中文摘要：

目的：MiR-378a-5p是一种被认为在多种肿瘤发生过程中具有抑制肿瘤生长的微小RNA。然而miR-378a-5p在鼻咽癌中的作用尚未见报道。因此,本文旨在通过临床样本的miRNA表达谱分析以及细胞学实验从而揭示miR-378a-5p在鼻咽癌肿瘤发生过程中的作用。方法与结果：我们通过生物信息学的方法获取了鼻咽癌临床样本中miR-378a-5p的表达信息并通过与正常组织的对比发现miR-378a-5p在鼻咽癌肿瘤组织中表达水平显著降低（P〈0.01）。其次,我们发现高表达miR-378a-5p的鼻咽癌CNE-1细胞增殖速度显著较对照组降低（约40%~50%）。克隆形成实验证实了瞬时转染miR-378a-5p的鼻咽癌CNE-1细胞的克隆形成数量显著减弱。我们通过将稳定表达miR-378a-5p的CNE-1细胞注射到裸鼠体内形成移植瘤并记录肿瘤生长曲线,结果显示miR-378a-5p高表达组的裸鼠移植瘤体积明显较对照组小约50%,肿瘤重量显著降低（对照组0.33 g,处理组0.15 g）。结论：本研究通过对临床样本的分析以及在细胞和动物水平的实验验证揭示了miR-378a-5p具有抑制鼻咽癌肿瘤细胞增殖和肿瘤生长的作用。

英文摘要：

Objective： MiR-378a-5p is reported as a tumor repressive miRNA in numerous cancers. However, no report has been released to investigate the correlation between mi R-378a-5p and nasopharyngeal carcinoma. Therefore, we aimed to disclose the potential function of mi R-378a-5p in nasopharyngeal carcinoma by analyzing miRNA profiling in clinical tumor tissues and studying through cellular biology approaches. Methods and Results： In this study, we discovered that mi R-378a-5p expresses in low-level in nasopharyngeal carcinoma tissue compares to normal nasopharynx tissue by analyzing miRNA profiling acquired from clinical samples. We demonstrated that mi R-378a-5p significantly inhibits cell proliferation（40%~50%） in mi R-378a-5p transient transfected CNE-1 cells and mi R-378a-5p stable expression cells. We also showed that the clone formation capability in mi R-378a-5p was greatly reduced by using clone formation assay. Finally, we injected mi R-378a-5p stable overexpression cell line and controls into nude mice. Results suggested mi R-378a-5p greatly represses tumor growth scaling by tumor volume（~50% repression） and weight（control average 0.33 g, treatment average 0.15g）.Conclusion： We concluded that the tumor-repressive effect of mi R-378a-5p in nasopharyngeal carcinoma through clinical sample profiling analysis as well as in vitro and in vivo experiments.