[Regulation by protein kinase C of TGF-beta 1 expression in cultured cells of breast adenocarcinoma].
In human breast carcinoma MCF-7 cells, phorbol diesters inhibit proliferation and induce cell maturation. We investigated the involvement of TGF-beta 1 in the PCK-mediated inhibition of breast cancer cell proliferation. Using an RNase protection assay, we showed that TPA induced a dose-dependent increase in levels of TGF-beta 1 mRNA that paralleled the inhibitory effect on MCF-7 proliferation. Similar results were obtained with another TPA-sensitive breast cancer cell line (BT-20). TPA did not increase TGF-beta 1 mRNA levels in the MCF-7:RPh-4 and T47D cell lines, which are both insensitive to the growth inhibitory effects of phorbol esters. In addition, the increase in TGF-beta 1 mRNA level was not observed after treatment of the MCF-7 cell with other inducers of cell differentiation such as forskolin, DMF, HMBA and sodium butyrate. The induction of TGF-beta 1 mRNA by TPA along with its inhibitory effect on cell proliferation suggests that TGF-beta 1 mediates, at least in part, the inhibitory effect of PKC activation.
Guerrin
M
M
Laboratoire de pharmacologie et de toxicologie fondamentales, CNRS, 205, Toulouse, France.
Guilbaud
N
N
Valette
A
A
D000230:Adenocarcinoma / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D011493:Protein Kinase C / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D013755:Tetradecanoylphorbol Acetate / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics*; D014407:Tumor Cells, Cultured
D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate
Régulation par la protéine kinase C de l'expression du TGF-beta 1 dans les cellules d'adénocarcinome mammaire en culture.