大黄素逆转非小细胞肺癌EGFR-TKI耐药的机制研究

目的 探讨大黄素逆转非小细胞肺癌（NSCLC）表皮生长因子受体酪氨酸激酶抑制剂（EGFR TKI）耐药的作用机制。方法 应用持续诱导的方法构建NSCLC EGFR-TKI耐药细胞株HCC827／GR；应用MTS法检测大黄素（30μmol／L）、吉非替尼（1μmol／L）及两药联合处理HCC827和HCC827／GR细胞48h后细胞增殖能力的变化；应用Western blotting法检测HCC827和 HCC827／GR细胞中p EGFR、p-AKT、p-ERK1／2及p-MET蛋白表达水平的变化。结果 MTS法检测结果显示，经单药吉非替尼或大黄素处理后，HCC827／GR细胞增殖能力未减弱，而两药联合处理组的细胞增殖能力明显下降，差异有统计学意义（P＜0.05）。Western blotting检测结果显示，HCC827、HCC827／GR细胞中p-EGFR、p-ERK1/2明显表达，而p-AKT表达微弱；HCC827／GR 中p-MET表达水平较HCC827明显上调。经单药吉非替尼处理后，HCC827细胞株p-EGFR、p-ERK1/2表达水平下调，HCC827／GR细胞株p-EGFR表达明显下调；大黄素可显著下调HCC827／GR细胞株p-MET表达，但对p-EGFR、p-ERK1/2的表达无影响；而大黄素与吉非替尼两药联用可明显抑制HCC827／GR细胞株p-EGFR、p-ERK1/2以及p-MET的表达。结论 大黄素可以逆转NSCLC EGFR-TKI耐药，可能是通过抑制c-Met的活化来实现。

The mechanism of rheum emodin reversed resistance of EGFR-TKI in NSCLC

Objective To investigate the mechanism of rheum emodin reversed resistance of epidermal growth factor receptor tyrosine kinase inhibitors（EGFR-TKI） in non-small cell lung cancer（NSCLC）. Methods NSCLC cell lines resistant to EGFR-TKI （HCC827/GR） was built by continuous induction method. MTS method was used＇ to detect the ability of cell proliferation by treating HCC827 and HCC827/GR cells with rheum emodin（30μmol/L）, gefitinib（ 1 μmol/L） and rheum emodin（30μmol/L） combined with gefitinib（1μmol/L）. The expressions of p-EGFR, p-AKT, p-ERK1/2 and p-MET in HCC827 and HCC827/GR cells were detected by Western blotting method. Results The proliferation ability of HCC827/GR cell was not decreased by treating gefitinib or rheum emodin monotherapy, but remarkably decreased by treating the combination of gefitinib and rheum emodin, with statistical difference （P 〈0. 05）. The expressions of p-EGFR and p-ERK were strong and p-AKT expression was weak in HCC827 and HCC827/GR. p-MET expression was significantly increased in HCC827/GR compared with HCC827. After treated with 1μmol/L gefitinib, the expressions of p-EGFR and p-ERK were down-regulated in HCC827, and the expression of p-EGFR was significantly descended in HCC827/GR cell. 30μmol/L rheum emodin could obviously reduce the expression of p-MET in HCC827/GR. Otherwise, after treated with rheum emodin and gefitinib, the expressions of p-EGFR, p-ERK1/2 and p-MET were markedly inhibited. Conclusion Rheum emodin may reverse the resistance of EGFR-TKI in NSCLC, probably by inhibiting the activation of c-Met.