目的 研究红花多糖通过阻断PI3K/Akt/mTOR通路诱导人乳腺癌MDA-MB-435细胞凋亡的作用及其作用机制。方法 将MDA-MB-435细胞分为对照组和红花多糖0.5、1.0 mg/mL组。MTT法及流式检测仪分别检测不同质量浓度红花多糖对MDA-MB-435细胞生长及凋亡的影响；RT-PCR及Western blotting法分别检测不同质量浓度红花多糖对MDA-MB-435细胞PI3K、Akt、mTOR mRNA和蛋白表达的影响。结果 与对照组比较，红花多糖0.5 mg/mL组MDA-MB-435细胞抑制率为（21.52±2.43）%，红花多糖1.0 mg/mL组细胞抑制率为（27.73±3.75）%，显著高于红花多糖0.5 mg/mL组（P<0.05）；与对照组比较，红花多糖能够显著提高MDA-MB-435细胞凋亡率（P<0.01），且呈剂量依赖性。RT-PCR及Western blotting实验结果显示，与对照组比较，红花多糖能够使MDA-MB-435细胞中PI3K、Akt、mTOR mRNA和蛋白表达显著降低（P<0.05、0.01）。结论 红花多糖能有效抑制MDA-MB-435细胞的生长，促进其凋亡，作用可能是通过对PI3K/Akt/mTOR通路的阻断实现的。

Objective To investigate the effect of safflower polysaccharide on apoptosis of human breast cancer MDA-MB-435 cells by blocking PI3K/Akt/mTOR pathway and explore its mechanism. Methods MDA-MB-435 cells were divided into control group and safflower polysaccharide 0.5 and 1.0 mg/mL groups. MTT assay and flow cytometry were used to detect the effects of different concentrations of safflower polysaccharide on the growth inhibition and apoptosis of MDA-MB-435 cells. RT-PCR and Western blotting were used to detect the effect of different concentrations of safflower polysaccharides on the mRNA and protein expression of PI3K, Akt, and mTOR in MDA-MB-435 cells. Results Compared with the control group, the inhibition rate of MDA-MB-435 cells in safflower polysaccharide 1.0 mg/mL group was (27.73 ±3.75)%, which was significantly higher than that[(21.52 ±2.43)%] in safflower polysaccharide 0.5 mg/mL group (P < 0.05). Compared with the control group, safflower polysaccharide could significantly increase the apoptosis rate of MDA-MB-435 cells in a dose-dependent manner (P < 0.01). The results of RT-PCR and Western blotting showed that, compared with the control group, safflower polysaccharide significantly decreased the mRNA and protein expression of PI3K, Akt, and mTOR in MDA-MB-435 cells (P < 0.05, 0.01). Conclusion Safflower polysaccharide can effectively inhibit the growth of MDA-MB-435 cells and promote their apoptosis, which may be achieved by blocking the PI3K/Akt/mTOR pathway.

国家自然科学基金面上项目（31570357）；河南省高等学校重点科研项目计划（15A350016）