Emergence of resistance to carbocyclic oxetanocin G in herpes simplex virus type 1 and genetic analysis of resistant mutants.

Abstract

AIM:

To elucidate the potentiality of emergence of drug-resistance to carbocyclic oxetanocin G (C.OXT-G), a new effective antiviral drug for herpetic keratitis during treatment and the mechanism of this drug resistance.

METHODS:

A C.OXT-G resistant strain (C.OXT-Gr) was established by serially propagating the herpes simplex virus (HSV) -1 in African green monkey kidney (VERO) cells in the presence of C.OXT-G. After the drug sensitivity assay and the thymidine kinase (TK) activity assay, the molecular basis for the drug resistance was studied using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis and PCR direct sequencing technology.

RESULTS:

After the 10th passage in 10 microm C.OXT-G, the ED50 of the C.OXT-Gr was 17.08-fold greater than that of the original strain on the average and the TK activities of these resistant strains were extremely reduced. PCR-SSCP analysis on TK gene of the wild HSV-1 and the C.OXT-Gr showed altered migration patterns in part 3 and part 4, while PCR-SSCP analysis on DNA polymerase gene showed no difference among the viruses. Sequence analysis revealed a deletion of G at position of 430 that caused frameshift, resulting in premature termination in the TK gene.

CONCLUSION:

The drug resistance to C.OXT-G may appear during the treatment due to the deficiency of TK activity caused by a single mutation in the TK gene of HSV-1.

• Authors: Nan Hu, Hiroshi Shiota
• Journal: Acta pharmacologica Sinica (Acta Pharmacol Sin) Vol. 25 Issue 7 Pg. 921-6 (Jul 2004) ISSN: 1671-4083 [Print] United States
• PMID: 15210066 (Publication Type: Journal Article)

Chemical References

• Antiviral Agents
• DNA, Viral
• Nucleic Acid Synthesis Inhibitors
• Guanine
• lobucavir
• Thymidine Kinase

Topics

• Animals
• Antiviral Agents (pharmacology)
• Chlorocebus aethiops
• DNA, Viral (genetics)
• Drug Resistance, Viral
• Gene Deletion
• Guanine (analogs & derivatives, pharmacology)
• Herpesvirus 1, Human (enzymology, genetics)
• Mutation
• Nucleic Acid Synthesis Inhibitors
• Polymerase Chain Reaction
• Polymorphism, Single-Stranded Conformational
• Thymidine Kinase (genetics, metabolism)
• Vero Cells