الملخص
Objective: To observe the inhibitory effect of astragalus polysaccharides (APS) on growth of human breast cancer MDA-MB-231 xenograft tumor in nude mice and its effect on the apoptosis of tumor cells, in order to study the effect of APS on growth and induction of apoptosis of triple negative breast cancer MDA-MB-231 and its possible molecular mechanism. Method: Human breast cancer cell MDA-MB-231 was inoculated into the right axillary subcutaneous of BALB/c-nu female nude mice to establish the transplanted tumor model of breast cancer. Eighteen nude mice were randomly divided into 3 groups:model group (saline per day), low-dose APS group (200 mg·kg-1 APS per day), and high-dose APS group (400 mg·kg-1 APS per day), with 6 rats in each group. The drug was administered by gavage (200 μL) daily for 21 days. In the experiment, the length and diameter of breast cancer transplanted tumor were measured every two days, and the tumor volume was recorded and calculated. At the end of the experiment, the changes of tumor mass and tumor volume of the low and high-dose APS groups and the model group were observed and compared, and the tumor inhibition rate was calculated. The cell morphology in tumor tissue was observed by hematoxylin-eosin (HE) staining, and Terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) was used to verify the apoptosis of breast cancer tissues. The expressions of apoptosis-related proteins, such as B-cell lymphoma/leukemia-2 protein (Bcl-2), Bcl-2 associated X protein (Bax), Caspase in tumor tissues was detected by Western blot. Result: The tumor volume of breast cancer decreased in the low and high-dose APS groups, and the tumor inhibition rates were 37.9%and 57.57%, respectively, with statistically significant differences from the model group (PP0.01). HE of tumor tissue cells showed that APS led to obvious morphological changes, with apoptosis in the tissue cells. TUNEL staining showed that the apoptosis rate of tumor cells in APS intervention groups was higher than that in control group. Western blot showed that expression of Bcl-2 protein decreased(PPPPConclusion: APS can effectively inhibit the growth of MDA-MB-231 breast cancer xenografts in nude mice and induce apoptosis in human breast cancer MDA-MB-231 cells. The mechanism may be related to the effect of APS on expressions of apoptosis-related proteins Bcl-2, Bax, Caspase-9 and Caspase-7 in breast cancer cells.