Silencing of lncRNA MIR31HG promotes nasopharyngeal carcinoma cell proliferation and inhibits apoptosis through suppressing the PI3K/AKT signaling pathway

Background: MIR31HG has been affirmed to regulate the tumorigenesis of head-neck squamous cell carcinoma (HNSC). This study aims to reveal the function of MIR31HG in nasopharyngeal carcinoma (NPC), which falls into the category of HNSC.

Methods: MIR31HG expression pattern in HNSC tissues was predicted by starBase. FISH and qRT-PCR were employed to detect MIR31HG expression in NPC tissues and to analyze the association between MIR31HG and clinicopathological features. NPC cell viability, colony formation, and Apoptosis were measured by MTT assay, colony formation assay, and flow cytometry. The expressions of protein kinase B (Akt), phosphorylated (p)-AKT, phosphoinositide 3-kinases (PI3K) and p-PI3K in NPC cells were analyzed by Western blot. The correlation between MIR31HG expression and AKT1 mRNA expression was analyzed by The Cancer Genome Atlas and starBase.

Results: MIR31HG was highly expressed in HNSC tissues and NPC tissues. Meanwhile, the association between high MIR31HG expression and aggressive clinicopathological traits was significant in NPC patients at tumor stage III-IV (T3-T4) and in those with lymph node metastasis 1-2 (N1-N2). Silencing of MIR31HG suppressed NPC cell viability and colony formation, promoted Apoptosis, and decreased the expressions of p-PI3K, and p-AKT. 740Y-P reversed the above effects of si-MIR31HG on NPC cells. Besides, MIR31HG expression was positively correlated with AKT1 mRNA expression in HNSC patients.

Conclusion: MIR31HG silencing promotes NPC cell proliferation and inhibits Apoptosis through suppressing the PI3K/Akt signaling pathway.

MIR31HG; PI3K/AKT signaling pathway; apoptosis; nasopharyngeal carcinoma; proliferation.