Laurent Bellon - Academia.edu (original) (raw)

Papers by Laurent Bellon

All polynucleotide polymerases have a similar structure and mechanism of catalysis, consistent wi... more All polynucleotide polymerases have a similar structure and mechanism of catalysis, consistent with their evolution from one progenitor polymerase. Viral RNA-dependent RNA polymerases (RdRp) are expected to have properties comparable to those from this progenitor and therefore may offer insight into the common- alities of all classes of polymerases. We examined RNA synthesis by the brome mosaic virus RdRp on

Nucleosides Nucleotides & Nucleic Acids, 1992

A synthetic pathway to reach easily the 4-thio-D-ribofuranose is described. Some corresponding py... more A synthetic pathway to reach easily the 4-thio-D-ribofuranose is described. Some corresponding pyrimidine α and β 4′-thioribonucleosides have been synthesized and evaluated as antiviral agents against various viruses.

Nucleosides and Nucleotides, 1993

We demonstrate that the procedure of Huang and Hui, applied to the D-ribose and involving Ph3P/I2... more We demonstrate that the procedure of Huang and Hui, applied to the D-ribose and involving Ph3P/I2/Imidazole reagent system do not lead to the desired 4-thio-D-ribofuranoside derivative but gives its diastereoisomer 4-thio-L-lyxofuranoside derivative 4

Mutation Research-genetic Toxicology and Environmental Mutagenesis, 2002

Industrial radiography is the process of using either gamma-emitting radionuclide sources or X-ra... more Industrial radiography is the process of using either gamma-emitting radionuclide sources or X-ray machines to examine the safety of industrial materials. Industrial radiographers are among the radiation workers who receive the highest individual occupational radiation doses. To assess occupationally induced chromosomal damage, we performed the cytokinesis-block micronucleus (CBMN) assay in peripheral lymphocytes of 29 male industrial radiographers, exposed to ionizing

Nucleosides and Nucleotides, 1997

Abstract A convergent approach, based on the reductive amination of 3′-phospho-glycaldehyde-riboz... more Abstract A convergent approach, based on the reductive amination of 3′-phospho-glycaldehyde-ribozyme 3 with 5′-aminohexyLribozyme 1 generated an amino-linked ribozyme 4 in good yields. Catalytic activity of the cross-linked ribozyme is discussed.

Journal of clinical pharmacology, 2000

The pharmacokinetics and tolerability of a chemically stabilized synthetic ribozyme (ANGIOZYME) t... more The pharmacokinetics and tolerability of a chemically stabilized synthetic ribozyme (ANGIOZYME) targeting the Flt-1 VEGF receptor mRNA were evaluated in healthy volunteers. In a placebo-controlled, single-dose escalation study, ribozyme was administered as a 4-hour i.v. infusion of 10 or 30 mg/m2 or as a s.c. bolus of 20 mg/m2. Peak ribozyme plasma concentrations of 1.5 and 3.8 micrograms/mL were observed after the 10 and 30 mg/m2 i.v. infusions, respectively. When normalized to dose, AUC values as well as peak concentrations increased proportionally as the dose was increased from 10 to 30 mg/m2. Peak concentrations of 0.9 microgram/mL were observed approximately 3.25 hours after a 20 mg/m2 s.c. bolus of ribozyme. The dose-normalized AUCs obtained after s.c. dosing were compared to the mean dose-normalized AUC after i.v. dosing to estimate an absolute s.c. bioavailability (f) of approximately 69%. An average elimination half-life of 28 to 40 minutes was observed after i.v. administr...

ChemInform, 1995

ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Nucleosides and Nucleotides, 1994

A new synthesis of 4′-thioribonucleosides is presented together with the enzymatic evaluation of ... more A new synthesis of 4′-thioribonucleosides is presented together with the enzymatic evaluation of the adenosine analogues with respect to adenosine kinase. The 4-thio-D-ribofuranosyl carbohydrate precursor 7 was obtained in good yield from D-ribose and further reacted with adenine and cytosine to give the α and β anomers of 4′-thioadenosine and 4′-thiocytidine, respectively. 4′-thio-β-D-adenosine, 12β. is a poor substrate for bovine

Nucleosides and Nucleotides, 1996

... Becky Haly, Laurent Bellont, Venkatraman Mohan and Yogesh Sanghvi* Medicinal Chemistry Depart... more ... Becky Haly, Laurent Bellont, Venkatraman Mohan and Yogesh Sanghvi* Medicinal Chemistry Department, Isis Pharmaceuticals, 2292 Faraday Avenue Carlsbad. CA 92008 ... Patrick Wheeler for the NMR studies and Ramesh Bharadwaj for preparing the starting materials. ...

