Epigenetic regulation of NR5A2 influences colorectal cancer cell stemness via a stemness-related transcription factor NANOG.

OBJECTIVE: Colorectal cancer (CRC) is an aggressive malignancy with high mortality, and the identification of upstream regulators of stemness represents a critical step toward developing more effective targeted therapies. This study aimed to define the role of NR5A2 in CRC, particularly in the context of cancer stem cells (CSCs). METHODS: We profiled DNA copy number alterations, DNA methylation status, and mRNA expression in 30 CRC specimens. Primary CRC cells and CSC-enriched sphere cultures were established in vitro. Functional assays included RNA sequencing, sphere- and colony-formation assays, cell viability and cytotoxicity assessments, qRT-PCR, western blotting, immunofluorescence staining, chromatin immunoprecipitation (ChIP), and in vivo patient-derived xenograft (PDX) models. RESULTS: Integrated genomic and epigenomic analyses implicated NR5A2 in the progression of an aggressive CRC subtype characterized by stemness gene expression. Our findings demonstrate that NR5A2 plays a key role in CRC. Mechanistically, NR5A2 promoted CSC maintenance by directly binding to the promoter and enhancer regions of NANOG, thereby upregulating its expression. Pharmacological inhibition of NR5A2 using Cmp3 significantly sensitized a subset of CRC PDX models to standard chemotherapy, resulting in enhanced tumor regression. CONCLUSION: This study identifies NR5A2 as a novel, actionable therapeutic target in CRC. Pharmacological modulation of NR5A2 disrupts CSC-driven stemness, potentially preventing relapse and improving treatment outcomes. These findings provide a strong rationale for the development of NR5A2-targeted therapies, either as monotherapy or in combination with chemotherapy, to optimize CRC patient care.