PAX6 promotes neuroendocrine phenotypes of prostate cancer via enhancing MET/STAT5A-mediated chromatin accessibility
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ABSTRACT: Neuroendocrine prostate cancer (NEPC) is a highly aggressive form of prostate cancer characterized by the loss of androgen receptor (AR) signaling and the acquisition of neuroendocrine (NE) characteristics. However, the underlying molecular mechanism, especially related to the drivers or the determinants responsible for NE transdifferentiation, remains unclear. In this study, we compared gene expression profiling of NEPC and non-NEPC specimens and paid a particular attention to those transcriptional factors affecting neural differentiation during development. We identified that Paired box 6 (Pax6) expression was significantly elevated in NEPC and negatively regulated by AR signaling. While knock-down of Pax6 in NEPC cells inhibited NEPC phenotypes, over-expression of Pax6 in non-NEPC cells led to development of NEPC. Mechanistically, loss of AR resulted in an enhanced expression of Pax6, which reprogramed the lineage plasticity of prostate cancer cells to develop NE phenotypes through the c-Met/Stat5a signaling. By performing ATAC-seq, we found that high expression level of Pax6 elicited enhanced chromatin accessibility mainly through attenuation of H4K20me3 that usually causes chromatin silence in cancer cells. Taken together, these findings highlight PAX6 as a novel molecule to drive NEPC progression and suggest that it might serve as a potential target for the management of NEPC.
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:Background: Neuroendocrine prostate cancer (NEPC), a lethal subset of prostate cancer, is characterized by loss of AR signaling and resulting resistance to AR-targeted therapy during neuroendocrine transdifferentiation, for which the molecular mechanisms remain unclear. Here, we report that SRY-Box transcription factor 4 (SOX4) is upregulated in NEPC, which induces neuroendocrine markers, neuroendocrine cell morphology, and NEPC cell aggressive behavior. Methods: To understand the function of SOX4 in the development and progression of NEPC, we detected malignancy characterization after over-expression or knock-down of SOX4 in prostate cancer cells. Xenograft tumors representing NEPC subtypes were analyzed by pathologists. Protein expression profiles were validated in patient tumor tissue. Diagnoses were complemented by transcriptome sequencing and ATAC sequencing of specific cell lines and public clinical datasets. Results: SOX4 expression was significantly elevated in NEPC. Activating SOX4 in non-NEPC cells induced NE transdifferentiation, while silencing it in NEPC cells impeded NEPC progression. SOX4 promote neuroendocrine characteristics by inducing PCK2-mediated metabolism changing. Conclusions: Elevated SOX4 drives NE transdifferentiation in PCa via PCK2-mediated . Altogether, these findings highlight SOX4 as a novel molecule to drive NEPC progression and suggest that it might be a potential therapeutic target for NEPC.
Project description:Most patients with prostate adenocarcinoma develop resistance to therapies targeting the androgen receptor (AR). Consequently, a portion of these patients develop AR-indifferent neuroendocrine prostate cancer (NEPC), a rapidly progressing cancer with limited therapies and poor survival outcomes. Current research to understand the transition to NEPC suggests a model of lineage plasticity, where AR-dependent luminal tumors progress towards an AR-independent neuroendocrine (NE) lineage. Genetic analysis of human NEPC showed a frequent loss of RB1 and TP53, and in experimental models, loss of both genes facilitates the transition to a NE lineage. Transcriptomics has shown the lineage transcription factors ASCL1 and NEUROD1 are present in NEPC. In this study, we used genetically engineered mouse models harboring Cre induced loss of Rb1 and Trp53 with MycT58A overexpression (RPM), to model prostate adenocarcinoma with NEPC by establishing prostate organoids that are subsequently used to generate subcutaneous allograft tumors. These tumors are heterogeneous and display adenocarcinoma, squamous, and NE features. ASCL1 and NEUROD1 are expressed within the NE defined regions, with ASCL1 being more predominant than NEUROD1. Genetic loss of ASCL1 in this model does not decrease tumor growth or tumor formation, however, there is a notable decrease in NE identity and an increase in cells with basal-like cell identity. This study provides a new in vivo model to study the progression of prostate cancer to NEPC and establishes the requirement for ASCL1 in driving neuroendocrine differentiation.
