LincRNA-immunity landscape analysis identifies EPIC1 as a regulator of tumor immune evasion and immunotherapy resistance.

Abstract

Through an integrative analysis of the lincRNA expression and tumor immune response in 9,626 tumor samples across 32 cancer types, we developed a lincRNA-based immune response (LIMER) score that can predict the immune cells infiltration and patient prognosis in multiple cancer types. Our analysis also identified tumor-specific lincRNAs, including <i>EPIC1</i>, that potentially regulate tumor immune response in multiple cancer types. Immunocompetent mouse models and in vitro co-culture assays demonstrated that <i>EPIC1</i> induces tumor immune evasion and resistance to immunotherapy by suppressing tumor cell antigen presentation. Mechanistically, lincRNA <i>EPIC1</i> interacts with the histone methyltransferase EZH2, leading to the epigenetic silencing of <i>IFNGR1</i>, <i>TAP1/2</i>, <i>ERAP1/2</i>, and MHC-I genes. Genetic and pharmacological inhibition of EZH2 abolish <i>EPIC1's</i> immune-related oncogenic effect and its suppression of interferon-γ signaling. The <i>EPIC1</i>-EZH2 axis emerges as a potential mechanism for tumor immune evasion that can serve as therapeutic targets for immunotherapy.