Objective: To investigate the role of microRNA-139-5p (miR-139-5p) in the occurrence and development of esophageal squamous cell carcinoma (ESCC) and its effects on cell proliferation and invasion of ESCC cells and its molecular mechanisms. Methods: Seventy-five cases of ESCC tissues and paired normal tissues were obtained from thoracic surgery of the First Affiliated Hospital of Zhengzhou University from February 2017 to March 2018. Experiment was divided into two group: ESCC (n=75) and normal esophageal tissues (n=75).GEO datasets and real-time quantitative PCR (qRT-PCR) were used to detect the expression of miR-139-5p in ESCC tissues and cells. miR-139-5p inhibitor, miR-139-5p mimic, negative control, control siRNA, T-box transcliption factor 1(TBX1) siRNA, pcDNA3.1 and pcDNA3.1-TBX1 were transfected into ESCC Eca109 and TE1 cells. qRT-PCR was used to detect the expressions of miR-139-5p and TBX1 in transfected ESCC cells. Cell counting kit 8 (CCK-8) and Transwell chamber were employed to detect cell proliferation and invasion of ESCC cells, respectively. Dual-Luciferase Reporter assay was used to analyze the interaction between miR-139-5p with TBX1. qRT-PCR, Western blot and immunohistochemistry were utilized to detect the expression of TBX1 in ESCC tissues. Western blot was used to detect the expressions of E-cadherin, N-cadherin and Vimentin after transfection. Results: The level of miR-139-5p in ESCC tissues was significantly lower than that in normal tissues (1.17±0.43 vs 5.16±3.62,P<0.001). Log-rank test showed that the survival rate of ESCC patients with high miR-139-5p level (n = 43) was significantly higher than that with low miR-139-5p level (n=32) (67.44% vs 25.00%, P = 0.005). The expression level of miR-139-5p in ESCC cells was significantly lower than that of normal esophageal epithelial cell Het-1A (all P<0.001). The proliferation and invasion ability of ECA109 and TE1 cells with high expression of miR-139-5p were significantly lower than those transfected with negative control (NC) (all P<0.05). Dual-Luciferase Reporter assay showed that miR-139-5p could bind to the 3'-untranslated region of TBX1. miR-139-5p mimic or inhibitor suppressed or promoted the expression of TBX1 protein in Eca109 and TE1 cells, respectively (all P<0.05). Downregulation of TBX1 significantly suppressed proliferation and invasion of ECA109 and TE1 cells, while overexpression of TBX1 significantly promoted proliferation and invasion of ECA109 and TE1 cells (all P<0.05). In addition, pcDNA3.1-TBX1 partially reversed the inhibition of miR-139-5p-mediated invasion ability (all P<0.05), while TBX1 siRNA partially reversed the enhancement of miR-139-5p inhibitor-mediated invasion ability (all P<0.05). Conclusion: miR-139-5p suppressed ESCC cell proliferation and invasion by targeting TBX1.
目的： 探讨微小RNA-139-5p（miR-139-5p）在食管鳞状细胞癌（ESCC）发生发展中的作用及其对ESCC细胞增殖和侵袭的影响和分子机制。 方法： 收集2017年2月至2018年3月在郑州大学第一附属医院胸外科手术获得的75例ESCC组织和癌旁正常食管组织标本。实验分2组：ESCC（n=75）和正常食管组织（n=75）。采用GEO数据集和实时荧光定量PCR（qRT-PCR）检测ESCC组织和细胞中miR-139-5p的表达。将miR-139-5p抑制剂、miR-139-5p模拟物、阴性对照、对照siRNA、T盒转录因子1（TBX1） siRNA、pcDNA3.1和pcDNA3.1-TBX1转染ESCC Eca109和TE1细胞，用qRT-PCR检测转染后ESCC细胞中miR-139-5p和TBX1的表达水平，分别用细胞计数试剂盒8（CCK-8）和Transwell小室检测ESCC细胞的增殖和侵袭。双荧光素酶报告实验分析miR-139-5p与TBX1的相互作用，qRT-PCR、Western印迹法和免疫组织化学检测TBX1在ESCC组织中的表达，Western印迹法检测转染后E-钙黏蛋白、N-钙黏蛋白和波形蛋白的表达。 结果： ESCC组织中miR-139-5p水平明显低于正常组织（1.17±0.43比5.16±3.62，P<0.001）。Log-rank检验发现，高miR-139-5p表达水平的ESCC患者（n=43）生存率显著高于低miR-139-5p水平的ESCC患者生存率（n=32）（67.44%比25.00%，P=0.005）。ESCC细胞中miR-139-5p的表达水平均显著低于正常食管上皮细胞Het-1A（均P<0.001）。miR-139-5p高表达的Eca109和TE1细胞的增殖和侵袭能力明显低于阴性对照（NC）转染的Eca109和TE1细胞（均P<0.05）。双荧光素酶报告实验表明，miR-139-5p能结合致TBX1的3′-非翻译区。miR-139-5p模拟物或抑制剂分别抑制或促进Eca109和TE1细胞TBX1蛋白表达（均P<0.05）。TBX1下调显著抑制Eca109和TE1细胞的增殖和侵袭，而TBX1的过表达显著促进Eca109和TE1细胞的增殖和侵袭（均P<0.05）。此外，pcDNA3.1-TBX1能部分逆转miR-139-5p介导的细胞侵袭能力的抑制（均P<0.05），而TBX1 siRNA能部分逆转miR-139-5p抑制剂介导的侵袭能力的增强（均P<0.05）。 结论： miR-139-5p通过靶向TBX1抑制ESCC细胞的增殖和侵袭。.