Effect of growth factors and antitumor drugs on normal and Vall2Ha-ras transformed C3H 10T1/2 cell transplasma membrane electron transport and growth

Summary Bothras and the transplasma membrane electron transport system have been implicated in the control of cell growth. Since the loss of growth regulation is at the heart of the cancerous phenotype, we have investigated the effect of factors like antitumor drugs, which inhibit cell growth, and growth factors which either cause or prepare the cells for growth. We have found that growth factors increase the plasma membrane electron transport of the normal cells but not that of the cells which have been transfected with oncogenicras (which have a 2–5-fold faster basal rate). In the presence of adriamycin the activity of the electron transport system is and cell numbers are decreased more in normal cells than in the cells which have been transfected with the oncogenic version of the Harveyras gene. Cisplatin inhibits cell growth but does not inhibit ferricyanide reduction. Ferricyanide alone or in conjunction with EGF or TPA does not stimulate cell proliferation with either cell line in the absence of fetal calf serum, so simple activation of plasma membrane electron transport is not sufficient to activate a complete growth response.Abbreviations EGF epidermal growth factor - TPA phorbol myristate acetate - PDGF platelet derived growth factor - MTT 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromides - SDS sodium dodecyl sulfate