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[摘要]
目的:探讨 miR-9 通过靶向 E 盒结合锌指蛋白 2(zinc finger E-box binding homeobox 2,ZEB2)对小细胞肺癌(small cell lung cancer,SCLC)细胞生物学行为的调控作用,分析miR-9在SCLC中的作用及其工作机制。方法:采用qPCR、WB和免疫组化方法检测于2018年2月至2019年11月于河北医科大学第四医院肿瘤内科接受手术治疗的67例SCLC患者癌组织及癌旁组织中ZEB2的表达。采用TargetScan预测miR-9的潜在靶基因并通过双荧光素酶报告基因试验、qPCR和WB法进行验证。CCK-8法、流式细胞术和Transwell实验检测miR-9和ZEB2 过表达对 NCI-H446 的生物学行为影响,WB法检测对细胞中E-cadherin,N-cadherin和Vimentin蛋白表达的影响。利用miR-9过表达NCI-H446细胞构建SCLC裸鼠移植瘤模型,观察miR-9对裸鼠移植瘤生长的影响。结果:SCLC组织中ZEB2的mRNA和蛋白表达水平明显高于癌旁正常组织(P<0.01)。miR-9在ZEB2的3' UTR上具有潜在的结合位点,与对照组相比,miR-9过表达组NCI-H446细胞中ZEB2的mRNA和蛋白表达水平明显降低(P<0.01),细胞增殖、迁移和侵袭能力均显著下降(P<0.05或P<0.01),促EMT蛋白表达减少,而同时过表达ZEB2能够逆转上述影响。体内实验中,miR-9过表达组移植瘤体积、重量均明显低于对照组(P<0.05或P<0.01)。miR-9组裸鼠肿瘤组织中和ZEB2蛋白的表达均较对照组明显降低(P<0.01)。结论:miR-9通过靶向调控ZEB2从而抑制SCLC细胞的生物学行为以及NCI-H446裸鼠移植瘤的生长。
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[Abstract]
Objective:To explore the regulatory effect of miR-9 on biological behaviors of small cell lung cancer (SCLC) cells by targeting zinc finger E-box binding homeobox 2 (ZEB2), and to analyze the role of miR-9 in SCLC and its possible mechanism.Methods: qPCR, WB and immunohistochemistry methods were used to detect the mRNA and protein expressions of ZEB2 in cancer tissues and corresponding adjacent tissues of 67 SCLC patients who received surgical treatment at the Department of Oncology, Fourth Hospital of Hebei Medical University from February 2018 to November 2019. TargetScan was used to predict the potential target gene of miR-9, which was later verified by Dual luciferase reporter gene assay, qPCR and WB methods. CCK-8 method, Flow cytometry and Transwell experiment were used to detect the effect of miR-9 and ZEB2 over-expression on the biological behaviors of NCI-H446 cells,and WB was used to detect the protein expressions of E-cadherin, N-cadherin and Vimentin in cells. NCI-H446 cells overexpressing miR-9 were used to construct SCLC nude mouse xenograft model, and the effect of miR-9 on the growth of xenografts was observed.Results: The mRNA and protein expression levels of ZEB2 in SCLC tissues were significantly higher than those in adjacent tissues (P<0.01). There is a potential binding site on the 3' UTR of ZEB2 to bind with miR-9. Compared with the control group, the mRNA and protein expression levels of ZEB2 in NCI-H446 cells of the miR-9 over-expression group were significantly reduced (P<0.01); the proliferation, migration and invasion abilities of NCI-H446 cells were significantly suppressed (P<0.05 or P<0.01), and the expression of EMT protein was reduced; However, simultaneous over-expression of ZEB2 could reverse above effects. In in vivo experiments, the size and weight of transplanted tumors in the miR-9 over-expression group were significantly lower than those in the control group (P<0.05 or P<0.01). The expression of ZEB2 protein in the tumor tissues of nude mice in the miR-9 overexpression group was significantly lower than that in the control group (P<0.01). Conclusion: miR-9 can inhibit the biological behaviors of SCLC cells and the growth of NCI-H446 transplanted tumors in nude mice by targeting and regulating ZEB2.
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[基金项目]
河北省 2018 年度医学科学研究重点课题资助项目(No. 20180576)