桔梗皂苷D联合伊马替尼对白血病耐药细胞K562/R的抑制增殖和作用机制研究

Inhibitory effect and mechanism of platycodin D combined with imatinib on K562/R

桔梗皂苷D（platycodin D,PD）对多种恶性肿瘤有显著抑制作用,对白血病细胞有明显的增殖抑制和诱导凋亡的作用,但其是否有效提高耐药细胞对伊马替尼的敏感性及其发挥功能的分子机制仍未阐明。为了研究PD与伊马替尼（imatinib,IM）联合用药对慢性粒细胞白血病耐药细胞株K562/R的作用及机制。细胞增殖实验检测桔梗皂苷D对伊马替尼增殖抑制功能的影响,采用CCK8测定PD和IM单药及联合用药对K562/R增殖的抑制作用;流式细胞术检测Annexin V-FITC/PI双标记细胞凋亡率的变化,Western blot法检测cleaved caspase-3,cleaved caspase-9,PARP,cleaved PARP,Bcr/abl,p-AKT,p-mTOR蛋白表达。结果显示桔梗皂苷D联合伊马替尼对K562/R细胞的增殖抑制作用和细胞凋亡率比单独用药组效果明显。Western blot法检测结果显示与单药组比较,联合用药组可以明显上调cleaved caspase-3,cleaved caspase-9,cleaved PARP蛋白表达,同时下调PARP,Bcr/abl,p-AKT,p-mTOR蛋白的表达。结果表明桔梗皂苷D可以提高耐药细胞对伊马替尼的敏感性,联合用药在抑制细胞增殖、诱导凋亡、抑制Bcr/abl蛋白和激活PI3K/AKT/mTOR信号通路方面明显优于单独用药。

Platycodin D（PD） has a significantly inhibitory effect on multiple malignant tumors,and can inhibit the proliferation of leukemia cells K562 and induce apoptosis. However,its effect in improving the sensitivity of drug-resistant cells to imatinib and their molecular mechanism remained unclear. To investigate the effect and mechanism of PD alone or combined with imatinib（ IM） in inhibiting CML imatinib resistant cell line K562/R,the cell proliferation was examined by CCK8 assay to reveal the effect of PD on the inhibitory function of imatinib. Cell apoptosis was detected by Annexin V-FITC/PI double staining. Protein expressions of cleaved caspase-3,cleaved caspase-9,PARP,cleaved PARP,Bcr/abl,p-AKT and p-mTOR were detected by Western blot. The results showed that the inhibitory effect of PD combined with imatinib on the proliferation and apoptosis of K562/R cells was significantly higher than that of the control group and the single drug group. Protein expressions of cleaved caspase-3,cleaved caspase-9 and cleaved PARP were significantly up-regulated in the combination group,and protein expressions of PARP,Bcr/abl,p-AKT and p-mTOR were down-regulated. The results indicated that PD increased the sensitivity of drug-resistant cells to imatinib,and the inhibitory effect of PD combined with imatinib was significantly better than the single drug on cell proliferation,induction of apoptosis,inhibition of Bcr/abl protein and PI3 K/AKT/mTOR signaling pathway.