Glioma-specific and cell cycle-regulated herpes simplex virus type 1 amplicon viral vector.
We have engineered a novel herpes simplex virus type 1 (HSV-1)-based amplicon viral vector, whereby gene expression is controlled by cell cycle events. In nondividing cells, trans-activation of the cyclin A promoter via interaction of the Gal4/NF-YA fusion protein with the Gal4-binding sites is prevented by the presence of a repressor protein, cell cycle-dependent factor 1 (CDF-1). CDF-1 is specifically expressed during the G(0)/G(1) phase of the cell cycle and its binding site is located within the cyclin A promoter. In actively proliferating cells, trans-activation could take place because of the absence of CDF-1. Our results showed that when all these cell cycle-specific regulatory elements are incorporated in cis into a single HSV-1 amplicon plasmid vector backbone (pC8-36), reporter luciferase activity is greatly enhanced. Transgene expression mediated by this series of HSV-1 amplicon plasmid vectors and amplicon viral vectors could be regulated in a cell cycle-dependent manner in a variety of cell lines. In a further attempt to target transgene expression to a selected group of actively proliferating cells such as glial cells, we have replaced the cytomegalovirus promoter of the pC8-36 amplicon plasmid with the glial cell-specific GFAP enhancer element. With this latter viral construct, cell type-specific and cell cycle-dependent transgene expression could subsequently be demonstrated specifically in glioma-bearing animals. Taken together, our results suggest that this series of cell cycle-regulatable HSV-1 amplicon viral vectors could potentially be adapted as useful tools for the treatment of human cancers.
Ho
Ivy A W
IA
Gene Vector Laboratory, Division of Cellular and Molecular Research, National Cancer Center, Singapore 169610.
Hui
Kam M
KM
Lam
Paula Y P
PY
D000818:Animals; D002453:Cell Cycle / Q000235:genetics*; D045744:Cell Line, Tumor; D004742:Enhancer Elements, Genetic; D005784:Gene Amplification; D015967:Gene Expression Regulation, Viral; D018014:Gene Transfer Techniques; D017930:Genes, Reporter; D005814:Genes, Viral; D005818:Genetic Engineering; D005822:Genetic Vectors; D005904:Glial Fibrillary Acidic Protein / Q000235:genetics; D005910:Glioma / Q000235:genetics* / Q000628:therapy / Q000821:virology; D006367:HeLa Cells; D018259:Herpesvirus 1, Human / Q000235:genetics*; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D041681:NIH 3T3 Cells; D019076:Transgenes
D005904:Glial Fibrillary Acidic Protein; D008156:Luciferases