二氢杨梅素通过SIRT1/ROS/JNK途径增强顺铂对乳腺癌细胞的杀伤活性

目的: 探讨天然药物活性成分二氢杨梅素是否对顺铂有协同抗乳腺癌效应并研究其机制。方法: MTT法和Annexin V染色流式细胞术检测二氢杨梅素和顺铂处理对乳腺癌细胞系MDA-MB-435细胞活力和细胞凋亡的影响。采用western blot方法检测二氢杨梅素是否影响MDA-MB-435细胞中SIRT1的表达。运用二氢乙啶(DHE)染色流式细胞术及western blot方法研究二氢杨梅素联合顺铂对MDA-MB-435细胞ROS/JNK通路的影响。结果: 顺铂联合二氢杨梅素对MDA-MB-435的细胞活力抑制率(61.5±5.1)和凋亡诱导率(36.8±2.9)显著高于顺铂单治疗组的的细胞活力抑制率(15.2±1.4,P<0.05)和凋亡诱导率(7.6±0.6,P<0.05)。流式细胞和western blot实验结果显示二氢杨梅素处理可显著抑制MDA-MB-435细胞SIRT1蛋白的表达水平并显著增强顺铂对MDA-MB-435细胞活性氧簇(ROS)的诱导、JNK蛋白的磷酸化和caspase-9、caspase-3的活化。另外,顺铂+二氢杨梅素+SIRT1组MDA-MB-435的细胞活力抑制率(19.7±1.6)和凋亡诱导率(10.8±0.9)显著低于顺铂联合二氢杨梅素组MDA-MB-435的细胞活力抑制率(61.5±5.1,P<0.05)和凋亡诱导率(36.8±2.9,P<0.05)。结论: 二氢杨梅素通过抑制SIRT1的表达增强顺铂对乳腺癌细胞的杀伤活性。

Dihydromyricetin enhances the cytotoxicity of cisplatin to breast cancer through inhibiting the SIRT1/ROS/JNK pathway

AIM: To investigate the synergistic effect and mechanism of dihydromyricetin on enhancing cisplatin-induced cytotoxicity to breast cancer. Methods: MTT assay and Annexin V staining were performed to investigate the effect of dihydromyricetin and cisplatin treatment on changing cell viability and apoptosis of MDA-MB-435 which is a breast cancer cell line. Western blot analysis was performed to investigate the effect of dihydromyricetin on changing the expression level of SIRT1 in MDA-MB-435 cells. DHE staining and western blot analysis were performed to investigate the pathway of ROS/JNK in MDA-MB-435 cells which were co-treated with cisplatin and dihydromyricetin. Results: Cell viability inhibitory rate (61.5±5.1) and apoptotic rate (36.8±2.9) of MDA-MB-435 co-treated with cisplatin and dihydromyricetin was significantly higher than the cell viability inhibitory rate (15.2±1.4, P<0.05) and apoptotic rate (7.6±0.6, P<0.05) of MDA-MB-435 cells treated with cisplatin individually. Results of flow cytometry and western blot assays showed that dihydromyricetin was able to inhibit the expression of SIRT1 followed by enhancing the cisplatin-induced ROS production, JNK phosphorylation and activation of caspase-9 and caspase-3 in MDA-MB-435 cells. In addition, cell viability inhibitory rate (19.7±1.6) and apoptotic rate (10.8±0.9) of MDA-MB-435 in cisplatin + dihydromyricetin + SIRT1 plasmid group was significantly lower than the cell viability inhibitory rate (61.5±5.1, P<0.05) and apoptotic rate (36.8±2.9, P<0.05) of MDA-MB-435 in cisplatin + dihydromyricetin group. Conclusion: Dihydromyricetin enhances the cytotoxicity of cisplatin to breast cancer through inhibiting the expression of SIRT1.