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

• 来源期刊: 中国药理学报（英文版）
• 关键词: carbocyclic oxetanocin G human herpesvirus l viral drug resistance thymidine kinase
• 年，卷（期）: 2004,（7）
• 页码范围: 921-926
• 页数: 6页
• 语种: 英文

摘要

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 μm 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.