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

Purpose:Posttranscriptional modifications are deeply involved in cancer progression; however, there remains knowledge gap regarding the function and immune regulatory mechanism of newly discovered mRNA acetylation modification.Methods: The expression of NAT10 in human tumor tissues was analyzed based on TCGA data. NAT10 knockout murine cell lines were generated to analyze the NAT10-associated tumor progression and anti-tumor immune response in tumor xenograft models. Immune cells and cytokines in TME were quantified by immunofluorescence, flow cytometry, quantitative reverse transcription-PCR, and ELISPOT assay. NAT10-associated differentially expressed genes were investigated in cancer cells and tissues with RNA-Seq. Results:Loss of tumoral NAT10 significantly stimulated tumor-specific cellular immune responses and suppressed tumor growth. Mechanistically, we identified MYC as a key downstream target of NAT10 via enhancing mRNA stability and translation efficiency. Inhibition of NAT10 blocked the MYC/CDK2/DNMT1 pathway, subsequently enhancing double-stranded RNAs (dsRNA) formation, which triggered type I interferon responses to enhance the in vivo response of tumor specific CD8+ T cells. Conclusions: Inhibition of NAT10 using either small molecule inhibitor (Remodelin) or PEI/PC7A/siNAT10 nanoparticles combined with PD-1 blockade synergistically enhanced the anti-tumor immune response and repressed tumor progression. Our findings uncovered the crucial role of tumor-intrinsic NAT10 in tumor immune microenvironment, representing a promising target for enhancing cancer immunotherapy.