title: Malignant transformation and antineoplastic actions of nonsteroidal antiinflammatory drugs (NSAIDs) on cyclooxygenase-null embryo fibroblasts.
abstract: In this study, we use primary embryonic fibroblasts derived from cyclooxygenase-deficient transgenic embryos to further investigate the role of the two cyclooxygenases, cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2), in the process of neoplastic transformation. Cells with either, neither, or both of the cyclooxygenases were transformed by Ha-ras and/or SV40. Our results show that when a cyclooxygenase enzyme is present, the transformed cells have marked increases in COX-2 and/or COX-1 expression. Nevertheless, each type of cell, deficient in either or both cyclooxygenases, can be readily transformed at almost equal efficiency. Different nonsteroidal antiinflammatory drugs (NSAIDs) were used to examine their possible antineoplastic effects on the transformed cells, which have various levels of expression of COX-1 or COX-2. Our results show that NSAIDs suppress the colony formation in soft agar in a dosage-dependent manner in the absence of the cyclooxygenase(s). Thymidine incorporation and apoptosis analyses further demonstrate that the NSAIDs are effective in the cyclooxygenase-null cells. Our findings with cyclooxygenase knockout cells confirm recent reports that some of the antiproliferative and antineoplastic effects of NSAIDs are independent of the inhibition of either COX-1 or COX-2. They also show that transformation is independent of the status of cyclooxygenase expression, suggesting that the involvement of the cyclooxygenases in tumorigenesis may occur at later steps.
authors.affiliation: Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA.
authors.forename: X
authors.initials: X
authors.lastname: Zhang
authors.forename: S G
authors.initials: SG
authors.lastname: Morham
authors.forename: R
authors.initials: R
authors.lastname: Langenbach
authors.forename: D A
authors.initials: DA
authors.lastname: Young
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000494:pharmacology*; D016718:Arachidonic Acid / Q000378:metabolism; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D002472:Cell Transformation, Viral; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D015232:Dinoprostone / Q000096:biosynthesis; D004622:Embryo, Mammalian / Q000166:cytology; D005347:Fibroblasts / Q000166:cytology; D007052:Ibuprofen / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology; D007527:Isoenzymes / Q000172:deficiency* / Q000235:genetics; D008565:Membrane Proteins; D051379:Mice; D018345:Mice, Knockout; D009578:Nitrobenzenes / Q000494:pharmacology; D009856:Oncogene Proteins, Viral; D010894:Piroxicam / Q000494:pharmacology; D011451:Prostaglandin-Endoperoxide Synthases / Q000172:deficiency* / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics; D012333:RNA, Messenger / Q000302:isolation & purification; D013539:Simian virus 40; D013449:Sulfonamides / Q000494:pharmacology; D013467:Sulindac / Q000494:pharmacology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000970:Antineoplastic Agents; D007527:Isoenzymes; D008565:Membrane Proteins; D009578:Nitrobenzenes; D009856:Oncogene Proteins, Viral; D012333:RNA, Messenger; D013449:Sulfonamides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D010894:Piroxicam; D013467:Sulindac; D016718:Arachidonic Acid; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; C496512:Ptgs1 protein, mouse; D016283:Proto-Oncogene Proteins p21(ras); D015232:Dinoprostone; D007052:Ibuprofen; D007213:Indomethacin