N4‐Acetylcytidine Drives Glycolysis Addiction in Gastric Cancer via NAT10/SEPT9/HIF‐1α Positive Feedback Loop

Anti‐angiogenic therapy has long been considered a promising strategy for solid cancers. Intrinsic resistance to hypoxia is a major cause for the failure of anti‐angiogenic therapy, but the underlying mechanism remains unclear. Here, it is revealed that N4‐acetylcytidine (ac4C), a newly identified mRNA modification, enhances hypoxia tolerance in gastric cancer (GC) cells by promoting glycolysis addiction. Specifically, acetyltransferase NAT10 transcription is regulated by HIF‐1α, a key transcription factor of the cellular response to hypoxia. Further, acRIP‐sequencing, Ribosome profiling sequencing, RNA‐sequencing, and functional studies confirm that NAT10 in turn activates the HIF‐1 pathway and subsequent glucose metabolism reprogramming by mediating SEPT9 mRNA ac4C modification. The formation of the NAT10/SEPT9/HIF‐1α positive feedback loop leads to excessive activation of the HIF‐1 pathway and induces glycolysis addiction. Combined anti‐angiogenesis and ac4C inhibition attenuate hypoxia tolerance and inhibit tumor progression in vivo. This study highlights the critical roles of ac4C in the regulation of glycolysis addiction and proposes a promising strategy to overcome resistance to anti‐angiogenic therapy by combining apatinib with ac4C inhibition.