title: Therapeutic improvement of a stroma-targeted CRAd by incorporating motives responsive to the melanoma microenvironment.
abstract: We have previously designed a conditionally replicative oncolytic adenovirus (CRAd) named Ad-F512 that can target both the stromal and the malignant melanoma cell compartments. The replication capacity of this CRAd is driven by a 0.5-Kb SPARC promoter fragment (named F512). To improve CRAd's efficacy, we cloned into F512 motives responsive to hypoxia (hypoxia-responsive element (HRE)) and inflammation (nuclear factor kappa B) to obtain a chimeric promoter named κBF512HRE. Using luciferase as a reporter gene, we observed 10-15-fold increased activity under hypoxia and 10-80-fold induction upon tumor necrosis factor-α addition. We next constructed a CRAd (Ad-κBF512HRE) where E1A activity was under κBF512HRE regulation. Treatment of nude mice harboring established tumors made of a mix of SB2 melanoma cells and WI-38 fibroblasts with Ad-κBF512HRE led to the complete elimination of tumors in 100% of mice (8/8). Moreover, Ad-5/3-κBF512HRE, a viral variant pseudotyped with a chimeric 5/3 fiber, exerted a strong lytic effect on CAR-negative melanoma cells and was highly effective in vivo on established tumors made of melanoma cells and WI-38 fibroblasts, leading to the complete elimination of 4/5 tumors. These results indicate that this improved stroma-targeted oncolytic adenovirus can override the resistance of melanoma tumors and might become of significant importance for melanoma therapeutics.
authors.affiliation: Laboratory of Molecular and Cellular Therapy, Leloir Institute-CONICET, Buenos Aires, Argentina.
authors.forename: Diego L
authors.initials: DL
authors.lastname: Viale
authors.affiliation: Laboratory of Molecular and Cellular Therapy, Leloir Institute-CONICET, Buenos Aires, Argentina.
authors.forename: Eduardo G
authors.initials: EG
authors.lastname: Cafferata
authors.affiliation: Bone and Joint Research Unit, University of London, London, UK.
authors.forename: David
authors.initials: D
authors.lastname: Gould
authors.affiliation: Laboratory of Molecular and Cellular Therapy, Leloir Institute-CONICET, Buenos Aires, Argentina.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Rotondaro
authors.affiliation: Bone and Joint Research Unit, University of London, London, UK.
authors.forename: Yuti
authors.initials: Y
authors.lastname: Chernajovsky
authors.affiliation: Division of Human Gene Therapy, Departments of Medicine, Obstetrics and Gynecology, Pathology and Surgery, Gene Therapy Center, University of Alabama at Birmingham, Birmingham, Alabama, USA; Biologic Therapeutics Center, Division of Cancer Biology, Department of Radiation Oncology, Washington University School of Medicine, St Louis, Missouri, USA.
authors.forename: David T
authors.initials: DT
authors.lastname: Curiel
authors.affiliation: Laboratory of Molecular and Cellular Therapy, Leloir Institute-CONICET, Buenos Aires, Argentina. Electronic address: opodhajcer@leloir.org.ar.
authors.forename: Osvaldo L
authors.initials: OL
authors.lastname: Podhajcer
authors.affiliation: Laboratory of Molecular and Cellular Therapy, Leloir Institute-CONICET, Buenos Aires, Argentina. Electronic address: mlopez@leloir.org.ar.
authors.forename: M
authors.initials: M
authors.lastname: Veronica Lopez
mesh_terms: D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D045744:Cell Line, Tumor; D005347:Fibroblasts / Q000166:cytology; D057809:HEK293 Cells; D006801:Humans; D008297:Male; D008545:Melanoma / Q000473:pathology / Q000628:therapy*; D051379:Mice; D008819:Mice, Nude; D050130:Oncolytic Virotherapy / Q000379:methods*; D011401:Promoter Regions, Genetic / Q000235:genetics; D012878:Skin Neoplasms / Q000473:pathology / Q000628:therapy*; D017154:Stromal Cells / Q000473:pathology / Q000821:virology*; D059016:Tumor Microenvironment / Q000502:physiology*; D023041:Xenograft Model Antitumor Assays