[Effect and mechanism of aspirin combined with vinorelbine on non-small cell lung cancer].

The study aimed to investigate the effect and mechanism of aspirin combined with vinorelbine on the proliferation and apoptosis of non-small cell lung cancer cells. 3-(4-dimethylthiazolyl-2)-2-diphenyltetrazolium bromide(MTT) was used to detect the cytotoxic effect of aspirin and vinorelbine on H460 and A549 cells, and half of inhibitory concentration(IC_(50)) value of drugs as well as synergistic effect were calculated. The results showed that both aspirin and vinorelbine inhibited the cancer cells proliferation by a concentration-dependent manner with IC_(50 )values of 1.553 mmol·L(-1) and 0.033 μmol·L(-1) in H460 cells, respectively. The IC_(50 )values of aspirin and vinorelbine were 1.70 mmol·L(-1)and more than 20 μmol·L(-1) in A549 cells. The combination index(CI) value was used to evaluate the combined effect of two drugs. Aspirin combined with vinorelbine had synergistic effects at the ratio of 100∶1 on H460 cells and 1∶10 on A549 cells(CI<1). Clone formation and 4',6-diamidino-2-phenylindole(DAPI)/propidium iodide(PI) staining assays were used to verify the effect of the combination of two drugs on proliferation of H460 cells. Compared with the aspirin single group, the combination group had stronger inhibitory effect on the proliferation of H460 cells and the clone formation rate was 49.5%(P<0.05). Furthermore, apoptosis, mitochondrial membrane potential, reactive oxygen species and Western blot experiments were used to explore the synergistic mechanism of aspirin combined with vinorelbine in inhibiting cell proliferation. The results showed that the cancer cell apoptosis rate was 52.8%, the mitochondrial membrane potential was decreased to 33.1%, and the levels of reactive oxygen species was increased to 73.3% in combination group, which were significantly different from those of the single drug treatment groups(P<0.05). Western blot showed that combination group significantly up-regulated the expressions of Bax, p53, cleaved caspase-3 and cytochrome C, while down-regulated the expression of anti-apoptosis proteins such as Bcl-xL and Bcl-2 when compared with single groups. Our results suggested that aspirin combined with vinorelbine could synergistically inhibit the proliferation of H460 cells by inducing the cell apoptosis through the mitochondrial pathway.