7,12-Dimethylbenz(a)anthracene induced breast cancer in Sprague Dawley rats proved by ultrasound imaging

摘要

Many studies have shown that some of cancer animal models have been established to study various aspects of cancer biology, including breast cancer. Substantial evidence has shown that administration of 7,12-dimethylbenz(a)anthracene (DMBA) in animal models can mimic human breast cancer in many ways. This preliminary research aimed to develop rat breast cancer models that will be used for a further study on phytotherapy as the alternative medicine for breast cancer. Four young Sprague Dawley female rats, aged 60 days, received a single subcutaneous injection of 25 mg DMBA mixed with 0.5 mL sunflower oil and 0.5 mL sodium chloride 0.9%. Control group received 0.5 ml of sunflower oil and 0.5 ml of saline only. Tumor detection by palpation and rats' body weight measurement were performed every week after DMBA induction. At 10-weeks after DMBA induction, the tumor development was examined by ultrasound imaging. No significant differences were observed in the body weight between DMBA-induced rats and non-induced rats during 8-weeks after induction. Starting from week ninth, the body weight of the DMBA group significantly decreased (p=0.02) compared to the counterpart. A solid mass on the breast area was firstly detected at week seventh in one rat. Three weeks later the solid masses were detected in all DMBA-induced rats that proved by the ultrasound images showing hypoechoic lesions with irregular margin and calcification indicating malignancies. DMBA induced malignant lesions in female rats that demonstrated by ultrasound imaging.