MiR-296-5p inhibits cell invasion and migration of esophageal squamous cell carcinoma by downregulating STAT3 signaling

Objective: Many studies have emphasized the function of microRNA-296 (miR-296) that inhibits tumor formation. To some extent, the role of miR-296 in esophageal squamous cell carcinoma (ESCC) remains misleading. Therefore, the current research was designed to investigate the regulatory mechanisms of miR-296 and signal transducer and activator of transcription 3 (STAT3) in ESCC.

Patients and methods: The mRNA expression of miR-296-5p and STAT3 in ESCC tissues or cell lines was measured via quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The protein level of STAT3 was measured by Western blotting assay. The Luciferase reporter assay was used to verify the binding sites between miR-296-5p and STAT3. The transwell assay was employed to identify cell migration and invasion.

Results: Down-regulation of miR-296-5p was detected in ESCC tissues and cell lines (p<0.01). Additionally, miR-296-5p was found to target STAT3 directly. Functionally, up-regulation of miR-296-5p or down-regulation of STAT3 significantly inhibited cell migration and invasion in ESCC.

Conclusions: MiR-296-5p inhibited cell invasion and migration in ESCC by downregulating STAT3. The overexpression of miR-296-5p by targeting STAT3 suppressed tumorigenesis of ESCC cells.