Introduction: Endometriomsis (EMs) is a complex and chronic gynecological disease characterized by distressing symptoms. Its pathogenesis remains unknown, and there is no effective treatment. Therefore, establishing patient-derived models is crucial for elucidating disease mechanisms and identifying potential therapeutic agents. We developed a coculture system combining epithelial organoids and stromal cells, enabling the study of their dynamic interactions. Using this model, we assessed the therapeutic efficacy of dienogest, a drug clinically used for treating endometriomas.
Material and methods: The epithelial gland-like organoids and stromal cells derived from patients with endometriomas were isolated and cultured, respectively. Both of them were cocultured in matrix for partially mimicking in vivo pathological features. Immunohistochemical (IHC) assay was used to identify their biomarkers. Cell viability was quantitatively assessed using the CellTiter-Glo® assay following drug treatment.
Results: We successfully cultured patient-derived epithelial gland-like organoids and stromal cells derived from patients with endometriomas, a form of endometriosis characterized by ovarian cysts. Morphological and immunohistochemical analyses confirmed high consistency with native endometriotic lesions. These models exhibited comparable expression profiles for key biological markers, including estrogen receptors (ERs), progesterone receptors (PRs), E-cadherin, CD44, Intercellular Adhesion Molecule-1 (ICAM1), Integrin Beta 3 (ITGB3), Cytokeratin 7 (CK7), Matrix Metalloproteinase 2/9 (MMP2/9), Tissue Inhibitor of Metalloproteinases 1 (TIMP1), and TIMP2. Notably, drug responsiveness varied among the patient-derived models by coculturing two types of cells, indicating potential interpatient heterogeneity in treatment outcomes. We propose that this patient-specific endometriomas model serves as a valuable platform for investigating disease mechanisms and screening drug in endometriomas.
Conclusions: We established a novel coculture system integrating epithelial organoids and stromal cells to recapitulate the intricate cellular interactions within the endometriotic microenvironment, providing a more relevant in vitro representation of the disease. Upon evaluation with dienogest, a clinically used therapeutic agent for endometriomas, the patient-derived models exhibited heterogeneous drug responses.
© 2026 The Author(s). Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).