title: Cyclooxygenase-2 expression in hamster and human pancreatic neoplasia.
abstract: Cyclooxygenase-2 (COX-2) has been implicated in the development of gastrointestinal malignancies. The aim of the present study was to determine COX-2 expression/activity throughout stages of experimental and human pancreatic neoplasia. COX-2 immunohistochemistry was performed in pancreata of hamsters subjected to the carcinogen N-nitrosobis-(2-oxopropyl)amine (BOP) and in human pancreatic tumors. COX-2 activity was determined by prostaglandin E2 assay in tumor versus matched normal pancreatic tissues. The activity of the COX inhibitor sulindac was tested in the PC-1 hamster pancreatic cancer model. COX-2 expression was elevated in all pancreatic intraepithelial neoplasias (PanINs) and adenocarcinomas. In BOP-treated hamsters, there were significant progressive elevations in COX-2 expression throughout pancreatic tumorigenesis. In human samples, peak COX-2 expression occurred in PanIN2 lesions and remained moderately elevated in PanIN3 and adenocarcinoma tissues. COX-2 activity was significantly elevated in hamster and human pancreatic cancers compared to pair-matched normal pancreas. Furthermore, hamster pancreatic tumor engraftment/formation in the PC-1 hamster pancreatic cancer model was reduced 4.9-fold by oral administration of sulindac. Increased COX-2 expression is an early event in pancreatic carcinogeneses. The BOP-induced hamster carcinogenesis model is a representative model used to study the role of COX-2 in well-differentiated pancreatic tumorigenesis. COX inhibitors may have a role in preventing tumor engraftment/formation.
authors.affiliation: Indiana University Cancer Center, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Pamela L
authors.initials: PL
authors.lastname: Crowell
authors.forename: C Max
authors.initials: CM
authors.lastname: Schmidt
authors.forename: Michele T
authors.initials: MT
authors.lastname: Yip-Schneider
authors.forename: Jesse J
authors.initials: JJ
authors.lastname: Savage
authors.forename: Dean A
authors.initials: DA
authors.lastname: Hertzler
authors.forename: William O
authors.initials: WO
authors.lastname: Cummings
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D006224:Cricetinae; D051546:Cyclooxygenase 2 / Q000096:biosynthesis*; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008647:Mesocricetus; D009368:Neoplasm Transplantation; D010190:Pancreatic Neoplasms / Q000201:enzymology* / Q000473:pathology; D013467:Sulindac / Q000494:pharmacology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000970:Antineoplastic Agents; D013467:Sulindac; D051546:Cyclooxygenase 2