Quantitative detection of cyclooxygenase-2 gene expression in carcinoma of larynx by real-time polymerase chain reaction

AIM: To quantify cyclooxygenase-2 (COX-2) mRNA in carcinoma of larynx and evaluate the correlation between the quantity of COX-2 mRNA and clinical staging or histological grade. METHODS: The expression of COX-2 mRNA in 30 cases of carcinoma of larynx tissue and adjacent non-cancerous tissues were evaluated by PCR, which includes a fluorescence dye , SYBR green Ⅰ, and the sequence specific primer. The GAPDH was used as control. RESULTS: The specificity of products was proved to be COX-2 and GAPDH by the analysis of the melting curve of the amplified products and agarose gel electrophoresis. The expression of COX-2 mRNA was detected in all cancerous tissues of 30 patients (100%), but only in 12 adjacent non-cancerous tissues of 30 patients (40%). The N_ COX value of carcinoma of larynx tissue and adjacent non-cancerous tissues was 16.54±13.27 and 9.24±6.91, respectively, and the expression levels of COX-2 mRNA elevated significantly in laryngeal squamous cell carcinoma tissue and there were significant correlation between the expression levels of COX-2 mRNA and clinical stage or histological grade. CONCLUSION: The expression of COX-2 mRNA in carcinoma of larynx can be determined by real-time PCR technique. An increase in COX-2 mRNA may be associated with carcinogenesis of carcinoma of larynx, and it may be useful as a biomarker in laryngeal cancer.