Pathology of spontaneous breast tumor in tree shrews (Tupaia belangeri chinenesis)

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K19277
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 42:Veterinary medical science, animal science, and related fields
• Research Institution: Tokyo Metropolitan Institute of Medical Science
• Principal Investigator: KOHARA Michinori 公益財団法人東京都医学総合研究所, 疾患制御研究分野, 特任研究員 (10250218)
• Project Period (FY): 2018-06-29 – 2023-03-31
• Keywords: ツパイ / 乳がん / 遺伝性

Outline of Final Research Achievements

Breast cancer has a high incidence in our country and its control is urgently needed. The tupai is a small mammal with genetic information similar to that of humans. Since mammary tumors in tupai have a structure similar to that of human papillary adenocarcinoma, it was expected to be an excellent model for the development of breast cancer. Histopathological examination of spontaneous mammary tumors in Tupai revealed that the mammary gland tumors were often ductal papillary carcinomas, and that the morphology and pathology of the tumors were very similar to those of human papillary adenocarcinomas. Cytological examination confirmed that the tumor was an epithelial malignant tumor.

Free Research Field

感染免疫学

Academic Significance and Societal Importance of the Research Achievements

ツパイはツパイ目ツパイ科に属す、体重が約150グラムの小型哺乳動物で、近年まで原猿類に分類されていた。また、ツパイは人に近い遺伝情報を持っており、ヒトとチンパンジーにしか感染しないB型肝炎ウイルスの感染受容体がツパイの肝細胞から同定されている。ツパイの乳腺の生理学的特徴と発育などはヒトに類似している。平均発生月齢は2年3ヶ月で、一番早くは10ヶ月齢に見られた。このことから、ツパイの自然発症乳腺腫瘍は遺伝性のものが多く、若年性のものもあることが示された。本研究から得られたこれらの新たな知見を元に、早期診断、予防、治療法開発に資する可能性が示された。