Objective    To study the anti-tumor effect of mycobacterium Ag85B/IL-2 fusion protein on syngenic mice bearing bladder cancer.     Methods    After being implanted BTT739 bladder transitional carcinoma cells from tumor bearing mice

80 T739 mice were divided into Ag85B protein

BCG

IL-2 and normal saline groups (n=20). Mycobacterium Ag85B/IL-2 protein was locally injected to the mice at the site of implanting tumor in the trial group

and Ag85B protein

BCG

IL-2 and normal saline to the control group mice. The weight and volume of tumor and the survival period were recorded after treatment.     Results    The average weight of Ag85B/IL-2 fusion protein treatment group was significantly lower than those of Ag85B

BCG，IL-2 and normal saline group （P0.01）. The average volume of Ag85B/IL-2 fusion protein treatment group was significantly lower than those of Ag85B

BCG，IL-2 and normal saline group （P0.05

P0.01）. The average survival period of Ag85B/IL-2 fusion protein treatment group was significantly longer than those of Ag85B

BCG，IL-2 and normal saline group （P0.05

P0.01）. The tumor weight and volume inhibition rate of Ag85B/IL-2 fusion protein were 64.50％ and 62.24％

respectively

and the survival period prolonging rate of Ag85B/IL-2 fusion protein was 48.66％. Under light microscope

the bladder tumor tissue treated by Ag85B/Il-2 presented obviously inflammatory cells infiltrating

neoplasm necrosis

hemorrhage. With transmission electron microscope

the bladder tumor cell membrane was un-integrated

organelles damaged

cytoplasm pycnosis

nucleus fragmentation

aggregation on chromatin

apoptosis body coming up

macrophage swollen and so on.     Conclusion    The results indicate that mycobacterium Ag85B/IL-2 protein has obvious anti-tumor effect in T739 mice bearing bladder cancer and can prolong its survival period.