MiR-125a suppresses viability and glycolysis and induces apoptosis by targeting Hexokinase 2 in laryngeal squamous cell carcinoma

Zhanwei Sun,Wenqi Zhang,Qian Li

doi:10.1186/s13578-017-0178-y

Abstract

BackgroundmiR-125a usually functions as a tumor suppressor in cancers. However, the role of miR-125a in laryngeal squamous cell carcinoma (LSCC) has not been determined.MethodsqRT-PCR was applied to measure the expression of miR-125a and HK2 mRNA in LSCC tissues and cells. CCK-8 kit and flow cytometry analysis were performed to detect cell viability and apoptosis. Luciferase reporter assay and RNA immunoprecipitation (RIP) were conducted to confirm the relationship between miR-125a and HK2. Commercial test kits were used to determine the concentrations of glucose and l-lactate. Xenograft in mice was constructed to validate the function and mechanism of miR-125a in LSCC tumor growth.ResultsA negative correlation was found between miR-125a expression and the level of Hexokinase 2 (HK2) mRNA in LSCC tissues. Functional experiments found that miR-125a inhibited viability and glycolysis and induced apoptosis in LSCC cells. Similarly, HK2 downregulation led to viability and glycolysis inhibition and induction of apoptosis in LSCC cells in vitro. Moreover, miR-125a overexpression suppressed LSCC xenograft growth in vivo. Mechanically, HK2 was verified to be a target of miR-125a by luciferase reporter assays and RNA immunoprecipitation (RIP) assays. Furthermore, restored HK2 expression reversed miR-125a-mediated proliferation and glycolysis inhibition and induction of apoptosis in LSCC cells.ConclusionsmiR-125a suppressed LSCC progression by targeting HK2 in vitro and in vivo, suggesting that miR-125a may be a potential molecular target for LSCC treatment.

Highlights

MiR-125a usually functions as a tumor suppressor in cancers
Results miR‐125a expression is negatively correlated with the level of HK in laryngeal squamous cell carcinoma (LSCC) tissues To detect the expression level of miR-125a and Hexokinase 2 (HK2) mRNA in LSCC tissues, total RNA of LSCC tissues form 23 patients (11 Stage 1, 2 and 12 Stage 3, 4) was extracted and reverse-transcripted into cDNA, qRT-PCR analysis was performed. qRT-PCR analysis revealed that miR125a expression was high in early-stage patients (Stage 1, 2) and low in late-stage patients (Stage 3, 4) (Fig. 1a)
All these results suggested that low-expressed miR-125a and elevated HK2 may be involved in LSCC pathogenesis

Summary

Introduction

MiR-125a usually functions as a tumor suppressor in cancers. the role of miR-125a in laryngeal squamous cell carcinoma (LSCC) has not been determined. Xu et al demonstrated that miR-106b could increase the proliferation and invasion of laryngeal carcinoma cells through targeting RUNX3, a critical tumor suppressor in many human cancer types [7]. MiR-24, functioning as a tumor suppressor in LSCC, could significantly suppress cell proliferation and invasion ability of Hep cells via downregulation of S100A8 [8]. MiR-203 was downregulated in the LSCC tissues, and restored miR-203 expression suppressed cellular proliferation, invasion and induced apoptosis, G1 phase cell cycle arrest of Hep-2 cells through targeting ASAP1 [9]. All these studies demonstrate that miRNAs play significant roles in LSCC. The function and molecular mechanisms of miR-125a in LSCC progression control have not been determined

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