title: Identification of additional mitochondrial DNA mutations in canine mast cell tumours.
abstract: BACKGROUND
  Research has revealed the presence of somatic mutations in mitochondrial DNA (mtDNA) of certain types of tumours. As this has not been studied for canine mast cell tumours, the aim of this study was to identify mutations in the hypervariable region of mtDNA in mast cell tumours in dogs and determine their association with the process of neoplastic transformation.
  
  
  RESULTS
  Samples from 17 dogs with histopathologically confirmed mast cell tumours were analysed. The samples consisted of tumour tissues (n = 17), normal tissues (n = 17), and blood (n = 17). Amplicons of the displacement loop (D-loop) were sequenced and the obtained nucleotide sequences were subjected to bioinformatics analyses. Somatic mutations were detected in seven positions of the D-loop nucleotide sequences in 47 % of the dogs, while polymorphisms were identified in 94 % of the dogs. Most of these changes were homoplasmic, while heteroplasmy was detected in two individuals. Six new haplotypes were established as being characteristic for canine mast cell tumours. There was no association between the presence of the mutations and sex, haplotype, or malignancy grade assessed in 3 and 2-grade scales.
  
  
  CONCLUSIONS
  Differences in the frequency of somatic mutations imply their direct association with the neoplastic transformation. However, their functional consequences and clinical significance are not clear. The mutations may be used for diagnosis and prognosis of canine mast cell tumours in the future.
authors.affiliation: Department of Pathological Anatomy, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Głęboka 30 St., 20-612, Lublin, Poland. anna.smiech@up.lublin.pl.
authors.forename: Anna
authors.initials: A
authors.lastname: Śmiech
authors.affiliation: Department of Biological Bases of Animal Production, Faculty of Animal Breeding and Biology, University of Life Sciences in Lublin, Akademicka 13 St., 20-950, Lublin, Poland.
authors.forename: Brygida
authors.initials: B
authors.lastname: Ślaska
authors.affiliation: Department of Biological Bases of Animal Production, Faculty of Animal Breeding and Biology, University of Life Sciences in Lublin, Akademicka 13 St., 20-950, Lublin, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Surdyka
authors.affiliation: Department of Oncology, Medical University of Lublin, Jaczewskiego 7 St., 20-090, Lublin, Poland.
authors.forename: Ludmiła
authors.initials: L
authors.lastname: Grzybowska-Szatkowska
authors.affiliation: Department of Pathological Anatomy, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Głęboka 30 St., 20-612, Lublin, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Łopuszyński
authors.affiliation: Department and Clinic of Animal Surgery, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka 13 St., 20-950, Lublin, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Różańska
mesh_terms: D000818:Animals; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D004283:Dog Diseases / Q000235:genetics*; D004285:Dogs; D005260:Female; D006239:Haplotypes; D008297:Male; D008407:Mast Cells / Q000473:pathology*; D034801:Mastocytoma / Q000235:genetics / Q000662:veterinary*; D009154:Mutation / Q000235:genetics*; D011110:Polymorphism, Genetic
chemical_list: D004272:DNA, Mitochondrial
keywords: D-loop; Dog; Mutations; Tumour; mtDNA