Experimental Study Of Administration With Cyclophosphamide And Interleukin-2on The Murin Breast Cancer Model

Objective:To observe the influence of administration with Interleukin-2andCyclophosphamide on the ratio of Regulatory T cell and tumor growth of BALB/cmurine breast cancer model.Methods:Murine breast cancer model were established by inoculating s. c. BALB/c micewith4T1breast cancer tumor cell line. Twenty BALB/c mice were randomly dividedinto four groups: IL-2group and CTX group and IL-2+CTX group and control group.Mice in IL-2group and IL-2+CTX group were treated with40000U IL-2bidintraperitoneally for4consecutive days since the tenth day after tumor has beenestablished. Mice in CTX group and IL-2+CTX group were treated with25mg/kgCTX intraperitoneally once at the twelfth day after tumor has been established. Micewere sacrificed at the sixteenth day. We examined Regulatory T cell ratio of spleencells by flow cytometry. Serum INF-γ concentration was measured using ELISA kit.Tumor weight was measured using a electronic scale.Results:1. The CD4+CD25+/CD4+ration in spleens of control group, IL-2group, CTXgroup and IL-2+CTX group are (16.63±4.69)%,(25.04±1.49)%,(10.02±2.44)%and (18.78±1.38)%respectively. The CD4+CD25+/CD4+rationof IL-2group is higher than the ration in control group (P<0.05). Otherwise, the Treg ration in CTX group is lower than the ration in control group (P<0.05). TheTreg ration in CTX+IL-2group is lower than the ration in IL-2group (P<0.05).2. The serum INF-γ concentration of control group, IL-2group, CTX groupand IL-2+CTX group are (200±11.0) pg/ml,(234±9.5) pg/ml,(239±7.3) pg/mland (243±7.1) pg/ml respectively. The serum INF-γ concentration of threetreatment groups are higher than the concentration of control group (P<0.05).Otherwise, there are no significant difference are observed among the threetreatment groups (P<0.05).3. The tumor weight of control group, IL-2group, CTX group and IL-2+CTXgroup are (1.27±0.46)g,(0.83±0.24)g,(0.81±0.44)g and (0.57±0.39)grespectively. No difference are observed among treatment groups(P>0.05).Compare with control group, Mice treated with IL-2combine single low doseCTX showed significant decrease in tumor weight (P<0.05).Conclusion:Combining single low dose CTX with IL-2inhibit tumor growth oftumor-bearing mice, the mechanism are probably related to Treg regulation because ofsingle low dose CTX and IL-2injection.