Phosphoenolpyruvate carboxykinase is induced in growth-arrested hepatoma cells.

Phosphoenolpyruvate carboxykinase (PEPCK) mRNA is elevated in H4IIEC3 rat hepatoma cells cultured at high density, suggesting that PEPCK expression and growth arrest may be coordinately regulated. Induction of growth arrest either by contact inhibition (high culture density) or by serum deprivation correlated with significant increases in PEPCK protein and its mRNA. The observation that PEPCK mRNA was induced by contact inhibition in the presence of serum indicates that the effect of high density is independent of insulin or any other serum component.