Deregulation of cyclo-oxygenase isozyme expression has been shown to be a consistent feature of inflammatory bowel diseases and colorectal cancer in humans. This study investigated the cellular localization of aberrant cyclo-oxygenase expression in normal and diseased colon. Biopsies of seven normal colonic tissues, eight tissue samples from patients suffering from Crohn's disease, five polyps from patients with familiar adenomatous polyposis coli, and ten sporadic adenocarcinomas were analyzed using isozyme-selective immunoprecipitation, western blotting, and immunohistochemistry. Cyclo-oxygenase-1 expression was demonstrated in normal human colon, Crohn's disease, and colorectal tumors. In normal colon and also in adenomatous polyps, cyclo-oxygenase-1 specific immunosignals were localized to epithelial cells of the upper part of the crypts and endocrine cells of the lower part. In Crohn's disease cyclo-oxygenase-1 expression was restricted to cells of the inflammatory infiltrate. While barely detectable in normal colon, cyclo-oxygenase-2 protein was strongly increased in epithelial cells located in the uppermost part of the crypts, in surface epithelial cells, and in mononuclear cells of the lamina propria of Crohn's disease. The constitutive overexpression of cyclo-oxygenase-2 protein observed in the majority of the adenomatous polyps and all adenocarcinomas was attributed to both epithelial and interstitial cells in that the latter predominated in adenomas, and epithelial cells were the prevailing cyclo-oxygenase-2 expressing cell type in adenocarcinomas. In conclusion, both autocrine and paracrine effects of aberrant cyclooxygenase-2 expression may contribute to the development of Crohn's disease and colonic tumor development.
Biliary tract cancer, or cholangiocarcinoma, comprises a heterogeneous group of malignant tumors that can emerge at any part of the biliary tree. This group is the second most common type of primary liver cancer. Diagnosis is usually based on symptoms, which may be heterogeneous, and nonspecific biomarkers in serum and biopsy specimens, as well as on imaging techniques. Endoscopy-based diagnosis is essential, since it enables biopsy specimens to be taken. In addition, it can help with locoregional staging of distal tumors. Endoscopic retrograde cholangiopancreatography is a key technique for the evaluation and treatment of malignant biliary tumors. Correct staging of cholangiocarcinoma is essential in order to be able to determine the degree of resectability and assess the results of treatment. The tumor is staged based on the TNM classification of the American Joint Committee on Cancer. The approach will depend on the classification of the tumor. Thus, some patients with early-stage disease could benefit from surgery; complete surgical resection is the cornerstone of cure. However, only a minority of patients are diagnosed in the early stages and are suitable candidates for resection. In the subset of patients diagnosed with locally advanced or metastatic disease, chemotherapy has been used to improve outcome and to delay tumor progression. The approach to biliary tract tumors should be multidisciplinary, involving experienced endoscopists, oncologists, radiologists, and surgeons.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.