Tumor immune evasion is a fundamental hallmark of cancer progression and a major barrier to effective immunotherapy. RNA epitranscriptomic modifications have emerged as a critical layer of post-transcriptional regulation that links RNA fate control with tumor immune remodeling. These reversible modifications, including m6A, m5C, ac4C, m¹A, m7G, pseudouridine, m6Am, Nm, and A-to-I RNA editing, are dynamically regulated by writers, erasers, and readers. By modulating RNA stability, splicing, nuclear export, translation efficiency, degradation, and innate immune recognition, RNA modifications reshape multiple immune-related processes in cancer. Mechanistically, they regulate tumor immune visibility by influencing antigen processing, MHC-I expression, interferon signaling, and dendritic cell-mediated cross-presentation. They also control immune checkpoint expression, particularly the PD-1/PD-L1 axis, inflammatory signaling pathways, immune-cell recruitment and exhaustion, and metabolic immunosuppression within the tumor immune microenvironment. Importantly, the functions of RNA modification regulators are highly context dependent. The same regulator may either promote immune escape or enhance antitumor immunity depending on cancer type, cellular source, target transcript, reader protein, and microenvironmental state. From a clinical perspective, RNA modification-based molecular subtypes, prognostic signatures, and risk-score models show potential for predicting patient prognosis, immune infiltration, and response to immune checkpoint blockade. In parallel, targeting RNA modification regulators, alone or in combination with immunotherapy, radiotherapy, chemotherapy, or targeted therapy, represents an emerging therapeutic strategy. However, clinical translation remains limited by insufficient specificity, tumor heterogeneity, complex crosstalk among RNA modifications, potential toxicity, and delivery barriers. Future studies integrating RNA modification mapping with single-cell, spatial, and multi-omics technologies will be essential to define cell-type-specific regulatory networks and develop precise RNA epitranscriptomic biomarkers and therapies for cancer immunotherapy.
Yanni Ma, Wenzhi Deng, Xiulin Jiang et al.· Frontiers in Immunology· 0 citations
Non-small cell lung cancer (NSCLC) is one of the leading causes of cancer incidence and mortality worldwide. In recent years, immune checkpoint inhibitors (ICIs), particularly those targeting the programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) axis, have significantly improved survival outcomes in a subset of patients. However, the magnitude and durability of clinical benefit vary considerably according to PD-L1 expression, treatment setting, histological subtype, oncogenic driver status, and whether ICIs are administered as monotherapy or in combination regimens. A substantial proportion of patients therefore exhibit either primary resistance or acquired resistance after an initial response. This review systematically summarizes the key mechanisms underlying immune resistance in lung cancer. These include defects in antigen presentation, such as abnormalities in major histocompatibility complex class I (MHC-I), transporter associated with antigen processing 2 (TAP2), and β2-microglobulin (B2M), as well as dysregulation of the interferon-γ/Janus kinase-signal transducer and activator of transcription (IFN-γ/JAK-STAT) signaling pathway. Tumors frequently exhibit an immune-excluded or ‘cold’ phenotype, which further limits immune recognition and reduces responsiveness to immunotherapy. This review summarizes immune resistance in NSCLC through a framework that distinguishes primary resistance from acquired resistance. Primary resistance reflects failure of immune activation at treatment initiation, usually due to pre-existing tumor-intrinsic or microenvironmental barriers, including impaired antigen presentation, defective IFN-γ/JAK-STAT signaling, low tumor immunogenicity, immune-cold or immune-excluded phenotypes, and suppressive TME states. In contrast, acquired resistance reflects adaptive tumor and immune ecosystem evolution under therapeutic pressure, leading to neoantigen loss, HLA or B2M alterations, compensatory checkpoint activation, progressive T cell exhaustion, TME remodeling, and epigenetic stabilization of immune escape. We further discuss mechanism-based biomarkers, translational correlates, and rational therapeutic strategies for overcoming resistance.
Bo Yuan, Wenzhi Deng, Juan Luo et al.· Frontiers in Immunology· 0 citations
