WNK4 restrains endometrial cancer progression by reprogramming macrophage polarization toward an M1-like phenotype.

BACKGROUND: Endometrial cancer lacks robust immune-linked biomarkers that can be translated into tractable therapeutic strategies. WNK4, a member of the with-no-lysine (WNK) kinase family, is involved in cancer-relevant signaling pathways; however, its immunological significance in endometrial cancer has yet to be defined. METHODS: Immune deconvolution and gene-immune correlation analyses were performed to relate WNK4 to immune-cell-associated signatures. WNK4 expression was assessed in clinical endometrial cancer tissues and cell lines by immunoblotting. Macrophage polarization was modeled using phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 macrophages with interleukin-4 (IL-4) induction, followed by WNK4 overexpression. Polarization status was evaluated by marker expression and flow cytometry. Conditioned macrophage states were tested in Transwell co-culture with Ishikawa and HEC-1-A cells to assess viability, clonogenicity, migration/invasion, and apoptosis. To confirm the impact on tumor growth and macrophage-marker expression within tumors, we established a nude-mouse xenograft model. RESULTS: WNK4 was reduced in endometrial cancer tissues and malignant endometrial cell lines. Correlation analyses linked WNK4 to immune-state features, including an inverse association with M2-like macrophage signatures. In THP-1-derived macrophages, WNK4 overexpression counteracted IL-4-driven M2-like polarization and shifted cells toward an M1-like profile. In co-culture, WNK4-modified macrophages suppressed proliferative and motile phenotypes of endometrial cancer cells and increased apoptotic signaling. In vivo, WNK4 overexpression inhibited xenograft growth and was accompanied by macrophage-marker changes consistent with reduced M2-like features. CONCLUSIONS: WNK4 acts as an immune-relevant suppressor in endometrial cancer, partly by limiting M2-like polarization and weakening macrophage-driven tumor support.