虫草素通过抑制NF-κB途径增强A549细胞对顺铂的敏感性

 目的 通过研究虫草素和顺铂单用或联用对肺癌细胞A549的抗肿瘤效应,探讨其可能的作用机制,为临床肿瘤治疗提供新思路。方法 四甲基偶氮唑盐法检测不同浓度的虫草素与顺铂单用或虫草素与顺铂(3 μg·mL^-1)联用对A549的增殖抑制作用,并计算IC₅₀;采用Hoechst 33258染色法及流式细胞术检测虫草素与顺铂单用或联用诱导A549细胞凋亡情况;Western blot法检测不同处理组的细胞核内NF-κBp65及凋亡相关蛋白Bax、Bcl-2表达水平。结果 虫草素与顺铂联用对A549细胞的抑制作用显著增加,增强了顺铂对A549的敏感性; Hoechst 33258染色及流式细胞术显示,与虫草素和顺铂单独用药相比,联合用药能够明显增加顺铂诱导的细胞凋亡;Western blot结果显示,与对照组相比顺铂能够增加细胞核内NF-κBp65的活性,然而虫草素却能抑制NF-κBp65的活性,联合用药后NF-κBp65的活性明显下调;与顺铂单独用药相比,联合用药组能够使促凋亡蛋白Bax表达显著增高,而抗凋亡蛋白Bcl-2的表达则降低。结论 虫草素能够增强顺铂对肺癌细胞A549的敏感性,其作用机制是通过抑制NF-κB途径,调节下游信号分子 Bax和Bcl-2的表达而实现。

Enhancement Effect of Cordycepin on the Chemosensitivity of Cisplatin on A549 Cells by Inhibiting the NF-kappa B Pathway

OBJECTIVE To investigate the effects and mechanisms of cisplatin(DDP) combined with cordycepin (Cor) on proliferation and apoptosis of A549 cells. METHODS Human lung cancer cell line A549 cells were treated with DDP(3 μg·mL^-1) alone or in combination with cordycepin(75 μmol·L^-1). MTS assay was used to detect cell proliferation. Hoechst 33258 staining and Annexin V/PI flow cytometry were used to determine the apoptosis of A549 cells. The protein expression of nuclear factor-κBp65 (NF-κBp65), Bax and Bcl-2 was determined by Western blot. RESULTS Cordycepin could enhance chemosensitivity of DDP on A549 cells. The RESULTS of Hoechst 33258 staining and flow cytometry indicated that the rate of A549 cells apoptosis inducted by the combination of DDP and cordycepin was obviously more than DDP alone. Compared with the control group, DDP made the expression levels of NF-κBp65 in A549 nucleus increasing, but cordycepin could decrease its expression , the combination of DDP and cordycepin could obviously reduce the indicators of NF-κBp65. The Western blotting RESULTS showed that compared with the DDP alone group ,the combination with cordycepin could significantly increase the expression of Bax and decrease the expression of Bcl-2. CONCLUSION Cordycepin could enhance chemosensitivity of cisplatin on A549 cells, the mechanism of action is achieved by inhibiting the NF-κB pathway, and regulating the expression of downstream signaling molecules: Bax and Bcl-2.