Phenotypic Properties of Liver Tumors Induced by Dehydroepiandrosterone in F‐344 Rats

Dehydroepiandrosterone (DHEA), a C19 adrenal steroid hormone, induces peroxisome proliferation in liver cells and is hepatocarcinogenic in the rat The present study deals with the phenotypic properties of DHEA‐induced liver lesions. A majority of the altered areas (80–87%), neoplastic nodules (>94%) and hepatocellular carcinomas (HCC, 80–100%) lacked the marker enzymes 7‐glutamyltranspeptidase and placental form of glutathione S‐transferase (GSTP). Northern blot analysis of HCC from 4 rats revealed no detectable GSTP mRNA. These HCC, however, showed a marked decrease in the staining of glucose‐6‐phosphatase and adenosine triphosphatase. These results indicate that the phenotypic properties of liver tumors induced by DHEA and amphipathic carboxylate peroxisome proliferators are similar.