Investigation About The Effect Of RU486 On Growth Inhibiting Of Breast Cancer Animal Model

OBJECTIVE: As 1,150,000 new cases every year,breast cancer become one of the most frequent malignant tumors. North America,Northern Europe and Western Europe were the higher disease incidence countries,and China belonged to the lower. But there was a ascending tendency of China breast cancer attack rate,and even took the first place in some major city. Breast cancer has become a world wild public health problem that threaten female health severely.Besides conventional operation,chemotherapy and radiotherapy, endocrine therapy is very important to hormone receptor positive breast cancer patients. Endocrine therapy occupies about 80 percent in American,48 percent in Japan and only 4 percent in China. Analyzing it's reason: one is that the new concept accepted by fewer breast chirurgeons. Another is there is some proper restriction of endocrine drugs used now,such as side effect,expensive et al. Purpose of this study is to discover a effective,lower side effect endocrine therapy drug. We have confirmed the growth inhibiting effect of RU486 towards breast cancer cells in vitro. With the purpose of verifying RU486's inhibitory action,we duplicated mammary adenocarcinoma model of athymic mouse and confirmed it's therapeutic efficacy.Wu duplicated mammary cancer animal model of athymic mouse with the two cell lines used in vitro. Then we observed the growth velocity of tumor before and after treatment of different doses of RU486.METHODS : Breast cancer animal model was made by Cell lines of exponential growth phase. They were divided into control group and treatment groups. The former was given vegetable oil 0.5ml/day,the latter were given MIV(25mg,50mg,100mg,200mg/kg.d),as the tumor range from 0.5 to 1.0cm and measured the gross tumor volume every other day till after 3 weeks. We sacrificed a part of animals after 2 week,the rest were after 3 weeks.RESULTS : (1) Growth velocity of tumour were slower than that of control(p<0.05). (2) index mentioned above were much significant in ER(+ +)/PR(+ +) group and had dose dependent.CONCLUSION: (1)RU486 can inhibit the growth of breast cancer model of athymic mouse.(2) Empirical study in vivo combined with that in vitro shows that RU486 can restrain the growth of breast cancer,especially the ER++/PR++ one and RU486 can be used in breast cancer endocrine therapy.