RESUMO
Objective To study the inhibitory effect of arsenic trioxide(As_2O_3) on the tumor growth of breast cancer cell line MCF-7 implanted subcutaneously in nude mice and its mechanism.Methods BALB/C-nu/nu nude mice were subcutaneously injected with MCF-7 breast cancer cell line,and treated with intraperitoneal injection of As_2O_3 and 5-FU in different concentrations.The implanted tumor was weighed,and the tumor inhibition rates were calculated.The apoptosis of the implanted tumor was detected by flow cytometry.The expressions of bcl-2 and Fas induced by As_2O_3 were examined by immunohistochemical method.Routine blood test and bone marrow test were used to observe the function of hematopoietic system after As_2O_3 treatment.Results The growth of implanted tumor was markedly inhibited with 5-FU,low dose and high dose As_2O_3,the inhibitory rates being 38.33%、51.42% and 62.43%,respectively.The inhibitory effect of As_2O_3 was significantly stronger than that of 5-FU(P
