USP14 de-ubiquitinates vimentin and miR-320a modulates USP14 and vimentin to contribute to malignancy in gastric cancer cells

// Ying Zhu 1, * , Yan Zhang 1, * , Zhenhua Sui 1 , Yi Zhang 1 , Min Liu 1 and Hua Tang 1 1 Tianjin Life Science Research Center, Department of Pathogen Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, 300070, China * These authors contributed equally to this work Correspondence to: Hua Tang, email: htang2002@yahoo.com , tangh@tijmu.edu.cn Keywords: vimentin, USP14, miR-320a, gastric cancer Received: January 27, 2016 Accepted: June 01, 2016 Published: July 19, 2016 ABSTRACT Vimentin plays important roles in the epithelial-to-mesenchymal transition (EMT). In this study, we found that vimentin was highly expressed in human gastric cancer (GC) tissues and cell lines and significantly promoted cell growth, migration and invasion. Ubiquitin-specific protease 14 (USP14) interacted with the vimentin protein, which led to its de-ubiquitination. miR-320a was found to bind to the 3′UTR of both vimentin and USP14 transcripts and downregulate the expression of both proteins. The downregulation of miR-320a upregulates vimentin expression by directly binding to the 3′UTR of vimentin to derepress expression and indirectly by augmenting USP14 to increase vimentin stability in GC cells. Taken together, these results provide new insight into malignancy in gastric cancers.