[摘要] 目的：探讨lncRNA HCG18/miR-17-5p/HMGA2 分子轴调控非小细胞肺癌（NSCLC）细胞增殖及迁移的分子机制。方法：收集2017 年6 月至2018 年6 月承德市中心医院62 例NSCLC组织及对应的癌旁组织标本，以及NSCLC细胞系A549、NCIH1299、H1650、NCI-H460 和人肺上皮细胞BEAS-B，用qPCR法检测NSCLC组织及细胞系中HCG18、miR-17-5p 及高迁移率族蛋白A2（HMGA2）的表达水平。分别用Si-HCG18、miR-17-5p、miR-17-5p+HCG18 或pcDNA3.1-HMGA2 转染A549 和NCI-H460 细胞，用CCK-8 法、Transwell 实验、Wb检测转染细胞的增殖、迁移、侵袭和HMGA2 及EMT相关蛋白的表达。用双荧光素酶报告基因验证HCG18 对miR-17-5p 或miR-17-5p 对HMGA2 的靶向调控作用。构建敲降HCG18 的A549 细胞小鼠移植瘤模型，观察对移植瘤的影响。结果：lncRNA HCG18 在NSCLC 组织和细胞中均高表达（均P<0.01），发生淋巴结转移及晚期NSCLC 患者中HCG18 的表达显著提高，且HCG18 高表达的NSCLC患者预后较差、生存率较低（均P<0.01）。转染Si-HCG18 显著抑制NSCLC细胞的增殖、迁移及侵袭能力（均P<0.01），上调上皮钙黏蛋白的表达（P<0.01）、下调神经钙黏蛋白和波形蛋白的表达（均P<0.01），小鼠移植瘤体积显著减小（P<0.05）。双荧光素酶报告基因验证了HCG18 与miR-17-5p 靶向结合，以及miR-17-5p 与HMGA2 靶向结合。转染miR-17-5p 后NSCLC 细胞的增殖、迁移及侵袭受到抑制（均P<0.01），促进上皮钙黏蛋白的表达（P<0.01）、抑制神经钙黏蛋白和波形蛋白的表达（均P<0.01），而转染miR-17-5p+HCG18 后可抑制miR-17-5p 的作用。结论：HCG18通过调控miR-17-5p/HMGA2 分子轴促进NSCLC细胞的增殖及迁移。

[Abstract] Objective: To investigate the mechanism of lncRNA HCG18/miR-17-5p/HMGA2 axis regulating the proliferation and metastasis of non-small cell lung cancer (NSCLC) cells. Methods: Sixty-two pairs of NSCLC tissues and corresponding para-cancerous tissues collected at Central Hospital of Chengde City from June 2017 to June 2018 were used for this study; in addition, NSCLC cell lines (A549, NCI-H1299, H1650, NCI-H460) and human lung epithelial BEAS-B cells were also collected. mRNA expression levels of HCG18, miR-17-5p and high-mobility group AT-hook 2 (HMGA2) in NSCLC tissues and cell lines were measured by quantitative Real-time polymerase chain reaction (qPCR). Si-HCG18, miR-17-5p, miR-17-5p+HCG18 or pcDNA3.1-HMGA2 were transfected into A549 cells and NCI-H460 cells; CCK-8 assay was used to detect the proliferation of transfected cells, Transwell assay was used to detect the migration and invasion ability of cells, and Wb was used to analyze the expressions of HMGA2 and EMT associated proteins (E-cadherin, N-cadherin and vimentin). The target relationships between HCG18 and miR-17-5p, or between miR-17-5p and HMGA2 were confirmed by dual luciferase reporter gene assay. Mice A549 cell xenograft model with HCG18 knockdown was constructed, and the growth of transplanted tumor was observed. Results: lncRNA HCG18 was highly expressed in NSCLC tissues and cells (all P<0.01); HCG18 level was significantly increased in patients at late stage or with lymphnode metastasis; and high HCG18 level was correlated with poor prognosis and low survival rates of NSCLC patients (all P<0.01). Knockdown of HCG18 significantly inhibited NSCLC cell proliferation, migration and invasion (all P<0.01), up-regulated E-cadherin expression but suppressed N-cadherin and vimentin expression (all P<0.01), and the volume of xenograft was obviously decreased (P<0.05). Dual luciferase reporter gene assay confirmed the relationship between HCG18 and miR-17-5p as well as miR-17-5p and HMGA2. miR-17-5p transfection significantly inhibited NSCLC cell proliferation, migration and invasion (all P<0.01), and up-regulated E-cadherin expression, reversely suppressed N-cadherin and vimentin expression (all P<0.01); however, miR-17-5p + HCG18 transfection reversed the effect of miR-17-5p on NSCLCcells. Conclusion:HCG18 promotes the proliferation and migration ofNSCLCcells through regulating miR-17-5p/HMGA2 axis.

河北省科技计划资助项目（No. 18277748D）