目的构建沉默信息调节因子(silent information regulaor,Sir)样蛋白1(Sirtuin 1,SIRT1)的特异性短发夹RNA(shRNA)慢病毒载体,获得敲低SIRT1的肝癌细胞系,以探讨其对肝癌细胞的增殖和耐药敏感性的作用。方法设计针对SIRT1靶点特异性的干涉序列,连接到经HpaⅠ和XhoⅠ双酶切的pSicoR-GFP载体,慢病毒包装293T产生病毒,感染肝癌细胞,建立肝癌细胞SIRT1低表达的稳定株。利用实时定量PCR检测SIRT1的干涉效果;通过平板克隆形成实验、CCK8细胞增殖实验检测SIRT1被干涉后对肝癌细胞增殖能力的影响;通过细胞耐药敏感性实验及实时定量PCR检测耐药基因的表达,考察SIRT1干涉对肝癌细胞耐药敏感性的影响。结果实时定量PCR实验证明该慢病毒干涉载体能显著抑制肝癌细胞中SIRT1的表达,SIRT1干涉可抑制肝癌细胞的增殖能力,下调耐药基因的表达,增强肝癌细胞的药物敏感性。结论 SIRT1抑制肝癌细胞耐药性。
Due to the low number of collectable stem cells from single umbilical cord blood(UCB)unit,their initial uses were limited to pediatric therapies.Clinical applications of UCB hematopoietic stem and progenitor cells(HSPCs)would become feasible if there were a culture method that can effectively expand HSPCs while maintaining their self-renewal capacity.In recent years,numerous attempts have been made to expand human UCB HSPCs in vitro.In this study,we report that caffeic acid phenethyl ester(CAPE),a small molecule from honeybee extract,can promote in vitro expansion of HSPCs.Treatment with CAPE increased the percentage of HSPCs in cultured mononuclear cells.Importantly,culture of CD34+HSPCs with CAPE resulted in a significant increase in total colony-forming units and high proliferative potential colony-forming units.Burst-forming unit-erythroid was the mostly affected colony type,which increased more than 3.7-fold in 1μg mL 1CAPE treatment group when compared to the controls.CAPE appears to induce HSPC expansion by upregulating the expression of SCF and HIF1-α.Our data suggest that CAPE may become a potent medium supplement for in vitro HSPC expansion.
The generation of red blood cells(RBCs)from stem cells provides a solution for deficiencies in blood transfusion.Currently,primary hematopoietic stem cells,embryonic stem cells and induced pluripotent stem cells have shown the potential to produce fully mature RBCs.Here,we discuss the advantages,induction protocols,progress and possible clinical applications of stem cells in RBC production.
