[Establishment of animal model of breast cancer dormancy].
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.


METHODS
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.
Su
Guang-yan
GY
Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences; School of Basic Medicine, Peking Union Medical College, Beijing 100005, China.
Liu
Yu-qin
YQ
Ren
Le-rong
LR
Liu
Xian-feng
XF
Gu
Bei
B
Dong
Ji-hong
JH
Gao
Jin
J
D000818:Animals; D001943:Breast Neoplasms / Q000473:pathology / Q000503:physiopathology*; D045744:Cell Line, Tumor; D002470:Cell Survival; D004195:Disease Models, Animal; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D009364:Neoplasm Recurrence, Local; D009368:Neoplasm Transplantation; D011897:Random Allocation; D002583:Uterine Cervical Neoplasms / Q000473:pathology / Q000503:physiopathology*