title: Assessing optimal promoter activity for constructs in gastrointestinal gene therapy.
abstract: BACKGROUND
  During recent decades, studies of various cancer-related genes has led to a growing understanding of molecular mechanisms of gastrointestinal cancer resulting in a genetic progression model. Nevertheless, with a few exceptions, our knowledge of participating genes has not been exploited for gene therapeutic approaches. Therefore, we monitored the promoter activity of genes shown to be significantly expressed in gastrointestinal tumors to select optimally active promoters for recombinant DNA constructs. Such molecules will contain a suicide gene under a suitable cell type-specific regulatory element.
  
  
  METHODS
  Using promoter-reporter gene (luciferase) constructs we compared the activities of KRT19, TFF1, SEL1L, MUC4, MUC1, CEL and hTERT by transfecting them into the gastrointestinal cell lines MKN45 and DAN-G for transient expression. Furthermore we tested the endogenous expression of these genes by RT-PCR.
  
  
  RESULTS
  From a selection of 9 promoter constructs SEL1L, KRT19 and MUC1 displayed the highest activity levels while others were moderately expressed.
  
  
  CONCLUSIONS
  These three appear the most capable ones to drive suicide genes, like thymidine kinase or cytosine deaminase, a study presently initiated.
authors.affiliation: Division of Molecular Genetics, University of Tübingen, Wilhelmstr 27, D-72074 Tübingen, Germany.
authors.forename: Rabea
authors.initials: R
authors.lastname: Mathlouthi
authors.forename: Susanne
authors.initials: S
authors.lastname: Aberle
authors.forename: Nicola
authors.initials: N
authors.lastname: Schug
authors.forename: Jan H
authors.initials: JH
authors.lastname: Küpper
authors.forename: Kristina
authors.initials: K
authors.lastname: Schröder
authors.forename: Gerhard
authors.initials: G
authors.lastname: Seitz
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Blin
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000628:therapy*; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins; D005091:Exons / Q000235:genetics; D005770:Gastrointestinal Neoplasms / Q000235:genetics / Q000628:therapy*; D015316:Genetic Therapy / Q000379:methods*; D019073:HT29 Cells; D006801:Humans; D007633:Keratins / Q000235:genetics; D008156:Luciferases / Q000235:genetics; D018396:Mucin-1 / Q000235:genetics; D055262:Mucin-2; D009077:Mucins / Q000235:genetics; D010455:Peptides / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011506:Proteins / Q000235:genetics; D019098:Telomerase / Q000235:genetics; D014162:Transfection; D000071163:Trefoil Factor-1; D025521:Tumor Suppressor Proteins
chemical_list: D004268:DNA-Binding Proteins; C524625:MUC2 protein, human; D018396:Mucin-1; D055262:Mucin-2; D009077:Mucins; D010455:Peptides; D011506:Proteins; C117384:SEL1L protein, human; C051838:TFF1 protein, human; D000071163:Trefoil Factor-1; D025521:Tumor Suppressor Proteins; D007633:Keratins; D008156:Luciferases; D019098:Telomerase