人参多糖与他莫昔芬联合对人乳腺癌MCF-7细胞凋亡的影响及其机制研究

目的： 探讨人参多糖 (ginseng polysaccharide，GPS)与他莫昔芬 (tamoxifen，TAM)联合对人乳腺癌MCF-7细胞凋亡的影响及其机制。方法：以不同浓度 (0、20、40、80和160 μg/mL)GPS作用于人乳腺癌MCF-7细胞株48 h，以MTT法检测细胞增殖抑制情况，以GPS的最小有作用剂量与不同浓度 (0、0.5、1、2和4 μg/mL)TAM联合处理细胞48 h，以金氏公式筛选出协同抑制作用最明显的联合剂量，以该联合剂量处理MCF-7细胞48 h后，用DAPI染色法、流式细胞术检测细胞凋亡情况；用Giemsa染色检测细胞有丝分裂指数；用Western blot检测细胞中Fas、Caspase-9 以及Parp的表达情况。结果：MTT法检测提示GPS在48 h对MCF-7细胞的最小有作用剂量为40 μg/mL，金氏公式计算结果提示40 μg/mL GPS+1 μg/mL TAM联合用药协同抑制细胞增殖作用最强 (q=1.82)；与GPS或TAM单独作用相比，DAPI染色发现联合用药组镜下可见大量凋亡小体；流式细胞仪检测发现，联合用药能够协同增加细胞凋亡率 ( q=2.19，P <0.05)；Giemsa染色结果显示联合用药能够协同抑制细胞有丝分裂 (均P<0.05)；Western blot检测发现，联合用药能增加细胞中Fas表达，促进Caspase-9以及Parp的活化。结论：GPS与TAM联合能够协同通过Fas信号通路促进人乳腺癌MCF-7细胞发生凋亡。

The effect and mechanism of ginseng polysaccharide on tamoxifen-induced apoptosis in human breast cancer MCF-7 cells

OBJECTIVE: To study the effect and mechanism of ginseng polysaccharide (GPS) on tamoxifen (TAM)-induced apoptosis in human breast cancer cells. METHODS： Human breast cancer cells MCF-7 were treated with different doses of GPS for 48 h. MTT assay was used to evaluate the minimal effective GPS dose. Then cells were treated with GPS at minimal effective dose combined with different doses of TAM. Bürgi formula was used to assess the synergy effect between GPS and TAM. Cellular mitosis was detected by Giemsa staining assay. Apoptosis was studied by DAPI staining analysis and flow cytometer. The expression of Fas，Caspase-9 and Parp was measured by Western blot. RESULTS：GPS at 40 μg/mL was the minimal effective dose on MCF-7 cells. Combined treatment of GPS at 40 μg/mL and TAM at 1 μg/mL showed the best effect in cell growth inhibition (q=1.82). Combination of GPS and TAM synergistically enhanced apoptosis of MCF-7 in comparison with GPS or TAM alone (q=2.19，P<0.05).Combinated treatment of GPS and TAM significantly inhibited cellular mitosis compared with GPS or TAM alone (P<0.05). Treatment of GPS+TAM induced increased level of Fas as well as cleavage of Caspases-9 and Parp. CONCLUSION：Combined treatment of GPS and TAM induced apoptosis in MCF-7 cell through Fas signal in a synergetic manner.