Inducible nitric oxide synthase activity is essential for inhibition of prostatic tumor growth by interferon-beta gene therapy.
We have previously reported that adenoviral vector-mediated interferon (IFN)-beta gene therapy inhibits orthotopic growth of human prostate cancer cells in nude mice. The purpose of this study was to determine efficacy and mechanisms of this therapy in immune-competent mice. TRAMP-C2Re3 mouse prostate cancer cells infected with 100 multiplicity of infection (MOI) of adenoviral vector encoding for mouse IFN-beta (AdmIFN-beta), but not AdE/1 (a control adenoviral vector), produced approximately 60 ng/10(5) cells/24 h of IFN-beta. The tumorigenicity of AdmIFN-beta-transduced cells was dramatically reduced in the prostates of C57BL/6 mice. A single intratumoral injection of 2 x 10(9) PFU (plaque-forming unit) of AdmIFN-beta inhibited tumor growth by 70% and prolonged survival of tumor-bearing mice. Intriguingly, this AdmIFN-beta therapy did not alter the growth of tumors in inducible nitric oxide synthase (iNOS)-null C57BL/6 mice. Immunohistochemical analysis revealed that treatment of tumors with AdmIFN-beta in wild-type C57BL/6 mice led to increased iNOS expression, decreased microvessel density, decreased cell proliferation, and increased apoptosis. Furthermore, quantitative reverse-transcriptional PCR analysis showed that AdmIFN-beta therapy, in C57BL/6 but not the iNOS-null counterparts, reduced levels of the mRNAs for angiopoietin, basic fibroblast growth factor, matrix metalloproteinase-9, transforming growth factor-beta1, vascular endothelial growth factor (VEGF)-A, and VEGF-B, as well as the antiapoptotic molecule endothelin-1. These data indicated that IFN-beta gene therapy could be effective alternative for the treatment of locally advanced prostate cancer and suggest an obligatory role of NO in IFN-beta antitumoral effects in vivo.
Department of Neuro-Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA.
M V
MV
Olson
J
J
Lee
F
F
Zhang
A
A
Wang
Z
Z
Dong
D000256:Adenoviridae; D000818:Animals; D016207:Cytokines / Q000378:metabolism; D019332:Endothelin-1 / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D015316:Genetic Therapy; D016899:Interferon-beta / Q000378:metabolism; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051379:Mice; D008817:Mice, Mutant Strains; D009374:Neoplasms, Experimental / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D052247:Nitric Oxide Synthase Type II / Q000172:deficiency / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000628:therapy*; D014161:Transduction, Genetic
D016207:Cytokines; D019332:Endothelin-1; D016899:Interferon-beta; D052247:Nitric Oxide Synthase Type II; D020780:Matrix Metalloproteinase 9; C501830:Mmp9 protein, mouse