Fig 4.

Celastrol enhances inhibitory effects of DNA-damaging agents on lung cancer cells. (a) A549 cells were pretreated with cisplatin (5–20 μM) or mitomycin C (MMC) (0.2–0.8 μg/mL) at indicated concentrations for 24 h, followed by celastrol (5 μM) incubation for an additional 12 h, and cell viability was detected by MTT assay. (b) A549 cells pretreated with cisplatin or MMC at indicated concentrations for 20 h, followed by celastrol incubation for an additional 4 h. The whole-cell extracts were used for detection of FANCD2, γ-H2AX and PARP by Western blot. (c, d) A549 cells were transfected with siRNA-NC or si-FANCD2, treated with cisplatin or MMC for 24 h, followed by celastrol treatment for an additional 12 h. The cells were analyzed by MTT assay (c) or lysed for Western blot using indicated antibodies (d). (e, f) A549 cells were transfected with pDONR201-vector or pDONR201-FANCD2, treated with cisplatin or MMC for 24 h, followed by celastrol treatment for an additional 12 h. The cells were analyzed by MTT assay (e) or lysed for Western blot using the indicated antibodies (f).