Therapeutic Targeting of MELK by Repurposed Drugs Netarsudil and Dutasteride Suppresses Triple‐Negative Breast Cancer Cell Progression: Evidence From Molecular Simulations and Functional Validations

Abstract Triple‐negative breast cancer (TNBC), the most aggressive breast cancer subtype, faces limited treatment options due to the absence of hormone receptors and frequent resistance to current therapies. This highlights the urgent need to uncover novel therapeutic targets and treatment strategies to address its progression. In this study, an integrated computational and experimental approach identified maternal embryonic leucine zipper kinase (MELK) as a consistently overexpressed oncogenic driver in TNBC, regulating cell cycle and survival pathways. To target MELK, a high‐throughput molecular simulation‐based drug repurposing screen of FDA‐approved drugs identified Netarsudil and Dutasteride as top candidates, exhibiting high binding affinities (−121.34 and −107.09 kJ mol −1 , respectively). Experimental validation in MDA‐MB‐231 and MDA‐MB‐468 TNBC cells demonstrate that both drugs effectively suppressed their proliferation and migration abilities. Additionally, they modulated MELK‐associated pathways, inducing 1.5–3‐fold changes in cyclins, p21, p53, and survivin expression. Mechanistically, the drugs effectively inhibit the role of MELK in mitotic progression and apoptosis evasion, evidenced by elevated reactive oxygen species (ROS), nuclear morphological alterations, and significant S‐phase cell cycle arrest. These findings position MELK as a promising therapeutic target and highlight the potential of repurposed drugs to influence oncogenic processes in TNBC cells, offering a novel targeted therapy for TNBC.