Abstract
BACKGROUND: The mechanism by which aspirin (ASA) acts to protect against human cancer is not yet known. We recently showed that ASA triggers the formation of a new series of potent bioactive eicosanoids, 15-epi-lipoxins (15-epi-LXs or ASA-triggered LX [ATL]), during interactions between prostaglandin endoperoxide synthase-2 (PGHS-2) in endothelial cells and 5-lipoxygenase (LO) in leukocytes. Here, we investigated the transcellular biosynthesis of these eicosanoids during costimulation of the human tumor A549 cell line (alveolar type II epithelial cells) and neutrophils, and evaluated their impact on cell proliferation. MATERIALS AND METHODS: A549 cells and isolated neutrophils were coincubated and mRNA expression levels of key enzymes in eicosanoid biosynthesis were measured. In addition, product formation was analysed by physical methods. The effect of LX on cell proliferation was determined by using a soluble microculture tetrazolium (MTT) assay and by measuring [3H]-thymidine incorporation. RESULTS: Interleukin-1 beta (IL-1 beta)-primed A549 cells showed selective elevation in the levels of PGHS-2 mRNA and generated 15-hydroxyeicosatetraenoic acid (15-HETE). ASA markedly increased 15-HETE formation by A549 cells, while treatment with an inhibitor of cytochrome P450 reduced by approximately 50%, implicating both PGHS-2- and cytochrome P450-initiated routes in 15-HETE biosynthesis in these cells. Maximal production of 15-HETE from endogenous sources occurred within 24 hr of cytokine (IL-1 beta) exposure and declined thereafter. Chiral analysis revealed that approximately 85% of ASA-triggered epithelial-derived 15-HETE carries its carbon 15 alcohol group in the R configuration. Costimulation of ASA-treated A549 cells and polymorphonuclear neutrophilic leukocytes (PMN) led to production of both LXA4 and LXB4, as well as 15-epi-LXA4 and 15-epi-LXB4 (9.5 +/- 0.5 ng LX/10(7) A549 cells). 15-epi-LXA4 accounted for approximately 88% of the total amount of LXA4 produced. In addition to LXs, stimulation of A549 cells and PMN also liberated substantial amounts (77.2 +/- 8.2 ng/10(7) A549 cells) of peptidoleukotrienes (pLTs), which were not generated by either cell type alone. Addition of ASA to these co-incubations led to an increase in the amounts of LXs generated that was paralleled by a decrease in pLTs. LXA4, LXB4, 15-epi-LXA4 and 15-epi-LXB4, as well as dexamethasone, inhibited cell proliferation at 100 nM range with a rank order of activity of 15-epi-LXB4 >>> LXB4 > dexamethasone > or = 15-epi-LXA4 > LXA4. CONCLUSIONS: These results indicate that ASA promotes the formation of antiproliferative 15-epi-LXs by epithelial cell-leukocyte interactions. Moreover, they suggest that these novel eicosanoids, when generated within the microenvironment of tissues, may contribute to ASA's therapeutic role in decreasing the risk of human cancer.
