[Effects of bufalin combined with doxorubicin on the proliferation and apoptosis of human lung cancer cell line A549 in vitro].

ABSTRACT

OBJECTIVE: To explore the effects of bufalin (BUF) combined with doxorubicin (DOX) on the proliferation and apoptosis in human lung cancer cell line A549 in vitro.
 Methods: Methyl thiazolyl tetrazolium (MTT) assay was used to measure the inhibitory effects of BUF, DOX and their combination on the growth of A549 cells. Hoechst 33342 staining was used to observe the changes of nucleus. Flow cytometry was used to investigate the apoptosis and cell cycle distribution of A549 cells. Western blot was used to examine the expression of apoptotic protein.
 Results: BUF and DOX showed inhibitory effect on the A549 cells in a dose and time-dependent manner. Compared with BUF or DOX alone, combination of BUF (1, 20, 100 nmol/L) with DOX (1.0 µg/mL) could significantly increase the growth inhibition rate of A549 cells at 24, 36, 72 h, respectively (all P<0.05). BUF and DOX alone could induce apoptosis, and their combination could significantly increase the apoptosis ratio. In addition, BUF combined with DOX could block the cell stage of A549 cells, keep the cell stage stay in S stage and up-regulate the expression of caspase-3.
 Conclusion: BUF combined with DOX can significantly inhibit the proliferation of A549 cells, which might be related to the induction of apoptosis, cell cycle S phase arrest and caspase-3 up-regulation.