title: Tumor-specific adenoviral gene therapy: transcriptional repression of gene expression by utilizing p53-signal transduction pathways.
abstract: Adenoviral gene expression that is repressed by p53 in nontransformed cells could provide a tumor-specific gene therapy approach for a large subset of tumors. Adenoviral infection in vivo induces stabilization of p53, which can be utilized for a strategy that includes p53-dependent expression of a transcriptional repressor and a target promoter,which is highly susceptible for transcriptional repression. Therefore, we constructed different versions of CMV-promoters (CMVgal) with binding sites for GAL4-DBD and investigated 11 GAL4-DBD fusion proteins to elucidate the most effective repressor domain to silence CMVgal activity. The transcriptional repressor GAL4-KRAB-A under control of a p53-dependent promoter facilitates strong CMVgal-mediated gene expression specifically in p53 mutant cells by a double-recombinant adenoviral vector (Ad-RGCdR). GAL4-KRAB-A mediates strong transcriptional repression of Ad-RGCdR in p53 wild-type cells, which could be further enhanced by preactivation of p53-signalling following low-dose chemotherapy prior to adenoviral infection. By utilizing p53 signalling involved in chemotherapy and adenoviral infection, more than 99% of Ad-RGCdR gene expression could be repressed in p53 wild-type cells. Controlled gene expression from CMVgal promoters by transcriptional repression utilizing functional p53 signalling thus provides a very effective tool for tumor-specific adenoviral gene therapy.
authors.affiliation: Department of Gastroenterology, Hepatology and Endocrinology, Medical School Hannover, Carl Neuberg Str. 1, 30625 Hannover, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Kühnel
authors.forename: Lars
authors.initials: L
authors.lastname: Zender
authors.forename: Thomas
authors.initials: T
authors.lastname: Wirth
authors.forename: Bernd
authors.initials: B
authors.lastname: Schulte
authors.forename: Christian
authors.initials: C
authors.lastname: Trautwein
authors.forename: Michael
authors.initials: M
authors.lastname: Manns
authors.forename: Stefan
authors.initials: S
authors.lastname: Kubicka
mesh_terms: D000256:Adenoviridae / Q000235:genetics* / Q000502:physiology; D000818:Animals; D045744:Cell Line, Tumor; D003587:Cytomegalovirus / Q000235:genetics; D015536:Down-Regulation; D015972:Gene Expression Regulation, Neoplastic; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D008297:Male; D051379:Mice; D009369:Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D009928:Organ Specificity; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics; D019076:Transgenes / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000378:metabolism*
chemical_list: D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53