Enhanced phosphatidylinositol kinase activity is associated with early stages of hepatocarcinogenesis and hepatocellular carcinoma.

Liver phosphatidylinositol (PI) kinase activity was determined in rats exposed to two different hepatocarcinogenic regimens. In contrast to partial treatment regimens the complete Solt and Farber hepatocarcinogenic regimen caused a significant increase in liver PI kinase activity at day 11 after partial hepatectomy. PI kinase activity in hepatocarcinomas removed 15 1/2 months after initiation of the complete Solt and Farber regimen was 2-fold higher than normal liver tissue surrounding the tumors. Compared to a choline supplemented diet a hepatocarcinogenic regimen consisting of a diet deficient in choline and methionine significantly increased liver PI kinase activity after 26 days. These data demonstrate that liver PI kinase activity is selectively elevated during hepatocarcinogenesis.