Fig. 5

SMC18 effectively inhibits MC38 tumor growth and enhances immune cell infiltration into tumor site, promoting IFN-γ secretion. A-B Experiment scheme A, tumor volume B (left) and body weight B (right) in MC38 tumor-bearing mice treated with normal saline (NS), SMC18 (2 mg/kg) and SMC18 (6 mg/kg). C The proportion of CD8⁺ T cells in tumor sites of mice were measured by flow cytometry. D, F The proportion of CD8⁺ T cells secreting IFN-γ evaluated using flow cytometry. Tumor-infiltrating lymphocytes D, draining lymph nodes E, and spleen F were isolated from the mice and stimulated with 20 ng/mL PMA, and 1 μM ionomycin for 4 h. Following the incubation period, the cells were collected and fixed to disrupt the cell membrane, and the proportion of CD8⁺ T cells secreting IFN-γ was evaluated using flow cytometry. G Flow cytometry analysis of the proportion of M1-type macrophages ((CD45⁺F4/80⁺CD11b⁺CD11c⁺) and M2-type macrophages (CD45⁺F4/80⁺CD11b⁺CD206⁺) within the tumor sites, specifically in tumor-associated macrophages (CD45⁺F4/80⁺CD11b⁺). n = 5. The data are presented as means ± S.E.M. Statistical significance was determined using the unpaired Student's t-test (**P < 0.01, ***P < 0.001)