Project description:Genome wide DNA methylation profiling of androgen-sensitive and –refractory prostate cancer cells. The Illumina Infinium HumanMethylation450 Beadchip was used to obtain DNA methylation profiles across approximately 480.000 CpGs in Prostate cancer cell lines showing different sensitivity to hormonal treatments. Samples included the androgen receptor negative cell lines PC3 and DU145, the androgen sensitive cell line LNCaP and the LNCaP abl cell line expressing androgen receptor but refractory prostate cancer cell line to hormonal treatments.
Project description:Prostate cancer (PC) onset and progression relies on the androgen receptor (AR) signaling. Anti-androgenic hormonal therapy (HT) is initially efficacious, but most patients evolve to a castration resistant stage (CRPC) for which no cure is currently available. Most proposed mechanisms of acquired resistance to HT focus on the transcriptional activity in CRPC cells. In this study, however, we have uncovered a new role of AR in alternative cleavage and polyadenylation (APA) regulation.
Project description:In castration-resistant prostate cancer (CRPC), clinical response to androgen receptor (AR) antagonists is limited mainly due to AR-variants expression and restored AR signaling. The metabolite spermine is most abundant in prostate and it decreases as prostate cancer progresses, but its functions remain poorly understood. Here, we show spermine inhibits full-length androgen receptor (AR-FL) and androgen receptor splice variant 7 (AR-V7) signaling and suppresses CRPC cell proliferation by directly binding and inhibiting protein arginine methyltransferase PRMT1. Spermine reduces H4R3me2a modification at the AR locus and suppresses AR binding as well as H3K27ac modification levels at AR target genes. Spermine supplementation restrains CRPC growth in vivo. PRMT1 inhibition also suppresses AR-FL and AR-V7 signaling and reduces CRPC growth. Collectively, we demonstrate spermine as an anticancer metabolite by inhibiting PRMT1 to transcriptionally inhibit AR-FL and AR-V7 signaling in CRPC, and we indicate spermine and PRMT1 inhibition as powerful strategies overcoming limitations of current AR-based therapies in CRPC.
Project description:Prostate cancer is initially dependent on androgens for survival and growth, making hormonal therapy the cornerstone treatment for invasive tumors. However, despite initial remission, the cancer will inevitably recur. The present study was set to investigate how androgen-dependent prostate cancer cells eventually survive and resume growth under androgen-deprived and antiandrogen supplemented conditions Microarray technology was used to analyze differences in gene expression between androgen-responsive and hormone-refractory prostate cancer cell lines. As model system, we used the androgen-responsive PC346C cells and its castration-resistant sublines: PC346DCC, PC346Flu1 and PC346Flu2. These sublines were derived from the parental PC346C by long-term androgen ablation (PC346DCC), supplemented with the antiandrogen hydroxyflutamide (PC346Flu1 and PC346Flu2). Previous studies revealed distinct AR modifications in all three castration-resistant sublines: AR overexpression (PC346Flu1), AR down-regulation (PC346DCC) and T877A AR mutation (PC346Flu2).
Project description:Castration-resistant prostate cancer is a lethal disease. The cell type(s) that survive androgen-deprivation remain poorly described despite global efforts to understand the various mechanisms of therapy resistance. We recently identified in wild type mouse prostates a rare population of luminal progenitor cells that we called LSCmed according to their FACS profile (Lin?/Sca-1+/CD49fmed). Here we investigated the prevalence and castration resistance of LSCmed in various mouse models of prostate tumorigenesis. In intact mice, we show that LSCmed prevalence remains low (5-10% of epithelial cells) when prostatic androgen receptor signaling unaltered (malignant Hi-Myc mice) but significantly increases in models exhibiting reduced prostatic androgen receptor signaling, rising up to 30% in premalignant tumors (Pb-PRL mice) and to >80% in castration-resistant prostate tumors driven by Pten loss (Ptenpc-/- mice). LSCmed tolerance to androgen deprivation was demonstrated by their persistence (Ptenpc-/-) or further enrichment (Pb-PRL) 2-3 weeks after castration as evidenced by FACS analysis. Transcriptomic analysis revealed that LSCmed represent a unique cell entity as their gene-expression profile is different from luminal and basal/stem cells, but shares markers of each. Their intrinsic androgen signaling is markedly decreased, which explains why LSCmed tolerate androgen-deprivation. This also enlightens why Ptenpc-/- tumors are castration-resistant since LSCmed represent the most prevalent cell type in this model. We validated CK4 as a specific marker for LSCmed on sorted cells and prostate tissues by immunostaining, allowing for the detection of LSCmed in various mouse prostate specimens. In castrated Ptenpc-/- prostates, BrdU staining revealed massive proliferation of CK4+ cells, further demonstrating their key role in castration-resistant prostate cancer progression. In all, this study identifies LSCmed as a probable source of prostate cancer relapse after androgen deprivation and as a new therapeutic target for the prevention of castrate-resistant prostate cancer.
