title: Heat stress cognate 70 host protein as a potential drug target against drug resistance in hepatitis B virus.
abstract: Heat stress cognate 70 (Hsc70) is a host protein associated with hepatitis B virus (HBV) replication. The goal of this study was to investigate whether Hsc70 could be an anti-HBV drug target. Our results showed that introducing Hsc70 increased HBV replication in HBV(+) human hepatocytes (HepG2.2.15 cells). The coiled-coil region on Hsc70 (nucleotides 1533 to 1608; amino acids 511 to 536) was the key sequence for HBV replication. Knockdown of Hsc70 expression by RNA interference (RNAi) largely inhibited HBV replication with no cytotoxicity to the host. Using an Hsc70 mRNA screening assay, the natural compound oxymatrine (OMTR) was found to be a selective inhibitor for Hsc70 expression. Then, OMTR was used to investigate the potential of Hsc70 as an anti-HBV drug target. OMTR inhibited Hsc70 mRNA expression by 80% and HBV DNA replication by over 60% without causing cytotoxicity. The anti-HBV effect of OMTR appeared to be mediated by destabilizing Hsc70 mRNA. The half-life (T(1/2)) of Hsc70 mRNA decreased by 50% in OMTR-treated hepatocytes. The Hsc70 mRNA 3'-untranslated-region (UTR) sequence was the element responsible for OMTR's destabilization activity. OMTR suppressed HBV de novo synthesis at the reverse transcription stage from pregenomic RNA (pgRNA) to DNA and was active against either wild-type HBV or strains resistant to lamivudine, adefovir, and entecavir. Therefore, host Hsc70 could be a novel drug target against HBV, and OMTR appears to inhibit HBV replication by destabilizing Hsc70 mRNA. As the target is not a viral protein, OMTR is active for either wild-type HBV or strains resistant to reverse transcriptase (RT) inhibitors.
authors.affiliation: Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Yu-Ping
authors.initials: YP
authors.lastname: Wang
authors.forename: Fei
authors.initials: F
authors.lastname: Liu
authors.forename: Hong-Wei
authors.initials: HW
authors.lastname: He
authors.forename: Yan-Xin
authors.initials: YX
authors.lastname: Han
authors.forename: Zong-Gen
authors.initials: ZG
authors.lastname: Peng
authors.forename: Bao-Wei
authors.initials: BW
authors.lastname: Li
authors.forename: Xue-Fu
authors.initials: XF
authors.lastname: You
authors.forename: Dan-Qing
authors.initials: DQ
authors.lastname: Song
authors.forename: Zhuo-Rong
authors.initials: ZR
authors.lastname: Li
authors.forename: Li-Yan
authors.initials: LY
authors.lastname: Yu
authors.forename: Shan
authors.initials: S
authors.lastname: Cen
authors.forename: Bin
authors.initials: B
authors.lastname: Hong
authors.forename: Chen-Heng
authors.initials: CH
authors.lastname: Sun
authors.forename: Li-Xun
authors.initials: LX
authors.lastname: Zhao
authors.forename: Barry
authors.initials: B
authors.lastname: Kreiswirth
authors.forename: David
authors.initials: D
authors.lastname: Perlin
authors.forename: Rong-Guang
authors.initials: RG
authors.lastname: Shao
authors.forename: Jian-Dong
authors.initials: JD
authors.lastname: Jiang
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D000470:Alkaloids / Q000494:pharmacology*; D000998:Antiviral Agents / Q000494:pharmacology*; D015536:Down-Regulation / Q000187:drug effects; D015195:Drug Design; D024882:Drug Resistance, Viral / Q000502:physiology; D050883:HSC70 Heat-Shock Proteins / Q000235:genetics* / Q000378:metabolism; D006509:Hepatitis B / Q000188:drug therapy* / Q000821:virology; D006515:Hepatitis B virus / Q000187:drug effects* / Q000235:genetics; D022781:Hepatocytes / Q000166:cytology / Q000821:virology; D006801:Humans; D066298:In Vitro Techniques; D011807:Quinolizines / Q000494:pharmacology*; D034741:RNA, Small Interfering; D014779:Virus Replication / Q000187:drug effects / Q000502:physiology; D000093842:Matrines
chemical_list: D020413:3' Untranslated Regions; D000470:Alkaloids; D000998:Antiviral Agents; D050883:HSC70 Heat-Shock Proteins; D011807:Quinolizines; D034741:RNA, Small Interfering; C494371:HSPA8 protein, human; C037573:oxymatrine; D000093842:Matrines