Restoration of RNA helicase DDX5 suppresses hepatitis B virus (HBV) biosynthesis and Wnt signaling in HBV-related hepatocellular carcinoma.

Abstract

Rationale: RNA helicase DDX5 is downregulated during hepatitis B virus (HBV) replication, and poor prognosis HBV-related hepatocellular carcinoma (HCC). The aim of this study is to determine the mechanism and significance of DDX5 downregulation for HBV-driven HCC, and identify biologics to prevent DDX5 downregulation. Methods: Molecular approaches including immunoblotting, qRT-PCR, luciferase transfections, hepatosphere assays, Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq), and RNA-seq were used with cellular models of HBV replication, HBV infection, and HBV-related liver tumors, as well as bioinformatic analyses of liver cancer cells from two independent cohorts. Results: We demonstrate that HBV infection induces expression of the proto-oncogenic miR17~92 and miR106b~25 clusters which target the downregulation of DDX5. Increased expression of these miRNAs is also detected in HBV-driven HCCs exhibiting reduced DDX5 mRNA. Stable DDX5 knockdown (DDX5KD) in HBV replicating hepatocytes increased viral replication, and resulted in hepatosphere formation, drug resistance, Wnt activation, and pluripotency gene expression. ATAC-seq of DDX5KD compared to DDX5 wild-type (WT) cells identified accessible chromatin regions enriched in regulation of Wnt signaling genes. RNA-seq analysis comparing WT versus DDX5KD cells identified enhanced expression of multiple genes involved in Wnt pathway. Additionally, expression of Disheveled, DVL1, a key regulator of Wnt pathway activation, was significantly higher in liver cancer cells with low DDX5 expression, from two independent cohorts. Importantly, inhibitors (antagomirs) to miR17~92 and miR106b~25 restored DDX5 levels, reduced DVL1 expression, and suppressed both Wnt activation and viral replication. Conclusion: DDX5 is a negative regulator of Wnt signaling and hepatocyte reprogramming in HCCs. Restoration of DDX5 levels by miR17~92 / miR106b~25 antagomirs in HBV-infected patients can be explored as both antitumor and antiviral strategy.

• Authors: Saravana Kumar Kailasam Mani, Bingyu Yan, Zhibin Cui, Jiazeng Sun, Sagar Utturkar, Adrien Foca, Nadim Fares, David Durantel, Nadia Lanman, Philippe Merle, Majid Kazemian, Ourania Andrisani
• Journal: Theranostics (Theranostics) Vol. 10 Issue 24 Pg. 10957-10972 ( 2020) ISSN: 1838-7640 [Electronic] Australia
• PMID: 33042264 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: © The author(s).

Chemical References

• Antagomirs
• MIR17HG, human
• MIRN106 microRNA, human
• MicroRNAs
• RNA, Long Noncoding
• Ddx5 protein, human
• DEAD-box RNA Helicases

Topics

• Antagomirs (pharmacology, therapeutic use)
• Carcinoma, Hepatocellular (drug therapy, genetics, pathology, virology)
• Cell Line, Tumor
• DEAD-box RNA Helicases (genetics, metabolism)
• Down-Regulation
• Gene Expression Regulation, Neoplastic (drug effects)
• Gene Knockdown Techniques
• Hepatitis B virus (drug effects, physiology)
• Hepatitis B, Chronic (drug therapy, genetics, pathology, virology)
• Hepatocytes
• Humans
• Liver (pathology, virology)
• Liver Neoplasms (drug therapy, genetics, pathology, virology)
• MicroRNAs (antagonists & inhibitors, metabolism)
• RNA, Long Noncoding (antagonists & inhibitors, metabolism)
• RNA-Seq
• Virus Replication (drug effects, genetics)
• Wnt Signaling Pathway (drug effects, genetics)