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- Alley M. C., Scudiero D. A., Monks A., Hursey M. L., Czerwinski M. J., Fine D. L., Abbott B. J., Mayo J. G., Shoemaker R. H., Boyd M. R. Feasibility of drug screening with panels of human tumor cell lines using a microculture tetrazolium assay. Cancer Res. 1988 Feb 1;48(3):589–601. [PubMed] [Google Scholar]
- Baud L., Sraer J., Perez J., Nivez M. P., Ardaillou R. Leukotriene C4 binds to human glomerular epithelial cells and promotes their proliferation in vitro. J Clin Invest. 1985 Jul;76(1):374–377. doi: 10.1172/JCI111972. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Böyum A. Isolation of mononuclear cells and granulocytes from human blood. Isolation of monuclear cells by one centrifugation, and of granulocytes by combining centrifugation and sedimentation at 1 g. Scand J Clin Lab Invest Suppl. 1968;97:77–89. [PubMed] [Google Scholar]
- Capdevila J., Yadagiri P., Manna S., Falck J. R. Absolute configuration of the hydroxyeicosatetraenoic acids (HETEs) formed during catalytic oxygenation of arachidonic acid by microsomal cytochrome P-450. Biochem Biophys Res Commun. 1986 Dec 30;141(3):1007–1011. doi: 10.1016/s0006-291x(86)80144-9. [DOI] [PubMed] [Google Scholar]
- Clària J., Serhan C. N. Aspirin triggers previously undescribed bioactive eicosanoids by human endothelial cell-leukocyte interactions. Proc Natl Acad Sci U S A. 1995 Oct 10;92(21):9475–9479. doi: 10.1073/pnas.92.21.9475. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cybulsky A. V., Goodyer P. R., Cyr M. D., McTavish A. J. Eicosanoids enhance epidermal growth factor receptor activation and proliferation in glomerular epithelial cells. Am J Physiol. 1992 Apr;262(4 Pt 2):F639–F646. doi: 10.1152/ajprenal.1992.262.4.F639. [DOI] [PubMed] [Google Scholar]
- Dixon R. A., Jones R. E., Diehl R. E., Bennett C. D., Kargman S., Rouzer C. A. Cloning of the cDNA for human 5-lipoxygenase. Proc Natl Acad Sci U S A. 1988 Jan;85(2):416–420. doi: 10.1073/pnas.85.2.416. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eberhart C. E., Coffey R. J., Radhika A., Giardiello F. M., Ferrenbach S., DuBois R. N. Up-regulation of cyclooxygenase 2 gene expression in human colorectal adenomas and adenocarcinomas. Gastroenterology. 1994 Oct;107(4):1183–1188. doi: 10.1016/0016-5085(94)90246-1. [DOI] [PubMed] [Google Scholar]
- Elias J. A., Zheng T., Einarsson O., Landry M., Trow T., Rebert N., Panuska J. Epithelial interleukin-11. Regulation by cytokines, respiratory syncytial virus, and retinoic acid. J Biol Chem. 1994 Sep 2;269(35):22261–22268. [PubMed] [Google Scholar]
- Funk C. D., FitzGerald G. A. Eicosanoid forming enzyme mRNA in human tissues. Analysis by quantitative polymerase chain reaction. J Biol Chem. 1991 Jul 5;266(19):12508–12513. [PubMed] [Google Scholar]
- Giovannucci E., Egan K. M., Hunter D. J., Stampfer M. J., Colditz G. A., Willett W. C., Speizer F. E. Aspirin and the risk of colorectal cancer in women. N Engl J Med. 1995 Sep 7;333(10):609–614. doi: 10.1056/NEJM199509073331001. [DOI] [PubMed] [Google Scholar]
- Herschman H. R. Prostaglandin synthase 2. Biochim Biophys Acta. 1996 Jan 5;1299(1):125–140. doi: 10.1016/0005-2760(95)00194-8. [DOI] [PubMed] [Google Scholar]
- Hla T., Neilson K. Human cyclooxygenase-2 cDNA. Proc Natl Acad Sci U S A. 1992 Aug 15;89(16):7384–7388. doi: 10.1073/pnas.89.16.7384. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Holtzman M. J., Turk J., Shornick L. P. Identification of a pharmacologically distinct prostaglandin H synthase in cultured epithelial cells. J Biol Chem. 1992 Oct 25;267(30):21438–21445. [PubMed] [Google Scholar]
- Jetten A. M. Growth and differentiation factors in tracheobronchial epithelium. Am J Physiol. 1991 Jun;260(6 Pt 1):L361–L373. doi: 10.1152/ajplung.1991.260.6.L361. [DOI] [PubMed] [Google Scholar]
