title: Erlotinib activates mitochondrial death pathways related to the production of reactive oxygen species in the human non-small cell lung cancer cell line A549.
abstract: 1. Erlotinib, a small-molecule epidermal growth factor receptor-tyrosine kinase (EGFR-TK) inhibitor, has been approved for the management of advanced non-small cell lung cancer. The aim of the present study was to investigate whether erlotinib exerts potent antitumour activities through the reactive oxygen species (ROS)-c-Jun N-terminal kinase (JNK) pathway in the human non-small cell lung cancer cell line A549. 2. The 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and Hoechst 33342 staining showed that erlotinib produced a decline in cell viability of A549 cells and induced cell apoptosis, coupled with quick accumulation of ROS. In addition, erlotinib increased the respiratory control ratio, NADPH oxidase catalytic subunit gp91(phox) expression and superoxide anion (O2(-)) generation, suggesting that erlotinib induced ROS production in A549 cells from both mitochondrial and NADPH oxidase sources. 3. Fluorescence microscopy with the JC-1 probe and western blot analysis indicated that erlotinib induced loss of mitochondrial membrane potential, the release of cytochrome c and apoptosis-inducing factor (AIF) and activation of JNK. 4. The results of the present study suggest that erlotinib has potent antitumour activity in A549 cells by activating ROS-dependent, JNK-driven cell apoptosis. These findings provide a novel insight into the mechanism of action of erlotinib in the treatment of human non-small cell lung cancer in addition to its effects in inhibiting EGFR-TK.
authors: Department of Pharmacology, Nanjing Medical University, Nanjing, Jiangsu, China.
authors: Xia
authors: X
authors: Qian
authors: Jing
authors: J
authors: Li
authors: Jianhua
authors: J
authors: Ding
authors: Zhiyuan
authors: Z
authors: Wang
authors: Wenjing
authors: W
authors: Zhang
authors: Gang
authors: G
authors: Hu
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D019069:Cell Respiration / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D000069347:Erlotinib Hydrochloride; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011799:Quinazolines / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D008562:Membrane Glycoproteins; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D017382:Reactive Oxygen Species; D000069347:Erlotinib Hydrochloride; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D048031:JNK Mitogen-Activated Protein Kinases