Relationship between hepatic ornithine decarboxylase activity and beta-carotene in human hepatocellular carcinoma

Various studies have reported that ornithine decarboxylase (ODC) activity, the rate-limiting enzyme in the biosynthesis of polyamines, is increased in many types of tumors. Various studies have proposed that beta-carotene (BC) inhibits cellular hyper-proliferation reducing ODC activity. Aim of our study was to investigate the relationship between ODC activity and BC in hepatocellular carcinoma (HCC) and in non-cancerous tissue from patients who had undergone liver resection. We found that ODC activity was higher and BC significant lower in HCC than non-cancerous tissue. A significant inverse correlation was found between ODC and BC in non-cancerous tissue, while a positive correlation was found between these variables in HCC. These findings suggest that lower levels of BC in liver tumor are accompanied by significant changes in the inhibitory effects of BC on ODC activity.