In Vitro Activity of 2,4-Diamino-6-[2-(Phosphonomethoxy)Ethoxy]-Pyrimidine against Multidrug-Resistant Hepatitis B Virus Mutants

ABSTRACT The susceptibilities of drug-resistant hepatitis B virus (HBV) mutants to lamivudine, adefovir, tenofovir, entecavir, and 2,4-diamino-6-[2-(phosphonomethoxy)ethoxy]-pyrimidine (PMEO-DAPym), a novel acyclic pyrimidine analogue, were assessed in vitro. Most drug-resistant mutants, including multidrug-resistant strains, remained sensitive to tenofovir and PMEO-DAPym. Therefore, the latter molecule deserves further evaluation for the treatment of HBV infection.

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Sensitivity of drug-resistant mutants of hepatitis B virus to poly-IC

Acta Virologica ◽

10.4149/av_2014_04_348 ◽

2014 ◽

Vol 58 (04) ◽

pp. 348-355

Author(s):

Q. ZHOU ◽

E. CHEN ◽

L. CHEN ◽

Y. NONG ◽

X. CHENG ◽

...

Keyword(s):

Hepatitis B Virus ◽

Hepatitis B ◽

Drug Resistant ◽

B Virus ◽

Resistant Mutants

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In Vitro Characterization of the Anti-Hepatitis B Virus Activity and Cross-Resistance Profile of 2′,3′-Dideoxy-3′-Fluoroguanosine

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.50.3.955-961.2006 ◽

2006 ◽

Vol 50 (3) ◽

pp. 955-961 ◽

Cited By ~ 22

Author(s):

A.-C. Jacquard ◽

M.-N. Brunelle ◽

C. Pichoud ◽

D. Durantel ◽

S. Carrouée-Durantel ◽

...

Keyword(s):

Hepatitis B Virus ◽

Hepatitis B ◽

Antiviral Activity ◽

Drug Resistant ◽

Free System ◽

Hbv Replication ◽

Duck Hepatitis ◽

Huh7 Cells ◽

B Virus

ABSTRACT The fluorinated guanosine analog 2′,3′-dideoxy-3′-fluoroguanosine (FLG) was shown to inhibit wild-type (wt) hepatitis B virus (HBV) replication in a human hepatoma cell line permanently expressing HBV. Experiments performed in the duck model of HBV infection also showed its in vivo antiviral activity. In this study, we investigated the mechanism of inhibition of FLG on HBV replication and its profile of antiviral activity against different HBV or duck hepatitis B virus (DHBV) drug-resistant mutants. We found that FLG-triphosphate inhibits weakly the priming of the reverse transcription compared to adefovir-diphosphate in a cell-free system assay allowing the expression of an enzymatically active DHBV reverse transcriptase. It inhibits more potently wt DHBV minus-strand DNA synthesis compared to lamivudine-triphosphate and shows a similar activity compared to adefovir-diphosphate. FLG-triphosphate was most likely a competitive inhibitor of dGTP incorporation and a DNA chain terminator. In Huh7 cells transiently transfected with different HBV constructs, FLG inhibited similarly the replication of wt, lamivudine-resistant, adefovir-resistant, and lamivudine-plus-adefovir-resistant HBV mutants. These results were consistent with those obtained in the DHBV polymerase assay using the same drug-resistant polymerase mutants. In conclusion, our data provide new insights in the mechanism of action of FLG-triphosphate on HBV replication and demonstrate its inhibitory activity on drug-resistant mutant reverse transcriptases in vitro. Furthermore, our results provide the rationale for further clinical evaluation of FLG in the treatment of drug-resistant virus infection and in the setting of combination therapy to prevent or delay drug resistance.

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Identification of Drug Resistant Mutants of HBV (Hepatitis B Virus) by Direct Sequencing in Iranian Patients Treated with Lamivudine

Iranian Journal of Virology ◽

10.21859/isv.5.4.17 ◽

2011 ◽

Vol 5 (4) ◽

pp. 17-20

Author(s):

E Fakhari ◽

M Norouzi ◽

SM Jazayeri ◽

◽

...

Keyword(s):

Hepatitis B Virus ◽

Hepatitis B ◽

Direct Sequencing ◽

Drug Resistant ◽

B Virus ◽

Resistant Mutants ◽

Iranian Patients

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Intracellular Metabolism and In Vitro Activity of Tenofovir against Hepatitis B Virus

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00138-06 ◽

2006 ◽

Vol 50 (7) ◽

pp. 2471-2477 ◽

Cited By ~ 161

Author(s):

William E. Delaney ◽

Adrian S. Ray ◽

Huiling Yang ◽

Xiaoping Qi ◽

Shelly Xiong ◽

...

