Fig 2: IFNy responsiveness of metabolically stressed tumor cells can be restored by PI3K inhibition. Tumor cells were cultured under normal, GD, OD, or OGD conditions together with IFNy for 24 h. a and c Western-blots of TC1 (a) and B16F10 (c) tumor cells. Representative data out of three experiments is shown. b and d Quantification of western-blot results of phospho-AKT expression in TC1 (b) and B16F10 (d) tumor cells. e and g TC1 (e) and B16F10 (g) tumor cells were cultured under normal or OGD conditions with or without LY294002 for 24 h. Representative western-blot results out of three experiments is shown. f and h Quantification of western-blot results of phospho-AKT expression in TC1 (f) and B16F10 (h) tumor cells. i and k Western-blots of TC1 (i) and B16F10 (k). Phospho-STAT1 and IRF-1 expression levels are shown. j, l, m and n Quantified data of (i and k). Data was quantified by calculating signal ratio between protein of interest and beta-actin. Unpaired t test was used to calculate significance; n.s., not significant *, p < 0.05, **, p < 0.01, ***, p < 0.001

Fig 3: Impaired phosphorylation of STAT1 responsible for impaired MHC-I upregulation. Tumor cells were cultured for 24 h under several nutrient limiting conditions with or without IFNy. a and b Western-blots of TC1 (a) and B16F10 tumor cells (b). Representative data out of three experiments is shown. c and e Quantification of western-blot results of total STAT1 protein expression of TC1 (c) and B16F10 (e). d, g and f, i Quantification of western-blot results of phosphorylated STAT1 at Y701 and S727 of TC1 (d, g) and B16F10 (f, i). h and j Quantification of western-blot results of IRF-1 protein expression of TC1 (h) and B16F10 (j). Data was quantified by calculating signal ratio between protein of interest and beta-actin. Unpaired t test was used to calculate significance; n.s., not significant *, p < 0.05, **, p < 0.01, ***, p < 0.001

Fig 4: Gene transcription levels of IFNy-STAT1 relevant genes of tumor cells. Tumor cells were cultured under several nutrient limiting conditions for 24 h with or without IFNy. a and b Jak1 and Jak2 gene expression levels of TC1 (a) and B16F10 tumor cells (b) measured by qPCR. c and d Stat1 and Irf-1 gene expression levels of TC1 (c) and B16F10 tumor cells (d) measured by qPCR. e and f Tap1 and H2-Kb (MHC-I) gene expression levels of TC1 (e) and B16F10 tumor cells (f) measured by qPCR. Relative mRNA expression is shown compared to normal culture conditions without IFNy stimulation and normalized to UBC housekeeping gene expression. Representative data is shown as mean + − SD (n = 3). Unpaired t test was used to calculate significance; n.s., not significant *, p < 0.05, **, p < 0.01, ***, p < 0.001