title: Activation of c-Jun NH2-terminal kinase is required for gemcitabine's cytotoxic effect in human lung cancer H1299 cells.
abstract: Although gemcitabine is a potent therapeutic agent in the treatment of human non-small cell lung cancer (NSCLC), resistance to gemcitabine is common. In this study, we investigated the molecular mechanisms involved in acquired gemcitabine resistance against NSCLC cells. Gemcitabine-resistant NSCLC H1299 cells (H1299/GR) were selected by long-term exposure of parental H1299 cells to gemcitabine. The median inhibitory concentrations of gemcitabine in H1299 and H1299/GR cells were 19.4 and 233.1 nM, respectively. Gemcitabine induced activation of c-Jun NH2-terminal kinase (JNK) in parental H1299 cells but not in H1299/GR cells after 48 h. Blocking JNK activation by pretreatment with SP600125, a specific JNK inhibitor, or by transfection with dominant-negative JNK vectors abrogated gemcitabine-induced apoptosis in parental H1299 cells as evidenced by interruption of caspase activation. Transient transfection with a JNKK2-JNK1 plasmid expressing constitutive JNK1 partially restored the effect of gemcitabine in H1299/GR cells. Our results indicate that gemcitabine-induced apoptosis in human NSCLC H1299 cells requires activation of the JNK signaling pathway. Attenuated JNK activation may contribute to development of acquired gemcitabine resistance in cancer cells.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Bivd., Houston, TX 77030, USA.
authors.forename: Fuminori
authors.initials: F
authors.lastname: Teraishi
authors.forename: Lidong
authors.initials: L
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Guo
authors.forename: Fengqin
authors.initials: F
authors.lastname: Dong
authors.forename: John J
authors.initials: JJ
authors.lastname: Davis
authors.forename: Anning
authors.initials: A
authors.lastname: Lin
authors.forename: Bingliang
authors.initials: B
authors.lastname: Fang
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000473:pathology*; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004351:Drug Resistance; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D000093542:Gemcitabine
chemical_list: D003841:Deoxycytidine; D048031:JNK Mitogen-Activated Protein Kinases; D020169:Caspases; D000093542:Gemcitabine