It has been reported that rapamycin can exert antitumor activity

with cytostatic activities such as G1 phase arrest and that it can exhibit anti-angiogenesis properties[13, 14]. Rapamycin was also demonstrated to have synergistic cytotoxic effect in conjunction with other chemotherapeutic agents on several cancer cell types[15–19]. Several rapamycin analogues have been synthesized and put under evaluation in phase |/‖ clinical trials, showing a promising antitumor effect in several types of refractory or advanced tumors. This GSK1120212 chemical structure evidence prompted us to examine whether the administration of rapamycin will result in some beneficial modulation of the cancer killing properties of docetaxel in lung cancer cells[20, 21]. To the best JAK assay of our knowledge, the effect of including rapamycin in combination therapies intended to treat advanced stage lung cancer has not been reported in the literature. This prompted us to examine whether juxtaposed administration of rapamycin will result in some beneficial modulation of the cancer killing properties of docetaxel in lung cancer cells. Our results showed that rapamycin can sensitize lung cancer cells for more effective killing

by docetaxel and suggested that such enhancement may involve down-regulation of the expression of Survivin and the inactivation of ERK signalling. Materials and methods Therapeutic NADPH-cytochrome-c2 reductase compounds and reagents Lung cancer cell lines A549, SPC-A-1, 95D and NCI-H446 were purchased from Shanghai Institue of Biochemistry and Cell Biology, Chinese Academy of Sciences. Rapamycin, DMSO and MTT were purchased from Sigma (St

Louis, MO, USA). Docetaxel was purchased from Shanghai Sanwei Pharmaceutical Company (Shanghai, China). Annexin V-FITC apoptosis detection kit was from Jingmei Biotech (Shenzhen, China). RPMI tissue culture medium and fetal bovine serum (FBS) were purchased from GIBCO (USA). Anti-Survivin, anti-caspase-3, anti-ERK1/2, anti-p-ERK1/2, anti-GAPDH and HRP-conjugated secondary antibodies were purchased from Santa Cruz Biotechnology (CA, USA). Chemiluminescence (ECL) reagent kit was purchased from Pierce Biotechnology (Rockford, IL, USA). Cell culture A549, SPC-A-1, 95D and NCI-H446 cells were cultured in RPMI-1640 medium containing 10% fetal bovine serum, 100 IU/ml penicillin and 100 μg/ml streptomycin. The cells were grown in a humidified incubator at 37°C and in an atmosphere of 5% CO2 in air. Cells were grown on sterile tissue culture petri dishes and passaged once every 2 to 3 days. MTT cell viability assay Cell were seeded in a 96-well plate at a density of 1 × 106/ml and cultured in medium for 24 h. Cell viability was determined using the conversion of MTT to formazan via mitochondrial oxidation. Various treatments of cells included the addition of rapamycin (12.