Objective: To investigate the expression and significance of nitric oxide synthase (cNOS) mRNA in primary hepatocellular carcinoma (HCC), cirrhotic liver and normal liver tissue.
Methods: cNOS mRNA expression in 80 HCC, 40 cirrhotic liver and 20 normal liver tissue were observed by in situ hybridization. CD34 immunostain was used to measure the microvascular density (MVD) and Ki-67 immunostain to proliferative index.
Results: Expression of cNOS mRNA was observed in the liver cancer cells, endothelial cells in the non-cancerous liver tissues and mononuclear and/or phagocytes. Expression of cNOS mRNA in tumor cells of HCC was higher than that in the liver cells of cirrhotic liver (P < 0.01) which was higher than the normal liver tissue. Expression in the endothelial cells was higher in HCC and cirrhotic liver than those in the normal liver tissue (P < 0.01). HCC with positive cNOS mRNA expression in the endothelial cells showed higher extent of neovascularization and degree of proliferative index. The more MVD, the higher proliferative index, which increased in metastatic tumors.
Conclusion: cNOS mRNA expression was involved in oncogenesis, angiogenesis and progression of hepatocellular carcinoma.