[Establishment of animal model of breast cancer dormancy]
Guang-yan Su1, Yu-qin Liu, Le-rong Ren
1Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences; School of Basic Medicine, Peking Union Medical College, Beijing 100005, China.
Objective:
Tumor dormancy has been defined clinically as a condition in which tumor cells are present but do not grow for a long period of time. Breast cancer is noted for its long periods of tumor dormancy and metastases can occur many years after treatment.
Method:
Simulating the characteristics of breast cancer patients after treatment, we established the animal model of breast cancer dormancy by inoculating 500 Ca761-03 cells into the limb muscle of 615 mice and then selecting animals with tumor dormancy 2 months post inoculation (corresponding to 5 years for humans).
Results:
Two months after inoculation of Ca761-03 cells into the muscle of 615 mice, tumor occurred in 30% of the mice. The remaining 70% of mice did not show tumor growth. After repeated traumatic stimulation, 90% of the mice developed tumors after 5 months, therefore representing tumor dormancy.
Conclusions:
These results demonstrate that breast cancer cells can remain in a dormant state for long periods of time in vivo. Trauma can stimulate the dormant tumor cells to proliferate again, and causes tumor relapse. This murine model system promises a sound animal model for the study of solid tumor dormancy.
