Objective    To investigate the effects of AMD3100

a specific antagonist of chemokine receptor-4

on the progression of Lewis lung carcinoma and the accumulation of myeloid derived suppressor cells (MDSCs) in tumor-bearing mice’s spleen.     Methods    Sixty C57BL/6 mice

inoculated subcutaneously Lewis lung carcinoma cell line LLC

were separated into 2 groups (n=30)

the PBS and AMD3100 group. The mice in the 2 groups were intraperitoneally injected with 0.2 ml PBS solution or 0.2 ml PBS solution dissolved with AMD3100 [2 mg/(kg·d)] separately. All the mice were injected once per day

and the injection was lasted for 26 d. The mice’s weight were measured every other day and the time of oncogenesis was recorded. In 26 d later

15 mice in every group were randomly sacrificed to count the number of pulmonary metastatic nodules and the weight of Lewis lung carcinoma. Flow cytometry and immunohistochemistry were used to detect the percentage of MDSCs in mice’s spleen and the tumor’s microvessel density (MVD) separately. Survival time of the remaining mice in the 2 groups were recorded.     Results    The time of oncogenesis in PBS and AMD3100 group were（8.03±1.47） and （9.97±1.50） d separately. The tumor’s weight

MVD

number of pulmonary metastatic nodules and percentage of MDSCs in PBS group were （3.54±0.93）g

（41.40±6.44）/HP

（18.27±9.78） nodules /animal

and (19.57±3.59)% respectively. But

in AMD3100 group

these indexes were （2.09±0.66）g

（32.47±5.33）/HP

（7.40±5.83） nodules /animal

and (31.42±5.04)% separately. The median survival time in PBS and AMD3100 group was 29 and 34 d separately. All the indexes between the 2 groups were significant（P0.01).     Conclusion    AMD3100 inhibits the progression of Lewis lung carcinoma

but it may also have some negative impacts on the immune of the mice bearing Lewis lung carcinoma.