Smart Materials and Structures, 2001

This paper proposes an experimental mock-up which aims to validate a new concept of a piezo-rubbe... more This paper proposes an experimental mock-up which aims to validate a new concept of a piezo-rubber mount. This new concept is based upon the combination of an electrically-monitored active piezoelectric block with a passive rubber mount. An adaptive control law is then used for an off-line identification and control of the force transmissibility. The new hybrid mount is shown to be very efficient and significantly improves the transfer between disturbances and receiving components.

Proceedings of the National Academy of Sciences, 1998

RNAs 33 nucleotides in length can direct accurate initiation of subgenomic RNA synthesis by the b... more RNAs 33 nucleotides in length can direct accurate initiation of subgenomic RNA synthesis by the brome mosaic virus RNA-dependent RNA polymerase (RdRp), provided that the native sequences are maintained at five positions: ؊17, ؊14, ؊13, ؊11, and the ؉1 initiation site. The functional groups in the bases of these essential nucleotides required to interact with RdRp were examined by using chemically synthesized RNAs containing base analogs at each of the five positions. Analysis using a template competition assay revealed that the mode of recognition for the initiation nucleotide (؉1) is distinct from that of the other essential nucleotides in the promoter. Competition experiments also determined that three template nucleotides are sufficient for stable interaction with RdRp. These results identify base moieties in the brome mosaic virus subgenomic promoter required for efficient RNA synthesis and support the hypothesis that the recognition of a RNA promoter by a viral RdRp is analogous to the recognition of DNA promoters by DNAdependent RNA polymerases.

Antisense and Nucleic Acid Drug Development, 2000

The potential acute toxicity of a ribozyme (ANGIOZYME™) targeting the/ft-1 vascular endothelial g... more The potential acute toxicity of a ribozyme (ANGIOZYME™) targeting the/ft-1 vascular endothelial growth factor (VEGF) receptor mRNA was evaluated in cynomolgus monkeys following i.V. infusion or s.c. injection. ANGIOZYME was administered as a 4-hour i.V. infusion at doses of 10,30, or 100 mg/kg or a s.c. bolus at 100 mg/kg. End points included blood pressure, electrocardiogram (ECG), clinical chemistry, hematology, complement factors, coagulation parameters, and ribozyme plasma concentrations. ANGIOZYME was well tolerated, with no drug-associated morbidity or mortality. There was no clear evidence of ANGIOZYME-related adverse effects in this study. Slight increases in spleen weight and lymphoid hyperplasia were observed in several animals. However, these changes were not dose dependent. Steady-state concentrations of ANGIOZYME were achieved during the 4-hour infusion of 10,30, or 100 mg/kg. Dose-dependent elimination of ANGIOZYME was observed, with faster clearance at the two highest doses. ANGIOZYME was slowly absorbed after s.c. administration, resulting in steady-state concentrations for the 9-hour sampling period. Monkeys in this toxicology study received significant plasma ANGIOZYME exposure by both the s.c. and i.v. routes.

Nucleosides, Nucleotides and Nucleic Acids, 1995

The syntheses and the study of nuclease resistance and hydrogen bonding of modified oligoribonucl... more The syntheses and the study of nuclease resistance and hydrogen bonding of modified oligoribonucleotides, i.e. 4′-thio-β-D-oligoribonucleotides (4′-S-RNA), are reported.

Nucleosides, Nucleotides and Nucleic Acids, 1995

... Yogesh S. Sanghvi*, Laurent Bellon, Franqois Morvan, Tomonori Hoshiko, Eric Swayze, Lendell C... more ... Yogesh S. Sanghvi*, Laurent Bellon, Franqois Morvan, Tomonori Hoshiko, Eric Swayze, Lendell Cummins, Susan Freier, Nicholas Dean, Brett Monia, Richard H. Griffey and P. Dan Cook ... 1992, 114, For the synthesis of 5 see: Sanghvi, YS; Ross, B.; Bharadwaj, R.; Vasseur, JJ. ...

