Transforming growth factor beta (TGF-beta) potentiates the inhibitory effect of retinoic acid on human breast carcinoma (MCF-7) cell proliferation.
Anchorage-dependent and -independent MCF-7 cell growth was dose-dependently inhibited by retinoic acid (RA) but was insensitive to TGF-beta (from 1 to 100 pM). Growth of MCF-7 monolayer cultures was inhibited (50%) when exposed to 10(-6) M RA. RA was unable to completely inhibit MCF-7 cell proliferation, as concentrations above 10(-6) M were rapidly cytotoxic. However, the combination of TGF-beta and RA resulted an increase in RA inhibitory effect on MCF-7 monolayer growth and a 80% reduction in colony formation in soft agar. These results demonstrate that although TGF-beta does not inhibit the growth of MCF-7 cells, it potentiates the antiproliferative effect of RA, suggesting that it may play a part, albeit indirect, in the regulation of MCF-7 cell growth.
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Laboratoire de Pharmacologie et Toxicologie Fondamentales, CNRS, Toulouse, France.
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D001943:Breast Neoplasms; D002455:Cell Division / Q000187:drug effects*; D004357:Drug Synergism; D006801:Humans; D015291:Transforming Growth Factors / Q000494:pharmacology*; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D014212:Tretinoin; D015291:Transforming Growth Factors