Long noncoding RNA DRAIC acts as a microRNA-122 sponge to facilitate nasopharyngeal carcinoma cell proliferation, migration and invasion via regulating SATB1

Abstract

Increasing evidences have revealed that long noncoding RNAs (lncRNAs) are frequently involved in various cancers. However, the expression and function of lncRNA DRAIC in nasopharyngeal carcinoma (NPC) remain unknown. In this study, we found that DRAIC was significantly increased in NPC tissues. Increased expression of DRAIC was positively correlated with advanced clinical stages of NPC patients. Functional assays revealed that ectopic expression of DRAIC enhances NPC cell growth, migration and invasion. DRAIC knockdown represses NPC cell growth, migration and invasion. Mechanistically, we identified two miR-122 binding sites on DRAIC. RNA pull-down, RNA immunoprecipitation, and dual-luciferase reporter assays confirmed the binding of DRAIC to miR-122. Via binding of miR-122, DRAIC upregulated the expression of miR-122 target SATB1, which was abolished by the mutation of miR-122 binding sites on SATB1. Moreover, the oncogenic roles of DRAIC on NPC were reversed by the mutation of miR-122 binding sites on SATB1, simultaneous overexpression of miR-122, or depletion of SATB1. In addition, the expression of SATB1 was also increased and positively associated with that of DRAIC in NPC tissues. In conclusion, these findings revealed the important roles of DRAIC-miR-122-SATB1 axis in NPC and suggested that DRAIC may be a potential therapeutic target for NPC.

Keywords

• Long noncoding RNA
• microRNA
• competing endogenous RNA
• nasopharyngeal carcinoma
• oncogene
• SATB1