title: CAR is a cell-cell adhesion protein in human cancer cells and is expressionally modulated by dexamethasone, TNFalpha, and TGFbeta.
abstract: The coxsackie adenovirus receptor (CAR) has become of interest for gene therapy due to its crucial function in adenoviral cell entry. In clinical trials with adenoviral vectors, dexamethasone is applied to reduce side effects such as inflammatory reactions or emesis. By using a beta-galactosidase-expressing adenovirus (AdGal), we observed that dexamethasone treatment resulted in decreased adenoviral gene transfer into human cancer cells. Expression of CAR and integrin alpha5beta1 was transcriptionally downregulated by dexamethasone as shown for HeLa cervical cancer cells and U87MG glioblastoma cells. TNFalpha increased CAR expression in HeLa and ovarian cancer cells but decreased CAR expression in U87MG cells. In all tested cancer cell lines, TNFalpha induced a significant increase in the expression of adenovirus-binding integrins alpha5beta1, alphavbeta3 and alphavbeta5. Pretreatment with TNFalpha increased AdGal gene transfer into cancer cells and enhanced the cytotoxic effect of a p53-expressing adenovirus. In contrast, TGFbeta reduced CAR expression level and adenoviral gene transfer into OV-UL-2 ovarian cancer cells. Confocal immunofluorescence analysis revealed localization of CAR at cell-cell adhesions in several human cancer cell lines and disruption of cell-cell contacts increased adenoviral gene transfer into human cancer cells. In clinical cancer gene therapy, efficiency of adenoviral gene delivery could be altered by cell adhesion, TNFalpha, TGFbeta, and dexamethasone.
authors.affiliation: Department of Obstetrics and Gynecology, Molecular Biology Laboratory, University of Freiburg, Hugstetter Strasse 55, D-79106 Freiburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Brüning
authors.forename: I B
authors.initials: IB
authors.lastname: Runnebaum
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000893:Anti-Inflammatory Agents / Q000009:adverse effects* / Q000494:pharmacology; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000235:genetics*; D002448:Cell Adhesion / Q000187:drug effects; D016207:Cytokines / Q000494:pharmacology*; D003907:Dexamethasone / Q000009:adverse effects* / Q000494:pharmacology; D005136:Eye Proteins; D005260:Female; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D005786:Gene Expression Regulation / Q000187:drug effects*; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000008:administration & dosage; D006367:HeLa Cells; D051597:Hippocalcin; D006801:Humans; D039081:Integrin alpha5beta1 / Q000235:genetics; D039302:Integrin alphaVbeta3 / Q000235:genetics; D016023:Integrins / Q000235:genetics; D008074:Lipoproteins; D009369:Neoplasms / Q000378:metabolism / Q000628:therapy*; D009419:Nerve Tissue Proteins; D019030:Receptors, Vitronectin / Q000235:genetics; D051603:Recoverin; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014161:Transduction, Genetic / Q000379:methods; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D019076:Transgenes; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D001616:beta-Galactosidase / Q000235:genetics
chemical_list: D000893:Anti-Inflammatory Agents; D002135:Calcium-Binding Proteins; D016207:Cytokines; D005136:Eye Proteins; D039081:Integrin alpha5beta1; D039302:Integrin alphaVbeta3; D016023:Integrins; D008074:Lipoproteins; D009419:Nerve Tissue Proteins; C496731:RCVRN protein, human; D019030:Receptors, Vitronectin; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; C064660:integrin alphaVbeta5; D051603:Recoverin; D051597:Hippocalcin; D003907:Dexamethasone; D001616:beta-Galactosidase