Project description:Resistance to androgen deprivation therapies and increased androgen receptor (AR) activity are major drivers of castration-resistant prostate cancer (CRPC). Prior work has focused on targeting AR directly; however, the identification and targeting of co-activators of AR signaling remains an underexplored area. Here we demonstrate that the MLL (mixed-lineage leukemia) complex, a well-known contributor in MLL-fusion-positive leukemia, acts as a co-activator of AR signaling. AR interacts with the MLL complex via its subunit, menin. Small molecule inhibition of the menin-MLL interaction blocks AR signaling and inhibits tumor growth in vivo. Furthermore, we find that menin is up-regulated in CRPC and high expression correlates with poor overall survival. Our study identifies the MLL complex as a co-activator of AR that can be targeted in advanced prostate cancer. ASH2L / Menin / MLL1 were knocked down using shRNA /siRNA in two prostate cancer cell lines, VCaP and LNCaP.
Project description:Resistance to androgen deprivation therapies and increased androgen receptor (AR) activity are major drivers of castration-resistant prostate cancer (CRPC). Prior work has focused on targeting AR directly; however, the identification and targeting of co-activators of AR signaling remains an underexplored area. Here we demonstrate that the MLL (mixed-lineage leukemia) complex, a well-known contributor in MLL-fusion-positive leukemia, acts as a co-activator of AR signaling. AR interacts with the MLL complex via its subunit, menin. Small molecule inhibition of the menin-MLL interaction blocks AR signaling and inhibits tumor growth in vivo. Furthermore, we find that menin is up-regulated in CRPC and high expression correlates with poor overall survival. Our study identifies the MLL complex as a co-activator of AR that can be targeted in advanced prostate cancer.
Project description:Enzalutamide (ENZA) is a potent second-generation antiandrogen commonly used to treat hormone-sensitive and castration-resistant prostate cancer (CRPC) patients. While initially effective, the response is only temporary and the disease almost always develops resistance. Given that many ENZA-resistant tumors are not driven by specific somatic mutations, there is increasing evidence that epigenetic factors can cause ENZA resistance. To explore how resistance arises we systematically tested all the epigenetic modifiers in castration-resistant and ENZA-resistant prostate cancer models using a custom epigenetic CRISPR library. From this, we identified and validated numerous epigenetic modifiers that were selectivity essential including SMARCC2, a core component of the SWI/SNF complex (or BAF complex) that regulates gene expression by altering DNA accessibility. Additionally, our data demonstrated canonical BAF complex dependency in ENZA-resistance that was also observed following the loss of DPF2, a canonical BAF-specific component. We showed that the chromatin occupancy of SMARCC2 and BRG1 was expanded in acquired ENZA resistance to the regions that overlap with transcriptional activity and CRPC-associated transcription factors that are significantly accessible in CRPC patients. Overall, our study revealed a regulatory role for SMARCC2 in ENZA-resistant prostate cancer and demonstrated the feasibility of targeting the SWI/SNF complex in late-stage PCa.
Project description:To elucidate the regulation of NSD2 in metastatic castration-resistant prostate cancer(CRPC), we performed ChIP-seq of H3K36me2, H3K27me3, H3K4me1, H3K4me3,H3K27ac and NSD2 against castration-sensitive prostate cancer cell line LNCaP and metastatic castration-resistant prostate cancer cell lines, PC3 and DU145, respectively. In metastatic CRPC, we found specific regions of activation with epigenetic changes.
Project description:aCGH experiment on cell-free DNA collected from the plasma of patients with castration-resistant prostate cancer. No replicates. castration-resistant prostate cancer vs male reference DNA
Project description:Xenografts are useful in vivo tumour models for investigating cancer progression, therapeutic responses and predicting anti-cancer drug response in patients with cancer of a similar phenotype. We have generated bulk RNA-seq data from LNCaP xenografts of a large and well-annotated prostate cancer progression study, investigating responsiveness and subsequent resistance to therapies targeting the androgen receptor (AR). LNCaP xenograft tumour establishment and initial growth are dependent on androgens in male mice (PRE-CX / pre-castration group). Upon castration, AR activity and tumour growth are suppressed (POST-CX / post-castration group), however, this initial responsiveness to castration reproducibly gives way to castration-resistance (CRPC / castration-resistant prostate cancer). Further treatment of CRPC with the AR targeting drug enzalutamide (ENZ) initially provides a therapeutic response (ENZ Sensitive; ENZS), however, resistance emerges in time (ENZ Resistant; ENZR).
Project description:The androgen receptor (AR) is a mediator of both androgen-dependent and castration- resistant prostate cancers. Identification of cellular factors affecting AR transcriptional activity could in principle yield new targets that reduce AR activity and combat prostate cancer, yet a comprehensive analysis of the genes required for AR-dependent transcriptional activity has not been determined. Using an unbiased genetic approach that takes advantage of the evolutionary conservation of AR signaling, we have conducted a genome-wide RNAi screen in Drosophila cells for genes required for AR transcriptional activity and applied the results to human prostate cancer cells. We identified 45 AR-regulators, which include known pathway components and genes with functions not previously linked to AR regulation, such as HIPK2 (a protein kinase) and MED19 (a subunit of the Mediator complex). Depletion of HIPK2 and MED19 in human prostate cancer cells decreased AR target gene expression and, importantly, reduced the proliferation of androgen-dependent and castration-resistant prostate cancer cells. We also systematically analyzed additional Mediator subunits and uncovered a small subset of Mediator subunits that interpret AR signaling and affect AR-dependent transcription and prostate cancer cell proliferation. Importantly, targeting of HIPK2 by an FDA approved kinase inhibitor phenocopied the effect of depletion by RNAi and reduced the growth of AR-positive, but not AR negative, treatment-resistant prostate cancer cells. Thus, our screen has yielded new AR regulators including drugable targets that reduce the proliferation of castration-resistant prostate cancer cells. HIPK2 and MED19 were identified via a genome-wide RNAi screen as new androgen receptor (AR) reulators. Our goal in performing this microarray was to identify the gene regulated by HIPK2 and MED19 in a late stage prostate cancer cell line (LNCaP-abl), and to see what genes are in common with known genes to be regulated by AR, and what genes are unique to HIPK2 or MED19. Knockdown of HIPK2 and MED19 was tested in LNCaP-abl cells against control. Each was performed in duplicates. Six samples were analyzed
Project description:Acquisition of resistance to the PARP inhibitor, Olaparib, constitutes a major challenge for the treatment of advanced prostate cancer. The purpose of this study was to identify molecular targets responsible for the development of acquired Olaparib resistance in advanced prostate cancer. Towards this goal, next-generation sequencing (NGS)-based gene expression profiling (RNA-Sequencing; RNA-Seq) was performed on castration-sensitive prostate cancer (CSPC)/Olaparib-sensitive LNCaP cells, castration-sensitive prostate cancer (CSPC)/Olaparib-resistant LN-OlapR cells, castration-resistant prostate cancer (CSPC)/Olaparib-sensitive C4-2B cells, and castration-resistant prostate cancer (CSPC)/Olaparib-resistant 2B-OlapR cells.