miR 375通过靶向NLK影响鼻咽癌的增殖及迁移

 目的探讨miR 375在鼻咽癌患者中表达的临床意义及其对鼻咽癌细胞的影响。方法收集67例鼻咽癌组织标本和53例慢性鼻咽炎症组织标本，采用qRT PCR检测组织标本和鼻咽癌细胞株CNE1、CNE2、C666 1及人永生化鼻咽上皮细胞株（NP69）中miR 375的表达水平；分别转染miR 375的模拟物或抑制物，CCK8法检测细胞的增殖，Transwell实验检测细胞的迁移；生物信息学靶基因预测miR 375的靶基因，并经双荧光素酶及蛋白质印迹法（Western blotting）验证靶基因。结果鼻咽癌组织中miR 375表达水平与慢性鼻咽炎症组织相比明显下调（P<0.05）；miR 375的表达水平与患者的临床分期、区域淋巴结受累情况以及肿瘤大小有关（P<0.05），但与患者年龄、性别、吸烟史、分化程度及组织类型无关(P>0.05)；鼻咽癌细胞与NP69相比较，miR 375的表达水平均显著低于NP69（P<0.05）；miR 375过表达后C666 1细胞增殖、迁移显著低于慢性鼻咽炎-模拟物组（P<0.05），Nemo样激酶（Nemo like kinase,NLK）的表达下调。miR 375抑制后CNE1细胞增殖、迁移显著高于慢性鼻咽炎-抑制物组（P<0.05），miR 375对NLK具有直接靶向调控作用。结论miR 375在鼻咽癌中呈低表达，并与患者的临床分期、区域淋巴结受累情况以及肿瘤大小有关，其可能是通过下调靶基因NLK，从而抑制鼻咽癌的增殖及迁移。

miR 375 inhibits the growth and invasion of nasopharygeal

 ObjectiveTo investigate the clinical significance of microRNA 375(miR 375) expression in nasopharyngeal carcinoma (NPC) and its impact on NPC cells.Methods67 NPC specimens and 53 chronic pharyngitis specimens were collected. Real time fluorescence quantitative polymerase chain reaction (qRT PCR) was used to detect the expression of miR 375 in the specimens, CNE1, CNE2, C666 1 and NP69 (an immortalized nasopharyngeal epithelial cells line) cells lines. All the cells were transfected with miR 375 mimics or inhibitors respectively. Cell proliferation was detected by CCK 8 assay kit and cell migration by transwell assay. Bioinformatics software was adopted to predict the target gene of miR 375, and the expression of the target gene was verified by Western blot and dual luciferase assay.ResultsThe expression of miR 375 in NPC specimens was markedly down regulated compared to that in the chronic pharyngitis tissues (P<0.05). The expression level of miR 375 was correlated with the size, lymph node metastasis and clinic stage of tumor (all P<0.05), but had no correlation with the patients'' age, gender and smoking history, histologic type and differentiation degree of the tumor (all P>0.05). The expression levels of miR 375 in the 4 types of NPC cells were significantly lower than that in the NP69 cell (all P<0.05). After overexpression of miR 375, proliferation and migration abilities of C666 1 cell were significantly lower than those of the chronic pharyngitis tissues (both P<0.05), and NLK expression was down regulated. After suppression of miR 375, the abilities of CNE1 cell were significantly higher than those of the chronic pharyngitis tissues (both P<0.05), and NLK expression was up regulated. The miR 375 targeted regulation on the NLK directly.ConclusionThe expression of miR 375 is down regulated in NPC, which is correlated with the size, regional lymph node involvement and clinic stage of the tumor. miR 375 may inhibit the proliferation and migration of NPC cells by down regulating its target NLK gene.