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

To study CD34, CD105, inducible nitric oxide synthase (iNOS), endogenous nitric oxide synthase (eNOS), and hypoxia-inducible factor 1 (HIF-1) alpha expression in human colorectal carcinomas.

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-1alpha was detected by immunohistochemistry (S-P).

iNOS and HIF-1alpha expression in colorectal carcinoma was significantly higher than in non-neoplasm colorectal mucosa (c2 = 43.166, P < 0.01; c2 = 10.4278, P < 0.01); eNOS expression in colorectal carcinoma was significantly lower than in non-neoplasm colorectal mucosa (c2 = 11.354, P < 0.01). The expression of iNOS correlated with differentiation (c2 = 18.141, P < 0.01), invasive depth (c2 = 4.748, P < 0.01), and Micro vessel density (MVD) (t = 2.327, P < 0.05). The expression of HIF-1alpha was correlated with infiltrating depth (c2 = 4.397, P < 0.05), Dukeos staging (c2 = 4.255, P < 0.05), and MVD (t = 2.272, P < 0.05). No correlation was found in eNOS expression.

Over-expression of iNOS and HIF-1alpha in colorectal carcinoma is correlated with the biological character MVD.