Lan SH, Wu SY, Zuchini R, Lin XZ, Su IJ, Tsai TF, Lin YJ, Wu CT, Liu HS. Autophagy suppresses tumorigenesis of hepatitis B virus-associated hepatocellular carcinoma through degradation of microRNA-224.
Hepatology 2014;
59:505-17. [PMID:
23913306 PMCID:
PMC4298796 DOI:
10.1002/hep.26659]
[Citation(s) in RCA: 160] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 07/24/2013] [Indexed: 12/12/2022]
Abstract
UNLABELLED
In hepatocellular carcinoma (HCC), dysregulated expression of microRNA-224 (miR-224) and impaired autophagy have been reported separately. However, the relationship between them has not been explored. In this study we determined that autophagy is down-regulated and inversely correlated with miR-224 expression in hepatitis B virus (HBV)-associated HCC patient specimens. These results were confirmed in liver tumors of HBV X gene transgenic mice. Furthermore, miR-224 was preferentially recruited and degraded during autophagic progression demonstrated by real-time polymerase chain reaction and miRNA in situ hybridization electron microscopy after extraction of autophagosomes. Our in vitro study demonstrated that miR-224 played an oncogenic role in hepatoma cell migration and tumor formation through silencing its target gene Smad4. In HCC patients, the expression of low-Atg5, high-miR-224, and low-Smad4 showed significant correlation with HBV infection and a poor overall survival rate. Autophagy-mediated miR-224 degradation and liver tumor suppression were further confirmed by the autophagy inducer amiodarone and miR-224 antagonist using an orthotopic SD rat model.
CONCLUSION
A noncanonical pathway links autophagy, miR-224, Smad4, and HBV-associated HCC. These findings open a new avenue for the treatment of HCC.
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