Project description:Vitamin D induces anti-proliferative and differentiating effects in prostate cancer. Thus calcitriol, the hormonally active form of Vitamin D, and its analogs have been extensively studied in prostate cancer cells. Yet despite its importance, relatively little is known about the genome-scale mechanisms by which Vitamin D, through its cognate nuclear vitamin D receptor (VDR), exerts its regulatory functions at the genomic level. In this study, we defined VDR transcriptional networks in the LNCaP prostate cancer cell line by mapping the genomic binding sites of VDR and by identifying differentially expressed genes upon calcitriol treatment. We found that VDR and androgen receptor (AR) antagonistically regulate a subset of cell cycle-related genes that are over-expressed in prostate cancer tumors. The expression balance of these genes is partially regulated through the competition dynamics between AR and VDR binding to shared cis-regulatory elements. On such shared elements, we found that FOXA1 mediates this competition by serving as a pioneering factor for both AR and VDR binding. We also found significant enrichment of AR-, VDR-, and AR/VDR overlapping binding sites in prostate cancer-associated single-nucleotide polymorphism (SNP) intervals identified from genome-wide association studies (GWAS), providing genetic evidence to link AR, VDR and their crosstalk to prostate cancer susceptibilities. In particular, we found that in a cis-regulatory element of the RFX6 gene implicated in prostate cancer progression, an allelic variant increases prostate cancer risk by switching the antagonism between AR and VDR into a synergistic interaction. Examination of AR, VDR, and FOXA1 binding in LNCaP cells, in biological replicates
Project description:Vitamin D induces anti-proliferative and differentiating effects in prostate cancer. Thus calcitriol, the hormonally active form of Vitamin D, and its analogs have been extensively studied in prostate cancer cells. Yet despite its importance, relatively little is known about the genome-scale mechanisms by which Vitamin D, through its cognate nuclear vitamin D receptor (VDR), exerts its regulatory functions at the genomic level. In this study, we defined VDR transcriptional networks in the LNCaP prostate cancer cell line by mapping the genomic binding sites of VDR and by identifying differentially expressed genes upon calcitriol treatment. We found that VDR and androgen receptor (AR) antagonistically regulate a subset of cell cycle-related genes that are over-expressed in prostate cancer tumors. The expression balance of these genes is partially regulated through the competition dynamics between AR and VDR binding to shared cis-regulatory elements. On such shared elements, we found that FOXA1 mediates this competition by serving as a pioneering factor for both AR and VDR binding. We also found significant enrichment of AR-, VDR-, and AR/VDR overlapping binding sites in prostate cancer-associated single-nucleotide polymorphism (SNP) intervals identified from genome-wide association studies (GWAS), providing genetic evidence to link AR, VDR and their crosstalk to prostate cancer susceptibilities. In particular, we found that in a cis-regulatory element of the RFX6 gene implicated in prostate cancer progression, an allelic variant increases prostate cancer risk by switching the antagonism between AR and VDR into a synergistic interaction. Gene expression profiling in LNCaP cells after 24hr treatment with different nuclear recpetor ligrands, with time-matching control, in triplicates Expression is assayed with Agilent G4112F.
Project description:Prostate cancer is the most common cancer in men and AR downstream signalings promote prostate cancer cell proliferation. We identified androgen-regulated long non-coding RNA, CTBP1-AS, located in the antisese region of CTBP1 gene. CTBP1-AS activate AR signaling by epigenetically repress AR-associated cofactors such as CTBP1 by interactign with RNA-binding protein PSF and recruiting HDAC complex to the target promoters. In order investigated the PSF target genes, we performed ChIP-seq analysis of PSF binding sites in prostate cancer cell line, LNCaP cells. We identified androgen dependent PSF binding regions in prostate cancer cell genome. We observed PSF bindings around the promoters of androgen repressed genes such as CTBP1, p53 and SMAD3. ChIP-sequence analysis of PSF binding sites in prostate cancer cells
Project description:Recurrent point mutations in SPOP define a distinct molecular subclass of prostate cancer. Here, we describe the first mouse model showing that mutant SPOP drives prostate tumorigenesis in vivo. Conditional expression of mutant SPOP in the prostate dramatically altered phenotypes in the setting of Pten loss, with early neoplastic lesions (high-grade prostatic intraepithelial neoplasia) with striking nuclear atypia, and invasive poorly differentiated carcinoma. In mouse prostate organoids, mutant SPOP drove increased proliferation and a transcriptional signature consistent with human prostate cancer. Using these models and human prostate cancer samples, we show that SPOP mutation activates both PI3K/mTOR and androgen receptor (AR) signaling, effectively uncoupling the normal negative feedback between these two pathways. Associated RNA-seq data deposited in GEO: GSE94839.
