Expression of NOS and HIF-1α in human colorectal carcinoma and implication in tumor angiogenesis

AIM: To study CD34, CD105, inducible nitric oxide synthase (NOS), endogenous nitric oxide synthase (eNOS), and hypoxia-inclucible factor 1 (HIF-1) alpha expression in human colorectal carcinomas. METHODS: The tissue microarrays (TMAs) were made up of 80 cases of colorectal carcinoma and 80 cases of non-neoplasm colorectal mucosa. The expression of CD34, CD105, NOS and HIF-1 alpha was detected by immunohistochemistry (S-P). RESULTS: NOS and HIF-1a expression in colorectal carcinoma was significantly higher than in non-neoplasm colorectal mucosa (chi(2) = 43.166, P < 0.01; chi(2) = 10.4278, P < 0.01); eNOS expression in colorectal carcinoma was significantly lower than in non-neoplasm colorectal mucosa (chi(2) = 11.354, P < 0.01). The expression of NOS correlated with differentiation (chi(2) = 1.8.141, P < 0.01), invasive depth (chi(2) = 4.748, P < 0.01), and Micro vessel density (MVD) (t = 2.327, P < 0.05). The expression of HIF-1 alpha was correlated with infiltrating depth (chi(2) = 4.397, P < 0.05), Duke's staging (chi(2) = 4.255, P < 0.05), and MVD (t = 2.272, P < 0.05). No correlation was found in eNOS expression. CONCLUSION: Over-expression of NOS and HIF-1 alpha in colorectal carcinoma is correlated with the biological character MVD. (c) 2006 The WJG Press. All rights reserved.