- Lieber M., Smith B., Szakal A., Nelson-Rees W., Todaro G. A continuous tumor-cell line from a human lung carcinoma with properties of type II alveolar epithelial cells. Int J Cancer. 1976 Jan 15;17(1):62–70. doi: 10.1002/ijc.2910170110. [DOI] [PubMed] [Google Scholar]
- Marcus A. J. Aspirin as prophylaxis against colorectal cancer. N Engl J Med. 1995 Sep 7;333(10):656–658. doi: 10.1056/NEJM199509073331011. [DOI] [PubMed] [Google Scholar]
- Marnett L. J. Aspirin and the potential role of prostaglandins in colon cancer. Cancer Res. 1992 Oct 15;52(20):5575–5589. [PubMed] [Google Scholar]
- Marshall N. J., Goodwin C. J., Holt S. J. A critical assessment of the use of microculture tetrazolium assays to measure cell growth and function. Growth Regul. 1995 Jun;5(2):69–84. [PubMed] [Google Scholar]
- Muerhoff A. S., Williams D. E., Reich N. O., CaJacob C. A., Ortiz de Montellano P. R., Masters B. S. Prostaglandin and fatty acid omega- and (omega-1)-oxidation in rabbit lung. Acetylenic fatty acid mechanism-based inactivators as specific inhibitors. J Biol Chem. 1989 Jan 15;264(2):749–756. [PubMed] [Google Scholar]
- Nakane T., Szentendrei T., Stern L., Virmani M., Seely J., Kunos G. Effects of IL-1 and cortisol on beta-adrenergic receptors, cell proliferation, and differentiation in cultured human A549 lung tumor cells. J Immunol. 1990 Jul 1;145(1):260–266. [PubMed] [Google Scholar]
- Nicolaou K. C., Marron B. E., Veale C. A., Webber S. E., Dahlén S. E., Samuelsson B., Serhan C. N. Identification of a novel 7-cis-11-trans-lipoxin A4 generated by human neutrophils: total synthesis, spasmogenic activities and comparison with other geometric isomers of lipoxins A4 and B4. Biochim Biophys Acta. 1989 May 15;1003(1):44–53. doi: 10.1016/0005-2760(89)90096-9. [DOI] [PubMed] [Google Scholar]
- Pankow D., Damme B., Schrör K. Acetylsalicylic acid--inducer of cytochrome P-450 2E1? Arch Toxicol. 1994;68(4):261–265. doi: 10.1007/s002040050066. [DOI] [PubMed] [Google Scholar]
- Peskar B. M., Hoppe U., Lange K., Peskar B. A. Effects of non-steroidal anti-inflammatory drugs on rat gastric mucosal leukotriene C4 and prostanoid release: relation to ethanol-induced injury. Br J Pharmacol. 1988 Apr;93(4):937–943. doi: 10.1111/j.1476-5381.1988.tb11483.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Samuelsson B., Dahlén S. E., Lindgren J. A., Rouzer C. A., Serhan C. N. Leukotrienes and lipoxins: structures, biosynthesis, and biological effects. Science. 1987 Sep 4;237(4819):1171–1176. doi: 10.1126/science.2820055. [DOI] [PubMed] [Google Scholar]
- Schreinemachers D. M., Everson R. B. Aspirin use and lung, colon, and breast cancer incidence in a prospective study. Epidemiology. 1994 Mar;5(2):138–146. doi: 10.1097/00001648-199403000-00003. [DOI] [PubMed] [Google Scholar]
- Serhan C. N. Lipoxin biosynthesis and its impact in inflammatory and vascular events. Biochim Biophys Acta. 1994 Apr 14;1212(1):1–25. doi: 10.1016/0005-2760(94)90185-6. [DOI] [PubMed] [Google Scholar]
- Serhan C. N. On the relationship between leukotriene and lipoxin production by human neutrophils: evidence for differential metabolism of 15-HETE and 5-HETE. Biochim Biophys Acta. 1989 Aug 8;1004(2):158–168. doi: 10.1016/0005-2760(89)90264-6. [DOI] [PubMed] [Google Scholar]
- Sigal E., Craik C. S., Highland E., Grunberger D., Costello L. L., Dixon R. A., Nadel J. A. Molecular cloning and primary structure of human 15-lipoxygenase. Biochem Biophys Res Commun. 1988 Dec 15;157(2):457–464. doi: 10.1016/s0006-291x(88)80271-7. [DOI] [PubMed] [Google Scholar]
- Vogel C., Döhr O., Abel J. Transforming growth factor-beta 1 inhibits TCDD-induced cytochrome P450IA1 expression in human lung cancer A549 cells. Arch Toxicol. 1994;68(5):303–307. doi: 10.1007/s002040050073. [DOI] [PubMed] [Google Scholar]



