Objective: To investigate the expression of microRNA-140-5p (miR-140-5p) in esophageal squamous cell carcinoma (ESCC) and its role in cell proliferation and invasion of ESCC. Methods: Real-time quantitative PCR (qPCR) was used to detect the expression levels of miR-140-5p in ESCC tissues and cells. Negative control and miR-140-5p mimic were transfected into Eca109 and KYSE70 cells. CCK-8 kit and Transwell assay were employed to examine the changes of cell proliferation and invasion ability after transfection, respectively. The dual-luciferase reporter assay was used to assess the interaction of miR-140-5p with Glut1. Western blot was utilized to detect the Glut1 protein expression after transfection. Results: Analysis of the related GEO datasets revealed that the expression of miR-140-5p in ESCC tissues was significantly lower than that in normal tissues (P<0.01). The qPCR testing demonstrated that the expression of miR-140-5p in ESCC tissues and cells was markedly lower than that in normal tissues and normal esophageal epithelial cell Het-1A (P<0.01). The miR-140-5p expression was closely associated with tumor differentiation, TNM staging and lymph node metastasis in ESCC patients. The survival rate of ESCC patients with high miR-140-5p level was higher than those with low miR-140-5p level (P<0.05). Besides, addition of miR-140-5p mimic significantly upregulated the expression of miR-140-5p in Eca109 and KYSE70 cells, and suppressed cell proliferation and invasion in Eca109 and KYSE70 cells. The dual-luciferase reporter assay showed that Glut1 was a direct target of miR-140-5p in ESCC cells, and its expression was upregulated in ESCC tissues. Glut1 expression was inversely associated with miR-140-5p expression in ESCC tissues. MiR-140-5p mimic dramatically inhibited the expression of Glut1 in Eca109 and KYSE70 cells. Conclusions: MiR-140-5p plays an essential role in ESCC development and progression. Targeting at miR-140-5p/Glut1 may be a novel therapeutic strategy for ESCC patients.
目的： 探讨微小RNA-140-5p（miR-140-5p）在食管鳞状细胞癌（esophageal squamous cell carcinoma，ESCC）中的表达及其在ESCC细胞增殖和侵袭中的作用。 方法： 即时荧光定量PCR（real-time quantitative PCR，qPCR）分析ESCC组织和细胞样本中miR-140-5p的表达。将阴性对照和miR-140-5p类似物转染Eca109和KYSE70细胞，细胞增殖与活性检测试剂盒（CCK-8）和Transwell分别检测转染后细胞的增殖和侵袭能力的变化，双荧光素酶报告实验证实miR-140-5p与葡萄糖转运蛋白1（Glut1）的相互作用，Western blot用来检测转染后Glut1蛋白的表达。 结果： GEO数据分析结果表明，ESCC组织中miR-140-5p的表达水平显著低于正常组织，差异均具有统计学意义（P<0.01）。qPCR结果显示，ESCC组织和细胞中miR-140-5p的表达均显著低于正常组织和正常食管上皮细胞Het-1A，差异均具有统计学意义（P<0.01）。miR-140-5p的表达与ESCC患者肿瘤的分化程度、TNM分期和淋巴结转移均密切相关，高表达miR-140-5p的ESCC患者生存率显著高于低表达患者，差异具有统计学意义（P<0.05）。miR-140-5p类似物显著上调Eca109和KYSE70细胞中miR-140-5p的表达，其表达上调显著抑制Eca109和KYSE70细胞的增殖和侵袭能力。双荧光素酶报告实验结果表明，Glut1是ESCC细胞中miR-140-5p的直接作用靶点，其在ESCC组织中表达显著上调，其与miR-140-5p表达呈负相关关系，miR-140-5p类似物显著抑制Eca109和KYSE70细胞中Glut1蛋白的表达。 结论： miR-140-5p在ESCC的发生发展中发挥重要作用，靶向miR-140-5p/Glut1可能成为ESCC患者新的治疗策略。.
Keywords: Carcinoma, squamous cell; Cell proliferation; Esophageal neoplasms; Glucose transporter type 1; MicroRNAs; Neoplasm invasiveness.