Epigenetic regulations in the IFNγ signalling pathway: IFNγ-mediated MHC class I upregulation on tumour cells is associated with DNA demethylation of antigen-presenting machinery genes [RVPC3_DAC]

Reversible MHC class I deficiency on tumour cells is commonly caused by coordinated silencing of antigen-presenting machinery genes and restorable by IFNγ. Here we describe association of DNA demethylation of selected antigen-presenting machinery gene regulatory regions located in the MHC genomic locus (TAP-1, TAP-2, LMP-2, LMP-7) upon IFNγ treatment with MHC class I upregulation on tumour cells. Our novel findings demonstrate that IFNγ acts as an epigenetic modifier upregulating the expression of antigen-presenting machinery genes through DNA demethylation. Our data also cast more light on the role of DNA methylation in tumour cell escape from specific immunity. RVP3 cultured cells treated with DAC/TSA or nothing. 3 biological replicates per condition.