Androgen signaling in cell fate and cell-cell communication during early prostate development at single-cell resolution
Ontology highlight
ABSTRACT: Androgens/androgen receptor (AR) mediated signaling pathways are essential for prostate development, morphogenesis, and regeneration. Here, using newly generated ArIRES-Cre mice with single-cell RNA sequencing (scRNAseq) and other experimental approaches, we profiled the transcriptomes of more than 9000 cells isolated from murine E17.5 UGS tissues and identified a variety of urogenital mesenchyme (UGM) and epithelia (UGE) cell populations. The expression of AR and other regulators were further assessed in different cell types at single cell resolution to determine their roles and interactions during early prostate development. Psuedotime analyses further explored the differentiation trajectory of UGM and UGE cell populations, and identified a Zeb1-expressing progenitor population. Using mouse genetic tools, the decisive role of mesenchymal AR action in prostate initiation was further demonstrated. These data provide fresh, high resolution, comprehensive insight into AR signaling and its roles in initiating dynamic interactions of with distinct signaling pathways between prostatic mesenchymal-epithelial cells.
Project description:Prostate embryonic development, pubertal and adult growth, maintenance, and regeneration are regulated through androgen signaling-mediated mesenchymal epithelial interactions. Specifically, the essential role of mesenchymal androgen signaling in the development of prostate epithelium has been observed for over 30 years. However, the identity of the mesenchymal cells responsible for this paracrine regulation and related mechanisms are still unknown. Here, we provide the first demonstration of an indispensable role of the androgen receptor (AR) in sonic hedgehog (SHH) responsive Gli1-expressing cells, in regulating prostate development, growth, and regeneration. Selective deletion of AR expression in Gli1-expressing cells during embryogenesis disrupts prostatic budding and impairs prostate development and formation. Tissue recombination assays showed that urogenital mesenchyme (UGM) containing AR-deficient mesenchymal Gli1-expressing cells combined with wildtype urogenital epithelium (UGE) failed to develop normal prostate tissue in the presence of androgens, revealing the decisive role of AR in mesenchymal SHH responsive cells in prostate development. Prepubescent deletion of AR expression in Gli1 expressing cells resulted in severe impairment of androgen-induced prostate growth and regeneration. RNA-sequencing analysis showed significant alterations in signaling pathways related to prostate development, stem cells, organ morphogenesis appeared showed significant changes in AR-deficient Gli1-expressing cells. The transforming growth factor β (TGFβ) pathway was up-regulated in AR-deficient Gli1-expressing cells. We further demonstrated the activation of TGF- b signaling in AR deleted prostatic Gli1-expressing cells, which inhibits prostate epithelium growth through paracrine regulation. These data demonstrate a novel role of the AR in the Gli1-expressing cellular niche for regulating prostatic cell fate, morphogenesis, and renewal, and elucidate the mechanism by which mesenchymal androgen-signaling through SHH-responsive cells elicits the growth and regeneration of prostate epithelium.
Project description:Androgen receptor (AR) signaling remains the key therapeutic target in the management of hormone-naïve advanced prostate cancer (PCa) and castration-resistant PCa (CRPC). Recently, landmark molecular features have been reported for CRPC, including the expression of constitutively active AR variants that lack the ligand-binding domain. Besides their role in CRPC, AR variants lead to the expression of genes involved in tumor progression. However, little is known about the specificity of their mode of action compared with that of wild-type AR (AR-WT). We performed AR transcriptome analyses in an androgen-dependent PCa cell line as well as cross-analyses with publicly available RNA-seq dataset and established that transcriptional repression capacity that was marked for AR-WT was pathologically lost by AR variants. Functional enrichment analyses allowed us to associate AR-WT repressive function to a panel of genes involved in cell adhesion and epithelial-to-mesenchymal transition. So, we postulate that a less documented AR-WT normal function in prostate epithelial cells could be the repression of a panel of genes linked to cell plasticity, and that this repressive function could be pathologically abrogated by AR variants in PCA.
Project description:Androgen receptor (AR) signaling remains the key therapeutic target in the management of hormone-naïve advanced prostate cancer (PCa) and castration-resistant PCa (CRPC). Recently, landmark molecular features have been reported for CRPC, including the expression of constitutively active AR variants that lack the ligand-binding domain. Besides their role in CRPC, AR variants lead to the expression of genes involved in tumor progression. However, little is known about the specificity of their mode of action compared with that of wild-type AR (AR-WT). We performed AR transcriptome analyses in an androgen-dependent PCa cell line as well as cross-analyses with publicly available RNA-seq dataset and established that transcriptional repression capacity that was marked for AR-WT was pathologically lost by AR variants. Functional enrichment analyses allowed us to associate AR-WT repressive function to a panel of genes involved in cell adhesion and epithelial-to-mesenchymal transition. So, we postulate that a less documented AR-WT normal function in prostate epithelial cells could be the repression of a panel of genes linked to cell plasticity, and that this repressive function could be pathologically abrogated by AR variants in PCA.
