Tumour suppressor role of microRNA-335-5p in esophageal squamous cell carcinoma by targeting TTK (Mps1).

BACKGROUND: Esophageal cancer is an aggressive malignancy. miR-335-5p is reported to possess both tumour suppressor and tumour promoter activities in different cancers. OBJECTIVES: We investigated the role of miR-335-5p in esophageal cancer by expression and functional studies. MATERIALS AND METHODS: The role of miR-335-5p in ESCC was evaluated using MTT assay, cell cycle analysis, colony formation assay, scratch assay, matrigel invasion, and migration assay. RESULTS: Our expression studies showed a significantly decreased expression of tissue and circulating miR-335-5p in esophageal cancer. Our results herein report a key tumour suppressive role of miR-335-5p in esophageal carcinogenesis by inhibiting proliferation, migration, and invasion in ESCC cells. Using RNA-seq and Insilico analysis we found TTK to be a newly identified direct target and confirmed it by using luciferase assay. CONCLUSION: Overall, our expression and functional analysis results demonstrated herein point towards the potential role of miR-335-5p in esophageal tumorigenesis. Moreover, this is the first report showing TTK as a downstream target of miR-335-5p.