Class I MHC molecules and doxorubicin resistant P388 murine leukemic cells

The major histocompatibility complex (MHC) encodes cell surface and secreted products involved in immune regulation and function. We have measured Class I MHC expression on doxorubicin (DOX) sensitive (P388/S) and resistant (P388/R84 and R84A) murine tumor cells using a monoclonal antibody to H-2d molecules. The present report shows a correlation between increased Class I MHC (H-2d) expression and drug resistance in P388 cells. Exposure of P388 cells to H-2d antibody diminished H-2d expression, whereas, treatment with murine recombinant gamma-interferon increased H-2d expression. Neither treatment significantly altered cellular DOX resistance or chemosensitivity. Thus, H-2d molecules can be used to identify DOX resistant P388 tumor cells but are probably not involved functionally in drug resistance.