Overexpression of lncRNA TINCR is associated with high-grade, invasive, and recurring tumors, and facilitates proliferation in vitro and in vivo of urothelial carcinoma of the bladder

Objectives: The aberrant expression of long noncoding RNAs (lncRNAs) plays roles in cancer development. In this work, we measured the expression of lncRNA terminal differentiation-induced non-coding RNA (TINCR) in urothelial carcinoma of the bladder (UCB), determined its impact on the proliferation of UCB in vitro and in vivo and identified its possible targets. Methods: The expression levels of genes were measured by Real-Time quantitative Polymerase Chain Reaction (qPCR). Cell proliferation, cell motility, and cell apoptosis were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, wound healing assay, and ELISA, respectively. Tumor growth in vivo was determined by xenograft formation assay in nude mice. The predicted binding site between TINCR and hsa-miR-125b was confirmed by dual luciferase reporter assay. Results: The expression levels of TINCR were higher in cancerous tissues than that in paired noncancerous tissues of UCB. Higher expression levels of TINCR were positively associated with high-grade, invasive, and recurring tumors. Depletion of TINCR retarded proliferation, decreased motility, increased apoptosis in UCB cells, and markedly reduced tumor growth in xenograft nude mice. The predicted binding site between TINCR and hsa-miR-125b was functional. TINCR downregulated hsa-miR-125b in UCB cells. Hsa-miR-125b mimic reversed the proliferation caused by TINCR up-expression in UCB cells. Conclusions: Up-regulation of TINCR may act as an unfavorable indicator for the diseasing status of UCB. TINCR facilitates bladder cancer proliferation in vitro and in vivo. Hsa-miR-125b is a target for TINCR in UCB. (C) 2019 Published by Elsevier Inc.