目的：探究miRNA-325-3p 及其靶基因细胞角蛋白13（cytokeratin 13，CK13）对鼻咽癌细胞CNE1 的放疗敏感性的影响。方法：通过miRBase、Targetscan 及Microcosm 三大数据库预测miRNA-325-3p 的潜在靶基因，并通过双荧光素酶活性检测实验进行验证，qPCR检测不同放射剂量下鼻咽癌细胞CNE1 中miRNA-325-3p 及其靶基因的表达水平变化，通过克隆形成实验观察不同放射剂量下过表达miRNA-325-3p 及敲低靶基因后CNE1 细胞克隆形成率的变化，流式细胞术验证过表达miRNA-325-3p及敲低靶基因后CNE1 在不同放射剂量下凋亡水平的变化，MTT法检测miRNA-325-3p 过表达和CK13 敲低组鼻咽癌细胞CNE1在不同放射剂量下的细胞存活率以验证其放疗敏感性的变化。结果：CK13 确认为miRNA-325-3p 的潜在靶基因，鼻咽癌细胞CNE1 经放射处理后，miRNA-325-3p 的表达水平显著升高、CK13 的表达水平显著降低（均P<0.05）。miRNA-325-3p 表达量上调和CK13 基因沉默均显著提高CNE1 细胞的存活率[miRNA上调时：（60.14±3.55）% vs（19.23±3.42）%，t=14.37、P<0.01；CK13 沉默时：（76.15±5.13）% vs（28.53±3.68）%，t=13.06、P<0.01]和克隆形成率，降低了凋亡率[miRNA 上调时：（27.95±2.67）% vs（51.68±3.47）%，t=9.39、P<0.01；CK13 沉默时：（20.31±2.62）% vs（38.14±3.83）%，t=6.66、P<0.01]。结论：miRNA-325-3p 能够通过下调靶基因CK13的表达降低鼻咽癌细胞CNE1 对放疗的敏感性。

Objective：To investigate the effect of miRNA-325-3p and its target gene cytokeratin 13 (CK13) on the radio-sensitivity of nasopharyngeal carcinoma cell line CNE1. Methods：The potential target gene of miRNA-325-3p was predicted by three databases:miRBase, Targetscan and microcosm, and verified by Double luciferase activity assay. QPCR was used to detect the expression levels of miRNA-325-3p and its target gene in nasopharyngeal carcinoma cell line CNE1 under different radiation doses; To verify the changes in radio-sensitivity of nasopharyngeal carcinoma cells, colony formation assay, Flow cytometery and MTT were used to observe the clone formation, apoptosis and cell viability of CNE1 cells after overexpression of miRNA-325-3p and knockdown of CK13 under different radiation doses, respectively. Results：CK13 was confirmed as a potential target gene of miRNA-325-3p. After radiotherapy, the expression level of miRNA-325-3p in CNE1 cell was significantly increased, while the expression level of CK13 was decreased (all P<0.05); up-regulation of miRNA-325-3p expression and silence of CK13 gene increased cell survival rate (upregulation of miRNA-325-3p: [60.14±3.55]% vs [19.23±3.42]%, t=14.37, P<0.01; silence of CK13: [76.15±5.13]% vs [28.53±3.68]%, t=13.06, P<0.01)and colony formation rate, and decreased apoptosis rate (upregulation of miRNA-325-3p: [27.95±2.67]% vs [51.68±3.47]%, t=9.39,P<0.01; silence of CK13: [20.31±2.62]% vs [38.14±3.83]%, t=6.66, P<0.01). Conclusion：miRNA-325-3p can reduce the sensitivity of nasopharyngeal carcinoma cell line CNE1 to radiotherapy by down-regulating the target gene CK13.

云南省科技厅-昆明医科大学应用基础研究联合专项基金资助[No. 2018FE001(-173)]