Figure 4. IFNγ induces metabolic reprogramming in melanoma cells for supporting immune evasion.

(A) PCA of transcriptome for WT primary melanoma cells and KO primary melanoma cells.

(B) Gene set enrichment analysis showing upregulated expression of genes on IFNγ response and cMyc targets in WT primary melanoma cells compared with KO primary melanoma cells.

(C) Significantly enriched transcription factors binding differentially accessible genomic loci in WT primary melanoma cells compared with KO primary melanoma cells.

(D and E) Ratios of basal OCR versus ECAR in WT primary melanoma cells (D) and KO primary melanoma cells (E) treated with control vehicle (Ctrl) or IFNγ for 48 h prior to assay (n = 4).

(F) Representative kinetic of OCR (left panel) following treatment with oligomycin (2 μM), FCCP (2 μM), etomoxir (40 μM), and antimycin A plus rotenone (0.5 μM each) in KO1 primary melanoma cells. Cells were incubated with control vehicle (Ctrl) or 100 ng mL⁻¹ IFNγ for 48 h prior to assay. Relative etomoxir-sensitive OCR, calculated by measuring the differences of OCR levels between etomoxir and FCCP treatment, in indicated primary melanoma cells treated with control vehicle and IFNγ 48 h prior to assay (right panel) (n ≥ 5 per group).

(G) Ratio of basal OCR versus ECAR in parental KO1 and escaped KO1 cells (left panel) and in parental KO7 and escaped KO7 cells (right panel).

(H) PCA of metabolites in Braf/Pten tumors from non-escaped and escaped inducible Braf/Pten melanomas upon discontinuation of T cells depletion as illustrated in Figure 3A.

(I) Metabolite set enrichment analysis of Braf/Pten melanomas from escaped versus non-escaped tumors.

Data are representative results of two independent experiments with similar results (D–G). Each symbol represents one individual. Data are means ± SEM and analyzed by two-tailed, unpaired Student’s t test.