miR-455-5p suppresses hepatocellular carcinoma cell growth and invasion via IGF-1R/AKT/GLUT1 pathway by targeting IGF-1R

Hepatocellular carcinoma (HCC) is among the most frequently observed forms of cancer. MicroRNAs (miRNAs) are increasingly thought to play a key role in regulating the onset and progression of a wide range of cancer types. In the present report, we found that miR-455-5p expression was significantly decreased in both HCC patient tumor tissues and cell lines, and that this reduction in expression was linked to poorer patient outcomes. When we overexpressed miR-455-5p in HCC cell lines (Huh7 and HepG2), this was linked with impaired proliferation, colony formation, migration, and invasion. We further found that this miRNA was able to directly bind the insulin growth factor receptor (IGF-1R) 3'-untranslated region, thereby suppressing IGF-1R expression in HCC cells. Consistent with this, miR-455-5p overexpression was associated with reduced glucose transporter (GLUT) 1 expression, which in turn inhibited HCC cell uptake of glucose, production of lactate, and generation of ATP. Together these results thus indicate that mIR-455-5p is able to suppress tumor functionality via impairing glycolysis in HCC cells, highlighting this miRNA as a potential target for anti-cancer therapeutic interventions.