Abstract
Triple-negative breast cancer (TNBC), being both aggressive and highly lethal, poses a major clinical challenge in terms of treatment. Its heterogeneity and lack of hormone receptors or HER2 expression further restrict the availability of targeted therapy. Breast cancer stem cells (BCSCs), known to fuel TNBC malignancy, are now being exploited as a vulnerability for TNBC treatment. Here, we dissected the transcriptome of BCSCs and identified kinesin family member 20A (KIF20A) as a key regulator of BCSC survival and TNBC tumorigenesis. Genetic depletion or pharmacological inhibition of KIF20A impairs BCSC viability and tumor initiation and development in vitro and in vivo. Mechanistically, KIF20A supports BCSC stemness through modulation of mitochondrial oxidative phosphorylation, which is repressed by SMARCA4, a component of the SWI/SNF chromatin remodeling complex. Therapeutically, KIF20A inhibition sensitizes TNBC xenografts to standard-of-care chemotherapy. Our study highlights the importance of targeting KIF20A to exploit BCSC vulnerabilities in TNBC.