Salinomycin modulates viability, invasion, and inflammatory responses in primary endometriotic stromal cell cultures in association with Wnt/β-catenin signaling

Abstract

Endometriosis is a chronic inflammatory disorder characterized by aberrant stromal-cell behavior, including enhanced invasion, resistance to apoptosis, and sustained cytokine production. Dysregulation of Wnt/β-catenin signaling has been linked to these pathological features, emphasizing its association with disease-related cellular phenotypes. Identifying non-hormonal approaches that selectively target endometriotic stromal cells remains an important research focus. In this study, primary endometriotic stromal cell cultures derived from ectopic lesions of women with ovarian endometrioma were compared with primary control endometrial stromal cell cultures from women without endometriosis. Vimentin and CK18 were evaluated in separate flow-cytometry tubes; therefore, the designation of these cultures as stromal cultures is operational and does not imply complete lineage purity. Cells were treated with Salinomycin, and MTT-derived viable-cell/metabolic activity, Matrigel invasion, cytokine secretion, and selected molecular markers related to Wnt/β-catenin signaling, cell-cycle regulation, invasion, and apoptosis were evaluated using MTT assays, Transwell assays, ELISA, and quantitative real-time PCR. Salinomycin induced a dose- and time-dependent reduction in MTT signal, with primary endometriotic cultures showing greater sensitivity than control cultures. At the selected experimental concentration, salinomycin reduced the viable-cell/metabolic signal and invasion in primary endometriotic stromal cell cultures and decreased IL-6 and IL-8 secretion. These phenotypic changes were accompanied by increased β-catenin phosphorylation at Ser45, reduced AXIN2, Cyclin D1, and MMP-9 expression, and increased Caspase-3 expression in ectopic cultures. Because MTT alone cannot distinguish reduced proliferation from cytotoxicity or altered metabolism, the findings are interpreted as viability-associated and proliferation-associated responses rather than direct proof of isolated growth arrest. These findings indicate that Salinomycin modulates disease-relevant features of primary endometriotic stromal cell cultures in association with Wnt/β-catenin pathway-related changes and support further mechanistic investigation of this experimental non-hormonal approach.