MicroRNA-126 as a Key Modulator of Stemness Phenotype and Gene Expression in Ovarian Cancer Cells

Objectives: MicroRNA-126 (miR-126) has been implicated in tumor suppression and regulation of stemness in various cancers, but its role in ovarian cancer remains unclear.This study aimed to investigate the regulatory effect of miR-126 on stemnessrelated transcription factors in ovarian cancer cells.Methods: The mRNA expression levels of SOX2, LIN28, C-MYC, and KLF4 were compared between normal ovarian cells and ovarian cancer cell lines, including HSC832, OVCA, and PA-1.Functional experiments using a miR-126-5p mimic and inhibitor were conducted to evaluate the impact of miR-126 modulation on gene expression.Results: SOX2, LIN28, C-MYC, and KLF4 were significantly upregulated in ovarian cancer cell lines compared to normal controls.Modulation of miR-126 by mimic or inhibitor altered the expression of these stemness genes, with distinct patterns among cell lines.In particular, co-treatment with a miR-126-5p mimic and inhibitor induced a marked increase in the expression of all four genes in OVCA cells, whereas HSC832 and PA-1 exhibited gene-specific changes.Conclusion: These findings suggest that miR-126 exerts a context-dependent regulatory role in ovarian cancer stemness and may serve as a potential molecular target for understanding ovarian cancer biology.This study was conducted using in vitro cell-line models and mRNA-level analyses.Therefore, protein-level and functional validations are required, and clinical extrapolation should be made with caution.