title: Delivery of the bacterial nitroreductase gene into endothelial cells prolongs the survival of tumour-bearing mice by bystander mechanisms.
abstract: A current target of cancer gene therapy is tumour vasculature. We present a gene-directed enzyme prodrug therapy (GDEPT) approach to target tumours in vivo by modifying endothelial cells (ECs) with the Escherichia coli nitroreductase (ntr) gene. Firstly, we isolated two ntr-transfected clones of the human umbilical vein endothelial cell line (HUV-EC-C/ntr+) that showed a differential sensitivity in vitro to the prodrug, dinitroaziridinylbenzamide (CB1954), with respect to untransfected HUV-EC-C cells (HUV-EC-C/ntr-). Then, these cells were injected subcutaneously into nude mice, either in association with the murine melanoma cell line, B16-F10 ('co-injected' groups), or into tumour-bearing animals ('post-injected' groups). After intratumoural injection, we demonstrated, using PCR analysis, that human ECs resided in the site of the injection without spreading to other organs, such as the liver or lung. After the treatment of mice with CB1954, we observed a prolonged survival of animals carrying the HUV-EC-C/ntr+ clones with respect to control animals injected with HUV-EC-C/ntr- cells. Significant differences in tumour growth were also observed and, after immuno-histological analysis, tumours carrying HUV-EC-C/ntr+ clones showed large areas of tumour necrosis, probably due to tumour ischemia, as well as the presence of major histocompatibility complex class-II (MHC-II) positive cells. Collectively, our data indicate that targeting of the tumour vasculature by this GDEPT strategy may be an efficient approach for cancer treatment in vivo, depending on two possible bystander mechanisms based on tumour ischemia and immune cell activation.
authors.affiliation: UPRES-2360 Ciblage et imagerie fonctionnels de la progression tumorale, Bobigny, France.
authors.forename: Malika
authors.initials: M
authors.lastname: Benouchan
authors.forename: Filipe
authors.initials: F
authors.lastname: Do Nascimento
authors.forename: Gérard Y
authors.initials: GY
authors.lastname: Perret
authors.forename: Bruno M
authors.initials: BM
authors.lastname: Colombo
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D001388:Aziridines / Q000494:pharmacology; D024201:Bystander Effect; D002470:Cell Survival; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D016503:Drug Delivery Systems; D042783:Endothelial Cells / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000187:drug effects; D004926:Escherichia coli / Q000235:genetics; D015316:Genetic Therapy; D006801:Humans; D008546:Melanoma, Experimental / Q000098:blood supply* / Q000517:prevention & control; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D009389:Neovascularization, Pathologic / Q000517:prevention & control; D009601:Nitroreductases / Q000235:genetics* / Q000378:metabolism; D011355:Prodrugs / Q000494:pharmacology; D014162:Transfection
chemical_list: D000970:Antineoplastic Agents; D001388:Aziridines; D011355:Prodrugs; C100099:tretazicar; D009601:Nitroreductases