title: Lysophosphatidic acid inhibits anti-Fas-mediated apoptosis enhanced by actin depolymerization in epithelial ovarian cancer.
abstract: Conflicting reports exist on the effect of actin depolymerization in anti-Fas-induced apoptosis. Lysophosphatidic acid (LPA) has been found to inhibit apoptosis in variable cell types. In this study, we evaluated LPA's protective effects on anti-Fas-induced apoptosis enhanced by actin depolymerization and possible mechanisms in epithelial ovarian cancer. OVCAR3 cells were pretreated with vehicle or LPA, then treated with Cytochalasin D (Cyto D), followed with anti-Fas mAb to induce apoptosis. Cells were stained with apoptotic markers and analyzed by flow cytometry. We report that LPA inhibited anti-Fas-induced apoptosis enhanced by actin depolymerization. Immunoprecipition of Fas death-inducing signaling complex (DISC) and Western blot suggested that the actin depolymerization accelerated caspase-8 activation, while LPA inhibited the association and activation of caspase-8 at the DISC. LPA inhibited caspase-3 and 7 activation induced by anti-Fas and/or Cyto D in cytosols. Phosphorylation of ERK and Bad112 by LPA may play a role in preventing caspase-3 activation through mitochondrial pathway induced by Cyto D. Our investigation found that LPA inhibited anti-Fas-induced apoptosis enhanced by actin depolymerization, and LPA may protect epithelial ovarian cancer from immune cell attack and cytoskeleton disrupting reagents induced apoptosis through multiple pathways.
authors.affiliation: Department of Obstetrics and Gynecology, and R H Lurie Comprehensive Cancer Center, Northwestern University Medical School, Chicago, IL 60611, USA. ruthmwk@yahoo.com
authors.forename: Yuru
authors.initials: Y
authors.lastname: Meng
authors.forename: Shijun
authors.initials: S
authors.lastname: Kang
authors.forename: David A
authors.initials: DA
authors.lastname: Fishman
mesh_terms: D000199:Actins / Q000378:metabolism*; D000906:Antibodies / Q000276:immunology; D017209:Apoptosis / Q000187:drug effects*; D002352:Carrier Proteins / Q000378:metabolism; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D015638:Cytochalasin D / Q000494:pharmacology; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005260:Female; D006801:Humans; D008246:Lysophospholipids / Q000494:pharmacology*; D010051:Ovarian Neoplasms / Q000378:metabolism* / Q000473:pathology*; D010766:Phosphorylation / Q000187:drug effects; D051025:bcl-Associated Death Protein; D019014:fas Receptor / Q000276:immunology / Q000378:metabolism*
chemical_list: D000199:Actins; D000906:Antibodies; C494819:BAD protein, human; D002352:Carrier Proteins; D061945:Caspase Inhibitors; D004791:Enzyme Inhibitors; D008246:Lysophospholipids; D051025:bcl-Associated Death Protein; D019014:fas Receptor; D015638:Cytochalasin D; D048049:Extracellular Signal-Regulated MAP Kinases; D020169:Caspases; C032881:lysophosphatidic acid