Localization of cyclo-oxygenase-2 in human recurrent colorectal cancer.

AIM The aim of this paper is to examine COX-2 expression in human recurrent colorectal carcinoma tissues using immunohistochemistry and quantative real-time PCR (qPCR). METHODS Colon and rectal specimens were obtained from 26 patients with recurrent colorectal carcinomas. We examined COX-2 expression in human recurrent colorectal carcinoma tissues using immunohistochemistry and quantative real-time PCR (qPCR). RESULTS In recurrent colorectal cancer a strong cytoplasmic and perinuclear staining of COX-2 was found. Moderate to strong immunosignals were detected in almost all of the carcinomas. We observed a strong specific staining of COX-2 in vascular endothelium. COX-2 immunoreactivity was also detected in stromal cells such as mononuclear cells, fibroblasts, and smooth muscle cells. The real-time PCR analyses demonstrated marked overexpression of the COX-2 gene in the cancer mucosa in concert with the immunohistochemistry data. CONCLUSION We investigated COX-2 expression at the level of its protein as well as its messenger RNA in a series of recurrent colorectal cancers. These observations give additional information about the possibility that COX-2 could be involved in tumor promotion during colorectal cancer progression.