title: Amplified Muc1-specific gene expression in colon cancer cells utilizing a binary system in adenoviral vectors.
abstract: Mucin-1 is expressed in a variety of colon carcinomas and Muc-1/DF3 promoters have been utilized to reduce systemic toxicity through specific gene expression. To overcome weak expression, which is much lower than the widely used cytomegalovirus-promoter (CMV), new adenoviral vectors containing a binary system of transgene amplification have been developed. The Muc-1/DF3 promoter was used to control the expression of a Gal4VP16 fusion protein. This vector also contained Gal4 binding sites enabling the fusion protein to act as a transactivator, inducing transgene expression within the same construct. Mucin-1 expression was analyzed in a variety of colon cancer cell lines. After infection with recombinant adenoviruses, transgene expression was quantified using the luciferase system. Integration of the Gal4VP16-binary resulted in an up to 250-fold increase of Muc-1/DF3-specific gene expression. In mucin-positive cell lines utilizing this amplified Muc-1/DF3 promoter, expression was up to 590-fold higher as compared to the CMV-promoter. Western blot detected the presence of Gal4VP16 in infected muc-1-positive but not-negative cell lines. These new adenoviral vectors combing highly efficient and specific transgene expression and will contribute to the safety and efficacy of experimental approaches in cancer gene therapy.
authors.affiliation: Department of Medicine and Gastroenterology, University of Hamburg, University Hospital Hamburg-Eppendort, Martinistrasse 52, D-20246 Hamburg, Germany. block@uke.uni-hamburg.de
authors.forename: Andreas
authors.initials: A
authors.lastname: Block
authors.forename: Dragan
authors.initials: D
authors.lastname: Milasinovic
authors.forename: Juergen
authors.initials: J
authors.lastname: Mueller
authors.forename: Peter
authors.initials: P
authors.lastname: Schaefer
authors.forename: Hansjoerg
authors.initials: H
authors.lastname: Schaefer
authors.forename: Heiner
authors.initials: H
authors.lastname: Greten
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D001483:Base Sequence; D015153:Blotting, Western; D003110:Colonic Neoplasms / Q000235:genetics* / Q000378:metabolism; D003587:Cytomegalovirus / Q000235:genetics; D005784:Gene Amplification; D015870:Gene Expression; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D018396:Mucin-1 / Q000096:biosynthesis / Q000235:genetics*; D011401:Promoter Regions, Genetic; D015534:Trans-Activators / Q000235:genetics; D015533:Transcriptional Activation; D019076:Transgenes / Q000235:genetics; D014407:Tumor Cells, Cultured
chemical_list: C070633:Gal-VP16; D018396:Mucin-1; D015534:Trans-Activators