miR-449b对GBM细胞替莫唑胺治疗敏感性的影响

The Critical Role of miR-449b in GBMcells Sensitivity to TMZ

目的 miR-449b在多种肿瘤细胞中都处于低表达状态,是潜在的肿瘤抑制因子。本课题主要探究miR-449b表达对GBM细胞替莫唑胺(TMZ)治疗敏感性的的影响及内在的调控机制。方法选用两株GBM细胞,T98G和LN229,将miR-449b模拟剂转入这两种细胞中,采用MTT法、克隆集落法和免疫印迹法检测miR-449b表达对不同剂量TMZ处理后的GBM细胞的存活、增殖能力和凋亡水平的影响;同时检测miR-449b表达对替莫唑胺治疗下GBM细胞ATP水平的影响,以及将外源ATP脂质体转入后对细胞活力的影响。结果 MTT研究表明,增加miR-449b表达可降低替莫唑胺治疗下GBM细胞的存活能力,表现为肿瘤细胞活力下调、克隆集落形成能力减弱及Cleaved-PARP的蛋白水平增加;ATP检测结果发现,miR-449b表达可降低替莫唑胺应激下肿瘤细胞ATP水平,并且外源性ATP补充可明显增强替莫唑胺治疗下肿瘤细胞的活力。结论以上研究结果提示,miR-449b可通过加剧替莫唑胺治疗下GBM细胞ATP水平消耗,进而促进GBM细胞对替莫唑胺治疗的敏感性,有利于提高替莫唑胺对GBM的治疗效果及其在临床上的应用。

Objective Mir-449h, a member of the miR-449 family, has been shown to be down-regulaled in a variety of human malignancies, and to be a potential tumor suppressor. The aim of this study was 1o study the role of miR-449b in （;BM ceils sensitivity to TMZ, and the inw^lved mechanism hv which miR-449h contributes GBM cells sensitivity to TMZ therapy.Methods （Jell biology, molecular biology, pharmacology experiment methods were used in this study.Results tropic, expression of miR- 449h with specific mimics significantly enhanced lhe cyloloxicity of TMZ therapy in GBM cells, as indicated by decreases in GBM cells viability and colony fl^rmation, and increase in lhe amount of Cleaved-PARP. ATP assay showed that miR-449b mimic greally diminished ATP level, and exogenous ATP supplementation partially reduced the eytotoxicily effect of TMZ in GBM cells. Conclusion These resnhs suggest that promoting ATP depletion contribute to the miR-449b mediated TMZ-sensitivity.