Increased COMT expression in pancreatic cancer and correlation with clinicopathologic parameters.

Catechol-O-methyl transferase (COMT) is an enzyme involved in estrogen metabolism. Proteomic and immunoproteomic screens suggested COMT might be an immunogenic membrane antigen in human pancreatic cancer. The aim of this study was to investigate the dynamic expression of COMT in pancreatic ductal adenocarcinoma (PDAC) and noncancerous pancreatic tissue, and to determine the relationship between COMT expression and clinicopathologic parameters. COMT expression was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and western blot in five pancreatic cell lines and five pairs of PDAC and noncancerous pancreatic tissue. Immunohistochemistry was used to evaluate COMT expression in tissue microarrays and 20 cases of paraffin-embedded clinical specimens. The results indicated that COMT expression was detected in AsPC-1, BxPC-3, MIA PaCa-2, Capan-1 and SW1990 pancreatic cell lines, and in five pairs of PDAC and noncancerous pancreatic tissue, at the mRNA and protein levels. Immunohistochemistry analysis revealed that COMT expression was significantly higher in PDAC than in nonmalignant pancreatic tissue. High expression of COMT significantly correlated to early T stages. Therefore, we conclude that COMT might serve as a potential biomarker for applied clinical pathology in PDAC.