五味子多糖对脑肿瘤干细胞的凋亡诱导及生长抑制作用

目的：探讨五味子多糖（SCP）对脑肿瘤干细胞（BTSCs）生长的抑制作用，阐明SCP抑制BTSCs生长的抑制机制。方法：培养原代人脑肿瘤细胞，CD133免疫磁珠法分选获得BTSCs，免疫荧光法鉴定BTSCs中神经干细胞标记抗原CD133和Nestin表达情况；将BTSCs分为对照组和不同剂量SCP组，分别用0、200、400和800 μg·L^-1SCP处理；噻唑蓝（MTT）法检测各组BTSCs的增殖率，Annexin Ⅴ-PI分析细胞凋亡率，酶联免疫吸附法（ELISA）检测各组BTSCs培养上清中Bax、Bcl-2和Cascpase-3蛋白表达水平。结果：免疫荧光染色，CD133和Nestin在BTSCs中呈阳性表达。MTT检测，与对照组比较，各剂量SCP组BTSCs增殖率降低，400和800 mg·L^-1组差异有统计学意义（P<0.05）。Annexin Ⅴ-PI检测，800 mg·L^-1SCP组细胞凋亡率明显升高，与对照组比较差异有统计学意义（P<0.05）。ELISA法检测，与对照组比较，各剂量SCP组BTSCs中Bax蛋白表达水平升高（P<0.05），800 mg·L^-1SCP组Bcl-2蛋白表达水平降低（P<0.05），各剂量SCP组Bax/Bcl-2比值明显升高（P<0.05）。与对照组比较，800 mg·L^-1 SCP组BTSCs中Caspase-3蛋白表达水平明显升高（P<0.01）。结论：SCP可抑制BTSCs生长，诱导细胞凋亡可能是其作用机制之一。

Apoptosis induction and growth inhibition effects of Schisandra chinensis polysaccharides on brain tumor stem cells

Objective:To investigate the effect of Schisandra chinensis polysaccharide(SCP)on the growth of brain tumor stem cells(BTSCs),and to clarify the mechanism of inhibiting the growth of BTSCs of SCP. Methods:The primary human glioma cells were cultured,then the BTSCs were isolated by CD133 immunomagnetic sorting.The neural stem cell surface markers CD133 and Nestin were detected by immunofluorescence assay.The proliferation rate of BTSCs was examined by MTT assay.Annexin V-PI analysis was used to analyze the apoptotic rate of BTSCs.The expression levels of Bax,Bcl-2 and Caspase-3 proteins in BTSCs in various groups were detected by ELISA assay.Results:The results of immunofluorescence staining showed that the expressions of CD133 and Nestin were positive in BTSCs.Compared with control group,the proliferation rates of BTSCs in 200,400 and 800 mg·L-1SCP groups were decreased,especially in 400 and 800 mg·L-1SCP groups(P<0.05).The results of Annexin V-PI analysis showed that the apoptotic rate of BTSCs in 800 mg·L-1SCP group was increased compared with control group(P<0.05).The ELISA results showed that the expression levels of Bax in 200,400 and 800 mg·L-1SCP groups were significantly increased(P<0.05),and the values of Bax/Bcl-2 were significantly increased(P<0.05);compared with control group,the Bcl-2 expression level in the BTSCs in 800 mg·L-1SCP group was decreased(P<0.05).The expression level of Caspase-3 protein in 800 mg·L-1SCP group was also significantly increased compared with control group(P<0.01).Conclusion:SCP could inhibit the growth of BTSCs,and the induction of apoptosis may be one of mechanisms.