title: eNOS protects prostate cancer cells from TRAIL-induced apoptosis.
abstract: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potent anti-cancer agent because it induces apoptosis of most tumor cells with little or no effect on normal cells. In this study, we investigated the effect of TRAIL on human prostate normal and cancer cell lines, and found that the prostate cancer cell lines PC-3, ALVA-31, DU 145 and TSU-Pr1 were sensitive to TRAIL-induced apoptosis, while normal PrEC cells and cancer cell line LNCaP were resistant. No correlation was found between the sensitivity of cells to TRAIL and the expression of TRAIL receptors DR4 and DR5, and pro-apoptotic proteins Bax and Bak. However, LNCaP cells displayed a high Akt activity. Furthermore, we found that endothelial nitric oxide synthase (eNOS), one of the Akt substrates, was highly expressed in LNCaP but not in other cells. Inhibition of eNOS activity by NOS inhibitor sensitized LNCaP cells to TRAIL. Moreover, PC-3 cell clones stably expressing eNOS were resistant to TRAIL-induced apoptosis. Taken together, these results indicate that eNOS can regulate the sensitivity of prostate cancer cells to TRAIL, and down-regulation of eNOS activity may sensitize prostate cancer cells to TRAIL-based therapy.
authors.affiliation: Children's Memorial Institute for Education and Research, The Robert H. Lurie Comprehensive Cancer Center, The Feinberg School of Medicine, Northwestern University, 2300 Children's Plaza, P.O. Box 209, Chicago, IL 60614, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Tong
authors.forename: Honglin
authors.initials: H
authors.lastname: Li
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins; D051023:BH3 Interacting Domain Death Agonist Protein; D002352:Carrier Proteins / Q000378:metabolism; D053181:Caspase 8; D020169:Caspases / Q000378:metabolism; D002478:Cells, Cultured; D015536:Down-Regulation; D019008:Drug Resistance, Neoplasm / Q000502:physiology*; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000494:pharmacology*; D008565:Membrane Proteins / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000502:physiology*; D052250:Nitric Oxide Synthase Type III; D011471:Prostatic Neoplasms / Q000201:enzymology / Q000473:pathology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D019253:Proto-Oncogene Proteins c-bcl-2; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D050998:bcl-2 Homologous Antagonist-Killer Protein; D051028:bcl-2-Associated X Protein
chemical_list: D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; C494772:BAK1 protein, human; C494826:BAX protein, human; D051023:BH3 Interacting Domain Death Agonist Protein; C494814:BID protein, human; D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; D053221:TNF-Related Apoptosis-Inducing Ligand; C505639:TNFRSF10B protein, human; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D050998:bcl-2 Homologous Antagonist-Killer Protein; D051028:bcl-2-Associated X Protein; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C494918:AKT1 protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; C505530:CASP8 protein, human; D053181:Caspase 8; D020169:Caspases