title: Evaluation of the global DNA methylation in canine mast cell tumour samples by immunostaining of 5-methyl cytosine.
abstract: Cutaneous mast cell tumours (MCT) are the most common skin tumour in dogs, and to our knowledge, there are no previous studies regarding the global methylation of these tumours. DNA hypomethylation and hypermethylation have been described in several tumours and both mechanisms can lead to carcinogenesis. The purpose of this study was to evaluate the global DNA methylation in canine MCT. A total of 48 MCT samples were classified in grades 1, 2 and 3 or high-grade or low-grade. Monoclonal antibodies were used for the immunohistochemical detection of the 5-methylcytosine. The immunostained nuclei were classified in strong, weak or negative pattern, and these were quantified in five distinct microscopic fields (40× objective) in each slide. The results showed that global DNA hypomethylation was predominant in grade 3, high-grade, less differentiated MCT. These epigenetic changes in neoplastic mast cells warrant further detailed investigation aiming the establishment of tumour epigenetic therapies.
authors.affiliation: Laboratory of Experimental and Comparative Oncology, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil.
authors.forename: C Y
authors.initials: CY
authors.lastname: Morimoto
authors.affiliation: Laboratory of Experimental and Comparative Oncology, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil.
authors.forename: M V
authors.initials: MV
authors.lastname: Tedardi
authors.affiliation: Laboratory of Experimental and Comparative Oncology, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil.
authors.forename: I I M
authors.initials: IIM
authors.lastname: da Fonseca
authors.affiliation: Laboratory of Experimental and Comparative Oncology, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil.
authors.forename: K C
authors.initials: KC
authors.lastname: Kimura
authors.affiliation: Laboratory of Experimental and Comparative Oncology, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil.
authors.forename: D S
authors.initials: DS
authors.lastname: Sanches
authors.affiliation: Laboratory of Experimental and Comparative Oncology, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil.
authors.forename: T F
authors.initials: TF
authors.lastname: Epiphanio
authors.affiliation: School of Animal Science and Food Engineering, University of São Paulo, Pirassununga, Brazil.
authors.forename: R
authors.initials: R
authors.lastname: de Francisco Strefezzi
authors.affiliation: Laboratory of Experimental and Comparative Oncology, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil.
authors.forename: M L Z
authors.initials: MLZ
authors.lastname: Dagli
mesh_terms: D044503:5-Methylcytosine / Q000378:metabolism*; D000818:Animals; D000911:Antibodies, Monoclonal; D019175:DNA Methylation; D004283:Dog Diseases / Q000378:metabolism* / Q000473:pathology; D004285:Dogs; D034701:Mastocytosis, Cutaneous / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*
chemical_list: D000911:Antibodies, Monoclonal; D044503:5-Methylcytosine
keywords: DNA methylation; epigenetics; mast cell tumour