Inhibitive effects of E838 combined radiotherapy and chemotherapy on malignant tumor in IRM-2 mice

Purpose To observe the inhibitive effects of E838 combined radiotherapy and chemotherapy on malignant anti-tumor and the effects on the number of bone marrow nucleated cells.Methods Establishment of mouse tumor model:to the radiotherapy group mice,2-3 mm3 tumors inoculated subcutaneously in the axillary region,to the chemotherapy group mice(NS),0.2 mL cell suspension(diluted with normal saline to the ratio of 1 to 3) were inoculated subcutaneously in forelimb armpit region.After 24 h of the establishment,the radiotherapy group mice were randomly divided into control group,radiotherapy alone group,low,middle and high dose E838 combined treatment group and drug combined irradiation group,the chemotherapy group was divided into control group,cyclophosphamide(CTX) group,low,medium,high dose E838 combined treatment group and CTX combined treatment group,CTX combined treatment group began administrating drugs(CTX 500 μg/0.2 mL),The drugs need to be injected 4 times every 2 days.In the treatment group drugs were intraperitoneal injected for 7 d,and mice in drug combined irradiation group were total-body irradiated by 1Gy 137 Cs γ-ray daily for 5 days from the 4th day of administration.On the 12 days,the mice were sacrificed and mice tumor were weighted and oncostatic rate was calculated.Results E838 combined 137 Cs γ-ray was a better tumor suppressor effect and the inhibition ratio was 65.43%,77.13% and 67.55% respectively.The inhibition ratio increased by 21.29%,6.39% and 17.55% compared with the treatment group and increased by 42.83% compared with the control group and there were significant differences(P0.001).The q values were 1.03,0.95 and 1.00 respectively which showed that there were synergistic antitumor effects combined with radiotherapy.In E838 combined CTX group,the inhibition ratio was 81.68%,82.70% and 82.14% respectively.The inhibition ratio increased by 42.9%,36.19% and 40.05% compared with the treatment group and increased by 21.0% compared with the cyclophosphamide(CTX) group and there were significant differences(P0.001).The q values were 1.07,1.04 and 1.06 respectively which showed that there were synergistic antitumor effects combined with chemotherapy.Conclusion E838 plays a great role in inhibiting malignant tumor growth in mice and E838 combined with radiotherapy and chemotherapy could enhance tumor inhibitory effect.