Project description:Increased treatment of metastatic castration resistant prostate cancer (mCRPC) with second-generation anti-androgen therapies (ADT) has coincided with a greater incidence of lethal, aggressive variant prostate cancer (AVPC) tumors that have lost androgen receptor (AR) signaling. AVPC tumors may also express neuroendocrine markers, termed neuroendocrine prostate cancer (NEPC). Recent evidence suggests kinase signaling may be an important driver of NEPC. To identify targetable kinases in NEPC, we performed global phosphoproteomics comparing AR-negative to AR-positive prostate cancer cell lines and identified multiple altered signaling pathways, including enrichment of RET kinase activity in the AR-negative cell lines. Clinical NEPC and NEPC patient derived xenografts displayed upregulated RET transcript and RET pathway activity. Pharmacologically inhibiting RET kinase in NEPC models dramatically reduced tumor growth and cell viability in mouse and human NEPC models. Our results suggest that targeting RET in NEPC tumors with high RET expression may be a novel treatment option.
Project description:Increased treatment of metastatic castration resistant prostate cancer (mCRPC) with second-generation anti-androgen therapies (ADT) has coincided with a greater incidence of lethal, aggressive variant prostate cancer (AVPC) tumors that have lost androgen receptor (AR) signaling. AVPC tumors may also express neuroendocrine markers, termed neuroendocrine prostate cancer (NEPC). Recent evidence suggests kinase signaling may be an important driver of NEPC. To identify targetable kinases in NEPC, we performed global phosphoproteomics comparing AR-negative to AR-positive prostate cancer cell lines and identified multiple altered signaling pathways, including enrichment of RET kinase activity in the AR-negative cell lines. Clinical NEPC and NEPC patient derived xenografts displayed upregulated RET transcript and RET pathway activity. Pharmacologically inhibiting RET kinase in NEPC models dramatically reduced tumor growth and cell viability in mouse and human NEPC models. Our results suggest that targeting RET in NEPC tumors with high RET expression may be a novel treatment option.
Project description:Castration resistant prostate cancer (CRPC) develops resistance to antiandrogens affecting Androgen Receptor (AR) signaling through a variety of mechanism. Because of this, the efficacy of androgen receptor targeted therapy remains limited for many patients with CRPC. We developed C42B-Abiraterone (Abi) and resistance cells to study changes in transcriptomic profile compared to parental cells.
Project description:Castration resistant prostate cancer (CRPC) develops resistance to antiandrogens affecting Androgen Receptor (AR) signaling through a variety of mechanism. Because of this, the efficacy of androgen receptor targeted therapy remains limited for many patients with CRPC. We developed C42B-enzalutamide (ENZU) and resistance cells to study changes in transcriptomic profile compared to parental cells.
Project description:Castration resistant prostate cancer (CRPC) develops resistance to antiandrogens affecting Androgen Receptor (AR) signaling through a variety of mechanism. Because of this, the efficacy of androgen receptor targeted therapy remains limited for many patients with CRPC. We developed LNCaP-enzalutamide (ENZU) and resistance cells to study changes in transcriptomic profile compared to parental cells.