Disrupting the interaction between androgen receptor and its coregulator WDR77 delays the growth of treatment-resistant prostate cancer.

Continued reliance on the androgen receptor (AR) after androgen deprivation therapy (ADT) fails causes 35,000 American prostate cancer (CaP) deaths annually. Targeting the AR's transcriptional activity could overcome this acquired resistance, but has been challenging. We demonstrate the therapeutic potential of disrupting interactions between the AR and its coregulator WDR77. WDR77 stimulated CaP growth, and its overexpression was associated with worse patient survival. AR and WDR77 cistromes overlapped considerably, and AR- and WDR77-bound genes correlated with aggressive CaP features. Direct WDR77-AR interaction occurred, which, when disrupted, prevented AR-WDR77 complex formation, reduced AR DNA-binding and AR-dependent gene expression, and decreased cell proliferation to the same extent as ADT. Such interference inhibited cell growth by ADT-resistant AR action and after ADT-resistance without impacting AR-negative CaP or benign cells. Blocking AR-WDR77 cooperation also delayed the growth of organoids from patient-derived xenografts and fresh CaP specimens. Disrupting coregulator control over AR action may thus improve survival from ADT-resistant CaP.