Cotargeting tumor and tumor endothelium effectively inhibits the growth of human prostate cancer in adenovirus-mediated antiangiogenesis and oncolysis combination therapy.
Tumor-endothelial interaction contributes to local prostate tumor growth and distant metastasis. In this communication, we designed a novel approach to target both cancer cells and their "crosstalk" with surrounding microvascular endothelium in an experimental hormone refractory human prostate cancer model. We evaluated the in vitro and in vivo synergistic and/or additive effects of a combination of conditional oncolytic adenovirus plus an adenoviral-mediated antiangiogenic therapy. In the in vitro study, we demonstrated that human umbilical vein endothelial cells (HUVEC) and human C4-2 androgen-independent (AI) prostate cancer cells, when infected with an antiangiogenic adenoviral (Ad)-Flk1-Fc vector secreting a soluble form of Flk1, showed dramatically inhibited proliferation, migration and tubular formation of HUVEC endothelial cells. C4-2 cells showed maximal growth inhibition when coinfected with Ad-Flk1-Fc and Ad-hOC-E1, a conditional replication-competent Ad vector with viral replication driven by a human osteocalcin (hOC) promoter targeting both prostate cancer epithelial and stromal cells. Using a three-dimensional (3D) coculture model, we found that targeting C4-2 cells with Ad-hOC-E1 markedly decreased tubular formation in HUVEC, as visualized by confocal microscopy. In a subcutaneous C4-2 tumor xenograft model, tumor volume was decreased by 40-60% in animals treated with Ad-Flk1-Fc or Ad-hOC-E1 plus vitamin D3 alone and by 90% in a combined treatment group, compared to untreated animals in an 8-week treatment period. Moreover, three of 10 (30%) pre-established tumors completely regressed when animals received combination therapy. Cotargeting tumor and tumor endothelium could be a promising gene therapy strategy for the treatment of both localized and metastatic human prostate cancer.
Jin
Fengshuo
F
Department of Urology, Molecular Urology and Therapeutic Program, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
Xie
Zhihui
Z
Kuo
Calvin J
CJ
Chung
Leland W K
LW
Hsieh
Chia-Ling
CL
D000230:Adenocarcinoma / Q000188:drug therapy / Q000235:genetics / Q000628:therapy*; D000256:Adenoviridae / Q000235:genetics; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage / Q000235:genetics / Q000627:therapeutic use; D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002762:Cholecalciferol / Q000008:administration & dosage / Q000627:therapeutic use; D042783:Endothelial Cells / Q000378:metabolism* / Q000473:pathology; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage / Q000235:genetics / Q000627:therapeutic use; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008819:Mice, Nude; D018613:Microscopy, Confocal; D009362:Neoplasm Metastasis / Q000188:drug therapy / Q000235:genetics / Q000628:therapy*; D009389:Neovascularization, Pathologic / Q000517:prevention & control*; D015675:Osteocalcin / Q000008:administration & dosage / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000628:therapy*; D013778:Tetrazolium Salts; D013844:Thiazoles; D014183:Transplantation, Heterologous; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000008:administration & dosage / Q000235:genetics / Q000627:therapeutic use*
D020533:Angiogenesis Inhibitors; D013778:Tetrazolium Salts; D013844:Thiazoles; D015675:Osteocalcin; D002762:Cholecalciferol; D040301:Vascular Endothelial Growth Factor Receptor-2; C022616:thiazolyl blue