Identification of new microtubule small-molecule inhibitors and microtubule-associated genes against triple negative breast cancer.

Breast cancer represents the leading cancer type and leading cause of cancer-related death among women in the world. Triple-negative breast cancer (TNBC) is a subset of breast cancer with the poorest prognosis and still lacking of effective therapeutic options. We recently screened a natural product library and identified 3 new hit compounds with selective and prominent anti-TNBC activities on different subtype of TNBC cell lines. Interestingly, all of these 3 hit compounds belong to "cytoskeletal drugs" that target tubulin and microtubule function. Our data also showed that these hit compounds showed consistently effective on TNBC cells which are resistant to those currently used antimicrotubule agents such as Paclitaxel. RNA-Sequencing analyses revealed the anti-TNBC mechanisms of these hit compounds and identified a subset of new cellular factors commonly affected by hit compounds in different subtypes of TNBC cells. Among them, we demonstrated AHCYL1 and SPG21 as new microtubule-associated proteins, which were required for TNBC cell survival with clinical implication through tissue array analysis. Our studies provide new insights into the mechanisms of TNBC pathogenesis and offer promising therapeutic directions for this aggressive breast cancer.