沉默HLA A2表达的骨髓间充质干细胞安全性的研究
Safety of the bone marrow derived mesenchymal stem cells after HLA A2 gene silencing

摘要：目的 探讨人白细胞抗原A2(HLA A2)表达沉默后人骨髓间充质干细胞(hBMSCs)的安全性。方法 实验分为对照组(正常培养至第8代细胞组)及实验组1和实验组2(分别为HLA A2表达沉默后第5代、第15代)。复苏HLA A2表达沉默的hBMSCs，通过观察细胞的生长曲线、端粒酶活性和抑癌基因P27的表达水平、细胞周期蛋白依赖激酶4(CDK4)和Cyclin D2的表达水平，分析细胞的安全性。并将细胞接种于裸鼠的皮下，24周后观察荷瘤组织的种类。结果 实验组1、实验组2与对照组相比，细胞生长曲线没有明显的左移或右移。HLA A2表达沉默的hBMSCs在沉默HLA A2表达后，3组间的端粒酶活性没有明显差异；3组的Cyclin D2、CDK4和抑癌基因P27的表达量也没有明显变化。细胞接种于裸鼠皮下24周，只有异位成骨，而没有形成肿瘤组织。 结论 人BMSCs的HLA A2表达沉默后，在实验周期内，没有明显证据表明有安全性的改变。
ABSTRACT: Objective To explore the safety of the human bone marrow-derived mesenchymal stem cells (hBMSCs) after silencing of human leukocyte antigen A2 expression. Methods We divided the cells into three groups: normal cultured cells of the 8th passage served as control group, and hBMSCs after HLA A2 silencing expression of the 5th and 15th passage as experimental groups 1 and 2, respectively. The hBMSCs were recultured by sterile methods. The growth curve, telomerase activation, and expressions of P27, cyclin D2 and cyclin-dependent kinase 4 (CDK4) were utilized to explore the safety of the hBMSCs induced by LV-siRNA-HLA A2. The BMSCs were transplanted to the subcutaneous layer of nude mice. Tissue types were detected 24 weeks after transplantation. Results The cell curves had no obvious left or right shift in all the groups. The telomerease activation in experimental groups 1 and 2 did not significantly differ from those in control group. The expressions of anti-oncogene P27, cyclin D2 and CDK4 had no obvious difference between the two experimental groups and control group, either. There was only ectopic osteogenesis 24 weeks after the BMSCs (HLA A2 gene silenced) were transplanted to the subcutaneous layer of the nude mice. Conclusion There was no obvious evidence to support that hBMSCs had undergone change in safety after the silencing of HLA A2 expression