Inhibition of tumor-intrinsic NAT10 enhances antitumor immunity by triggering type I interferon response via MYC/CDK2/DNMT1 pathway.

Posttranscriptional modifications are involved in cancer progression. However, the function and regulatory mechanism of mRNA acetylation modification remains largely unknown. Here, we discover an unexpected role of N4-acetylcytidine (ac4C) RNA acetyltransferase NAT10 in reshaping the tumor immune microenvironment. By analyzing patients' data, we find that NAT10 is upregulated in tumor tissues, and negatively correlated with immune cell infiltration and overall survival. Loss of tumoral NAT10 enhances tumor-specific cellular immune response and suppresses tumor growth. Mechanistically, MYC is identified as a key downstream target of NAT10 via enhancing mRNA ac4C modification. Inhibition of NAT10 blocks the MYC/CDK2/DNMT1 pathway, enhances double-stranded RNA (dsRNA) formation, which triggers type I interferon response and improves tumor specific CD8 T cell response in vivo. More importantly, the inhibition of NAT10, using either small molecule inhibitor (Remodelin) or PEI/PC7A/siNAT10 nanoparticles, synergize PD-1 blockade in elevating anti-tumor immune response and repressing tumor progression. Our findings thus uncover the crucial role of tumor-intrinsic NAT10 in tumor immune microenvironment, which represents a promising target for enhancing cancer immunotherapy.