The androgen receptor (AR) was found to suppress hepatocellular carcinoma (HCC) metastasis at late stages. Due to this discovery, we searched for some AR enhancers to increase the efficacy of Sorafenib chemotherapy, and identified the microRNA (miR)-367-3p, whose expression is positively correlated with AR expression in advanced HCC, as an HCC metastasis suppressor. Combining miR-367-3p with Sorafenib showed better efficacy to suppress HCC cell invasion in vitro and in vivo. Mechanism dissection revealed that miR-367-3p could increase AR expression via directly targeting the 3'UTR of MDM2 to decrease MDM2 protein expression. The resultant increase of AR expression might then promote the expression of FKBP5 and PHLPP, thus dephosphorylating and inactivating AKT and ERK, to suppress the HCC cell invasion. Interestingly, the suppression of pAKT by miR-367-3p could subsequently attenuate the phosphorylation of AR and MDM2, giving rise to additional enhancement of AR protein expression, effectively forming a positive feedback loop. Together, these results suggest that miR-367-3p may function as an AR enhancer to increase Sorafenib chemotherapy efficacy via altering the MDM2/AR/FKBP5/PHLPP/(pAKT and pERK) signals to better suppress HCC metastasis. Successful development of this newly combined chemotherapy in the future may help us to better suppress the HCC metastasis at late stages.
Keywords: Androgen receptor; Hepatocellular carcinoma; Metastasis; miR-367-3p.
Copyright © 2016. Published by Elsevier B.V.