Cyclooxygenase-2, inducible nitric oxide synthase protein expression and vasculature during experimental rat lung carcinogenesis / 中国肺癌杂志

ABSTRACT

<p><b>BACKGROUND</b>To investigate the expression of cyclooxygenase-2 (COX-2) protein and inducible nitric oxide synthase (iNOS) protein during the experimental lung carcinogenesis in rats, as well as their association with microvessel density (MVD).</p><p><b>METHODS</b>Diethylinitrosamine and 3-methylcholanthrene were instilled into the left lobar bronchus to induce lung squamous cell carcinoma in 88 Wistar rats, and 10 nomal rats as controls. COX-2, iNOS expression and MVD count of the specimens obtained from the rats were examined by immunohistochemistry.</p><p><b>RESULTS</b>A total of 155 specimens of various pathological phase during the carcinogenesis were obtained 14 hyperplasia, 25 squamous metaplasia, 33 dysplasia, 12 carcinoma in situ, 54 infiltration carcinoma, and 17 metastasis. The immunohistochemical score (IHS) of COX-2 significantly increased in dysplasia, carcinoma in situ and metastasis (P < 0.01,P < 0.05,P < 0.01). IHS of iNOS significantly increased in hyperplasia and metastasis (P < 0.05,P < 0.01 ). Remarkably increased MVD was found in carcinoma in situ, infiltration carcinoma and metastasis (P < 0.01, P < 0.01, P < 0.01). There was a positive correlation between COX-2 and iNOS (r=0.601 6,P < 0.001) expression. Expression of COX-2 or iNOS were remarkably related to MVD count (P < 0.01,P < 0.01)</p><p><b>CONCLUSIONS</b>COX-2 and iNOS may play important roles in the carcinogenesis of experimental rat lung squamous cell carcinoma as well as its progress, and it may be associated with stimulating angiogenesis.</p>