miR-4458, a new tumor-suppressor, was reported to down-regulated in human hepatocellular carcinoma. The expression status, roles and inhibitory mechanisms of miR-4458 in other tumors still need to be clarified. The aim of this study is to investigate the effects of miR-4458 and to elucidate the potential mechanism in colon cancer cells. Using bioinformatic databases, we predicted that hexokinase2 (HK2), a rate-limiting enzyme in the glycolytic pathway, was a target of miR-4458, so the effects of miR-4458 on glycolysis and lactate production was assessed in colon cancer cells. We found that miR-4458 was down regulated and HK2 was up-regulated in colon cancer cells. Overexpression of miR-4458 inhibited proliferation, glycolysis, and lactate production under both normoxic and hypoxic conditions. Luciferase activity assays showed that HK2 was a direct target of miR-4458. Moreover, knockdown of HK2 by specific RNAi also suppressed proliferation, glycolysis, and lactate production under both normoxic and hypoxic conditions. In conclusion, our findings suggested that miR-4458 inhibited the progression of colon cancer cells by inhibition of glycolysis and lactate production via directly targeting HK2 mRNA. (C) 2015 Elsevier Inc. All rights reserved.