紫杉醇脂质体对乳腺癌细胞SK-BR-3的放疗增敏作用及其机制

Effect of paclitaxel liposome on the radiosensitization in breast cancer cell line SK-BR-3 and related mechanisms

目的探索紫杉醇脂质体(力扑素)对乳腺癌细胞株SK-BR-3是否具有放疗增敏作用及其放疗增敏机制。方法利用MTT法检测放疗组、单药紫杉醇脂质体(以下简称单药组)及紫杉醇脂质体联合放疗(以下简称联合组)在不同时间对乳腺癌细胞SK-BR-3的生长抑制作用。利用流式细胞仪检测放疗组、单药组及联合组对细胞周期及凋亡的影响。利用Western blot检测凋亡相关蛋白Caspase-3、Bcl-2及Bax在不同处理组中的表达,探索紫杉醇脂质体放疗增敏作用的机制。结果 MTT结果显示放疗组、单药组及联合组均具有细胞生长抑制作用,与细胞对照组相比差异具有统计学意义(P<0.05),而且联合组较单药及放疗组具有更显著的细胞生长抑制作用,差异具有统计学意义(P<0.05);细胞凋亡结果显示放疗组、单药组及联合组凋亡细胞均明显增加,与对照组相比差异具有统计学意义(P<0.05),并且联合组在细胞周期中均出现了明显的凋亡峰;Western blot结果显示,促凋亡蛋白Caspase-3和Bax的表达在放疗组、单药组和联合组中均升高,与对照组相比差异具有统计学意义(P<0.05),并且联合组升高较放疗组及单药组更为显著,差异具有统计学意义(P<0.05),而抗凋亡蛋白Bcl-2的表达在放疗组、单药组及联合组均减低,与对照组相比差异具有统计学意义(P<0.05),而联合组较放疗组及单药组降低更明显,差异具有统计学意义(P<0.05)。结论紫杉醇脂质体具有明显的放疗增敏作用,并且可能通过调控凋亡相关蛋白的表达引起细胞凋亡来发挥其放疗增敏作用。

Objective To explore the effect of paclitaxel liposome on the radiosensitization in breast cancer cell line SK-BR-3 and its related mechanisms.Methods MTT assay was used to test the inhibitory effect of paclitaxel liposome on breast cancer cell line SK-BR-3.Flow cytometry was used to detect the cell cycle and apoptosis.Western blot was used to detect apoptosis-related proteins Bcl-2,Bax and Casepase-3.ResultsPaclitaxel liposome combined with radiotherapy could inhibit cell growth more significantly than single paclitaxel liposome or single radiotherapy（P 0.05）.The number of apoptotic cells increased more significantly in the combination group than in radiotherapy group or single paclitaxel liposome group（P〈0.05）.The combination group had an obvious apoptosis peak during the cell cycles.Western blot results showed that the expressions of Caspase-3and Bax were significantly upregulated in radiotherapy group,single paclitaxel liposome group and the combination group compared with the control group（P〈0.05）,and that the effect was more obvious in the combination group（P〈0.05）.The expression of the anti-apoptosis protein Bcl-2 was downregulated in radiotherapy group,single paclitaxel liposome group and the combination group compared with the control group（P〈0.05）,and the effect was more obvious in the combination group（P 0.05）.Conclusion Through regulating the expression of apoptosis-related proteins,paclitaxel liposome has an obvious radiosensitization effect.