RESUMO
Objective This study was to investigate the relation of nitric oxide synthase with cell proliferation and apoptosis in hepatocellular carcinoma (HCC). Methods The expression and localization of inducible nitric oxide synthase (iNOS) and PCNA in 21 patients with HCC were studied by immunohistochemistry. Apoptotic cell in tissue section was detected by TUNEL (terminal deoxynucleotidyl transferase [TdT] mediated desoxyuridinetriphosphate [dUTP] nick end labeling). Results The iNOS protein was markedly expressed in the liver tissue of hepatic cirrhosis or chronic liver hepatitis, which was close to tumor edge. Meanwhile it was weakly or undetectable in the liver tissue localized beyond 1.5 cm from the tumor edge. The iNOS protein was markedly expressed at the invasive tumor edge and HCC cells that invased into stroma, but it was weakly or undetectable at the most tumor core. The expression of iNOS was correlated with the proliferative activity of cells, and the number of apoptotic cells was correlated to the number of PCNA positive cells ( P