Long Non-coding RNA TUSC7, a Target of miR-23b, Plays Tumor-Suppressing Roles in Human Gliomas

Abstract

<i>Tumour suppressor candidate 7</i> (<i>TUSC7</i>) is a novel tumor suppressor gene generating long non-coding RNA (lncRNAs) in several types of human cancers. The expression and function of <i>TUSC7</i> in human brain glioma has yet to be elucidated. In this study, <i>TUSC7</i> was poorly expressed in tissues and cell lines of glioma, and the lower expression was correlated with glioma of the worse histological grade. Moreover, TUSC7 is a prognostic biomarker of glioma patients. Up-regulation of <i>TUSC7</i> suppressed cellular proliferation and invasion of glioma cells, and accelerated cellular apoptosis. Bioinformatics analysis showed that TUSC7 specifically binds to miR-23b. MiR-23b was up-regulated in glioma and negatively correlated with the expression of TUSC7. The miR-23b expression was inhibited remarkably by the upregulation of TUSC7 and the reciprocal inhibition was determined between TUSC7 and miR-23b.RNA pull-down and luciferase reporter assays were used to validate the sequence-specific correlation between miR-23b and TUSC7. TUSC7 inhibited the proliferation, migration and invasion of glioma cells and promoted cellular apoptosis largely bypassing miR-23b. We conclude that the lncRNA TUSC7 acted as a tumor suppressor gene negatively regulated by miR-23b, suggesting a novel therapeutic strategy against gliomas.