title: Significance of EZH2 expression in canine mammary tumors.
abstract: BACKGROUND
  Current studies report that aberrations in epigenetic regulators or chromatin modifications are related to tumor development and maintenance. EZH2 (Enhancer of zeste homolog 2) is one of the catalytic subunits of Polycomb repressive complex 2, a crucial epigenetic regulator. EZH2 has a master regulatory function in such processes as cell proliferation, stem cell differentiation, and early embryogenesis. In humans, EZH2 is linked to oncogenic function in several carcinomas, including breast cancer, and dysregulation of EZH2 has been particularly associated with loss of differentiation and the development of poorly differentiated breast cancer. In our present study, we were interested in determining whether EZH2 is increased in canine mammary tumors, which show similarities to human breast cancer.
  
  
  RESULTS
  Investigation of the expression of EZH2 in canine mammary tumors revealed that EZH2 protein was overexpressed in canine mammary carcinomas, as in human breast cancer. In addition, the immunohistochemical expression level of EZH2 was associated with the degree of malignancy in canine mammary carcinoma. This is the first report to describe EZH2 expression in canine mammary tumors.
  
  
  CONCLUSIONS
  Because the expression of EZH2 was similar in canine mammary carcinoma and human breast cancer, spontaneous canine mammary tumors may be a suitable model for studying EZH2 and treatment development.
authors: Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea.|Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, South Korea.
authors: Hyun-Ji
authors: HJ
authors: Choi
authors: Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea.|Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, South Korea.
authors: Sungwoong
authors: S
authors: Jang
authors: Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea.|Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, South Korea.
authors: Jae-Eun
authors: JE
authors: Ryu
authors: Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea.|Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, South Korea.
authors: Hyo-Ju
authors: HJ
authors: Lee
authors: Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea.|Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, South Korea.
authors: Han-Byul
authors: HB
authors: Lee
authors: Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea.
authors: Woo-Sung
authors: WS
authors: Ahn
authors: Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, South Korea.
authors: Hye-Jin
authors: HJ
authors: Kim
authors: Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, South Korea.
authors: Hyo-Jin
authors: HJ
authors: Lee
authors: Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, South Korea.
authors: Hee Jin
authors: HJ
authors: Lee
authors: Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, South Korea.
authors: Gyung-Yub
authors: GY
authors: Gong
authors: Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea. wcson@amc.seoul.kr.|Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, South Korea. wcson@amc.seoul.kr.
authors: Woo-Chan
authors: WC
authors: Son
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004283:Dog Diseases / Q000503:physiopathology*; D004285:Dogs; D000071221:Enhancer of Zeste Homolog 2 Protein / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015674:Mammary Neoplasms, Animal / Q000503:physiopathology*
chemical_list: D000071221:Enhancer of Zeste Homolog 2 Protein
keywords: Canine mammary tumor; Comparative oncology; Dog; EZH2