Upregulated Long Non-coding RNA Lnc-MRPL39-2:1 Induces the Growth and Invasion of Nasopharyngeal Carcinoma by Binding to HuR and Stabilizing β-Catenin mRNA

Long non-coding RNAs (lncRNAs) have been to regulate tumor progression and therapy resistance through various molecular mechanisms. In this study, we investigated the role of lncRNAs in nasopharyngeal carcinoma (NPC) and the underlying mechanism. Using lncRNA arrays to analyze the lncRNA profiles of the NPC and para-tumor tissues, we detected the novel lnc-MRPL39-2:1, which was validated by in situ hybridization and by the 5' and 3' rapid amplification of the cDNA ends. Further, its role in NPC cell growth and metastasis was verified in vitro and in vivo. The researchers conducted the RNA pull-down assays, mass spectrometry (MS), dual-luciferase reporter assays, RNA immunoprecipitation (RIP) assays, and the MS2-RIP assays were then used to identify the lnc-MRPL39-2:1-interacting proteins and miRNAs. We found that lnc-MRPL39-2:1, which was highly expressed in in NPC tissues, was related to a poor prognosis in NPC patients. Furthermore, lnc-MRPL39-2:1 was shown to induce the growth and invasion of NPC by interacting directly with the Hu-antigen R (HuR) to upregulate β-catenin expression both in vivo and in vitro. Lnc-MRPL39-2:1 expression was also suppressed by microRNA (miR)-329. Thus, these findings indicate that lnc-MRPL39-2:1 is essential in NPC tumorigenesis and metastasis and highlight its potential as a prognostic marker and therapeutic target for NPC.