Integrative multi-omics analysis implicates RSAD2-associated CXCL1–CXCR1/2 signaling in tumor–macrophage communication and progression of endometrial cancer

Immunotherapy in endometrial cancer (EC) faces challenges due to patient-specific heterogeneity and biomarkers linking tumor-intrinsic programs to the tumor microenvironment remain limited. This study aimed to identify immune-related prognostic factors and investigate the role of RSAD2 in EC progression and tumor–macrophage communication. Integrative multi-omics analyses of TCGA-UCEC were used to construct a prognostic signature and prioritize Radical S-adenosyl methionine domain-containing protein 2 (RSAD2) for further investigation. The functional effects of RSAD2 were evaluated using gain- and loss-of-function assays and a xenograft model. Bulk RNA sequencing, public single-cell RNA sequencing, qRT-PCR, ELISA, and macrophage conditioned-medium and co-culture assays with the CXCR1/2 inhibitor SX-517 were performed to explore RSAD2-associated signaling. Clinical relevance was assessed by immunohistochemistry, multiplex immunohistochemistry, and survival analyses in a retrospective EC cohort ( n = 254). The multi-omics score stratified TCGA-UCEC patients according to survival and distinct immune features, and RSAD2 showed an adverse survival association with macrophage-related immune signatures. RSAD2 overexpression enhanced EC-cell proliferation, migration, invasion, colony and sphere formation, and xenograft growth, whereas RSAD2 knockdown produced the opposite effects. Transcriptomic and biochemical analyses associated RSAD2 with RAF–MEK–ERK activation and increased CXCL1 expression, and CXCL1 secretion changed concordantly with RSAD2 expression under inflammatory stimulation. Conditioned medium from RSAD2-overexpressing EC cells enhanced THP-1-derived macrophage chemotaxis and induced a mixed activation-associated transcriptional response, which was attenuated by CXCR1/2 inhibition. In the clinical cohort, RSAD2 expression was increased in EC tissues and was associated with immune-cell infiltration and poorer survival outcomes in univariable analyses. RSAD2 is a candidate biomarker of EC progression. Our findings support a potential role for RSAD2 associated CXCL1–CXCR1/2 signaling in tumor–macrophage communication, although further ligand-specific, genetic, and immune-competent validation is required to establish its mechanistic and translational significance.