title: Leukotriene B4 receptor antagonist LY293111 induces S-phase cell cycle arrest and apoptosis in human pancreatic cancer cells.
abstract: We have previously shown that the leukotriene B4 receptor antagonist, LY293111 inhibits proliferation and induces apoptosis in human pancreatic cancer cells both in vitro and in vivo. In the current study, we investigated the molecular mechanisms of LY293111-induced apoptosis and cell cycle arrest. Two human pancreatic cancer cell lines were used in this study, MiaPaCa-2 and AsPC-1. Cell cycle analysis by flow cytometry showed a dramatic increase in the percentage of apoptotic cells as well as S-phase arrest after treatment with 250 nmol/l LY293111 for up to 48 h. Western blotting indicated that LY293111 treatment induced cytochrome c release from the mitochondria into the cytosol, accompanied by caspase-9, caspase-7 and caspase-3 activation, and cleavage of poly ADP-ribose polymerase. Caspase-8 was not activated by LY293111. A decrease was found in the expression of the antiapoptotic proteins, Bcl-2 and Mcl-1, and an increase in the proapoptotic protein, Bax. LY293111 reduced the expression of CDK2, cyclin A and cyclin E, consistent with the S-phase arrest observed in these cells. The expression of cyclin-dependent kinase inhibitors, p21 and p27 was not affected by LY293111 treatment. In conclusion, LY293111 induces apoptosis in human pancreatic cancer cells through the mitochondria-mediated pathway. LY293111 also induces S-phase arrest with downregulation of CDK2, cyclin A and cyclin E. Blockade of leukotriene B4 metabolic pathway may provide a novel treatment for human pancreatic cancer.
authors.affiliation: Department of Surgery, Robert H. Lurie Comprehensive Cancer Center, Northwestern University School of Medicine, Chicago, Illinois 60611, USA.
authors.forename: Wei-Gang
authors.initials: WG
authors.lastname: Tong
authors.forename: Xian-Zhong
authors.initials: XZ
authors.lastname: Ding
authors.forename: Mark S
authors.initials: MS
authors.lastname: Talamonti
authors.forename: Richard H
authors.initials: RH
authors.lastname: Bell
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Adrian
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D001565:Benzoates / Q000494:pharmacology*; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects*; D045744:Cell Line, Tumor; D019925:Cyclin A / Q000037:antagonists & inhibitors; D019927:Cyclin E / Q000096:biosynthesis; D051357:Cyclin-Dependent Kinase 2 / Q000037:antagonists & inhibitors; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005434:Flow Cytometry; D019254:Genes, bcl-2 / Q000235:genetics; D006801:Humans; D020024:Leukotriene Antagonists / Q000494:pharmacology*; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins / Q000235:genetics; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D018102:Receptors, Leukotriene B4 / Q000037:antagonists & inhibitors*; D016196:S Phase / Q000187:drug effects*; D051028:bcl-2-Associated X Protein / Q000096:biosynthesis
chemical_list: D001565:Benzoates; D019925:Cyclin A; D019927:Cyclin E; D050759:Cyclin-Dependent Kinase Inhibitor p21; C094099:LY 293111; D020024:Leukotriene Antagonists; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D019253:Proto-Oncogene Proteins c-bcl-2; D018102:Receptors, Leukotriene B4; D051028:bcl-2-Associated X Protein; D050760:Cyclin-Dependent Kinase Inhibitor p27; D045304:Cytochromes c; D011065:Poly(ADP-ribose) Polymerases; D051357:Cyclin-Dependent Kinase 2; D053148:Caspase 3; D053179:Caspase 7; D053453:Caspase 9