Nucleic Acids Research, 1993

ABSTRACT We present the synthesis and the study of properties of a new series of modified oligonu... more ABSTRACT We present the synthesis and the study of properties of a new series of modified oligonucleotides, namely 4'-thio-oligo-beta-D-ribonucleotides (4'-S-RNA). Homo-oligonucleotides of this class (4'-SU6 and 4'-SU12) were prepared from the previously known thionucleosides using the phosphoramidite methodology. The comparison of the substrate properties of 4'-SU6 and its natural analog U6 with respect to four nucleases indicates that the former is much more resistant than the latter. Such resistance to nucleases in addition to relatively high Tm values for 4'-SU12 hybridized with Poly(A) show that these new 4'-S-RNA are good candidates for potential antisense effects. The oligonucleotides 4'-SU6 and 4'-SU12 have been also evaluated as non sequence specific inhibitors of HIV-1 reverse transcriptase. All available evidences, based primarily on fluorescence measurements, are consistent with the binding of 4'-SU6 and 4'-SU12 to RT at a site which is different from the polymerase site of the enzyme.

Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 2002

Increased micronucleated cell rates, dicentric chromosomes, and other chromosomal damages have be... more Increased micronucleated cell rates, dicentric chromosomes, and other chromosomal damages have been reported in lymphocytes of cancer patients prior to the initiation of chemotherapy, and/or radiotherapy. The cause of these chromosomal damages in these lymphocytes remains unclear. In the present work, we investigated whether these micronuclei mainly reflect structural or numerical chromosomal aberrations by applying the cytokinesis-blocked micronucleus (CBMN) assay in combination with fluorescent in situ hybridization (FISH) of a DNA centromeric probe on blood samples of 10 untreated cancer patients (UCPs), and 10 healthy subjects (HSs). Micronucleated binucleated lymphocyte rate was significantly increased in patients (mean±S.D.: 19.0‰±14.1 versus 9.2‰±4.6 in controls). Trinucleated cytokinesis-blocked cells were not significantly higher in patients than in controls. Acentromeric, centromeric, and multicentromeric micronucleus levels were two-fold higher in patients than in controls, but the difference was significant only with acentromeric micronuclei. The percentage of micronuclei containing one or more centromeres averaged 69.2, and 71.5% in patients, and controls, respectively. The percentage of micronuclei containing several centromeres was 44.7% in patients, and 54.6% in controls. Among centromere-positive micronuclei, the percentage of micronuclei containing several centromeres averaged 59.7% in patients, and 75.4% in controls. These results indicate that genetic instability in peripheral blood lymphocytes of UCPs occurs because of enhanced chromosome breakage. However, a substantial proportion of this genetic instability occurs because of defects in chromosome segregation.

Journal of the American Chemical Society, 1996

... Christopher Workman, Jon Scherrer, Nassim Usman, and Francine Wincott*. Department of Chemist... more ... Christopher Workman, Jon Scherrer, Nassim Usman, and Francine Wincott*. Department of Chemistry and Biochemistry Ribozyme Pharmaceuticals, Inc. 2950 Wilderness Place, Boulder, Colorado 80301. J. Am. Chem. Soc. ... Gilham, PT J. Am. Chem. Soc. 1972, 94, 8921−8922. ...

Rna-a Publication of The Rna Society, 1999

Hepatology, 2000

Ribozymes are catalytic RNA molecules that can be designed to cleave specific RNA sequences. To i... more Ribozymes are catalytic RNA molecules that can be designed to cleave specific RNA sequences. To investigate the potential use of synthetic stabilized ribozymes for the treatment of chronic hepatitis C virus (HCV) infection, we designed and synthesized hammerhead ribozymes targeting 15 conserved sites in the 5Ј untranslated region (UTR) of HCV RNA. This region forms an internal ribosome entry site that allows for efficient translation of the HCV polyprotein. The 15 synthetic ribozymes contained modified nucleotides and linkages that stabilize the molecules against nuclease degradation. All 15 ribozymes were tested for their ability to reduce expression in an HCV 5Ј UTR/ luciferase reporter system and for their ability to inhibit replication of an HCV-poliovirus (HCV-PV) chimera. Treatment with several ribozymes resulted in significant downregulation of HCV 5Ј UTR/luciferase reporter expression (range 40% to 80% inhibition, P F .05). Moreover, several ribozymes showed significant inhibition (G90%, P F .001) of chimeric HCV-PV replication. We further show that the inhibitory activity of ribozymes targeting site 195 of HCV RNA exhibits a sequence-specific dose response, requires an active catalytic ribozyme core, and is dependent on the presence of the HCV 5Ј UTR. Treatment with synthetic stabilized anti-HCV ribozymes has the potential to aid patients who are infected with HCV by reducing the viral burden through specific targeting and cleavage of the viral genome. (HEPATOLOGY 2000;31:769-776.)

