摘要目的 探讨miR-199a-3p通过靶向结合p21蛋白激活激酶4(p21 protein activated kinase 4,PAK4)对胶质瘤U251细胞放疗敏感性的影响.方法 选取人恶性胶质瘤体外细胞系U251,细胞培养、辐照完成后,用RT-PCR检测U251细胞中miR-199a-3p表达水平,CCK-8、克隆形成实验及流式细胞术检测辐照条件下miR-199a-3p或PAK4对胶质瘤U251细胞增殖、克隆形成及凋亡的影响.结果 与未接受辐射U251细胞相比,U251细胞中miR-199a-3p的表达明显降低(P＜0.05);4 Gy辐射后,过表达miR-199a-3p可降低U251细胞的增殖、克隆形成能力,并促进细胞凋亡(P＜0.05或P＜0.01);miR-199a-3p通过与PAK4的3UTR区结合抑制PAK4的表达(P＜0.05);PAK4过表达明显降低miR-199a-3p对U251细胞活性的抑制作用(P＜0.05).结论 miR-199a-3p可通过抑制PAK4的表达增强胶质瘤对放疗的敏感性.

abstractsObjective To explore the enhanced effect of miR-199a-3p on radiotherapy sensitivity of glioma U251 by the targeting p21 protein activated kinase 4 (PAK4).Methods Human malignant glioma U251 was chosen for study.Following culture and radiation of the harvested cells,RT-PCR was used to detect the expression level of miR-199a-3p in the glioma tissues and cells of U251,CCK-8,cloning formation assay and flow cytometry were used to detect the effects of miR-199a-3p/PAK4 on the proliferation,cloning formation and apoptosis of glioma U251 cells when treated with irradiation.Results As compared with the U251 cells without radiation,the expression level of miR-199a-3p in the irradiated glioma tissues was lower(P ＜ 0.05).The overexpression of miR-199a-3p could reduce the growth and clonal formation of U251 cells,and promoted cell apoptosis,when treated with 4 Gy-irradiation.Statistical significance could be noted,when comparisons were made between them(P ＜ 0.05 or P ＜ 0.01) MiR-199a-3p could inhibit the expression of PAK4 by direct binding to the 3'UTR of PAK4.Moreover,the overexpression of PAK4 could significantly weaken the roles of miR-199a-3p in the inhibition of U251 cell activity.Conclusion This study has demonstrated that miR-199a-3p could enhance the radiosensitivity of glioma by inhibiting the expression of PAK4.