Targeting FOXA1 and FOXA2 Disrupts the Lineage-Specific Oncogenic Output in Prostate Cancer [ChIP-seq]

Activation of the androgen receptor (AR) is the key lineage-specific oncogenic pathway and the primary therapeutic target in prostate cancer. While AR signaling is enabled by the pioneer transcription factor FOXA1, its homologue FOXA2 is specifically expressed in advanced lineage plasticity prostate cancers that have lost the AR signaling axis. However, their roles and utility as a drug target remain incompletely characterized. Here, we show an unexpected collaboration of FOXA1 and FOXA2 in mediating AR-independent cell proliferation in different lineage plasticity cancer subtypes. Conversely, joint loss-of-function or pharmacologic disruption of FOXA1 and FOXA2 leads to the collapse of lineage-specific oncogenic transcription factors followed by cell cycle arrest. In summary, our findings uncover a druggable dependency for AR-positive and -negative prostate cancers. Overall design: To investigate the role of FOXA1 and FOXA2 in CRPCs, we used different prostate cancer cell lines LNCaP in the context of AR inhibition, FOXA2 over expression and PC3 for double knock down of FOXA1 and FOXA2 and a small compound T treatment.