Downregulation of miR-196-5p Induced by Hypoxia Drives Tumorigenesis and Metastasis in Hepatocellular Carcinoma.

Abstract

In hepatocellular carcinoma (HCC), the hypoxic tumor microenvironment can drive enhance tumor malignancy and recurrence. The microRNA (miRNA) miR-196-5p has been shown to modulate the progression of several cancer types, but its roles in HCC remain uncertain. In the present report we observed significant miR-196-5p downregulation in HCC tissues and cells, and we found that the expression of this miRNA significantly impaired the proliferation and metastatic potential of HCC in vitro and in vivo. We identified high-mobility group AT-hook 2 (HMGA2) as a miR-196-5p target gene that was associated with the ability of miR-196-5p to modulate the progression of HCC. Expression of miR-196-5p and HMGA2 were correlated with the clinical characteristics and poor outcomes in patients with HCC. Finally, we found that hypoxic conditions were linked with reduced miR-196-5p expression in the context of HCC. Together these results highlight the role for miR-196-5p as an inhibitor of the proliferation and metastasis of HCC via the targeting of HMGA2, with this novel hypoxia/miR-196-5p/HMGA2 pathway serving as a potential target for future therapeutic intervention.