All polynucleotide polymerases have a similar structure and mechanism of catalysis, consistent wi... more All polynucleotide polymerases have a similar structure and mechanism of catalysis, consistent with their evolution from one progenitor polymerase. Viral RNA-dependent RNA polymerases (RdRp) are expected to have properties comparable to those from this progenitor and therefore may offer insight into the common- alities of all classes of polymerases. We examined RNA synthesis by the brome mosaic virus RdRp on

Nucleosides Nucleotides & Nucleic Acids, 1992

A synthetic pathway to reach easily the 4-thio-D-ribofuranose is described. Some corresponding py... more A synthetic pathway to reach easily the 4-thio-D-ribofuranose is described. Some corresponding pyrimidine α and β 4′-thioribonucleosides have been synthesized and evaluated as antiviral agents against various viruses.

Nucleosides and Nucleotides, 1993

We demonstrate that the procedure of Huang and Hui, applied to the D-ribose and involving Ph3P/I2... more We demonstrate that the procedure of Huang and Hui, applied to the D-ribose and involving Ph3P/I2/Imidazole reagent system do not lead to the desired 4-thio-D-ribofuranoside derivative but gives its diastereoisomer 4-thio-L-lyxofuranoside derivative 4

Mutation Research-genetic Toxicology and Environmental Mutagenesis, 2002

Industrial radiography is the process of using either gamma-emitting radionuclide sources or X-ra... more Industrial radiography is the process of using either gamma-emitting radionuclide sources or X-ray machines to examine the safety of industrial materials. Industrial radiographers are among the radiation workers who receive the highest individual occupational radiation doses. To assess occupationally induced chromosomal damage, we performed the cytokinesis-block micronucleus (CBMN) assay in peripheral lymphocytes of 29 male industrial radiographers, exposed to ionizing

Nucleosides and Nucleotides, 1997

Abstract A convergent approach, based on the reductive amination of 3′-phospho-glycaldehyde-riboz... more Abstract A convergent approach, based on the reductive amination of 3′-phospho-glycaldehyde-ribozyme 3 with 5′-aminohexyLribozyme 1 generated an amino-linked ribozyme 4 in good yields. Catalytic activity of the cross-linked ribozyme is discussed.

Journal of clinical pharmacology, 2000

The pharmacokinetics and tolerability of a chemically stabilized synthetic ribozyme (ANGIOZYME) t... more The pharmacokinetics and tolerability of a chemically stabilized synthetic ribozyme (ANGIOZYME) targeting the Flt-1 VEGF receptor mRNA were evaluated in healthy volunteers. In a placebo-controlled, single-dose escalation study, ribozyme was administered as a 4-hour i.v. infusion of 10 or 30 mg/m2 or as a s.c. bolus of 20 mg/m2. Peak ribozyme plasma concentrations of 1.5 and 3.8 micrograms/mL were observed after the 10 and 30 mg/m2 i.v. infusions, respectively. When normalized to dose, AUC values as well as peak concentrations increased proportionally as the dose was increased from 10 to 30 mg/m2. Peak concentrations of 0.9 microgram/mL were observed approximately 3.25 hours after a 20 mg/m2 s.c. bolus of ribozyme. The dose-normalized AUCs obtained after s.c. dosing were compared to the mean dose-normalized AUC after i.v. dosing to estimate an absolute s.c. bioavailability (f) of approximately 69%. An average elimination half-life of 28 to 40 minutes was observed after i.v. administr...

ChemInform, 1995

ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Nucleosides and Nucleotides, 1994

A new synthesis of 4′-thioribonucleosides is presented together with the enzymatic evaluation of ... more A new synthesis of 4′-thioribonucleosides is presented together with the enzymatic evaluation of the adenosine analogues with respect to adenosine kinase. The 4-thio-D-ribofuranosyl carbohydrate precursor 7 was obtained in good yield from D-ribose and further reacted with adenine and cytosine to give the α and β anomers of 4′-thioadenosine and 4′-thiocytidine, respectively. 4′-thio-β-D-adenosine, 12β. is a poor substrate for bovine

Nucleosides and Nucleotides, 1996

... Becky Haly, Laurent Bellont, Venkatraman Mohan and Yogesh Sanghvi* Medicinal Chemistry Depart... more ... Becky Haly, Laurent Bellont, Venkatraman Mohan and Yogesh Sanghvi* Medicinal Chemistry Department, Isis Pharmaceuticals, 2292 Faraday Avenue Carlsbad. CA 92008 ... Patrick Wheeler for the NMR studies and Ramesh Bharadwaj for preparing the starting materials. ...

