title: Mesalazine and thymoquinone attenuate intestinal tumour development in Msh2(loxP/loxP) Villin-Cre mice.
abstract: OBJECTIVE
  Lynch syndrome is caused by germline mutations in DNA mismatch repair genes leading to microsatellite instability (MSI) and colorectal cancer. Mesalazine, commonly used for the treatment of UC, reduces MSI in vitro. Here, we tested natural compounds for such activity and applied mesalazine and thymoquinone in a Msh2(loxP/loxP) Villin-Cre mouse model for Lynch syndrome.
  
  
  METHODS
  Flow cytometry was used for quantitation of mutation rates at a CA13 microsatellite in human colon cancer (HCT116) cells that had been stably transfected with pIREShyg2-enhanced green fluorescent protein/CA13, a reporter for frameshift mutations. Mice were treated for 43 weeks with mesalazine, thymoquinone or control chow. Intestines were analysed for tumour incidence, tumour multiplicity and size. MSI testing was performed from microdissected normal intestinal or tumour tissue, compared with mouse tails and quantified by the number of mutations per marker (NMPM).
  
  
  RESULTS
  Besides mesalazine, thymoquinone significantly improved replication fidelity at 1.25 and 2.5 µM in HCT116 cells. In Msh2(loxP/loxP) Villin-Cre mice, tumour incidence was reduced by mesalazine from 94% to 69% (p=0.04) and to 56% (p=0.003) by thymoquinone. The mean number of tumours was reduced from 3.1 to 1.4 by mesalazine (p=0.004) and to 1.1 by thymoquinone (p<0.001). Interestingly, MSI was reduced in normal intestinal tissue from 1.5 to 1.2 NMPM (p=0.006) and to 1.1 NMPM (p=0.01) by mesalazine and thymoquinone, respectively. Thymoquinone, but not mesalazine, reduced MSI in tumours.
  
  
  CONCLUSIONS
  Mesalazine and thymoquinone reduce tumour incidence and multiplicity in Msh2(loxP/loxP) Villin-Cre mice by reduction of MSI independent of a functional mismatch repair system. Both substances are candidate compounds for chemoprevention in Lynch syndrome mutation carriers.
authors.affiliation: Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Kortüm
authors.affiliation: Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria.
authors.forename: Christoph
authors.initials: C
authors.lastname: Campregher
authors.affiliation: Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria.
authors.forename: Michaela
authors.initials: M
authors.lastname: Lang
authors.affiliation: Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria.
authors.forename: Vineeta
authors.initials: V
authors.lastname: Khare
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine 3, Medical University of Vienna, Vienna, Austria.
authors.forename: Matthias
authors.initials: M
authors.lastname: Pinter
authors.affiliation: Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria Division of Gastroenterology and Hepatology, Department of Medicine 3, Medical University of Vienna, Vienna, Austria.
authors.forename: Rayko
authors.initials: R
authors.lastname: Evstatiev
authors.affiliation: Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria.
authors.forename: Gerald
authors.initials: G
authors.lastname: Schmid
authors.affiliation: Center for Medical Statistics, Informatics, and Intelligent Systems, Medical University of Vienna, Vienna, Austria.
authors.forename: Martina
authors.initials: M
authors.lastname: Mittlböck
authors.affiliation: Institute for Applied Statistics and IT, University of Natural Resources and Life Sciences, Vienna, Austria.
authors.forename: Theresa
authors.initials: T
authors.lastname: Scharl
authors.affiliation: Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Melanie H
authors.initials: MH
authors.lastname: Kucherlapati
authors.affiliation: Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, USA.
authors.forename: Winfried
authors.initials: W
authors.lastname: Edelmann
authors.affiliation: Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria Division of Gastroenterology and Hepatology, Department of Medicine 3, Medical University of Vienna, Vienna, Austria.
authors.forename: Christoph
authors.initials: C
authors.lastname: Gasche
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology / Q000627:therapeutic use*; D016227:Benzoquinones / Q000494:pharmacology / Q000627:therapeutic use*; D049109:Cell Proliferation / Q000187:drug effects; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000235:genetics / Q000473:pathology / Q000517:prevention & control*; D004195:Disease Models, Animal; D005260:Female; D016368:Frameshift Mutation; D045325:HCT116 Cells; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D019804:Mesalamine / Q000494:pharmacology / Q000627:therapeutic use*; D051379:Mice; D053842:Microsatellite Instability / Q000187:drug effects; D051718:MutS Homolog 2 Protein / Q000235:genetics* / Q000378:metabolism; D059645:Mutation Rate; D047368:Tumor Burden / Q000187:drug effects
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D016227:Benzoquinones; D019804:Mesalamine; C497173:Msh2 protein, mouse; D051718:MutS Homolog 2 Protein; C003466:thymoquinone