Effect of glucocorticoid hormones on DNA synthesis and expression of ras proto-oncogenes in proliferating rat liver cells

A single injection of partially hepatectomized rats with glucocorticoids results in the blocking of DNA synthesis as well as in the inhibition of the protooncogene Ha-ras-1 mRNA accumulation in proliferating rat liver cells. The kinetics of the both hormone-induced effects differ from those observed for tyrosine aminotransferase induction. The effect of glucocorticoids persists for at least 48 hours and does not depend on the time of the hormone injection.