NSCLC cell lines A549, HCC4006 and Calu-1 (three human lung adenocarcinoma cell lines), and SK-MES-1 and KLN205 (two human lung squamous carcinoma cell lines) were obtained from the Shanghai Institute for Biological Science (China). All cell lines were purchased between 2012 and 2015 and authenticated based on growth rate, morphology, and viability and were frequently confirmed to be mycoplasma free. The cells were cultured in RPMT 1640 media supplemented with 10% heat-inactivated fetal calf serum (FBS), L-glutamine and 100 U/ml penicillin, and 100 μg/ml streptomycin sulfate. The cells were maintained in a humidified incubator in 5% CO2 at 37 °C.
Antibodies to various antigens were as follows: CHK1, PCHK1 (S296), PCHK1 (S317), PCHK1 (S345), CHK2, PCHK2 (T68), PCHK2 (S516), Cdc25A, PCdc25C (S216), H2AX, γH2AX (S139), PH3 (S10histone), ATM, PATM (S1981), DNA-PKCs, PDNA-PKCs (S2056), and GAPDH were from Cell Signaling. FANCL, FANCD2, BRCA2, PARP1, RAD51, caspase-3, cleaved caspanse-3, PARP and cleaved PARP from Santa Cruz. Gemcitabine was from Hanson Pharmaceutic (China), Cisplatin from Yangtze River Pharmaceutic (China), MK-8776 from Selleck Chemicals, CHK2 inhibitor II from Abcam. Gemcitabine was dissolved in PBS. Cisplatin, MK-8776 and CHK2 inhibitor II were dissolved in DMSO and used at the specified concentrations.
Antibodies to various antigens were as follows: CHK1, PCHK1 (S296), PCHK1 (S317), PCHK1 (S345), CHK2, PCHK2 (T68), PCHK2 (S516), Cdc25A, PCdc25C (S216), H2AX, γH2AX (S139), PH3 (S10histone), ATM, PATM (S1981), DNA-PKCs, PDNA-PKCs (S2056), and GAPDH were from Cell Signaling. FANCL, FANCD2, BRCA2, PARP1, RAD51, caspase-3, cleaved caspanse-3, PARP and cleaved PARP from Santa Cruz. Gemcitabine was from Hanson Pharmaceutic (China), Cisplatin from Yangtze River Pharmaceutic (China), MK-8776 from Selleck Chemicals, CHK2 inhibitor II from Abcam. Gemcitabine was dissolved in PBS. Cisplatin, MK-8776 and CHK2 inhibitor II were dissolved in DMSO and used at the specified concentrations.