目的：探讨肺腺癌组织中miR-142-5p的表达及其对H1650细胞增殖、侵袭、迁移及上皮间质转化（epithelieal-mesenchymal transition，EMT）的影响及其作用机制。方法：收集2014年1月至2015年1月在河北医科大学第四医院胸外科行肿瘤切 除并经病理证实的107例肺腺癌患者的癌组织及其癌旁组织标本，以及人肺腺癌细胞系H1650、HCC827、 A549、 H1975、PC9和人 支气管上皮细胞BEAS-2B， 用qPCR实验检测肺腺癌组织及细胞中miR-142-5p的表达水平及其与患者临床特征的关系。分别用 miR-142-5p模拟物（mimics）、miR-阴性对照质粒（miR-NC）转染H1650细胞后， 用CCK8、细胞划痕愈合和Transwell侵袭实验分 别检测H1650细胞的增殖、侵袭和迁移能力。使用生物信息学工具预测miR-142-5p的靶基因，通过双荧光素酶报告基因实验验 证miR-142-5p对靶基因的调控作用，Western blotting检测细胞周期蛋白依赖性激酶5（cyclin-dependent kinase 5，CDK5）及EMT 相关蛋白的表达水平。结果：肺腺癌组织及细胞系中miR-142-5p表达水平显著低于癌旁组织及BEAS-2B细胞（均P<0.01）；107 例肺腺癌组织中， 61例（57.01%）低表达miR-142-5p，其表达水平与患者的TNM分期、淋巴结转移密切相关（均P<0.01）。转染 miR-142-5p模拟物后， H1650细胞中miR-142-5p高表达，细胞的增殖、侵袭和迁移能力显著降低（均P<0.05或P<0.01）。生物信息 学工具预测CDK5是miR-142-5p的靶基因，经双荧光素酶报告基因验证，miR-142-5p可显著降低H1650细胞中CDK5的表达水 平，显著提高E-cadherin表达，降低N-cadherin和Snail的表达水平（均P<0.01）。结论：miR-142-5p在肺腺癌组织和细胞中呈低表 达状态，其通过下调CDK5表达影响EMT抑制H1650细胞的侵袭与迁移能力。

Objective: To study the expression of miR-142-5p in lung adenocarcinoma tissues, and to explore its effect on proliferation, invasion, migration and epithelieal-mesenchymal transition (EMT) of H1650 cells and the potential mechanisms. Methods:Atotal of 107 pairs of lung adenocarcinoma tissues and corresponding para-cancerous tissues from patients, who underwent tumor resection and were pathologically confirmed at the Department of Thoracic Surgery, the Fourth Hospital of Hebei Medical University between Jan. 2014 and Jan. 2015, were collected for this study; in addition, human lung adenocarcinoma cell lines (H1650, HCC827, A549, H1975, PC9) and human bronchial epithelial BEAS-2B cells were also used in this study. qPCR was used to detect the expression of miR-142-5p in lung adenocarcinoma tissues and cell lines. The correlation between expression of miR-142-5p and clinical features was analyzed.After transfection with miR-142-5p mimics or miR-negative control (miR-NC) plasmid, the proliferation, invasion and migration of H1650 cells were detected with CCK-8, Transwell invasion assay and Wound healing assay, respectively. The bioinforamtics tool was used to predict the target genes of miR-142-5p, and Luciferase reporter gene assay was performed to validate the regulation of miR-142-5p on target gene. Western blotting (WB) was used to detect the expressions of cyclin-dependent kinase 5 (CDK5) and EMTrelated protein. Results: Compared to Para-cancerous tissues and BEAS-2B cells, the expression of miR-142-5p was lower in lung adenocarcinoma tissues and cell lines (all P<0.01). Of the 107 cases of lung adenocarcinoma tissues, 61 cases (57.01%) showed decreased miR-142-5 expression, which was correlated with the TNM stage and lymph node metastasis (both P<0.01). Transfection of miR-142-5p mimics significantly up-regulated the expression of miR-142-5p and decreased the proliferation, invasion and migration of H1650 cells (all P<0.05 or P<0.01). Bioinformatics showed that CDK5 was a target gene of miR-142-5p. Luciferase reporter gene assay and WB validated that miR-142-5p could significantly down-regulate CDK5 expression in H1650 cells, up-regulate the expression of E-cadherin and down-regulate the expressions of N-cadherin, Twist and Snail in H1650 cells (all P<0.01). Conclusion: miR-142-5p is low expressed in lung adenocarcinoma tissues and cell lines; it suppresses the EMT process to inhibit, invasion and migration of H1650 cells via down-regulating the expression of CDK5.

国家自然科学基金资助项目（No. 81871894）；河北省自然科学基金资助项目（No. H2018206318）