Modulation of c-myc expression by transforming growth factor beta 1 in human hepatoma cell lines.
The effects of transforming growth factor beta 1 (TGF-beta 1) on cell proliferation of human hepatoma cell lines, PLC/PRF/5 and Mahlavu, were investigated under serum-free conditions. DNA synthesis was strongly inhibited in the PLC/PRF/5 cells by addition of TGF-beta 1 (0.5 to 4.0 ng/ml), but remained unchanged in the Mahlavu cells. Also the expression of c-myc mRNA was suppressed by the addition of TGF-beta 1 in the PLC/PRF/5 cells but not in the Mahlavu cells. These results indicate that TGF-beta 1 might regulate cell growth, in part, by modulating c-myc expression, although there is no direct proof that c-myc expression is really relevant to DNA synthesis mediated by TGF-beta 1.
Ito
N
N
Second Department of Internal Medicine, Osaka University Medical School.
Kawata
S
S
Tamura
S
S
Takaishi
K
K
Saitoh
R
R
Tarui
S
S
D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D004273:DNA, Neoplasm / Q000096:biosynthesis; D015870:Gene Expression; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger / Q000032:analysis; D015291:Transforming Growth Factors / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D004273:DNA, Neoplasm; D011518:Proto-Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D015291:Transforming Growth Factors