Keyword(s):

Chronic Hepatitis ◽

Hepatitis B Virus ◽

Hepatitis B ◽

Chronic Hepatitis B ◽

Vitro Activity ◽

Single Mutation ◽

In Vitro Activity ◽

B Virus ◽

Tenofovir Df

ABSTRACT Tenofovir is an acyclic nucleotide analog with activity against human immunodeficiency virus (HIV) and hepatitis B virus (HBV). Tenofovir disoproxil fumarate (tenofovir DF), a bis-alkoxyester prodrug of tenofovir, is approved for the treatment of HIV and is currently being developed to treat chronic hepatitis B. In this report, we further characterize the in vitro activity of tenofovir against HBV as well as its metabolism in hepatic cells. We show that tenofovir is efficiently phosphorylated to tenofovir diphosphate (TFV-DP) in both HepG2 cells and primary human hepatocytes. TFV-DP has a long intracellular half-life (95 h) and is a potent and competitive inhibitor of HBV polymerase (Ki = 0.18 μM). Tenofovir has a 50% effective concentration of 1.1 μM against HBV in cell-based assays, and potency is improved >50-fold by the addition of bis-isoproxil progroups. Tenofovir has previously demonstrated full activity against lamivudine-resistant HBV in vitro and clinically. Here we show that the major adefovir resistance mutation, rtN236T, confers three- to fourfold-reduced susceptibility to tenofovir in cell culture; the clinical significance of this susceptibility shift has not yet been determined. The rtA194T HBV polymerase mutation recently identified in tenofovir DF-treated HIV/HBV-coinfected patients did not confer in vitro resistance to tenofovir as a single mutation or in a lamivudine-resistant viral background. Overall, the antiviral and metabolic profile of tenofovir supports its development for the treatment of chronic hepatitis B.

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Phenylpropenamide Derivatives AT-61 and AT-130 Inhibit Replication of Wild-Type and Lamivudine-Resistant Strains of Hepatitis B Virus In Vitro

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.46.9.3057-3060.2002 ◽

2002 ◽

Vol 46 (9) ◽

pp. 3057-3060 ◽

Cited By ~ 108

Author(s):

William E. Delaney ◽

Ros Edwards ◽

Danni Colledge ◽

Tim Shaw ◽

Phil Furman ◽

...

Keyword(s):

Hepatitis B Virus ◽

Hepatitis B ◽

Nucleoside Analogue ◽

Wild Type ◽

Hbv Replication ◽

B Virus ◽

Resistant Strains

ABSTRACT The phenylpropenamide derivatives AT-61 and AT-130 are nonnucleoside analogue inhibitors of hepatitis B virus (HBV) replication. They inhibited the replication of wild-type HBV with 50% inhibitory concentrations of 21.2 ± 9.5 and 2.40 ± 0.92 μM, respectively, compared to 0.064 ± 0.020 μM lamivudine. There were no significant differences in sensitivity between wild-type and nucleoside analogue-resistant (rtL180M, rtM204I, and rtL180M + rtM204V) HBV.

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In vitro activity of cepharanthine hydrochloride against clinical wild-type and lamivudine-resistant hepatitis B virus isolates

European Journal of Pharmacology ◽

10.1016/j.ejphar.2012.02.030 ◽

2012 ◽

Vol 683 (1-3) ◽

pp. 10-15 ◽

Cited By ~ 34

Author(s):

Yu-Bing Zhou ◽

Ya-Feng Wang ◽

Yan Zhang ◽

Li-Yun Zheng ◽

Xiao-Ang Yang ◽

...

Keyword(s):

Hepatitis B Virus ◽

Hepatitis B ◽

Vitro Activity ◽

In Vitro Activity ◽

Wild Type ◽

B Virus ◽

Virus Isolates

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Basal Core Promoter and Precore Mutations in the Hepatitis B Virus Genome Enhance Replication Efficacy of Lamivudine-Resistant Mutants

Journal of Virology ◽

10.1128/jvi.78.16.8524-8535.2004 ◽

2004 ◽

Vol 78 (16) ◽

pp. 8524-8535 ◽

Cited By ~ 80

Author(s):

Frank Tacke ◽

Christina Gehrke ◽

Tom Luedde ◽

Albert Heim ◽

Michael P. Manns ◽

...

