灵芝多糖调控抗氧化因子表达抑制乳腺癌恶性表型研究

目的 研究灵芝多糖对乳腺癌MCF-7、MDA-MB-231细胞凋亡的影响及作用机制。方法 MCF-7和MDA-MB-231细胞分别给予灵芝多糖（25、50、75mg/mL）干预后，MTS法检测灵芝多糖对乳腺癌细胞增殖的影响；TUNEL染色及流式细胞术探测灵芝多糖对乳腺癌细胞凋亡的影响；采用流式细胞术检测细胞内活性氧（reactive oxygen species，ROS）水平；检测细胞内谷胱甘肽（glutathione，GSH）水平；采用qRT-PCR技术检测抗氧化相关基因谷氨酸-半胱氨酸连接酶调节亚基（glutamate-cysteine ligase regulatory subunit，GCLM）、谷氨酸半胱氨酸连接酶催化亚基（glutamate-cysteine ligase catalytic subunit，GCLC）、人硫氧还蛋白还原酶1（human thioredoxin reductase 1，TXNRD1）、苹果酸酶1（malic enzyme 1，ME1）、硫氧还蛋白（thioredoxin，TXN）mRNA表达；采用Western blotting检测GCLM、TXNRD1蛋白表达。结果 给予灵芝多糖干预后，MCF-7、MDA-MB-231细胞活性明显降低（P＜0.01），凋亡率显著升高（P＜0.05、0.01），细胞内ROS水平显著升高（P＜0.05、0.01），GSH水平明显下降（P＜0.01）；抗氧化因子mRNA及蛋白表达水平显著下调（P＜0.05、0.01）。结论灵芝多糖能够通过抑制GCLM等抗氧化基因表达诱导ROS生成，促进乳腺癌细胞凋亡，进而抑制乳腺癌恶性进展。

Ganoderma lucidum polysaccharide inhibits malignant phenotype of breast cancer via regulation of antioxidant factor expressions

Objective To study the effect and mechanism of Ganoderma lucidum polysaccharide (GLP) on apoptosis of MCF-7 and MDA-MB-231 breast cancer cells.Methods MCF-7 cells and MDA-MB-231 cells were treated with GLP (25, 50, 75 mg/mL), MTS method was used to detect the effect of GLP on the proliferation of breast cancer cells; TUNEL staining and flow cytometry were used to detect the effect of GLP on apoptosis of breast cancer cells; The level of reactive oxygen species (ROS) in cells was detected by flow cytometry; The intracellular glutathione (GSH) level was detected; The mRNA expressions of antioxidant related genes glutamate cysteine ligase regulatory subunit (GCLM), glutamate cysteine ligase catalytic subunit (GCLC), human thioredoxin reductase 1 (TXNRD1), malic enzyme 1 (ME1) and thioredoxin (TXN) were detected by qRT-PCR technique; Western blotting was used to detect the expressions of GCLM and TXNRD1 proteins.Results After GLP intervention, activities of MCF-7 and MDA MB-231 cells were significantly decreased (P<0.01), apoptosis rate was increased (P<0.05, 0.01), intracellular ROS level was increased (P<0.05, 0.01), and GSH level was decreased (P<0.01); mRNA and protein expressions of antioxidant factors were significantly decreased (P<0.05, 0.01).Conclusion GLP can induce ROS production by inhibiting the expression of antioxidant genes such as GCLM, promote the apoptosis of breast cancer cells, and then inhibit the malignant progress of breast cancer.