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:We investigated the composition of chromatin protein network around endogenous androgen receptor (AR) in VCaP castration resistant prostate cancer cells using recently developed chromatin-directed proteomic approach called ChIP-SICAP . The androgen-induced AR chromatin protein network contained expected TFs, e.g. HOXB13, chromatin remodeling proteins, e.g. SMARCA4, and several novel candidates not previously associated with AR, e.g. prostate cancer biomarker SIM2. Based on these findings, the role of SMARCA4 and SIM2 was further characterized at AR chromatin domains . Silencing of SIM2 altered chromatin accessibility at a similar number of AR-binding sites as SMARCA4, an established ATPase subunit of the BAF chromatin remodeling complex, often aberrantly expressed in prostate cancer. Despite the wide co-occurrence on chromatin of SMARCA4 and AR, depletion of SMARCA4 influenced chromatin accessibility and expression of a restricted set of AR target genes, in particular those involved in cell morphogenetic changes in epithelial-mesenchymal transition. Silencing of SIM2, in turn, affected the expression of a much larger group of androgen-regulated genes, e.g. those involved in cellular responses to external stimuli and steroid hormone stimulus. The silencing also reduced proliferation of VCaP cells and tumor size in chick embryo chorioallantoic membrane assay, further suggesting the importance of SIM2 in the regulation prostate cancer cells.
Project description:Analysis of transcriptome of tissue recombinants (mouse seminal vesicle epithelial [SVE] cells or prostate epithelial [PE] cells, and rat urogenital sinus [UGS] mesenchymal cells) grown under the kidney capsule in athymic nude mice for 3 months. Total RNA obtained from tissue recombinants generated from combining engineered mouse epithelial cells (SVE or PE from 2-month-old C57Bl/6J mice) and rat UGS mesenchymal cells. Tissue recombinants were harvested and processed for RNA isolation and transcriptome analysis using the RNeasy kit (Qiagen).
Project description:Prostate organogenesis is regulated by interactions between mesenchymal and epithelial cells, and via androgen signalling though androgen receptors (AR) expressed in mesenchymal cells. However, there is little knowledge of AR target genes and we have used high resolution genomic methods to examine AR function in subsets of mesenchyme during prostate development. Using ChIP-seq, we defined genomic AR binding sites (ARBS) in microdissected mesenchymal tissues of neonatal male and female rats during prostate growth. By comparing female tissue subsets (ventral mesenchymal pad and urethral smooth muscle) with male tissues (ventral prostate and dorsolateral prostate), we were able to identify sexually dimorphic ARBS. Females had a distinct AR binding profile from males with enrichment of ARBS proximal to gene transcriptional start sites as well as binding to non-classical AR binding sequence motifs. Using both tissue RNA-sequencing and single-cell RNA-sequencing of the same mesenchymal subsets, we identified 128 differentially expressed transcripts between males and females. Comparison of these to ChIP-seq ARBS allowed us to define sexually dimorphic AR target genes. Selected candidates were validated as sexually dimorphic at both the mRNA and protein level in both rat and human developing prostate tissues by qPCR and western blot. Response to testosterone stimulation was examined using ex vivo rat tissue organ cultures and qPCR. In single cell RNAseq data we observed subpopulations of mesenchymal cells in males and females as well as subpopulations common to both. The distribution of AR and target genes did not follow the subpopulation distribution, suggesting that AR action is not restricted by subset identity.Our study is the first to apply multiple transcriptomic approaches to prostate mesenchyme, and we have identified unique AR targets. We have identified sexually dimorphic, androgen responsive mesenchymal target genes that may underlie sexually dimorphic development of the prostate. We suggest that the analysis of transcription factor binding and transcriptomes in cell subsets will be informative when applied to tumour cells and stroma – since these show similar cellular heterogeneity and subset specific activity.
Project description:Analysis of transcriptome of tissue recombinants (mouse seminal vesicle epithelial [SVE] cells or prostate epithelial [PE] cells, and rat urogenital sinus [UGS] mesenchymal cells) grown under the kidney capsule in athymic nude mice for 3 months.
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: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. Gene expression profiling of LNCaP in response to ETOH (vehicle) or DHT (5α-dihydrotestosterone) stimulation across different treatment time-points using microarray.