title: Lipid rafts and nonrafts mediate tumor necrosis factor related apoptosis-inducing ligand induced apoptotic and nonapoptotic signals in non small cell lung carcinoma cells.
abstract: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is capable of inducing apoptosis in non-small cell lung carcinoma (NSCLC). However, many of the human NSCLC cell lines are resistant to TRAIL, and TRAIL treatment of the resistant cells leads to the activation of nuclear factor-kappaB (NF-kappaB) and extracellular signal-regulated kinase 1/2 (ERK1/2). TRAIL can induce apoptosis in TRAIL-sensitive NSCLC cells through the induction of death-inducing signaling complex (DISC) assembly in lipid rafts of plasma membrane. In the DISC, caspase-8 is cleaved and initiates TRAIL-induced apoptosis. In contrast, TRAIL-DISC assembly in the nonraft phase of the plasma membrane leads to the inhibition of caspase-8 cleavage and NF-kappaB and ERK1/2 activation in TRAIL-resistant NSCLC cells. Receptor-interacting protein (RIP) and cellular Fas-associated death domain-like interleukin-1beta-converting enzyme-inhibitory protein (c-FLIP) mediates the DISC assembly in nonrafts and selective knockdown of either RIP or c-FLIP with interfering RNA redistributes the DISC from nonrafts to lipid rafts, thereby switching the DISC signals from NF-kappaB and ERK1/2 activation to caspase-8-initiated apoptosis. Chemotherapeutic agents inhibit c-FLIP expression, thereby enhancing the DISC assembly in lipid rafts for caspase-8-initiated apoptosis. These studies indicate that RIP and c-FLIP-mediated assembly of the DISC in nonrafts is a critical upstream event in TRAIL resistance and thus targeting of either RIP or c-FLIP may lead to the development of novel therapeutic strategies that can overcome TRAIL resistance in human NSCLC.
authors.affiliation: Department of Pathology and Laboratory Medicine, Emory University School of Medicine, 1365-C Clifton Road, Atlanta, GA 30322, USA.
authors.forename: Jin H
authors.initials: JH
authors.lastname: Song
authors.forename: Margaret C L
authors.initials: MC
authors.lastname: Tse
authors.forename: Anita
authors.initials: A
authors.lastname: Bellail
authors.forename: Surasak
authors.initials: S
authors.lastname: Phuphanich
authors.forename: Fadlo
authors.initials: F
authors.lastname: Khuri
authors.forename: Norman M
authors.initials: NM
authors.lastname: Kneteman
authors.forename: Chunhai
authors.initials: C
authors.lastname: Hao
mesh_terms: D017209:Apoptosis; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D002784:Cholesterol / Q000378:metabolism; D006801:Humans; D008055:Lipids / Q000737:chemistry; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology*; D021962:Membrane Microdomains / Q000737:chemistry* / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D053422:Receptor-Interacting Protein Serine-Threonine Kinases / Q000378:metabolism; D015398:Signal Transduction; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000737:chemistry / Q000502:physiology*; D013997:Time Factors
chemical_list: D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; D008055:Lipids; D016328:NF-kappa B; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D002784:Cholesterol; C506249:RIPK1 protein, human; D053422:Receptor-Interacting Protein Serine-Threonine Kinases