DMAP1 Deficiency Suppresses Lung Cancer Progression by Destabilizing Replication Fork and Activating IFN Signaling‐Mediated Anti‐tumor Immunity

ABSTRACT Despite substantial progress in targeted and immune therapies, lung cancer remains the leading cause of cancer‐related mortality, highlighting the urgent need for novel therapeutic strategies. Through a CRISPR‐based knock‐out screen, we identified the DNA methyltransferase 1‐associated protein 1 (DMAP1) as a critical regulator of lung cancer progression. Functional studies demonstrated that DMAP1 deficiency exerts its anti‐tumor effects through attenuating tumor cell proliferation and activating T cell‐mediated adaptive anti‐tumor effects. Mechanistically, DMAP1 deficiency causes replication fork retardance, disturbs genome stability, and induces endogenous DNA damage, thereby activating IFN signaling‐mediated anti‐tumor immune response. Clinical data analyses revealed that high DMAP1 expression is associated with a “cold” tumor microenvironment and poorer overall survival in lung cancer. These findings significantly advance our knowledge of DMAP1's function in lung cancer development and offer a scientific basis for designing novel treatment approaches.