title: Short hairpin RNA-expressing oncolytic adenovirus-mediated inhibition of IL-8: effects on antiangiogenesis and tumor growth inhibition.
abstract: RNA interference, due to its target specificity, may be highly effective as a novel therapeutic modality, but direct delivery of synthetic small interfering RNA still remains a major obstacle for this approach. To induce long-term expression and specific gene silencing, novel delivery vector system is also required. In this study, we have generated an efficient oncolytic adenovirus (Ad)-based short hairpin (shRNA) expression system (Ad-DeltaB7-U6shIL8) against IL-8, a potent proangiogenic factor. To demonstrate IL-8-specificity of this newly engineered Ad-based shRNA, we also manufactured replication-incompetent Ads (Ad-DeltaE1-CMVshIL8 and Ad-DeltaE1-U6shIL8) under the control of the cytomegalovirus (CMV) and U6 promoters, respectively. Ad-DeltaE1-U6shIL8 was highly effective in reducing IL-8 expression, and was much more effective in driving IL-8-specific shRNA than the CMV promoter-driven vector. The reduced IL-8 expression then translated into decreased angiogenesis in vitro as measured by migration, tube formation and rat aortic ring sprouting assays. In addition to its effect on endothelial cells, Ad-DeltaE1-U6shIL8 also effectively suppressed the migration and invasion of cancer cells. In vivo, intratumoral injection of Ad-DeltaB7-U6shIL8 significantly inhibited the growth of Hep3B and A549 human tumor xenografts. Histopathological analysis of Ad-DeltaB7-U6shIL8-treated tumors revealed an increase in apoptotic cells and a reduction in vessel density. Finally, Ad-DeltaB7-U6shIL8 was also shown to inhibit the growth of disseminated MDA-MB-231 breast cancer metastases. Taken together, these findings demonstrate the utility and antitumor effectiveness of oncolytic Ad expressing shRNA against IL-8.
authors.affiliation: Brain Korea 21 Project for Medical Sciences, Institute for Cancer Research, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: J Y
authors.initials: JY
authors.lastname: Yoo
authors.forename: J-H
authors.initials: JH
authors.lastname: Kim
authors.forename: J
authors.initials: J
authors.lastname: Kim
authors.forename: J-H
authors.initials: JH
authors.lastname: Huang
authors.forename: S N
authors.initials: SN
authors.lastname: Zhang
authors.forename: Y-A
authors.initials: YA
authors.lastname: Kang
authors.forename: H
authors.initials: H
authors.lastname: Kim
authors.forename: C-O
authors.initials: CO
authors.lastname: Yun
mesh_terms: D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D001943:Breast Neoplasms / Q000628:therapy*; D045744:Cell Line, Tumor; D042783:Endothelial Cells / Q000378:metabolism; D005260:Female; D020868:Gene Silencing; D005818:Genetic Engineering; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D016209:Interleukin-8 / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D008175:Lung Neoplasms / Q000556:secondary / Q000628:therapy; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000032:analysis / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D009389:Neovascularization, Pathologic / Q000235:genetics; D050130:Oncolytic Virotherapy / Q000379:methods*; D011401:Promoter Regions, Genetic; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000008:administration & dosage*; D014161:Transduction, Genetic / Q000379:methods; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
chemical_list: D016209:Interleukin-8; D034741:RNA, Small Interfering; D042461:Vascular Endothelial Growth Factor A; D020778:Matrix Metalloproteinase 2