Smart Materials and Structures, 2001

This paper proposes an experimental mock-up which aims to validate a new concept of a piezo-rubbe... more This paper proposes an experimental mock-up which aims to validate a new concept of a piezo-rubber mount. This new concept is based upon the combination of an electrically-monitored active piezoelectric block with a passive rubber mount. An adaptive control law is then used for an off-line identification and control of the force transmissibility. The new hybrid mount is shown to be very efficient and significantly improves the transfer between disturbances and receiving components.

Proceedings of the National Academy of Sciences, 1998

RNAs 33 nucleotides in length can direct accurate initiation of subgenomic RNA synthesis by the b... more RNAs 33 nucleotides in length can direct accurate initiation of subgenomic RNA synthesis by the brome mosaic virus RNA-dependent RNA polymerase (RdRp), provided that the native sequences are maintained at five positions: ؊17, ؊14, ؊13, ؊11, and the ؉1 initiation site. The functional groups in the bases of these essential nucleotides required to interact with RdRp were examined by using chemically synthesized RNAs containing base analogs at each of the five positions. Analysis using a template competition assay revealed that the mode of recognition for the initiation nucleotide (؉1) is distinct from that of the other essential nucleotides in the promoter. Competition experiments also determined that three template nucleotides are sufficient for stable interaction with RdRp. These results identify base moieties in the brome mosaic virus subgenomic promoter required for efficient RNA synthesis and support the hypothesis that the recognition of a RNA promoter by a viral RdRp is analogous to the recognition of DNA promoters by DNAdependent RNA polymerases.

Antisense and Nucleic Acid Drug Development, 2000

The potential acute toxicity of a ribozyme (ANGIOZYME™) targeting the/ft-1 vascular endothelial g... more The potential acute toxicity of a ribozyme (ANGIOZYME™) targeting the/ft-1 vascular endothelial growth factor (VEGF) receptor mRNA was evaluated in cynomolgus monkeys following i.V. infusion or s.c. injection. ANGIOZYME was administered as a 4-hour i.V. infusion at doses of 10,30, or 100 mg/kg or a s.c. bolus at 100 mg/kg. End points included blood pressure, electrocardiogram (ECG), clinical chemistry, hematology, complement factors, coagulation parameters, and ribozyme plasma concentrations. ANGIOZYME was well tolerated, with no drug-associated morbidity or mortality. There was no clear evidence of ANGIOZYME-related adverse effects in this study. Slight increases in spleen weight and lymphoid hyperplasia were observed in several animals. However, these changes were not dose dependent. Steady-state concentrations of ANGIOZYME were achieved during the 4-hour infusion of 10,30, or 100 mg/kg. Dose-dependent elimination of ANGIOZYME was observed, with faster clearance at the two highest doses. ANGIOZYME was slowly absorbed after s.c. administration, resulting in steady-state concentrations for the 9-hour sampling period. Monkeys in this toxicology study received significant plasma ANGIOZYME exposure by both the s.c. and i.v. routes.

Nucleosides, Nucleotides and Nucleic Acids, 1995

The syntheses and the study of nuclease resistance and hydrogen bonding of modified oligoribonucl... more The syntheses and the study of nuclease resistance and hydrogen bonding of modified oligoribonucleotides, i.e. 4′-thio-β-D-oligoribonucleotides (4′-S-RNA), are reported.

Nucleosides, Nucleotides and Nucleic Acids, 1995

... Yogesh S. Sanghvi*, Laurent Bellon, Franqois Morvan, Tomonori Hoshiko, Eric Swayze, Lendell C... more ... Yogesh S. Sanghvi*, Laurent Bellon, Franqois Morvan, Tomonori Hoshiko, Eric Swayze, Lendell Cummins, Susan Freier, Nicholas Dean, Brett Monia, Richard H. Griffey and P. Dan Cook ... 1992, 114, For the synthesis of 5 see: Sanghvi, YS; Ross, B.; Bharadwaj, R.; Vasseur, JJ. ...

