Correlation between activation of quiescent 3T3 cells by retinoic acid and increases in uridine phosphorylation and cellular RNA synthesis

Abstract

Short exposure of cultured quiescent cells to micromolar quantities of beta-all-trans-retinoic acid (RA) has been reported to potentiate the effects of phorbol myristate acetate in promoting the transition from the resting to growing states of these cells. Longer periods of exposure to RA result in substantial inhibition of cellular proliferation. We now show that short-term treatment of quiescent Swiss 3T3 cells with RA yields marked increases in uridine phosphorylation and total cellular RNA synthesis as well as 2-deoxyglucose uptake. Upon subsequent treatment of the cells with phorbol myristate acetate, a direct correlation between the comitogenic activity of RA and its stimulation of uridine phosphorylation and RNA synthesis is apparent. The increases in 2-deoxyglucose uptake persist after long-term exposure of the cells to RA when the growth-inhibitory effects of this agent are observed.