Background: Many microRNAs (miRNAs) are involved in the progression of nasopharyngeal carcinoma (NPC). This study aimed to examine the expression and clinical significance of microRNA (miR)-362-3p in NPC, especially in Epstein–Barr virus (EBV)-positive patients, and explore its potential mechanism in NPC progression.
Methods: miR-362-3p levels and Jumonji C domain 2A (JMJD2A) mRNA levels were detected by quantitative real-time PCR. The diagnostic value of miR-362-3p to distinguish NPC patients and EBV-positive cases was evaluated using receiver operating characteristic analysis. The association of miR-362-3p with NPC survival was assessed by Kaplan–Meier curves and Cox regression analysis. NPC cell proliferation, migration and invasion were determined using Cell Counting Kit-8 and Transwell assays, respectively. A luciferase reporter assay was used to confirm the interaction between miR-362-3p and JMJD2A.
Results: miR-362-3p expression was decreased in the serum and tissues of NPC patients and had diagnostic value for screening NPC. According to the survival follow-up, NPC survivors had significantly higher miR-362-3p, and miR-326-3p was demonstrated as an independent prognostic indicator of NPC. Interestingly, it is found that EBV-positive NPC patients and cells had significantly lower miR-362-3p compared with EBV-negative NPC patients and cells and had certain ability to distinguish EBV-positive patients. Moreover, miR-362-3p inhibited the proliferation, migration and invasion of both EBV-positive and -negative NPC cells, and these effects might be mediated by targeting JMJD2A.
Conclusion: Abnormal miR-362-3p expression is related to EBV-infection and prognosis in NPC patients and may be involved in NPC progression by targeting JMJD2A.
Keywords: microRNAs, Epstein–Barr virus, prognosis, nasopharyngeal carcinoma, tumor progression, diagnosis