Antiviral agents in hepatitis B virus transfected cell lines: inhibitory and cytotoxic effect related to time of treatment

Kruining, J.; Heijtink, R. A.; Schalm, Solko W.

doi:10.1016/0168-8278(95)80277-0

Cited by 36 publications

(33 citation statements)

References 19 publications

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“…Our results demonstrated a greater suppression of DHBV replication by adefovir than by lamivudine, in agreement with previous data obtained with avian cells transfected with the DHBV genome (42). On the other hand, lamivudine was shown to be as effective as or more effective than adefovir in human hepatoma cell lines transfected with the HBV genome (14,24,39). These differences in activity may reflect differences between the species of hepadnavirus and of the cell type.…”

Section: Discussionsupporting

confidence: 82%

Inhibitory Effect of Adefovir on Viral DNA Synthesis and Covalently Closed Circular DNA Formation in Duck Hepatitis B Virus-Infected Hepatocytes In Vivo and In Vitro

Delmas

Schorr

Jamard

et al. 2002

Antimicrob Agents Chemother

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The elimination of viral covalently closed circular DNA (CCC DNA) from the nucleus of infected hepatocytes is an obstacle to achieving sustained viral clearance during antiviral therapy of chronic hepatitis B virus (HBV) infection. The aim of our study was to determine whether treatment with adefovir, a new acyclic nucleoside phosphonate, the prodrug of which, adefovir dipivoxil, is in clinical evaluation, is able to suppress viral CCC DNA both in vitro and in vivo using the duck HBV (DHBV) model. First, the effect of adefovir on viral CCC DNA synthesis was examined with primary cultures of DHBV-infected fetal hepatocytes. Adefovir was administered for six consecutive days starting one day before or four days after DHBV inoculation. Dose-dependent inhibition of both virion release in culture supernatants and synthesis of intracellular viral DNA was observed. Although CCC DNA amplification was inhibited by adefovir, CCC DNA was not eliminated by antiviral treatment and the de novo formation of CCC DNA was not prevented by pretreatment of the cells. Next, preventive treatment of experimentally infected ducklings with lamivudine or adefovir revealed that both efficiently suppressed viremia and intrahepatic DNA. However, persistence of viral DNA even when detectable only by PCR was associated with a recurrence of viral replication following drug withdrawal. Taken together, our results demonstrate that adefovir is a potent inhibitor of DHBV replication that inhibits CCC DNA amplification but does not effectively prevent the formation of CCC DNA from incoming viral genomes.Despite the existence of efficient vaccines, chronic hepatitis B virus (HBV) infection continues to be a major public health problem worldwide, with more than 350 million chronic carriers. These individuals are at high risk of developing cirrhosis and hepatocellular carcinoma (28). Interferon alpha therapy is only moderately effective and often is limited by dose-dependent side effects (20). The discovery that certain nucleoside inhibitors of human immunodeficiency virus reverse transcriptase, such as lamivudine, also inhibit HBV polymerase has led to the development of these agents for the treatment of HBV infection. Lamivudine has been shown to be highly effective in inhibiting HBV replication (10, 25) and has recently been licensed in many countries for the therapy of chronic hepatitis B. However, analysis of the kinetics of viral clearance during lamivudine therapy revealed that since lamivudine does not completely inhibit viral replication and the rate of clearance of infected cells is slow, prolonged therapy is required for elimination of virus (38). The initial reactions required for the conversion of the incoming relaxed circular (RC) DNA into covalently closed circular (CCC DNA) are still not elucidated, but it can be hypothesized that HBV polymerase (23) and cellular enzymes (2) may be required for this process. CCC DNA serves as the template for viral transcription (46), and its production is regulated and amplified by an intracellular pa...

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Section: Discussionsupporting

confidence: 82%

Inhibitory Effect of Adefovir on Viral DNA Synthesis and Covalently Closed Circular DNA Formation in Duck Hepatitis B Virus-Infected Hepatocytes In Vivo and In Vitro

Delmas

Schorr

Jamard

et al. 2002

Antimicrob Agents Chemother

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“…2). Comparable results were obtained for the two drugs with an estimated 50% effective concentration of 0.02 mM, as previously described for 3TC (14). …”

Section: Antiviral Activity Of 3tc and Cf 1109 Against Extracellular supporting

confidence: 64%

“…The procedure of CEM cell infection with mutant HIV-1 strains, preparation of the samples for PCR assays, amplification of the proviral DNA, and sequencing of the 727 bp fragment covering amino acid residues 50-270 have been reported earlier (11,14). The first set of primers (5-GTAGAATTCTGTTGACTCAGATTGG-3 and 5-TTCTGCCAGTTCTAGCTCTGCTTCT-3) gave a 900-bp product of the proviral RT gene.…”

Section: Synthesis Of 3tc 5-[phenyl Methoxyalaninyl]phosphate (Cf1109)mentioning

confidence: 99%

Anti-HIV and Anti-HBV Activity and Resistance Profile of 2′,3′-Dideoxy-3′-Thiacytidine (3TC) and Its Arylphosphoramidate Derivative CF 1109

