目的:咖啡酸苯乙酯(CAPE)对几种癌症类型具有抗癌作用,包括乳腺癌.脉冲电磁场(PEMF)提高了一些化疗药物的效率。在这项研究中,我们研究了PEMF刺激对MCF-7乳腺癌细胞中CAPE抗癌活性的影响以及潜在的信号转导途径。
方法:将MCF-7细胞接种并孵育24小时。每种药物(5-氟尿嘧啶,紫杉醇,吉非替尼,或CAPE)在第0天添加到细胞中。然后,每天三次(每次间隔4小时)用60分钟的PEMF疗程立即刺激细胞,持续1-3天。通过流式细胞术和台盼蓝染料排除测定评估细胞死亡和活力。通过westernblot分析证实了参与细胞死亡的分子机制。
结果:与单独使用CAPE治疗相比,与CAPE和PEMF共同处理更强烈地降低了MCF-7细胞的活力,进一步增加了亚G1人口的百分比,聚(ADP-核糖)聚合酶(PARP)裂解,凋亡胱天蛋白酶的激活,促凋亡蛋白的上调,如Fas细胞表面死亡受体(FAS)和BCL2相关的X,凋亡调节因子(BAX),并减少抗凋亡蛋白的表达,如BCL-2凋亡调节因子(BCL-2),MCL-1凋亡调节因子,BCL-2家族成员(MCL-1),和幸存者。PEMF刺激还增加CAPE诱导的p53磷酸化,并且p53的抑制部分恢复CAPE处理的MCF-7细胞的PEMF降低的活力。
结论:PEMF刺激通过激活p53增强CAPE诱导的细胞死亡,p53调节凋亡相关分子的表达,随后激活MCF-7细胞中caspase依赖性凋亡途径,提示PEMF可用作佐剂以增强CAPE对乳腺癌细胞的作用。
OBJECTIVE: Caffeic acid phenethyl ester (CAPE) exerts anticancer effects against several cancer types, including breast cancer. Pulsed electromagnetic field (PEMF) improves the efficiency of some chemotherapeutic drugs. In this study, we examined the effects of PEMF stimulation on the anticancer activity of CAPE in MCF-7 breast cancer cells and the underlying signal transduction pathways.
METHODS: MCF-7 cells were seeded and incubated for 24 h. Each of the drugs (5-fluorouracil, paclitaxel, gefitinib, or CAPE) was added to the cells on day 0. Then, cells were immediately stimulated with a 60-min PEMF session thrice a day (with 4-h interval between sessions) for 1-3 days. Cell death and viability were assessed by flow cytometry and trypan blue dye exclusion assay. Molecular mechanisms involved in cell death were confirmed by western blot assay.
RESULTS: Compared with treatment with CAPE alone, co-treatment with CAPE and PEMF more strongly reduced the viability of MCF-7 cells, further increased the percentage of the sub-G1 population, poly (ADP-ribose) polymerase (PARP) cleavage, activation of apoptotic caspases, up-regulation of pro-apoptotic proteins, such as Fas cell surface death receptor (FAS) and BCL2 associated X, apoptosis regulator (BAX), and reduced the expression of anti-apoptotic proteins, such as BCL-2 apoptosis regulator (BCL-2), MCL-1 apoptosis regulator, BCL-2 family member (MCL-1), and survivin. PEMF stimulation also increased CAPE-induced phosphorylation of p53, and inhibition of p53 partially restored the PEMF-reduced viability of CAPE-treated MCF-7 cells.
CONCLUSIONS: PEMF stimulation enhanced CAPE-induced cell death by activating p53, which regulates the expression of apoptosis-related molecules, subsequently activating the caspase-dependent apoptotic pathway in MCF-7 cells, suggesting that PEMF can be utilized as an adjuvant to enhance the effect of CAPE on breast cancer cells.