Targeting the CD47-HCK-LGALS9 axis disrupts proliferation-immunosuppression coupling in early-stage endometrial cancer

Significant heterogeneity was observed in the epithelial-derived endometrial cancer (EC), which contributes to different prognostic outcomes. While the mechanisms involved in this heterogeneity in the tumor microenvironment (TME) of early-stage EC remain poorly defined. Single-cell RNA sequencing, spatial transcriptomics, and multiplex immunofluorescence (mIF) were applied to characterize cellular subpopulations in early-stage EC. EC cell proliferation was assessed by CCK-8 and flow cytometry (FC). Furthermore, the epithelial dynamics and macrophage interactions were also investigated in vitro by molecular docking and GST pull-down mass spectrometry. Phagocytic activity was also evaluated by FC and immunofluorescence. Moreover, the upstream transcription factors were identified using CUT&Tag. For in vivo study, an organoid–macrophage co-culture model was established to mimic the EC microenvironment, and altered organoid proliferation and macrophage phagocytosis were confirmed. CD47 was evaluated as a potential prognostic marker by proteomic analysis and immunohistochemistry. We identified a previously unrecognized epithelial subpopulation (CD47⁺CDK1⁺) that was strongly linked to cell-cycle signaling and malignant proliferation. This subpopulation interacts closely with macrophages through the CD47–Galectin 9 (LGALS9) receptor-ligand pair. Functionally, CD47 inhibition suppressed EC cell proliferation and induced apoptosis, while CD47 overexpression enhanced the proliferative capacity of EC patient-derived organoids (PDOs). EC cells and PDOs engaged macrophages through the CD47–HCK (Hemopoietic Cell Kinase) axis, driving the secretion of immunosuppressive molecules LGALS9, IL-10, and TGF-β1 and forming an immunosuppressive TME. In turn, macrophage-derived LGALS9 reinforced EC cell and PDO proliferation via CD47, establishing a positive feedback loop involving CD47–HCK–LGALS9. Furthermore, estrogen-related receptor gamma (ERRγ) was identified as an upstream transcriptional regulator of CD47, and its expression was suppressed by progesterone. Regulated by ERRγ, an optimistic therapeutic target, the CD47-HCK-LGALS9 axis modulated cellular proliferation-immunosuppression coupling in early-stage EC.