Figure 4.

LSD1 inhibition drives MHC-I upregulation. A, Distributions of H-2K^b surface staining from representative RP-48_OVA-LLO190 flank tumors collected after 10 days of treatment with vehicle, bomedemstat (45 mg/kg daily), anti-PD1 (250 μg twice weekly), or bomedemstat and anti-PD1 (normalized to modal value). B, Percent of H-2K^b positive cells and, C, geometric mean fluorescence intensity (gMFI) of cells in the positive gate in CD45- (tumor) cells from RP-48_OVA-LLO190 flank tumors (n=7 in each group) (mean±SEM). One-way ANOVA with followup comparison of all groups, with Sidak’s correction for multiple comparisons, *P<0.05, **P<0.01, ***P<0.001. D, Distributions of H-2K^b surface staining from representative replicates and, E, percent of H-2K^b positive RP-48_OVA-LLO190 cultured cells treated with bomedemstat (1 μM, BOM) or DMSO for a total of 72h, with addition of varying concentrations of interferon gamma (IFN-g) from 48-72h. Multiple unpaired t tests with unequal variance and Sidak’s correction for multiple testing, *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001. F, Percent of H-2K^b positive FH-B6RP-01 cells, G, pan-MHC-I positive H510 cells and, H, pan-MHC-I positive H146 cells treated with bomedemstat (1 μM) or DMSO for a total of 96h, with addition of varying concentrations of interferon gamma (IFN-g) from 72-96h. Multiple unpaired t tests with unequal variance and Sidak’s correction for multiple testing, *P<0.05, ***P<0.001. I, Immunoblot analysis and, J, percent of H-2K^b positive RP-48_OVA-LLO190 cells transduced with a CRISPR knockout vector encoding a non-targeting (control) or LSD1-targeting sgRNA. One-way ANOVA with followup comparison of each control sgRNA with each LSD1 sgRNA, with Sidak’s correction for multiple comparisons, *P<0.05, **P<0.01, ***P<0.001, ***P<0.0001.