Inhibition of CDC42 in adenomyosis reduces the proliferation of endometrial stromal cells and the migration of epithelial cells.

OBJECTIVES: Adenomyosis severely impairs fertility and quality of life. This study investigated the pathophysiologic role of cell division cycle 42 (CDC42) in adenomyosis by profiling its expression, identifying its binding partners, and performing functional assays on endometrial cells. METHODS: Immunofluorescence was used to evaluate CDC42 expression in endometrial cells from adenomyosis patients. RNA sequencing (RNA-seq) was used to analyze transcriptomic changes following CDC42 knockdown. The effects of CDC42 inhibition on endometrial stromal cell proliferation and migration were assessed using cell viability and migration assays. Furthermore, coimmunoprecipitation coupled with mass spectrometry (Co-IP/MS) was conducted to identify CDC42-interacting proteins. Finally, conditioned medium from CDC42-knockdown stromal cells was used to evaluate the effects of paracrine signaling on endometrial epithelial cell migration. RESULTS: CDC42 expression was significantly upregulated in the endometrial cells of adenomyosis patients. Transcriptomic analysis revealed that CDC42 knockdown downregulated the expression of genes associated with the cell cycle and cytokine signaling. Functionally, CDC42 inhibition markedly reduced stromal cell proliferation and attenuated the migration of both stromal and epithelial cells. Notably, conditioned medium from CDC42-knockdown cells also suppressed epithelial cell migration. Co-IP/MS revealed 70 CDC42-interacting proteins, and subsequent Gene Ontology (GO) enrichment analysis indicated their primary involvement in mRNA metabolism, cell adhesion, and Rho GTPase signaling pathways. CONCLUSIONS: CDC42 contributes to the pathogenesis of adenomyosis by promoting endometrial stromal cell proliferation and epithelial cell migration, likely by mediating cell cycle regulation and Rho GTPase signaling networks. Therefore, targeting CDC42 is a promising therapeutic strategy for the management of adenomyosis.