YTHDF1 functions as a non-canonical nuclear checkpoint that couples R-loop homeostasis to innate immune restraint and adaptive immune resistance in cancer（CUT&Tag）

Innate immune signaling within cancer cells plays an important role in shaping antitumor immunity, yet the nuclear mechanisms that restrain inappropriate immune activation remain incompletely defined. YTHDF1 is an mRNA-binding protein previously characterized as a cytoplasmic m⁶A reader. Emerging evidence indicates that YTHDF1 also functions in the nucleus, where it associates with chromatin and contributes to the regulation of R-loop homeostasis. Loss of YTHDF1 results in R-loop accumulation, genomic instability, cytosolic DNA release, and activation of the cGAS–STING–type I interferon pathway. Mechanistically, YTHDF1 interacts with the chromatin remodeler ARID1A at immune-associated genomic regions, suggesting a cooperative role in maintaining genome stability and regulating immune-related transcriptional programs. To investigate the transcriptomic and chromatin-level consequences of YTHDF1 and ARID1A perturbation, we generated RNA sequencing (RNA-seq) and R-loop CUT&Tag datasets in A549 human lung cancer cells. RNA-seq was performed in two experimental settings: (1) wild-type (WT) and YTHDF1 knockout (YTHDF1-KO) cells; and (2) WT, YTHDF1-KO, ARID1A knockdown (siARID1A), and combined YTHDF1-KO with ARID1A knockdown cells. In parallel, R-loop CUT&Tag profiling was conducted under the same respective conditions to assess genome-wide R-loop distribution. These datasets provide integrated transcriptomic and chromatin profiling resources for studying the roles of YTHDF1 and ARID1A in regulating R-loop dynamics and tumor-intrinsic innate immune signaling