Modulation of MHC class I surface expression in B16F10 melanoma cells by methylseleninic acid

ABSTRACTThe essential trace element selenium (Se) might play a role in cancer prevention as well as for cancer therapy. Its metabolite methylselenol is able to kill cells through distinct mechanisms including induction of reactive oxygen species, DNA damage and apoptosis. Since methylselenol affects innate immune responses by modulating the expression of NKG2D ligands, the aim of this study was to determine whether the methylselenol generating compound methylseleninic acid (MSA) influences the expression of the MHC class I surface antigens and growth properties thereby reverting immune escape.Treatment of B16F10 melanoma cells expressing low basal MHC class I surface antigens with dimethyldiselenide (DMDSe) and MSA, but not with selenomethionine and selenite resulted in a dose-dependent upregulation of MHC class I cell surface antigens. This was due to a transcriptional upregulation of some major components of the antigen processing machinery (APM) and the interferon (IFN) signaling pathway and accompanie...