Centrosome depletion rewires mitosis to impose dependence on the AURK-TPX2 axis

Abstract

Centrosomes are key microtubule-organizing centers required for accurate spindle assembly and chromosome segregation, and their dysfunction in cancer creates therapeutic vulnerabilities. Prior work identified a synthetic lethal interaction between TRIM37 overexpression and Polo-like kinase 4 inhibition (PLK4i) in 17q23-amplified tumors, motivating the clinical development of centrosome-depleting PLK4 inhibitors. However, the broader determinants of sensitivity and resistance to PLK4 inhibition remain poorly defined. Using genome-wide CRISPR-Cas9 screening, we identify multiple genetic suppressors of sensitivity to centrosome depletion, including loss of PPP6C as a general escape mechanism, mediated by enhanced activation of Aurora kinase A (AURKA) on the spindle. This process requires NuMA, which scaffolds robust acentrosomal spindle assembly, and operates independently of the TRIM37-regulated pathway that restores pericentriolar material (PCM) foci to reconstitute microtubule-organizing center activity. We further show that centrosome depletion creates a dependence on the AURKA-TPX2 axis for spindle assembly, such that modulation of this pathway shapes cellular responses to PLK4 inhibition. Loss of PPP6C elevates AURKA activity and confers resistance, whereas disruption of the AURKA-TPX2 axis sensitizes cells to centrosome depletion. Together, these findings reveal how centrosome depletion rewires mitotic organization, rendering cells dependent on distinct adaptive spindle assembly pathways.