Aim To investigate the antiproliferative effects and mechanism of sunitinib on epidermal growth factor receptor tyrosine kinase inhibitors ( ECFR TKI )resistant human non-small cell lung cancer cell line A549 in vitro. Methods A549 cells were exposed to sunitinib. MTT assay was applied to assess the antiproliferative effect. The apoptosis was observed by fluorescence microscope. Cell cycle distributions were analyzed by flow cytometry. The expression of alteration for Bcl-2 was measured by Western blot. Results MTT assay demonstrated sunitinib had remarkable antiproliferative effects and dose-dependent and time-dependent growth inhibition on A549 at the concentration ranged from 0. 4 to 12. 8 μmol · L-1. At 24 .48 ,72 h the ICso of sunitinib on A549 cells was( 7.34 ±0. 76 ).( 5. 54 ± 0. 62 ),( 3. 68 ± 0. 53 )μmol · L-1,respectively. Typical apoptotic morphologic changes,such as karyopyknosis and volume reduction were observed by fluorescence microscope. Cell cycle arrest was significantly observed at the G0/G1 phase. Western blot showed that sunitinib down-regulated the protein level of Bcl-2. With the drug concentration increasing,the expression level for Bcl-2 were gradually suppressed. Coriclusioris Sunitinib can inhibit the growth of EGFR TKI-resistant A549 cells and have the dose-dependent and time-dependent growth inhibition.The mechanism of antitumor may be related to inducing cell cycle arrest and down-regulating the expression of Bcl-2 .%目的 探讨舒尼替尼(sunitinib)体外对表皮生长因子受体酪氨酸激酶抑制剂(EGFR TKI)耐药的非小细胞肺癌A549细胞的生长抑制作用及其机制.方法 MTT法检测sunitinib对A549细胞的生长抑制作用;荧光显微镜观察sunitinib诱导的细胞凋亡;流式细胞术检测sunitinib作用后细胞周期变化;Western blot检测sunitinib作用后Bcl-2蛋白水平的变化.结果 在0.4～12.8 μmol·L-1浓度范围内,sunitinib抑制A549细胞增殖,且具有浓度和时间依赖性,24、48、72 h的半数抑制浓度(IC50)分别为(7.34 ± 0.76)、(5.54 ± 0.62)、(3.68 ± 0.53) μmol·L-1.荧光显微镜观察发现sunitinib能够诱导细胞出现核固缩、体积缩小等凋亡形态学改变.细胞周期显示sunitinib将A549细胞阻滞于G0/G1期.Western blot显示sunitinib能够降低Bcl-2蛋白的表达水平,且随着sunitinib浓度的升高,Bcl-2蛋白的表达水平逐渐降低.结论 sunitinib能够抑制EGFR TKI抵抗的A549细胞生长,并具有浓度和时间依赖性,其抗肿瘤的机制可能与诱导细胞周期阻滞和下调Bcl-2的表达有关.
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