DMBA Induced Breast Tumors In Tree Shrews (Tupaia Belangeri Chinenesis)

The establishment of a suitable animal model for study of human breast cancer development, metastasis and other aspects is more crucial.7, 12-dimethylbenzanthracene (DMBA) has potential to induce experimental breast tumors in rat. Tree shrew is a more appropriate animal for making disease models due to its genetic makeup similarities with human as compared with rodent and spontaneous breast cancers in tree shrews were already reported. Therefore, we attempt to induce breast tumor in tree shrews by DMBA treatment. In the present study, ten female tree shrews lost their babies after delivery were employed and half of them were received a single dose of 100 mg/kg DMBA by the lumbar bilateral mammary fatty pad injection, while the others treated without DMBA as control. As a result of DMBA administration, two of five candidates had developed infiltrative ductal carcinoma (IDC), while others had developed into ductal carcinoma in situ, diagnosed with morphological features of pathological sections stained by H&E and immunohistochemistry to detect the expression of ki-67, estrogen receptor, progesterone receptor, human epidermal growth factor receptor-2, E-cadherin, and p120-catenin. The results demonstrated that induced breast tumors in tree shrews have shown similar morphological and pathological characteristics with humans IDC. From the results of experiment, the approach we take mammary gland injection DMBA in female tree shrew who had lost their baby after delivery is feasible. Histological features of induced tumor are similar to human mammary tumor, the induced tumor expressed molecular biology markers of human breast cancer, and the expression is similar to human mammary tumor. It is suggested that DMBA-induced mammary tumor model in tree shrews provide a proper animal models in research of its occurrence, progression.metastasis, recurrence and treatment.