Fig. 2

Inhibition of SPHK1 suppresses tumor growth by promotion of anti-tumor immunity in melanoma immunocompetent mouse models. a Schematics of the treatment plan using a C57BL/6 female mouse model, established by subcutaneously injecting B16F10. Mice were then either treated with high-dose PF543 (10 mg/kg), low-dose PF543 (5 mg/kg), or solvent (vehicle). b Image of B16F10 tumors, as captured on the ninth day. c Summary tumor volume data harvested on the ninth day. Plots of mice tumor volumes (d) and body weight (e) measured every other day. See also Supplementary Tables 1-2. Flow cytometric analyses of CD45⁺ cells (f), CD3⁺ in CD45⁺ cells (g), CD4⁺ or CD8⁺ in CD3⁺ cells (h, i), GZMB⁺CD8⁺ TILs (j), and PD-L1 on CD45^- subsets (k) from B16F10 tumor samples. See also Supplementary Fig. 2a–e. l Representative images of trichrome immunohistochemical staining of DAPI, CD8α, and PD-L1 of B16F10 tumor-bearing mice treated with vehicle, PF543 (5 mg/kg or 10 mg/kg). Scale bars, 50 μm. Violin plots indicating densities of CD8α⁺ (m) and PD-L1⁺ (n) cells/mm² in IHC sections of B16F10 allografts. 5 mice per cohort. Data represent mean ± SEM. ns non-significant, p > 0.05, *p < 0.05, **p < 0.01, and ***p < 0.001, as determined by one-way ANOVA and Tukey’s multiple comparisons test (c, f–k, m, n)