. Moreover, we have shown that a human squamous cell carcinoma cell line (SCC‐25) expresses mRNA coding for HBGF‐2/bFGF, suggesting that the gene may become activated in some carcinomas.