title: Cell cycle effects of nonsteroidal anti-inflammatory drugs and enhanced growth inhibition in combination with gemcitabine in pancreatic carcinoma cells.
abstract: Increased cyclooxygenase-2 (COX-2) expression in human pancreatic adenocarcinomas, as well as the growth-inhibitory effect of nonsteroidal anti-inflammatory drugs (NSAIDs) in vitro, suggests that NSAIDs may be an effective treatment for pancreatic cancer. Gemcitabine is currently the most effective chemotherapeutic drug available for patients with pancreatic cancer, but is only minimally effective against this aggressive disease. Clearly, other treatment options must be identified. To design successful therapeutic strategies involving compounds either alone or in combination with others, it is necessary to understand their mechanism of action. In the present study, we evaluated the effects of three NSAIDs (sulindac, indomethacin, and NS-398) or gemcitabine in two human pancreatic carcinoma cell lines, BxPC-3 (COX-2-positive) and PaCa-2 (COX-2-negative), previously shown to be growth-inhibited by these NSAIDs. Effects on cell cycle and apoptosis were investigated by flow cytometry or Western blotting. Treatment with NSAIDs or gemcitabine altered the cell cycle phase distribution as well as the expression of multiple cell cycle regulatory proteins in both cell lines, but did not induce substantial levels of apoptosis. Furthermore, we demonstrated that the combination of the NSAID sulindac or NS-398 with gemcitabine inhibited cell growth to a greater degree than either compound alone. These results indicate that the antiproliferative effects of NSAIDs and gemcitabine in pancreatic tumor cells are primarily due to inhibition of cell cycle progression rather than direct induction of apoptotic cell death, regardless of COX-2 expression. In addition, NSAIDs in combination with gemcitabine may hold promise in the clinic for the treatment of pancreatic cancer.
authors.affiliation: Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA. mtipschn@iupui.edu
authors.forename: M T
authors.initials: MT
authors.lastname: Yip-Schneider
authors.forename: C J
authors.initials: CJ
authors.lastname: Sweeney
authors.forename: S H
authors.initials: SH
authors.lastname: Jung
authors.forename: P L
authors.initials: PL
authors.lastname: Crowell
authors.forename: M S
authors.initials: MS
authors.lastname: Marshall
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002453:Cell Cycle / Q000187:drug effects*; D018797:Cell Cycle Proteins / Q000096:biosynthesis; D002455:Cell Division / Q000187:drug effects; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D007527:Isoenzymes / Q000096:biosynthesis / Q000187:drug effects; D008297:Male; D008565:Membrane Proteins; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis / Q000187:drug effects; D013467:Sulindac / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D000093542:Gemcitabine
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D018797:Cell Cycle Proteins; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D008565:Membrane Proteins; D003841:Deoxycytidine; D013467:Sulindac; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D000093542:Gemcitabine