Project description: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 homolog FOXA2 is specifically expressed in advanced lineage plasticity prostate cancers that have lost the AR signaling axis. However, their roles and utility as drug targets 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.
Project description:This SuperSeries is composed of the following subset Series: GSE30622: Dual Role of FoxA1 in Androgen Receptor Binding to Chromatin, Androgen Signaling and Prostate Cancer [Expression Array] GSE30623: Dual Role of FoxA1 in Androgen Receptor Binding to Chromatin, Androgen Signaling and Prostate Cancer [ChIP_seq, DHS_seq] Refer to individual Series
Project description:Despite recent advances in the treatment of pancreatic adenocarcinoma (PDAC), clinical outcome remains poor. Previous evidence linked the pioneer transcription factor FOXA1 as a mediator of new regulatory elements that drive tumour progression in models of late-stage disease. Given the critical role of FOXA1 as a pioneer factor for nuclear receptor (NR) transcription factors (TF) in breast and prostate cancer (Estrogen Receptor and Androgen Receptor), we hypothesised that FOXA1 might function with a NR in PDAC (1) (2). Using RIME, our unbiased approach for discovering endogenous protein complexes, we identified HNF4A and HNF4G as reproducible, FOXA1-associated proteins, a finding that was validated in clinical samples of PDAC. Using complex and diverse PDAC models, we show that gene transcription in the classical subtype of pancreatic cancer is regulated by FOXA1/GATA5/6 and HNF4G. We show that HNF4G drives primary disease, in part by recruiting the methyltransferase PRMT1 to regulatory regions. In primary tumour context, HNF4G is the dominant protein and the presence of HNF4G masks FOXA1 activity, resulting in FOXA1 being present, but functionally redundant in primary disease. During transition to metastasis however, HNF4G expression decreases, which unmasks FOXA1 activity, where it becomes transcriptionally active and a subsequent driver of metastasis. We provide new molecular insight into the key TFs in PDAC and the stage-specific activity of these proteins.
Project description:We report the dual role of FoxA1 in androgen receptor recruitment to the chromatin of androgen responsive prostate cancer cell line LNCaP-1F5 using ChIP-sequencing. Depletion of FoxA1 reprograms both androgen and glucocorticoid receptor recruitment and subsequent gene expression. The ChIP-seq has been performed using AR, FoxA1, GR, H3K4me2 antibodies. We have also mapped the DNaseI-hypersensitive sites (DHS) using deep sequencing. Examination of AR, FoxA1, GR, H3K4me2 binding sites and DHS sites in parental and FoxA1 depleted LNCaP-1F5 cells.