The suppressive effects of microRNA-139-5p on proliferation and invasion of esophageal squamous cell carcinoma

Abstract

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.