Figure 3.

Pharmacological inhibition of EZH2 upregulates interferon-induced major histocompatibility complexes expression. (A–B) Flow cytometry analysis of A375 and SKMEL-5 cell lines treated with the indicated EZH2 inhibitor for 5 days. Single cell suspensions were stained with fluorophore-conjugated antibodies HLA-DR. *p<0.05 and **p<0.01, one-sample t-test against a fold change of 1. (C) After stimulation with IFN-γ for 24–48 hours, whole cell protein lysates were extracted from A375, SKMEL-5, and COLO829 cells treated with DMSO or EZH2 inhibitor before being probed for the indicated proteins. Data shown represents three independent experiments. (D–E) Relative expression of EZH2, CIITA, and CD74 mRNA extracted from melanoma cell lines treated with GSK343 or tazemetostat and stimulated with IFN-γ for 24–48 hours. Samples were normalized to GAPDH mRNA and calculated as fold expression relative to the DMSO control. CIITA, class II major histocompatibility complex transactivator I; DMSO, dimethyl sulfoxide; EZH2, enhancer of zeste 2 polycomb repressive complex 2 subunit; HLA-DR, human leukocyte antigen-DR; IFN, interferon; MFI, mean flourescence intensity; mRNA, messenger RNA; PD-L1, programmed death ligand 1.