Influence of hormones on the growth of hepatomas and induction of adenylate and pyruvate kinases.

Tumor growth and the induction of adenylate kinase (EC 2.7.4.3) and pyruvate kinase (EC 2.7.1.40) in transplantable rat hepatomas were studied in organ-ablated and hormonally treated rats that were fed different diets. Tumor growth was slowed when the rats were (a) fasted, (b) diabetic and fed chow, or (c) diabetic and fasted. Tumor growth increased in diabetic rats fed high-glucose diets or treated with insulin. Adenylate kinase, which was induced by fasting and/or hydrocortisone and which was repressed by glucose and/or insulin in normal rat liver, was found to be hyperresponsive to hydrocortisone and hyporesponsive to glucose and/or insulin in hepatomas. Pyruvate kinase, which was induced by glucose and/or insulin in normal rat liver, was not responsive to glucose and/or insulin in the liver tumors but was hyperresponsive to hydrocortisone in the hepatomas. The results from these studies illustrate a "commonness"