Superior cytostatic activity of the ganciclovir elaidic acid ester due to the prolonged intracellular retention of ganciclovir anabolites in herpes simplex virus type 1 thymidine kinase gene-transfected tumor cells

Gene Ther. 1998 Mar;5(3):419-26. doi: 10.1038/


Ganciclovir (GCV) and its lipophilic elaidic acid ester prodrug E-GCV were evaluated for their antiherpetic, cytostatic and metabolic properties, E-GCV proved exquisitely inhibitory to the replication of herpes simplex virus type 1 (HSV-1) and HSV-2 in cell cultures (50% effective concentration (EC50): 0.002 microM). It was five- to 10-fold more effective than its parent drug GCV. E-GCV was at least 2000-fold more cytostatic to HSV-1 or HSV-2 thymidine kinase (tk) gene-transfected mammary carcinoma FM3A tk-/HSVtk+ tumor cells than to the corresponding nontransfected tumor cells. The cytostatic activity of E-GCV to the HSVtk gene-transfected tumor cells was far superior to that of GCV. Metabolic studies revealed that both GCV and E-GCV were converted to the mono-, di- and tri-phosphate derivatives of GCV to a markedly higher extent in FM3Atk-/HSV-1 tk+ cells than in wild-type FM3A/0 cells. Strikingly, mono-, di- and tri-phosphate metabolites of GCV were retained for a substantially longer time in E-GCV-treated cells (half-life approximately 50 h) than in GCV-treated cells (half-life approximately 20 h). The longer retention time of the GCV metabolites most likely explains why E-GCV is superior to GCV against herpes simplex virus replication and HSVtk gene-transfected tumor cell proliferation. Taking into account the marked stability of E-GCV in human plasma and its much higher lipophilicity than GCV, E-GCV should be considered as an effective lipophilic prodrug of GCV with a markedly enhanced cytostatic activity in HSVtk gene-transfected tumor cells compared with parental ganciclovir. Its usefulness in the combined gene/chemotherapy of HSVtk gene-transfected tumors should be further pursued.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antiviral Agents / metabolism
  • Antiviral Agents / pharmacology*
  • Cell Division / drug effects
  • Female
  • Ganciclovir / analogs & derivatives*
  • Ganciclovir / metabolism
  • Ganciclovir / pharmacology
  • Genetic Therapy
  • Half-Life
  • Herpesvirus 1, Human / drug effects*
  • Herpesvirus 1, Human / physiology
  • Humans
  • Mammary Neoplasms, Experimental / metabolism*
  • Mammary Neoplasms, Experimental / pathology
  • Mice
  • Prodrugs / metabolism
  • Prodrugs / pharmacology*
  • Thymidine Kinase / genetics
  • Transfection
  • Tumor Cells, Cultured
  • Virus Replication / drug effects


  • Antiviral Agents
  • Prodrugs
  • ganciclovir elaidate
  • Thymidine Kinase
  • Ganciclovir