阿帕替尼通过阻断VEGF通路增强胃癌放疗疗效

目的:探讨血管内皮生长因子(VEGF)受体2酪氨酸激酶抑制剂阿帕替尼对胃癌细胞株SGC-7901放疗疗效的影响及其可能机制。方法:试验设对照组、阿帕替尼组、单纯放疗组与联合组。CCK-8法检测细胞活力,流式细胞术分析细胞凋亡比例与细胞周期,免疫荧光染色观察细胞核内γ-H_2AX的表达,Western blot法检测细胞增殖和凋亡相关蛋白。结果:与阿帕替尼组或单纯放疗组相比,阿帕替尼联合X射线显著降低SGC-7901细胞的生长活力(P0.01),增殖相关蛋白p-PLCγ1和p-ERK1/2的水平下降;细胞凋亡比例明显升高(P0.01),凋亡相关蛋白PARP、cleaved caspase-9和cleaved caspase-3蛋白水平上调,Bcl-2表达下降;SGC-7901细胞核内γ-H_2AX焦点淬灭延迟,表明阿帕替尼干扰放射线诱导的DNA双链断裂的修复;SGC-7901 G_2期细胞比例显著增高(P0.01)。结论:阿帕替尼通过阻断VEGF通路增加胃癌细胞对X射线照射的敏感性。

Apatinib increases radiosensitivity of gastric cancer by inhibiting VEGF pathway

AIM: To investigate radiosensitization effect of apatinib, a vascular endothelial growth factor (VEGF) receptor2 tyrosine kinase inhibitor, on human gastric carcinoma cell line SGC-7901 and its mechanism.METHODS: SGC-7901 cells were divided into control group, apatinib group, radiotherapy group and combination group. The cell viability was measured by CCK-8 assay. The changes of cell apoptosis and cell cycle were analyzed by flow cytometry. The protein levels of cell apoptosis biomarkers, such as PARP, cleaved caspase-9, cleaved caspase-3 and Bcl-2, and cell proliferation biomarkers, p-PLCγ1 and p-ERK1/2, were detected by Western blot. γ-H₂AX expression was detected by immunofluorescence.RESULTS: Compared with apatinib group and radiation group, the cell viability was inhibited after treatment with both apatinib and X-ray (P<0.01). The protein levels of cell proliferation markers p-PLCγ1 and p-ERK1/2 were down-regulated. The cell apoptosis was enhanced (P<0.01). The protein levels of cell apoptosis makers such as PARP, cleaved caspase-9 and cleaved caspase-3 were up-regulated, while Bcl-2 was down-regulated. The disappearance of γ-H₂AX foci in the nucleus was delayed, indicating that apatinib impaired the repair of radiation-induced DNA double-strand breaks. The proportion of G₂ phase was significantly increased (P<0.01). The combination treatment had more significant effect on SGC-7901 cells than treating with apatinib or radiotherapy alone.CONCLUSION: Apatinib increases the radiosensitivity of gastric cancer cells via blocking VEGF pathway.