Therapeutic efficacy of inactivated 5-fluoracil-treated CT-26 cells plus granulocyte-macrophage colony stimulating factor (GM-CSF) against subcutaneous CT-26 tumor in Balb/C mice. (A) Tumor volume of mice in the FU-CT-26 + GM-CSF group decreased significantly compared with other groups. (P < 0.05, ANOVA) Error bars represent the standard deviation. (B) Kaplan-Meier survival analysis shows that mice treated with inactivated FU-CT-26 cells combined with GM-CSF had longer survival than other groups (P < 0.01). CT-26 cells (106) were injected subcutaneously into Balb/C mice on day 0. Tumor-bearing mice were vaccinated subcutaneously on days 3, 6, 9, 13, 18, and 25 with different cell vaccines. FU-CT-26+GM: mice immunized with mitomycin C (MMC)-inactivated FU-CT-26 cells (106) plus GM-CSF. FU-CT-26: mice immunized with MMC-inactivated FU-treated CT-26 cells (106). CT-26+GM: mice immunized with MMC-inactivated CT-26 cells (106) plus GM-CSF. CT-26: mice immunized with MMC-inactivated CT-26 cells (106). Control: mice treated with phosphate-buffered saline. Experiments were repeated three times with similar results.