Activation of β-catenin cooperates with loss of Pten to drive AR-independent castration-resistant prostate cancer

Rachana Patel, Elspeth A Brzezinska, Peter Repiscak, Imran Ahmad, Ernest Mui, Meiling Gao, Arnaud Blomme, Victoria Harle, Ee Hong Tan, Gaurav Malviya, Agata Mrowinska, Carolyn J. Loveridge (+9 others)
2019 Cancer Research  
Inhibition of the androgen receptor (AR) is the main strategy to treat advanced prostate cancers. AR-independent treatment-resistant prostate cancer is a major unresolved clinical problem. Patients with prostate cancer with alterations in canonical WNT pathway genes, which lead to β-catenin activation, are refractory to AR-targeted therapies. Here, using clinically relevant murine prostate cancer models, we investigated the significance of β-catenin activation in prostate cancer progression and
more » ... treatment resistance. β-Catenin activation, independent of the cell of origin, cooperated with Pten loss to drive AR-independent castration-resistant prostate cancer. Prostate tumors with β-catenin activation relied on the noncanonical WNT ligand WNT5a for sustained growth. WNT5a repressed AR expression and maintained the expression of c-Myc, an oncogenic effector of β-catenin activation, by mediating nuclear localization of NFκBp65 and β-catenin. Overall, WNT/β-catenin and AR signaling are reciprocally inhibited. Therefore, inhibiting WNT/β-catenin signaling by limiting WNT secretion in concert with AR inhibition may be useful for treating prostate cancers with alterations in WNT pathway genes. SIGNIFICANCE: Targeting of both AR and WNT/β-catenin signaling may be required to treat prostate cancers that exhibit alterations of the WNT pathway.
doi:10.1158/0008-5472.can-19-1684 pmid:31719098 fatcat:tv5ogadujrgqvnwjc775ynnzva