rBTI联合紫杉醇通过激活NFκB/p65促进MCF-7细胞凋亡

rBTI、紫杉醇均有抑制肿瘤细胞增殖、促进肿瘤细胞凋亡等作用,但两者联合用药对肿瘤细胞的影响尚不明确.本文通过MTT比色法检测rBTI与紫杉醇联合作用对MCF-7细胞增殖的影响;采用流式细胞术分析,对MCF-7细胞凋亡以及ROS水平进行检测;利用qRT-PCR和Western印迹方法,检测rBTI与紫杉醇联合作用后凋亡因子表达情况.结果表明,rBTI(2.5μmol/L)与紫杉醇(0.05~0.5μmol/L)联合作用于MCF-7细胞后,能显著抑制其增殖.将rBTI与紫杉醇进行联合协同用药,诱导了MCF-7细胞凋亡及ROS的产生;同时与rBTI单独作用时相比,联合作用明显上调了p53、Bax的表达,促进了IκBα蛋白的磷酸化以及NFκB/p65的核转位;与rBTI组和紫杉醇单独作用组相比,两者联合用药明显下调了Bcl-2和CyclinD1的表达.本研究证实,rBTI联合紫杉醇通过诱导ROS的产生,激活NFκB/p65信号转导途径,协同促进MCF-7细胞的凋亡.

Combination of rBTI with Paclitaxel Induce Apoptosis by Activating NFκB/p65 Pathway in MCF-7 Cells

rBTI and paclitaxel can both inhibit proliferation and induce apoptosis of tumor cells. However, the effects of the combination of rBTI with paclitaxel on tumor cells are little understood. In this study, the effects of rBTI combined with paclitaxel on the proliferation of MCF-7 cells were tested by MTT assays. Flow cytometry was used to determine cell apoptosis and ROS level, as well as the expression level of apoptotic factors by qRT-PCR and Western blotting. As the result, MTT assay showed that 2.5 μmol/L rBTI combined with 0.05～0.5 μmol/L paclitaxel could significantly inhibit the viability of MCF-7 cells in vitro. Flow cytometry showed that rBTI combined with paclitaxel synergistically induced apoptosis and the generation of ROS. Meanwhile, rBTI combined with paclitaxel could significantly up-regulate the expression of p53 and Bax, promote IκBα phosphorylation and nuclear localization of NF-κB/p65 compared with rBTI only. The combination of rBTI with paclitaxel down regulate the expression of Bcl-2 and CyclinD1 compared with using either rBTI or paclitaxel only. Taken together, combination of rBTI and paclitaxel could promote the ROS generation, activate NFκB/p65, thereby synergetically inducing MCF-7 cell apoptosis.