bafilomycin-a and Carcinoma--Non-Small-Cell-Lung

Shikonin, a natural naphthoquinone pigment purified from Lithospermum erythrorhizon, induces necroptosis in various cancer types, but the mechanisms underlying the anticancer activity of shikonin in lung cancer are not fully understood. This study was designed to clarify whether shikonin causes necroptosis in non-small cell lung cancer (NSCLC) cells and to investigate the mechanism of action.. Multiplex and caspase 8 assays were used to analyze effect of shikonin on A549 cells. Cytometry with annexin V/PI staining and MTT assays were used to analyze the mode of cell death. Western blotting was used to determine the effect of shikonin-induced necroptosis and autophagy. Xenograft and orthotopic models with A549 cells were used to evaluate the anti-tumor effect of shikonin in vivo.. Most of the cell death induced by shikonin could be rescued by the specific necroptosis inhibitor necrostatin-1, but not by the general caspase inhibitor Z-VAD-FMK. Tumor growth was significantly lower in animals treated with shikonin than in the control group. Shikonin also increased RIP1 protein expression in tumor tissues. Autophagy inhibitors, including methyladenine (3-MA), ATG5 siRNA, and bafilomycin A, enhanced shikonin-induced necroptosis, whereas RIP1 siRNA had no effect on the apoptotic potential of shikonin.. Our data indicated that shikonin treatment induced necroptosis and autophagy in NSCLC cells. In addition, the inhibition of shikonin-induced autophagy enhanced necroptosis, suggesting that shikonin could be a novel therapeutic strategy against NSCLC.

Topics: A549 Cells; Animals; Apoptosis; Carcinoma, Non-Small-Cell Lung; Caspase 8; Cell Line, Tumor; Gene Silencing; Humans; Imidazoles; Indoles; Lithospermum; Lung Neoplasms; Macrolides; Mice; Mice, Inbred BALB C; Mice, Nude; Naphthoquinones; Necrosis; Neoplasm Transplantation; RNA, Small Interfering; X-Ray Microtomography

Pemetrexed, a multitarget antifolate used to treat malignant mesothelioma and non-small cell lung cancer (NSCLC), has been shown to stimulate autophagy. In this study, we determined whether autophagy could be induced by pemetrexed and simvastatin cotreatment in malignant mesothelioma and NSCLC cells. Furthermore, we determined whether inhibition of autophagy drives apoptosis in malignant mesothelioma and NSCLC cells. Malignant mesothelioma MSTO-211H and A549 NSCLC cells were treated with pemetrexed and simvastatin alone and in combination to evaluate their effect on autophagy and apoptosis. Cotreatment with pemetrexed and simvastatin induced greater caspase-dependent apoptosis and autophagy than either drug alone in malignant mesothelioma and NSCLC cells. 3-Methyladenine (3-MA), ATG5 siRNA, bafilomycin A, and E64D/pepstatin A enhanced the apoptotic potential of pemetrexed and simvastatin, whereas rapamycin and LY294002 attenuated their induction of caspase-dependent apoptosis. Our data indicate that pemetrexed and simvastatin cotreatment augmented apoptosis and autophagy in malignant mesothelioma and NSCLC cells. Inhibition of pemetrexed and simvastatin-induced autophagy was shown to enhance apoptosis, suggesting that this could be a novel therapeutic strategy against malignant mesothelioma and NSCLC.

Topics: Adenine; AMP-Activated Protein Kinases; Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Autophagy; Autophagy-Related Protein 5; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Drug Synergism; Humans; Lung Neoplasms; Macrolides; Mesothelioma; Mesothelioma, Malignant; Mice, Nude; Microtubule-Associated Proteins; Pemetrexed; Pepstatins; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; RNA Interference; Signal Transduction; Simvastatin; Time Factors; TOR Serine-Threonine Kinases; Transfection; Tumor Burden; Xenograft Model Antitumor Assays

We have investigated the effects of H(+)-ATPase inhibitors, bafilomycin A1 and 7-chloro-4-nitro-benz-2-oxa-1,3 diazole (NBD), and the Golgi inhibitor, brefeldin A, on daunorubicin accumulation and doxorubicin intracellular distribution in the non-P-glycoprotein-mediated multidrug-resistant cell line COR-L23/R. This cell line overexpress a 190 kDa protein which is probably the product of the MRP gene and shows an anthracycline accumulation defect and a drastically altered intracellular anthracycline distribution from the parental cell line COR-L23/P. We found that all three agents could selectively increase the cellular accumulation of daunorubicin in resistant cells. However, these effects were only seen at doses of the modifiers which were equal to or greater than the IC50 of the modifier alone. Effects of the modifiers on the intracellular distribution of doxorubicin fluorescence could, however, be seen at doses lower than those required to produce significant effects on daunorubicin accumulation. However, when used in a continuous MTT chemosensitivity assay none of the agents, used at maximum non-toxic doses, was able to sensitise COR-L23/R cells to doxorubicin or to colchicine. Although these lead compounds are unlikely to be useful as clinical modifiers, development of more selective analogues may prove useful in the modification of non-P-glycoprotein-mediated multidrug resistance.

Topics: 4-Chloro-7-nitrobenzofurazan; Anti-Bacterial Agents; Antibiotics, Antineoplastic; ATP Binding Cassette Transporter, Subfamily B, Member 1; Brefeldin A; Carcinoma, Non-Small-Cell Lung; Carrier Proteins; Cell Nucleus; Cyclopentanes; Cytoplasm; Daunorubicin; Doxorubicin; Drug Interactions; Drug Resistance; Drug Screening Assays, Antitumor; Golgi Apparatus; Humans; Lung Neoplasms; Macrolides; Membrane Glycoproteins; Protein Synthesis Inhibitors; Proton-Translocating ATPases; Tetrazolium Salts; Thiazoles; Tumor Cells, Cultured