Targeting EGFR-binding protein SLC7A11 enhancing antitumor immunity of T cells via inducing MHC-I antigen presentation in nasopharyngeal carcinoma.

Abstract

Approximately 80% of nasopharyngeal carcinoma (NPC) patients exhibit EGFR overexpression. The overexpression of EGFR has been linked to its potential role in modulating major histocompatibility complex class I (MHC-I) molecules. We discovered that EGFR, operating in a kinase-independent manner, played a role in stabilizing the expression of SLC7A11, which subsequently inhibited MHC-I antigen presentation. This mechanism, in turn, provided protection to NPC cells against T cell-mediated cytotoxicity. The underlying molecular processes revealed that the high and stable expression of SLC7A11 hindered the nuclear entry of GR, thereby suppressing TAP1 transcription and the presentation of MHC-I molecules. Additionally, elevated SLC7A11 expression led to an increase in FAF2 expression and triggered ERAD-dependent degradation of MHC-I, resulting in a reduction of MHC-I molecules on the cell membrane. The NPC patients exhibiting high EGFR and low MHC-I expression, combined with a scarcity of CD8⁺ T cells (EGFR^highMHC-I^lowCD8^few phenotype), experienced considerably shorter overall survival times compared to other situations. What is more, our study demonstrated that sorafenib had the capability to enhance the MHC-I antigen presentation process, thereby facilitating T cell-mediated killing of NPC cells via targeting SLC7A11. Consequently, targeting SLC7A11 with sorafenib emerges as a promising therapeutic strategy for the treatment of NPC.