MiR-143 inhibits tumor cell proliferation and invasion by targeting STAT3 in esophageal squamous cell carcinoma

Abstract Although increasing evidence shows that miR-143 could act as a tumor suppressor in several cancers, little is known about the role of miR-143 in human esophageal squamous cell carcinoma (ESCC). In the present study, we found that the expression level of miR-143 is significantly reduced in clinical ESCC tissues compared with normal tissues and is correlated with lymph node metastasis (LNM), invasion and TNM stage groups. Kaplan-Meier analysis shows that miR-143 expression predicts a favorable outcome for ESCC patients. Functional experiments show that overexpression of miR-143 inhibits cell proliferation blocks the G1/S phase transition, and suppresses cell migration and invasion in vitro and in vivo. Dual luciferase assays reveal that STAT3 is a direct target gene of miR-143. Moreover, the restored expression of STAT3 protein in miR-143-overexpressing cells attenuated the suppressive effects of miR-143 on ESCC cells. Further studies verified that miR-143 repressed cell cycle and epithelial-mesenchymal transition (EMT) signaling pathways by targeting STAT3, resulting in suppressing ESCC cell proliferation, migration and invasion. We are the first to report the interaction between miR-143 and STAT3 in ESCC and in this study provide new insights into the role of miR-143 in the development of ESCC, and also implicate the potential application of miR-143 in cancer therapy.