Keyword(s):

Chronic Hepatitis ◽

Hepatitis B Virus ◽

Hepatitis B ◽

Virus Replication ◽

Drug Sensitivity ◽

Core Promoter ◽

Basal Core Promoter ◽

B Virus ◽

Resistant Mutants

ABSTRACT During chronic hepatitis B virus (HBV) infection, mutations in the precore (PC) or basal core promoter (BCP) region affecting HBV e antigen (HBeAg) expression occur commonly and represent the predominant virus species in patients with HBeAg-negative chronic hepatitis B. The PC mutation (G1896A+C1858T) creates a translational stop codon resulting in absent HBeAg expression, whereas BCP mutations (A1762T/G1764A) reduce HBeAg expression by transcriptional mechanisms. Treatment of chronic HBV infection with lamivudine (LMV) often selects drug-resistant strains with single (rtM204I) or double (rtL180M+rtM204V) point mutations in the YMDD motif of HBV reverse transcriptase. We cloned replication-competent HBV vectors (genotype A, adw2) combining mutations in the core (wild type [wt], PC, and BCP) and polymerase gene (wt, rtM204I, and rtL180M/M204V) and analyzed virus replication and drug sensitivity in vitro. Resistance to LMV (rtM204I/rtL180M+rtM204V) was accompanied by a reduced replication efficacy as evidenced by reduced pregenomic RNA, encapsidated progeny DNA, polymerase activity, and virion release. PC mutations alone did not alter virus replication but restored replication efficacy of the LMV-resistant mutants without affecting drug resistance. BCP mutants had higher replication capacities than did the wt, also in combination with LMV resistance mutations. All nine HBV constructs showed similar sensitivities to adefovir. In conclusion, BCP-PC mutations directly impact the replication capacity of LMV-resistant mutants. PC mutations compensated for replication inefficiency of LMV-resistant mutants, whereas BCP mutations increased viral replication levels to above the wt baseline values, even in LMV-resistant mutants, without affecting drug sensitivity in vitro. Adefovir may be an effective treatment when combinations of core and polymerase mutations occur.

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Identification and Characterization of Clevudine-Resistant Mutants of Hepatitis B Virus Isolated from Chronic Hepatitis B Patients

Journal of Virology ◽

10.1128/jvi.02066-09 ◽

2010 ◽

Vol 84 (9) ◽

pp. 4494-4503 ◽

Cited By ~ 28

Author(s):

So Young Kwon ◽

Yong Kwang Park ◽

Sung Hyun Ahn ◽

Eun Sook Cho ◽

Won Hyeok Choe ◽

...

Keyword(s):

Chronic Hepatitis ◽

Hepatitis B Virus ◽

Hepatitis B ◽

Chronic Hepatitis B ◽

Drug Susceptibility ◽

Compensatory Mutation ◽

B Virus ◽

Resistant Mutants

ABSTRACT Clevudine (CLV) is a nucleoside analog with potent antiviral activity against chronic hepatitis B virus (HBV) infection. Viral resistance to CLV in patients receiving CLV therapy has not been reported. The aim of this study was to characterize CLV-resistant HBV in patients with viral breakthrough (BT) during long-term CLV therapy. The gene encoding HBV reverse transcriptase (RT) was analyzed from chronic hepatitis B patients with viral BT during CLV therapy. Sera collected from the patients at baseline and at the time of viral BT were studied. To characterize the mutations of HBV isolated from the patients, we subjected the HBV mutants to in vitro drug susceptibility assays. Several conserved mutations were identified in the RT domain during viral BT, with M204I being the most common. In vitro phenotypic analysis showed that the mutation M204I was predominantly associated with CLV resistance, whereas L229V was a compensatory mutation for the impaired replication of the M204I mutant. A quadruple mutant (L129M, V173L, M204I, and H337N) was identified that conferred greater replicative ability and strong resistance to both CLV and lamivudine. All of the CLV-resistant clones were lamivudine resistant. They were susceptible to adefovir, entecavir, and tenofovir, except for one mutant clone. In conclusion, the mutation M204I in HBV RT plays a major role in CLV resistance and leads to viral BT during long-term CLV treatment. Several conserved mutations may have a compensatory role in replication. Drug susceptibility assays reveal that adefovir and tenofovir are the most effective compounds against CLV-resistant mutants. These data may provide additional therapeutic options for CLV-resistant patients.

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