Acute effects of growth factors on T-47D breast cancer cell cycle progression.
Growth factors play a major role in the control of human breast cancer cell proliferation but their acute effects on cell cycle progression have not been well studied in these cells. T-47D cells, growth-inhibited by serum deprivation, were induced to re-enter the cell cycle in a concentration- and time-dependent manner by addition of insulin, insulin-like growth factor (IGF)-I, epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha) or basic fibroblast growth factor (bFGF). After a lag of approximately 10 h semi-synchronous entry into S phase was observed. The relative potencies of maximal concentrations of growth factors were in the order: insulin approximately IGF-I approximately bFGF > TGF alpha > EGF, identifying bFGF as among the most potent mitogens for these cells. Insulin or IGF-I alone resulted in growth rates comparable with those observed in fetal calf serum. These data demonstrate that single growth factors can induce a significant proportion of T-47D cells to traverse the cell cycle. The kinetics for entry into S phase were similar, indicating that the basis of differential sensitivity to the growth factors tested was the proportion of cells that responded and ultimately entered S phase.
Musgrove
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EA
Cancer Biology Division, Garvan Institute for Medical Research, St. Vincent's Hospital, Darlinghurst, NSW, Australia.
Sutherland
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RL
D001943:Breast Neoplasms / Q000473:pathology*; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D006133:Growth Substances / Q000494:pharmacology*; D006801:Humans; D007328:Insulin / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D013997:Time Factors; D016211:Transforming Growth Factor alpha / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D006133:Growth Substances; D007328:Insulin; D016211:Transforming Growth Factor alpha; D016222:Fibroblast Growth Factor 2; D004815:Epidermal Growth Factor; D007334:Insulin-Like Growth Factor I