Immune Netw.  2001 Apr;1(1):45-52. 10.4110/in.2001.1.1.45.

Antitunor effect of carcinoma cells transduced with herpes simplex virus - thymidine kinase by gancyclovir and radiation

• Lee JW
• Oh ST
• Ahn CH
• Lim KW
• Cho HI
• Kim GR
• Kim TG

• KMID: 2150556
• DOI: http://doi.org/10.4110/in.2001.1.1.45

Abstract

BACKGROUND: Many types of cancer become resistant to current chemotherapeutic and radiotherapeutic intervention. To overcome this situation application of gene therapy by the introduction of suicide genes followed by their prodrugs may be promising. A viral enzyme, Herpes simplex thymidine kinase (HSV-tk), which converts ganciclovir from an inactive prodrug to a cytotoxic agent by phosphorylation, are being actively investigated for use in gene therapy for cancer. The purpose of this study was to determine whether combining prodrug-activating gene therapy and irradiation might result in enhanced antitumor effects.
METHODS
The HSV-tk gene was cloned into the retroviral vector, pLXSN and established the clones producing retroviruses carrying the HSV-tk gene. The carcinoma cell line, HCT116 and Huh-7 were transduced with high-titer recombinant retroviruses. These cell lines were treated with ganciclovir before or after irradiation for the defining combinational effect of suicide gene therapy and radiotherapy.
RESULTS
The titers of cloned PA3 17 amphotropic retroviruses ranged from 4 to 6 X 10(6) CFU/ml . After selectional periods, the expression of HSV-tk was confirmed by reverse-transcriptase polymerase chain reaction (RT-PCR). The growth of cells expressing HSV-tk was inhibited as increase of GCV dose after 48 hr and the growth inhibitory effect of GCV was much higher after 72 hr. When the cells transduced with HSV-tk gene were exposed to radiation, the growth inhibitory effect of GCV was significantly increased, as compared with non-transduced parental cells.
CONCLUSIONS
The result s suggest that the addition of HSV-tk gene therapy to standard radiation therapy may improve the effectiveness of treatment for solid tumors.

Keyword

HSV - tk; ganciclovir; suicide gene therapy; radiotherapy

MeSH Terms

Cell Line
Clone Cells
Ganciclovir*
Genetic Therapy
Herpes Simplex*
Humans
Parents
Phosphorylation
Polymerase Chain Reaction
Prodrugs
Radiotherapy
Retroviridae
Simplexvirus*
Suicide
Thymidine Kinase*
Thymidine*
Zidovudine
Ganciclovir
Prodrugs
Thymidine
Thymidine Kinase
Zidovudine