2025/07/16 by Bartimée Galvan, Loïc Ongena, Jonathan Bruyr +22 · 1 voice
Biochemistry, Genetics and Molecular Biology · Medicine · #RNA Research and Splicing #Sarcoma Diagnosis and Treatment #RNA modifications and cancer
paper · pdf · doi:10.1038/s41467-025-61725-x
openalex publication_date 2025/07/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
Many cancers are defined by gene fusions that frequently encode oncogenic transcription factors (TFs), such as EWSR1::FLI1 in Ewing sarcoma (EwS). Here, we report that independently to its canonical roles in transcription, EWSR1::FLI1 also functions as an mRNA decay factor, reshaping mRNA stability in EwS. This function participates in EWSR1::FLI1 tumorigenicity and involves interactions of EWSR1::FLI1 with the CCR4-NOT deadenylation complex via its EWSR1-derived low-complexity domain and with the RNA-binding protein HuR/ELAVL1 via its FLI1-derived region. Strikingly, we find that EWSR1::FLI1-mediated mRNA decay antagonizes the normal mRNA protective function of HuR and renders EwS cells highly sensitive to HuR inhibition. Our findings uncover a post-transcriptional function of EWSR1::FLI1 and suggest that targeting mRNA stability mechanisms may offer therapeutic opportunities for EwS. The EWSR1::FLI1 fusion protein is the oncogenic driver of Ewing sarcoma (EwS). Here, the authors find that EWSR1::FLI1 plays a non-canonical role in mRNA decay via interactions with the CCR4-NOT deadenylation complex and the RNA-binding protein HuR. This role uncovers a new therapeutic vulnerability of EwS to HuR inhibition.