Project description:Androgen receptor (AR) orchestrates an intricate transcriptional regulatory network that governs prostate cancer initiation, development and progression. To understand this network in detail, we generated genome-wide maps of AR occupancy by ChIP-seq in LNCaP cells. We found NKX3-1, an androgen-dependent homeobox protein well-characterized for its role in prostate development and differentiation, being recruited to AR binding sites (ARBS) in response to androgen signaling. We identified 6,359 NKX3-1 binding sites, most of which overlapped with AR. In addition to its novel collaborative transcriptional role at well-known prostate cancer model genes, our binding and knockdown studies further suggested that NKX3-1 potentially regulates AR in a feed-forward manner. Integrative analysis of Oncomine molecular concepts showed that these androgen-regulated AR and NKX3-1 associated genes are significantly overexpressed in prostate carcinoma as well as advanced and recurrent prostate tumors. From our transcriptomic profiling and Gene Ontology analysis, we observed that AR and NKX3-1 co-regulate genes involved in "protein trafficking" processes, which are mandatory events in the integration of oncogenic signaling pathways leading to prostate cancer development and progression. Interestingly, we found that AR and NKX3-1 co-regulate several members of the RAB GTPase family of secretory/trafficking proteins via the involvement of FoxA1 in a ternary complex and we believe that these AR/NKX3-1/FoxA1 co-regulated RAB genes could serve as expression signatures in prostate carcinogenesis. More specifically, through functional analyses, we showed that NKX3-1, together with AR and FoxA1, could promote prostate cancer cell survival through activation of RAB3B expression. Collectively, our study has provided important insights into the hierarchical transcriptional regulatory network established between AR and NKX3-1 and sought to elucidate the important genetic-molecular-phenotypic paradigm in androgen-dependent prostate cancer. Genome-wide binding analyses of AR, NKX3-1 and FoxA1 in LNCaP with or without DHT (5alpha-dihydrotestosterone) stimulation using ChIP-Seq.
Project description:Prostate cancer is the most common cancer in men and AR downstream signalings promote prostate cancer cell proliferation. To investigate the AR signaling, we performed ChIP sequence analysis in AR positive prostate cancer cell line, LNCaP and VCaP. In addition, we used hormone-refractory prostate cancer model cells, long term androgen deprivation (LTAD) to explore the differences of androgen signaling in prostate cancer progression.
Project description:Upon androgen stimulation, PKN1-mediated histone H3 threonine 11 phosphorylation (H3T11P) promotes AR target genes activation. However, the underlying mechanism is not completely understood. Here, we show that WDR5, a subunit of the SET1/MLL complex, interacts with H3T11P and this interaction facilitates the recruitment of the SET1/MLL complex and subsequent H3K4 trimethylation (H3K4me3). Using ChIP-seq, we find that androgen stimulation results in a six-fold increase in the number of H3T11P-marked regions and induces WDR5 colocalization to one third of H3T11P-enriched promoters, thus establishing a genome-wide relationship between H3T11P and recruitment of WDR5. Accordingly, PKN1 knock-down or chemical inhibition severely blocks WDR5 association and H3K4me3 on AR target genes. Finally, WDR5 is critical in prostate cancer cell proliferation, and is hyperexpressed in human prostate cancers. Together, these results identify WDR5 as a critical epigenomic integrator of histone phosphorylation and methylation and a major driver of androgen-dependent prostate cancer cell proliferation. Identification of Histone 3 threonine 11 phosphorylation (H3T11P) marks and WDR5 binding sites in LNCaP cells treated with R1881 ligand (androgen) or solvent control.
Project description:Prostate cancer is the most common cancer in men and AR downstream signalings promote prostate cancer cell proliferation. To investigate the AR signaling, we performed ChIP sequence analysis in AR positive prostate cancer cell line, LNCaP. In addition, we used hormone-refractory prostate cancer model cells, Bicalutamide-resistant (BicR) to explore the differences of androgen signaling in prostate cancer progression. ChIP sequence analysis of AR binding sites and epigenetic condition in two prostate cancer cells