Disabled infectious single cycle herpes simplex virus (DISC-HSV) is a candidate vector system for gene delivery/expression of GM-CSF in human prostate cancer therapy.
BACKGROUND
DISC-HSV is a replication incompetent herpes simplex virus that is a highly efficient vector for the transduction of genes in vivo and in vitro. We examine the ability of DISC-HSV to infect human prostate cancer cell-lines and xenograft tumor models, and induce expression of reporter and therapeutic cytokine genes.


METHODS
Infection was confirmed by cellular staining for the beta-galactosidase reporter gene product, and by EM. Human GM-CSF production following DISC-hGMCSF infection was measured using ELISA. The metabolic activity of infected cells was determined by NADP/NADPH assay. Cell death was estimated by cell-cycle analysis using flow cytometry with propidium iodide staining.


RESULTS
Infection of DU145, PC3 and LNCaP cells with DISC-HSV was dose dependent. Cells infected with DISC-hGM-CSF released significant levels of hGM-CSF for 3 days. NADP/NADPH assay suggested that infected cells continued to be metabolically active for 3 days post-infection, which was consistent with flow cytometry findings that cell death did not occur within 7 days of infection. Tumor xenografts injected with DISC-HSV expressed beta-galactosidase, and intracellular viral particles were demonstrated using EM.


CONCLUSIONS
We have previously reported the rejection of established tumors following intra-tumoral injection of DISC-GMCSF. This study demonstrates the ability of DISC-HSV to infect prostate cancer and express GMCSF at significant levels. We suggest that prostate cancer is a potential target for therapy using DISC-HSV containing GM-CSF.
Parkinson
Richard J
RJ
School of Science, Nottingham Trent University, Clifton, Nottingham, United Kingdom.
Mian
Shahid
S
Bishop
Michael C
MC
Gray
Trevor
T
Li
Geng
G
McArdle
Stephanie E B
SE
Ali
Selman
S
Rees
Robert C
RC
D000818:Animals; D015870:Gene Expression; D017930:Genes, Reporter; D015316:Genetic Therapy / Q000379:methods*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics* / Q000378:metabolism; D006561:Herpes Simplex / Q000378:metabolism*; D006801:Humans; D007167:Immunotherapy / Q000379:methods; D008297:Male; D051379:Mice; D008819:Mice, Nude; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000628:therapy* / Q000821:virology; D018139:Simplexvirus / Q000235:genetics* / Q000254:growth & development; D014407:Tumor Cells, Cultured / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays; D001616:beta-Galactosidase / Q000235:genetics
D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D001616:beta-Galactosidase