[Primary Mechanisms of CD34CD38--KG1a Leukemia Stem Cells Apoptosis Induced by FA-2-b-β Extracted from Qinba Selenium- Mushroo].

Objective: To investigate the apoptosis of CD34CD38-KG1a leukemia stem cells induced by Qinba selenium-mushroom extract(FA-2-b-β), and its related mechanism.

Methods: CD34CD38--KG1a cells were isolated from KG1a cell line by magnetic activated cell sorting. The proliferation ability of KG1a stem cells treatd by various concentration of FA-2-b-β(1.2-2.4 mg/ml) in vitro for 24 and 48 hours were tested by cell counting Kit-8(CCK8). Flow cytometry was used to detect the apoptosis rate of KG1a stem cells in each group after treated by FA-2-b-β in vitro. Expression of BAX,BCL-2,Casepase-3 and Cyclin D1 protein were detected by Western blot.

Results: The proportion of CD34CD38--KG1a stem cells was (95.35±2.63）% after immunomagnetic isolation. The proliferation of KG1a stem cells was inhibited significantly by FA-2-b-β, which shows a time- and dose-dependent manner (24 h,r=0.943; 48 h,r=0.976). Flow cytometry shows that with the increasing of drug concentration, the apoptosis was also increased, when KG1a stem cells was treated by FA-2-b-β for 24 h. Western blot indicated that the expression of apoptosis-related protein BAX and Casepase-3 were up-regulated, the expression of BCL-2 and Cyclin D1 were down-regulated.

Conclusion: FA-2-b-β can regulate proliferation and apoptosis KG1a stem cells, the involved mechanism may be related with the activation of mitochondrial-mediated apoptotic pathway.