Abstract：OBJECTIVE: The treatment of leukemia is limited by diffusion of leukemia cells.The aim of this study was to investigate the effectiveness and feasibility of immune therapy for leukemia by vaccination with granulocyte-macrophage colony-stimulating factor(GM-CSF). METHODS: The biological characteristics of FBL-3-GM-CSF cells were studied by the growth curve and tumorigenicity experiment in vivo. The GM-CSF gene-modified tumor vaccines were prepared with mitomycin-C inactivated FBL-3-GM-CSF cells. The effects of vaccination with mitomycin-C inactivated FBL-3-GM-CSF on immune prophylaxis and immune therapy of leukemia were investigated in animal experiments. RESULTS: There was no significant difference in the biological characteristics (cellular morphology and growth rate) between FBL-3-GM-CSF,FBL-3-vect and FBL-3 cells. In mice vaccinated with the FBL-3-GM-CSF cells, tumor formation was later and the tumor volume was smaller than those vacinated with FBL-3-vect or FBL-3 cells. Vaccination with mitomycin-C inactivated FBL-3-GM-CSF in mice could significantly induce potent anti-tumor immune reaction compared with that with FBL-3- vect cells, FBL-3 cells or PBS. The growth rate of tumor in mice vaccinated with FBL-3-GM-CSF was markedly slower and the survival time was dramatically longer compared with in those vaccinated with the FBL-3-vect cells,FBL-3 cells or PBS. CONCLUSIONS: The vaccination with mitomycin-C inactivated FBL-3-GM-CSF for the treatment of leukemia is effective and feasible. The study provided experimental and theoretical data for further clinical study and application of GM-CSF gene-modified cancer vaccines.
