HSV-tk/GCV gene therapy mediated by EBV-LMP1 for EBV-associated cancer.
BACKGROUND
To investigate the feasibility of gene therapy in treating Epstein-Barr virus (EBV)-associated cancer by employing the suicide gene, herpes simplex virus thymidine kinase/ganciclovir (HSV-tk/GCV), which uses the signaling pathway through the HIV-long terminal repeat (LTR) gene which is expressed from a nuclear factor-kappaB (NF-kappaB)-binding motif-containing promoter that is regulated by EBV-latent membrane protein 1 (LMP1) via NF-kappaB.


METHODS
First, we constructed the plasmid pVLTR-tk, which was regulated by EBV-LMP1 via NF-kappaB, and then investigated the cytotoxic effect of the pVLTR-tk/GCV on cancer cells, using MTT assays, clonogenic assays, flow cytometry, and animal experiments.


RESULTS
The activation of TK was increased after transfection of the pVLTR-tk into the EBV-LMP1 positive cells. After GCV treatment, the clonogenicity and survival of the cells substantially declined, and a bystander effect was also observed. The LMP1 positive cells exhibited remarkable apoptosis following pVLTR-tk/GCV treatment, and the pVLTR-tk/GCV restrained tumor growth in vivo for EBV-LMP1 positive cancers.


CONCLUSIONS
The pVLTR-tk/GCV suicide gene system may be used as a new gene targeting strategy for EBV-associated cancer.
Lifang
Yang
Y
Molecular Biology Research Center, Cancer Research Institute, XiangYa School of Medicine, Central South University, ChangSha, Hunan, 410078, PR China. anglifang99@hotmail.com
Min
Tang
T
Midan
Ai
A
Ya
Cao
C
D000818:Animals; D000998:Antiviral Agents / Q000627:therapeutic use; D045744:Cell Line, Tumor; D020031:Epstein-Barr Virus Infections / Q000628:therapy*; D015774:Ganciclovir / Q000494:pharmacology / Q000627:therapeutic use*; D041722:Genes, Transgenic, Suicide; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000235:genetics; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D016328:NF-kappa B / Q000378:metabolism; D018139:Simplexvirus / Q000201:enzymology; D020079:Terminal Repeat Sequences; D013937:Thymidine Kinase / Q000235:genetics*; D014162:Transfection; D014763:Viral Matrix Proteins / Q000235:genetics* / Q000378:metabolism
D000998:Antiviral Agents; C037662:EBV-associated membrane antigen, Epstein-Barr virus; D016328:NF-kappa B; D014763:Viral Matrix Proteins; D013937:Thymidine Kinase; D015774:Ganciclovir