RT Journal Article
SR Electronic
T1 MicroRNA Regulation of Oncolytic Herpes Simplex Virus-1 for Selective Killing of Prostate Cancer Cells
JF Clinical Cancer Research
JO Clin Cancer Res
FD American Association for Cancer Research
DO 10.1158/1078-0432.CCR-09-0051
A1 Lee, Cleo Y. F.
A1 Rennie, Paul S.
A1 Jia, William W.G.
YR 2009
UL http://clincancerres.aacrjournals.org/content/early/2009/08/10/1078-0432.CCR-09-0051.abstract
AB Purpose: Advanced castration-resistant prostate cancer, for which there are few treatment options, remains one of the leading causes of cancer death. MicroRNAs (miRNA) have provided a new opportunity for more stringent regulation of tumor-specific viral replication. The purpose of this study was to provide a proof-of-principle that miRNA-regulated oncolytic herpes simplex virus-1 (HSV-1) virus can selectively target cancer cells with reduced toxicity to normal tissues.Experimental Design: We incorporated multiple copies of miRNA complementary target sequences (for miR-143 or miR-145) into the 3′-untranslated region (3′-UTR) of an HSV-1 essential viral gene, ICP4, to create CMV-ICP4-143T and CMV-ICP4-145T amplicon viruses and tested their targeting specificity and efficacy both in vitro and in vivo.Results: Although miR-143 and miR-145 are highly expressed in normal tissues, they are significantly down-regulated in prostate cancer cells. We further showed that miR-143 and miR-145 inhibited the expression of the ICP4 gene at the translational level by targeting the corresponding 3′-UTR in a dose-dependent manner. This enabled selective viral replication in prostate cancer cells. When mice bearing LNCaP human prostate tumors were treated with these miRNA-regulated oncolytic viruses, a >80% reduction in tumor volume was observed, with significantly attenuated virulence to normal tissues in comparison with control amplicon viruses not carrying these 3′-UTR sequences.Conclusion: Our study is the first to show that inclusion of specific miRNA target sequences into the 3′-UTR of an essential HSV-1 gene is a viable strategy for restricting viral replication and oncolysis to cancer cells while sparing normal tissues. (Clin Cancer Res 2009;15(16):5126–35)