The inhibition of arsenic trioxide on subcutaneously implanted tumors of colon carcinoma cells

Objective To study the effect of arsenic trioxide( As2O3) on subcutaneously implanted tumors of colon carcinoma cells( CT26) in mice.Methods CT26 cells were cultivated and inoculated into subcutaneous tissue of right armpit of mice to copy subcutaneous implanted tumor model successfully.The mice were randomly divided into three groups:saline group( Group C),low concentration of As2O3 group[11.0 mg/( kg·d),Group L],high concentration of As2O3 group[12.0 mg/( kg·d),Group H].The mice were sacrificed 24 hours after of the last treatment on the 10th day.The tumor volumes and weight were measured.Tumor growth inhibition rate was also calculated.Histopathology was performed,while immunohistochemistry was applied for assessment of the expression of Ki-67,Survivin,Bcl-2 and Caspase-3,and Western blot was used for assessment of the expression of Caspase-3.Results The volume and weight of the tumors were significantly smaller and lighter in the treatment groups.Suppressed proliferation and reduced mitosis were observed in treatment groups,especially in Group H.The expression of Ki-67,Survivin and Bcl-2 was significantly lower,while the positive Caspase-3 rates were significantly higher in the treatment groups.The expression of Caspase-3 in the treatment groups were significantly up-regulated in treatment groups.Conclusion As2O3 effectively inhibits the growth of implanted tumors of colon carcinoma via proliferation suppression and apoptosis promotion of CT26 cells.