Global DNA methylation of peripheral blood leukocytes from dogs bearing multicentric non-Hodgkin lymphomas and healthy dogs: A comparative study

Tatiane Moreno Ferrarias Epiphanio; Natália Coelho Couto de Azevedo Fernandes; Tiago Franco de Oliveira; Priscila Assis Lopes; Rodrigo Albergaria Réssio; Simone Gonçalves; Náyra Villar Scattone; Marcello Vannucci Tedardi; Leslie Domenici Kulikowski; Jullian Damasceno; Ana Paula de Melo Loureiro; Maria Lucia Zaidan Dagli

doi:10.1371/journal.pone.0211898

Global DNA methylation of peripheral blood leukocytes from dogs bearing multicentric non-Hodgkin lymphomas and healthy dogs: A comparative study

PLoS One. 2019 Mar 25;14(3):e0211898. doi: 10.1371/journal.pone.0211898. eCollection 2019.

Affiliations

¹ Laboratory of Experimental and Comparative Oncology, Department of Pathology, University of São Paulo, São Paulo, São Paulo, Brazil.
² Department of Pathology, Adolfo Lutz Institute, São Paulo, São Paulo, Brazil.
³ Department of Pharmacoscience, Federal University of Health Sciences of Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil.
⁴ Veterinary Laboratory, Veterinary Image Institute, IVI, São Paulo, São Paulo, Brazil.
⁵ Veterinary Hemotherapy Center, Hemovet, São Paulo, São Paulo, Brazil.
⁶ Cytogenomic Laboratory, Department of Pathology, University of São Paulo, São Paulo, São Paulo, Brazil.
⁷ Department of Clinical and Toxicological Analysis, University of São Paulo, São Paulo, São Paulo, Brazil.

Abstract

Non-Hodgkin lymphomas are among the most common types of tumors in dogs, and they are currently accepted as comparative models of the disease in humans. Aberrant patterns of DNA methylation seem to play a key role in the development of hematopoietic neoplasms in humans, constitute a special mechanism of transcriptional control, and may be influenced by genetic and environmental factors. Blood leukocyte DNA global methylation has been poorly investigated in dogs. The aim of this study is to examine whether peripheral blood global DNA methylation is associated with canine multicentric lymphomas. Peripheral venous blood samples from ten healthy dogs and nine dogs bearing multicentric lymphomas were collected, and the buffy coat was separated. Global DNA methylation was analyzed by High Performance Liquid Chromatography (HPLC) and immunocytochemistry (ICC). In both analyses, leukocytes from dogs with lymphoma presented lower global DNA methylation than in healthy dogs (HPLC: p = 0.027/ 5MeCyt immunoreactivity scores: p = 0.015). Moderate correlation was observed between the results obtained by HPLC and ICC (correlation coefficient = 0.50). For the identification of differently methylated genes between both groups, the Infinium Human Methylation (HM) EPIC BeadChip (850K) was used. Of the 853,307 CpGs investigated in the microarray, there were 34,574 probes hybridized in the canine samples. From this total, significant difference was observed in the methylation level of 8433 regions, and through the homologous and orthologous similarities 525 differently methylated genes were identified between the two groups. This study is pioneer in suggesting that dogs bearing non-Hodgkin lymphoma presented DNA global hypomethylation of circulating leukocytes compared with healthy dogs. Although canine samples were used in an assay developed specifically for human DNA, it was possible to identify differently methylated genes and our results reiterate the importance of the use of peripheral blood leukocytes in cancer research and possible new biomarkers targets.

Publication types

Comparative Study
Research Support, Non-U.S. Gov't

MeSH terms

Animals
Case-Control Studies
CpG Islands
DNA Methylation*
Dog Diseases / genetics*
Dog Diseases / metabolism
Dogs
Female
Leukocytes* / metabolism
Lymphoma, Non-Hodgkin / genetics*
Lymphoma, Non-Hodgkin / metabolism
Male

Grants and funding

The study was supported by grants from the Brazilian National Council for Scientific and Technological Development, CNPq (Process number 447985/2014-0).