洛铂对人胃癌细胞株BGC823放射敏感性的影响

目的 观察洛铂（LBP）对人胃癌细胞株BGC823放射敏感性及凋亡相关蛋白表达的影响。方法 采用四甲基偶氮唑盐MTT法获得LBP处理24h后对BGC823细胞的半数抑制浓度（IC50），并以20％的IC50剂量为增敏浓度；克隆集落形成实验检测单纯照射组与LBP（增敏浓度）+照射组在0、2、4、6、8Gy X线照射后的细胞存活率，并根据单击多靶模型绘制出的细胞存活曲线分析LBP增敏比；Western blotting和流式细胞术分别检测空白对照组、单纯照射组和LBP（增敏浓度）+照射组24h后的凋亡相关蛋白（Bcl-2、Bax和Cleaved caspase-3）的表达水平和细胞周期及凋亡率。结果 LBP对BGC823细胞的IC50为16.08μg／ml，增敏浓度为3.20μg／ml；随照射剂量增大，单纯照射组与LBP+照射组的细胞存活率均逐渐下降，从4Gy起，LBP+照射组的细胞存活率低于单纯照射组（P＜0.05），LBP增敏比为113；LBP+照射组的G2／M期细胞比例、凋亡率及Bax和Cleaved caspase-3水平均高于其他两组，S期细胞比例、Bcl-2水平均低于其他两组（P＜0.05）。结论 LBP对胃癌细胞株BGC823具有放射增敏作用，同时可诱导细胞凋亡及G2／M期阻滞。

Effects on radiosensitivity of lobaplatin on human gastric cancer cell line BGC823

Objective To observe the effect of lobaplatin （LBP） on the radiosensitivity of human gastric cancer cell line BGC823 and the expression of apoptosis-associated protein. Methods MTI assay was employed to obtain the 50% inhibition concen- tration （ ICs0 ） of LBP on BGC823 cells at 24h after treatment. 20% of the ICs0 dose was treated as sensitizing concentration. The clono- genic assay was used to analyze the cell viability of radiation group and LBP （ sensitizer concentration） plus radiation group with X-ray of 0, 2, 4, 6 and 8Gy. The cell survival curve plotted by a single-hit multi-target model was used to analyze the sensitization ratio of LBP. Western blotting and flow cytometry were used to detect the expression levels of apoptosis-related protein （ Bcl-2, Bax and cleaved caspase-3）, cell cycle and apoptosis in control group, radiation group and LBP＋radiation group after 24h treatment, respectively. Re- salts The ICs0 of LBP on BGC823 cells was 16. 08p,μg/ml and the sensitizing concentration was 3. 20μg/ml. The cell viability got de- creased with increasing radiation dose in radiation group and LBP plus radiation group. The cell viabilities of LBP plus radiation group were lower than those of radiation group at the dose of 4, 6 and 8Gy, and the sensitization ratio of LBP was 1.13. There were higher percentage in the GJM phase, apoptosis rate and levels of Bax and cleaved easpase-3, and lower percentage in the S phase and level of Bcl-2 in LBP plus radiation group versus the other two groups （P〈0. 05）. Conclusion LBP can enhance the radiosensitivity of BGC823 cells, induce apoptosis and GJM phase arrest.