TCOF1 DRIVES STEMNESS OF TRIPLE-NEGATIVE BREAST CANCER THROUGH KIT

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with poor prognosis. The high malignancy of TNBC is contributed by its heterogeneity and enrichment of cancer stem cells. By performing multiomic profiling, we recently uncovered super-enhancer heterogeneity between breast cancer subtypes. Here, we identify TCOF1 as a novel super-enhancer-regulated gene that promotes TNBC growth and stemness. TCOF1, which plays a critical role in craniofacial development, is frequently upregulated in TNBC and its elevated expression correlates with shorter overall survival. Whereas TCOF1 depletion has potent effects on the growth and stemness of basal-like TNBC, it has no effect on mesenchymal-like cells, highlighting the distinct molecular dependency in different subgroups of TNBC. Whole genome RNA sequencing uncovers several stem cell molecules regulated by TCOF1. We further demonstrate that the upregulation of KIT by TCOF1 mediates TNBC stemness. These findings provide a rationale for developing therapeutics targeting TCOF1 in basal-like TNBC. Examination of mRNA profiles of MDA-MB-468 mammosphere with or without TCOF1 knockout