Balzarini

Wedgwood

Kruining

et al. 1996

Biochemical and Biophysical Research Communications

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A novel membrane-soluble prodrug of the 5-monophosphate derivative of 3TC containing a phenyl group and the methyl ester of L-alanine linked to the phosphorus through a phosphoramidate bond with the primary amino moiety (designated Cf 1109) was prepared. The 3TC prodrug proved less potent an inhibitor of HIV-1 and HIV-2 replication in CEM cell cultures than 3TC, but lost only 20-fold antiviral potency in 2-deoxycytidine kinase-deficient CEM/dCK 0 cells compared with a more than 2,000-fold decrease of activity of 3TC. In contrast, 3TC and Cf 1109 proved equally highly effective in inhibiting HBV release in supernatants of HBV-transfected Hep G2 2.2.15 cell cultures (50% effective concentration Ç 0.02 mM). Both compounds easily selected for highly resistant HIV-1 strains at a comparable speed of breakthrough. The mutant viruses contained an 184-Ile and/or 184-Val amino acid change in their reverse transcriptase. Our data are suggestive for a relatively poor delivery of 3TC-MP in the intact CEM cells but a remarkably high delivery of 3TC and/or 3TC-MP in the intact Hep G2 2.2.15 cells. ᭧ 1996 Academic Press, Inc.The most recently approved 2,3-dideoxynucleoside (ddN) derivative for treatment of HIV infections is 2,3-dideoxy-3-thiacytidine (3TC, lamivudine) (Fig. 1). This drug is also subject of clinical trials in human hepatitis B virus (HBV)-infected patients. In contrast with the other approved (b-D) ddN derivatives has 3TC the b-L(0) isomeric conformation. 3TC needs to be converted to its 5-triphosphate derivative by cellular enzymes to be inhibitory to the reverse transcriptase (RT) of HIV, and is endowed with low if any cytotoxicity (1-5). However, the first activation (phosphorylation) step is catalysed by cytosolic 2-deoxycytidine kinase (dCK) which has a relatively poor affinity for 3TC (K i /K m Ç 50) resulting in a moderate efficiency of conversion of 3TC to its 5-monophosphate derivative (6). In addition, a potential drawback of 3TC is the rapid emergence of drug-resistant HIV-1 strains (7-11). Indeed, mutant virus strains that emerged in the presence of 3TC were shown to contain an amino acid change from methionine (Met) to valine (Val) or isoleucine (Ile) at position 184 of the RT. Such virus is highly resistant to the inhibitory effects of 3TC in cell culture (7-11), and is reported to show low-level cross-resistance to 2,3-dideoxycytidine (ddC) (Fig. 1) and 2,3-dideoxyinosine (ddI).In an attempt to circumvent the first intracellular phosphorylation step of 3TC, we synthesized the arylphosphoramidate derivative of 3TC containing a methylester of L-alanine linked to the 5-phosphate of 3TC-MP through its primary amino group (Fig. 1). The corresponding 2,3-didehydro-2,3-dideoxythymidine (d4T, stavudine) analogue (So324) was previously shown to be able to deliver directly the 5-monophosphate derivative of d4T into intact cells and to efficiently bypass the first (thymidine kinase-directed) phosphorylation of d4T (12,13). The antiviral potency and resistance profile of Cf 1109 is described compared to 3TC.

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“…The routine approach for screening compounds to treat HBV infection is based on their inhibitory activities against HBV-DNA production and antigen expression [30,31] . In this study, the anti-HBV activities of traditional Chinese medicine R. palmatum L. ethanol extract (RPE) and isolated compounds were evaluated using HepG2 2.2.15 cell line as a model.…”

Section: Discussionmentioning

confidence: 99%

Identification of Natural Compounds with Anti-Hepatitis B Virus Activity from <i>Rheum palmatum</i> L. Ethanol Extract

Sun

et al. 2007

Chemotherapy

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Background: Hepatitis B virus (HBV) infection is a severe health problem in the world; however, there is still no satisfactory therapeutic strategy for the HBV infection. In search for new anti-HBV agents with higher efficiency and less side effects, the anti-HBV activities of traditional Chinese medicine Rheum palmatum L. ethanol extract (RPE) and isolated anthraquinones were evaluated. Methods: The anti-HBV activities of RPE and isolated anthraquinones were demonstrated in a stable HBV-producing cell line HepG2 2.2.15 by using real-time polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA) and Southern blot analysis. Results: RPE could inhibit HBV-DNA production and HBsAg expression in a dose-dependent manner. The concentration of 50% HBV-DNA inhibition (IC₅₀) of RPE was calculated at 212.36 ± 11 µg/ml. Six anthraquinones were isolated from RPE by using RP-HPLC. Five free anthraquinones showed weakly or slightly inhibitory activities against HBV. The only combined anthraquinone chrysophanol 8-O-β-D-glucoside exhibited significant activity against HBV DNA production and antigens expression with an IC₅₀ value of 36.98 ± 2.28 µg/ml on HBV DNA inhibition. Endogenous HBV DNA polymerase activity assay indicated that chrysophanol 8-O-β-D-glucoside might be a potential inhibitor of the HBV DNA polymerase. Conclusions: The results suggested that RPE could effectively inhibit HBV. The combined anthraquinone chrysophanol 8-O-β-D-glucoside is the major active compound in RPE and could be a promising candidate for the development of new anti-HBV drugs in the treatment of HBV infection.

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Antiviral agents in hepatitis B virus transfected cell lines: inhibitory and cytotoxic effect related to time of treatment

Cited by 36 publications

References 19 publications

Inhibitory Effect of Adefovir on Viral DNA Synthesis and Covalently Closed Circular DNA Formation in Duck Hepatitis B Virus-Infected Hepatocytes In Vivo and In Vitro

Inhibitory Effect of Adefovir on Viral DNA Synthesis and Covalently Closed Circular DNA Formation in Duck Hepatitis B Virus-Infected Hepatocytes In Vivo and In Vitro

Anti-HIV and Anti-HBV Activity and Resistance Profile of 2′,3′-Dideoxy-3′-Thiacytidine (3TC) and Its Arylphosphoramidate Derivative CF 1109

Identification of Natural Compounds with Anti-Hepatitis B Virus Activity from <i>Rheum palmatum</i> L. Ethanol Extract

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