title: Developing adenoviral vectors encoding therapeutic genes toxic to host cells: comparing binary and single-inducible vectors expressing truncated E2F-1.
abstract: Adenoviral vectors are highly efficient at transferring genes into cells and are broadly used in cancer gene therapy. However, many therapeutic genes are toxic to vector host cells and thus inhibit vector production. The truncated form of E2F-1 (E2Ftr), which lacks the transactivation domain, can significantly induce cancer cell apoptosis, but is also toxic to HEK-293 cells and inhibits adenovirus replication. To overcome this, we have developed binary- and single-vector systems with a modified tetracycline-off inducible promoter to control E2Ftr expression. We compared several vectors and found that the structure of expression cassettes in vectors significantly affects E2Ftr expression. One construct expresses high levels of inducible E2Ftr and efficiently causes apoptotic cancer cell death by activation of caspase-3. The approach developed in this study may be applied in other viral vectors for encoding therapeutic genes that are toxic to their host cells and/or inhibit vector propagation.
authors.affiliation: Department of Surgery, University of Louisville School of Medicine, Louisville, KY 40292, USA.
authors.forename: Jorge G
authors.initials: JG
authors.lastname: Gomez-Gutierrez
authors.forename: Xiao-Mei
authors.initials: XM
authors.lastname: Rao
authors.forename: Aracely
authors.initials: A
authors.lastname: Garcia-Garcia
authors.forename: Hongying
authors.initials: H
authors.lastname: Hao
authors.forename: Kelly M
authors.initials: KM
authors.lastname: McMasters
authors.forename: H Sam
authors.initials: HS
authors.lastname: Zhou
mesh_terms: D000256:Adenoviridae / Q000235:genetics* / Q000254:growth & development; D017502:Adenovirus E2 Proteins / Q000235:genetics*; D018929:Cell Culture Techniques / Q000379:methods; D002460:Cell Line; D015870:Gene Expression; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors; D006801:Humans; D011994:Recombinant Proteins / Q000235:genetics* / Q000633:toxicity*; D015533:Transcriptional Activation
chemical_list: D017502:Adenovirus E2 Proteins; D011994:Recombinant Proteins