Despite overexpression of N-acetyltransferase 10 (NAT10) in colorectal cancer (CRC), its immunomodulatory role in the tumor microenvironment remains elusive. Here, we reveal that NAT10 promotes immune evasion through N4-acetylcytosine-dependent (ac4C-dependent) mRNA stabilization. Using syngeneic mouse models (MC38/CT-26), intestinal epithelial-cell specific Nat10 conditional KO (Nat10cKO) mice, patient-derived organoids, and clinical specimens, we show that Nat10 ablation enhanced CD8+ T cell-mediated antitumor immunity. Single-cell RNA-seq revealed increased cytotoxic CD8+ T cell infiltration in Nat10cKO tumors, which was corroborated by the inverse correlation of tumoral NAT10 expression and CD8+ T cell number in clinical specimens. Multi-omics integration analysis identified DKK2 as the predominant NAT10-regulated transcript. NAT10 stabilized DKK2 mRNA via ac4C modification, leading to high expression of the DKK2 protein. Secreted DKK2 engaged LRP6 receptors to activate AKT-mTOR signaling, inducing cholesterol accumulation in CD8+ T cells and impairing their cytotoxicity. Pharmacological NAT10 inhibition (Remodelin treatment) or DKK2 neutralization restored CD8+ T cell function and synergized with anti-PD-1 therapy. Our findings establish the NAT10/DKK2/LRP6/AKT-mTOR/cholesterol axis as a critical regulator of CD8+ T cell dysfunction in CRC, positioning NAT10/DKK2 as a potential target to enhance immunotherapy efficacy.
Keywords: Cancer immunotherapy; Colorectal cancer; Epigenetics; Gastroenterology; Immunology; Oncology.