miRNA-132通过靶向调控Bmi-1表达影响鼻咽癌细胞对放射治疗敏感性

miRNA-132 affects the sensitivity of nasopharyngeal carcinoma cells to radiotherapy via targeted regulation of Bmi-1 expression

目的研究miRNA-132对鼻咽癌细胞放射治疗敏感性的影响。方法使用miRNA芯片技术,对比5-8F(亲代细胞)和5-8F/R(放射治疗抵抗细胞)中miRNA表达水平差异,从中挑选差异最为明显的miRNA-132作后续研究。使用流式细胞仪检测miRNA-132对细胞凋亡的影响。使用双荧光报告素酶、蛋白免疫印迹法等方式验证miRNA-132的下游靶基因。结果 miRNA-132可以促进鼻咽癌5-8F/R细胞的凋亡,提高其对放射治疗的敏感性,还可以抑制其体内的生长能力。miRNA-132可以抑制Bmi-1信使RNA和蛋白质表达水平。结论 miRNA-132可通过抑制下游靶基因Bmi-1来发挥其放射治疗增敏功能。

Objective To investigate the effect of miRNA-132 on the sensitivity of nasopharyngeal carcinoma （NPC） cells to radiotherapy. Methods The expression levels of miRNAs were compared between 5-8F parental cells and 5-8F/R radioresistant cells using a miRNA array; miRNA-132, which showed the most prominent changes between the two cell lines, was chosen for further study. The effect of miRNA-132 on apoptosis was examined using flow cytometry. A dual-luciferase reporter assay and western blotting were employed for the identification and verification of the downstream targets of miRNA-132. Results miRNA-132 promoted apoptosis, enhanced radiosensitivity in 5-8F/R cells and inhibited the in vivo growth of 5-8F/R cells. In addition, miRNA-132 suppressed Bmi-1 expression at both the mRNA and protein levels. Conclusion miRNA- 132 enhanced the radiosensitivity of NPC cells via negative regulation of its downstream target Bmi-1.