[Celastrol inhibits growth and increases apoptosis of human lung cancer A549 cells].

Objective To investigate the inhibitory effect of celastrol on the proliferation of human lung cancer A549 cells and its possible mechanism. Methods A549 cells were treated with 0, 1, 2, 3, 4, 5, 6 μmol/L celastrol for 0, 24, 48, 72 hours. The effects of different concentrations and durations on the cell proliferation were evaluated by MTT assay to determine the optimal concentration and treatment time. In the subsequent experiments, A549 cells were treated with (0, 1, 3) μmol/L of celastrol for 48 hours. The effects of celastrol on the expression of BAX, B-cell lymphoma 2 (Bcl2), caspase-3, caspase-8, caspase-9 mRNA in A549 cells were detected by real-time quantitative PCR. The protein levels of BAX, Bcl-2, cleaved caspase-3(c-caspase-3), c-caspase-8, c-caspase-9 were assessed by Western blot analysis. Results Celastrol inhibited the viability of A549 cells in a concentration- and time-dependent manner. Compared with the group without celastrol treatment, the mRNA and protein level of Bcl2 in A549 cells treated with (1, 3) μmol/L celastrol decreased significantly, while the expression levels of BAX, caspase-3, caspase-8, caspase-9, c-caspase-3, c-caspase-8, c-caspase-9 increased significantly. Conclusion Celastrol could suppress the proliferation and induced the apoptosis of A549 cells through mitochondrial pathway.