KMT5C‐Mediated H4K20me3 Recruits EWSR1 to Propel Clear Cell Renal Cell Carcinoma Progression via Regulating ACADM Transcription and m ⁶ A Modification

ABSTRACT

Clear cell renal cell carcinoma (ccRCC) exhibits notable genetic and epigenetic heterogeneity. Although H4K20me3 is markedly enriched in ccRCC samples, the precise functional role of this histone modification in ccRCC pathogenesis remains elusive. The expression and prognostic value of KMT5C, the catalytic enzyme responsible for H4K20me3, were investigated using public databases and clinical specimens from our institute. Functional experiments were conducted to elucidate the role of KMT5C in ccRCC progression. Mechanistically, comprehensive molecular approaches, including peptide pull‐down, shotgun proteomics, co‐immunoprecipitation, microscale thermophoresis, RNA‐seq, ChIP‐qPCR, and RIP‐qPCR, were employed to dissect the signaling pathway. The levels of H4K20me3 and KMT5C were significantly elevated in ccRCC. And elevated level of KMT5C was associated with the poor prognosis. Functional experiments demonstrated the oncogenic role of KMT5C in ccRCC proliferation and migration. Mechanistically, we identified EWSR1, an RNA/DNA‐binding protein, as a direct interaction partner of H4K20me3. Downregulation of EWSR1 significantly inhibited cell proliferation and migration of ccRCC cells. Transcriptomic analysis combined with ChIP and RIP experiments revealed that KMT5C and EWSR1 co‐regulate the expression of ACADM. Specifically, KMT5C‐mediated H4K20me3 directly suppressed ACADM transcription, whereas EWSR1 further reduced ACADM mRNA stability by modulating its m ⁶ A modification level. Importantly, the combination of A‐196 (KMT5C inhibitor) and sunitinib effectively inhibited tumor growth in a xenograft model, demonstrating significant therapeutic potential. Our study revealed that KMT5C‐mediated H4K20me3 promotes ccRCC progression by suppressing ACADM transcription and destabilizing its mRNA through recruitment of EWSR1. Targeting KMT5C with A‐196 in combination with sunitinib represents a promising therapeutic strategy for ccRCC.