title: Systemic administration of a PEGylated adenovirus vector with a cancer-specific promoter is effective in a mouse model of metastasis.
abstract: Cancer gene therapy by adenovirus vectors (Advs) for metastatic cancer is limited because systemic administration of Adv produces low therapeutic effect and severe side effects. In this study, we generated a dual cancer-specific targeting vector system by using PEGylation and the telomere reverse transcriptase (TERT) promoter and attempted to treat experimental metastases through systemic administration of the vectors. We first optimized the molecular size of PEG and modification ratios used to create PEG-Ads. Systemic administration of PEG-Ad with 20-kDa PEG at a 45% modification ratio (PEG[20K/45%]-Ad) resulted in higher tumor-selective transgene expression than unmodified Adv. Next, we examined the effectiveness against metastases and side effects of a TERT promoter-driven PEG[20K/45%]-Ad containing the herpes simplex virus thymidine kinase (HSVtk) gene (PEG-Ad-TERT/HSVtk). Systemic administration of PEG-Ad-TERT/HSVtk showed superior antitumor effects against metastases with negligible side effects. A cytomegalovirus (CMV) promoter-driven PEG[20K/45%]-Ad also produced antimetastatic effects, but these were accompanied by side effects. Combining PEG-Ad-TERT/HSVtk with etoposide or 5-fluorouracil enhanced the therapeutic effects with negligible side effects. These results suggest that modification with 20-kDa PEG at a 45% modification ratio is the optimal condition for PEGylation of Adv, and PEG-Ad-TERT/HSVtk is a prototype Adv for systemic cancer gene therapy against metastases.
authors.affiliation: Department of Biotechnology and Therapeutics, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan.
authors.forename: X
authors.initials: X
authors.lastname: Yao
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshioka
authors.forename: T
authors.initials: T
authors.lastname: Morishige
authors.forename: Y
authors.initials: Y
authors.lastname: Eto
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
authors.forename: Y
authors.initials: Y
authors.lastname: Okada
authors.forename: H
authors.initials: H
authors.lastname: Mizuguchi
authors.forename: Y
authors.initials: Y
authors.lastname: Mukai
authors.forename: N
authors.initials: N
authors.lastname: Okada
authors.forename: S
authors.initials: S
authors.lastname: Nakagawa
mesh_terms: D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage; D003131:Combined Modality Therapy; D004195:Disease Models, Animal; D005472:Fluorouracil; D018390:Gene Targeting; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D051379:Mice; D009362:Neoplasm Metastasis / Q000628:therapy*; D009369:Neoplasms / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D011092:Polyethylene Glycols; D011401:Promoter Regions, Genetic; D019098:Telomerase / Q000235:genetics; D014158:Transcription, Genetic; D014161:Transduction, Genetic
chemical_list: D000970:Antineoplastic Agents; D011092:Polyethylene Glycols; D019098:Telomerase; D005472:Fluorouracil