MiR-125b-5p suppressed the glycolysis of laryngeal squamous cell carcinoma by down-regulating hexokinase-2

Laryngeal squamous cell carcinoma (LSCC) is the most common form of laryngeal carcinoma with poor prognosis. Exploring novel factors involved in the progression of LSCC is quite necessary for understanding the mechanisms and designing therapeutic strategies for LSCC. In this study, we showed that miR-125b-5p was significantly down-regulated in LSCC tissues and cell lines. The decreased expression of miR-125b-5p was associated with the tumor differentiation, metastasis and high clinical stage of the LSCC patients. Overexpression of miR-125b-5p suppressed the proliferation and induced apoptosis of LSCC cells. Bioinformatics analysis predicted hexokinase-2 (HK2), an essential enzyme involved in the glycolysis of cancer cells, as one of the downstream targets of miR-125b-5p. Further molecular studies showed that highly expressed miR-125b-5p bound the 3'-UTR of HK2 and decreased both the mRNA and protein levels of HK2. Consistent with the function of HK2 in glycolytic metabolism, overexpression of miR-125b-5p significantly suppressed the glucose consumption and lactate production of LSCC cells. Notably, restoration the expression of HK2 attenuated the inhibitory effect of miR-125b-5p on the glycolysis of LSCC cells. The inverse correlation between the expression of miR-125b-5p and HK2 in LSCC tissues further supported the involvement of miR-125b-5p-HK2 axis in the progression of LSCC. Collectively, these finding suggested the miR-125b-5p-HK2 pathway as a novel mechanism in regulating the glycolysis and progression of LSCC.