Nucleic Acids Research, 1993

ABSTRACT We present the synthesis and the study of properties of a new series of modified oligonu... more ABSTRACT We present the synthesis and the study of properties of a new series of modified oligonucleotides, namely 4'-thio-oligo-beta-D-ribonucleotides (4'-S-RNA). Homo-oligonucleotides of this class (4'-SU6 and 4'-SU12) were prepared from the previously known thionucleosides using the phosphoramidite methodology. The comparison of the substrate properties of 4'-SU6 and its natural analog U6 with respect to four nucleases indicates that the former is much more resistant than the latter. Such resistance to nucleases in addition to relatively high Tm values for 4'-SU12 hybridized with Poly(A) show that these new 4'-S-RNA are good candidates for potential antisense effects. The oligonucleotides 4'-SU6 and 4'-SU12 have been also evaluated as non sequence specific inhibitors of HIV-1 reverse transcriptase. All available evidences, based primarily on fluorescence measurements, are consistent with the binding of 4'-SU6 and 4'-SU12 to RT at a site which is different from the polymerase site of the enzyme.

Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 2002

Increased micronucleated cell rates, dicentric chromosomes, and other chromosomal damages have be... more Increased micronucleated cell rates, dicentric chromosomes, and other chromosomal damages have been reported in lymphocytes of cancer patients prior to the initiation of chemotherapy, and/or radiotherapy. The cause of these chromosomal damages in these lymphocytes remains unclear. In the present work, we investigated whether these micronuclei mainly reflect structural or numerical chromosomal aberrations by applying the cytokinesis-blocked micronucleus (CBMN) assay in combination with fluorescent in situ hybridization (FISH) of a DNA centromeric probe on blood samples of 10 untreated cancer patients (UCPs), and 10 healthy subjects (HSs). Micronucleated binucleated lymphocyte rate was significantly increased in patients (mean±S.D.: 19.0‰±14.1 versus 9.2‰±4.6 in controls). Trinucleated cytokinesis-blocked cells were not significantly higher in patients than in controls. Acentromeric, centromeric, and multicentromeric micronucleus levels were two-fold higher in patients than in controls, but the difference was significant only with acentromeric micronuclei. The percentage of micronuclei containing one or more centromeres averaged 69.2, and 71.5% in patients, and controls, respectively. The percentage of micronuclei containing several centromeres was 44.7% in patients, and 54.6% in controls. Among centromere-positive micronuclei, the percentage of micronuclei containing several centromeres averaged 59.7% in patients, and 75.4% in controls. These results indicate that genetic instability in peripheral blood lymphocytes of UCPs occurs because of enhanced chromosome breakage. However, a substantial proportion of this genetic instability occurs because of defects in chromosome segregation.

Journal of the American Chemical Society, 1996

... Christopher Workman, Jon Scherrer, Nassim Usman, and Francine Wincott*. Department of Chemist... more ... Christopher Workman, Jon Scherrer, Nassim Usman, and Francine Wincott*. Department of Chemistry and Biochemistry Ribozyme Pharmaceuticals, Inc. 2950 Wilderness Place, Boulder, Colorado 80301. J. Am. Chem. Soc. ... Gilham, PT J. Am. Chem. Soc. 1972, 94, 8921−8922. ...

Rna-a Publication of The Rna Society, 1999

Hepatology, 2000

Ribozymes are catalytic RNA molecules that can be designed to cleave specific RNA sequences. To i... more Ribozymes are catalytic RNA molecules that can be designed to cleave specific RNA sequences. To investigate the potential use of synthetic stabilized ribozymes for the treatment of chronic hepatitis C virus (HCV) infection, we designed and synthesized hammerhead ribozymes targeting 15 conserved sites in the 5Ј untranslated region (UTR) of HCV RNA. This region forms an internal ribosome entry site that allows for efficient translation of the HCV polyprotein. The 15 synthetic ribozymes contained modified nucleotides and linkages that stabilize the molecules against nuclease degradation. All 15 ribozymes were tested for their ability to reduce expression in an HCV 5Ј UTR/ luciferase reporter system and for their ability to inhibit replication of an HCV-poliovirus (HCV-PV) chimera. Treatment with several ribozymes resulted in significant downregulation of HCV 5Ј UTR/luciferase reporter expression (range 40% to 80% inhibition, P F .05). Moreover, several ribozymes showed significant inhibition (G90%, P F .001) of chimeric HCV-PV replication. We further show that the inhibitory activity of ribozymes targeting site 195 of HCV RNA exhibits a sequence-specific dose response, requires an active catalytic ribozyme core, and is dependent on the presence of the HCV 5Ј UTR. Treatment with synthetic stabilized anti-HCV ribozymes has the potential to aid patients who are infected with HCV by reducing the viral burden through specific targeting and cleavage of the viral genome. (HEPATOLOGY 2000;31:769-776.)