Project description:Neuroendocrine prostate cancer (NEPC) arises primarily through neuroendocrine transdifferentiation (NEtD) as an adaptive mechanism of therapeutic resistance. Models to define the functional effects of putative drivers of this process on androgen receptor (AR) signaling and NE cancer lineage programs are lacking. We adapted a genetically defined strategy from the field of cellular reprogramming to directly convert AR-active prostate cancer (ARPC) to AR-independent NEPC using candidate factors. We delineated critical roles of the pioneer factors ASCL1 and NeuroD1 in NEtD and uncovered their abilities to silence AR expression and signaling by remodeling chromatin at the somatically acquired AR enhancer and global AR binding sites with enhancer activity. We also elucidated the dynamic temporal changes in the transcriptomic and epigenomic landscapes of cells undergoing acute lineage conversion from ARPC to NEPC which should inform future therapeutic development. Further, we distinguished the activities of ASCL1 and NeuroD1 from the inactivation of RE-1 silencing transcription factor (REST), a master suppressor of a major neuronal gene program, in establishing a NEPC lineage state and in modulating the expression of genes associated with major histocompatibility complex class I (MHC I) antigen processing and presentation.
Project description:Neuroendocrine prostate cancer (NEPC) arises primarily through neuroendocrine transdifferentiation (NEtD) as an adaptive mechanism of therapeutic resistance. Models to define the functional effects of putative drivers of this process on androgen receptor (AR) signaling and NE cancer lineage programs are lacking. We adapted a genetically defined strategy from the field of cellular reprogramming to directly convert AR-active prostate cancer (ARPC) to AR-independent NEPC using candidate factors. We delineated critical roles of the pioneer factors ASCL1 and NeuroD1 in NEtD and uncovered their abilities to silence AR expression and signaling by remodeling chromatin at the somatically acquired AR enhancer and global AR binding sites with enhancer activity. We also elucidated the dynamic temporal changes in the transcriptomic and epigenomic landscapes of cells undergoing acute lineage conversion from ARPC to NEPC which should inform future therapeutic development. Further, we distinguished the activities of ASCL1 and NeuroD1 from the inactivation of RE-1 silencing transcription factor (REST), a master suppressor of a major neuronal gene program, in establishing a NEPC lineage state and in modulating the expression of genes associated with major histocompatibility complex class I (MHC I) antigen processing and presentation.
Project description:Neuroendocrine prostate cancer (NEPC) arises primarily through neuroendocrine transdifferentiation (NEtD) as an adaptive mechanism of therapeutic resistance. Models to define the functional effects of putative drivers of this process on androgen receptor (AR) signaling and NE cancer lineage programs are lacking. We adapted a genetically defined strategy from the field of cellular reprogramming to directly convert AR-active prostate cancer (ARPC) to AR-independent NEPC using candidate factors. We delineated critical roles of the pioneer factors ASCL1 and NeuroD1 in NEtD and uncovered their abilities to silence AR expression and signaling by remodeling chromatin at the somatically acquired AR enhancer and global AR binding sites with enhancer activity. We also elucidated the dynamic temporal changes in the transcriptomic and epigenomic landscapes of cells undergoing acute lineage conversion from ARPC to NEPC which should inform future therapeutic development. Further, we distinguished the activities of ASCL1 and NeuroD1 from the inactivation of RE-1 silencing transcription factor (REST), a master suppressor of a major neuronal gene program, in establishing a NEPC lineage state and in modulating the expression of genes associated with major histocompatibility complex class I (MHC I) antigen processing and presentation.
Project description:Neuroendocrine prostate cancer (NEPC) arises primarily through neuroendocrine transdifferentiation (NEtD) as an adaptive mechanism of therapeutic resistance. Models to define the functional effects of putative drivers of this process on androgen receptor (AR) signaling and NE cancer lineage programs are lacking. We adapted a genetically defined strategy from the field of cellular reprogramming to directly convert AR-active prostate cancer (ARPC) to AR-independent NEPC using candidate factors. We delineated critical roles of the pioneer factors ASCL1 and NeuroD1 in NEtD and uncovered their abilities to silence AR expression and signaling by remodeling chromatin at the somatically acquired AR enhancer and global AR binding sites with enhancer activity. We also elucidated the dynamic temporal changes in the transcriptomic and epigenomic landscapes of cells undergoing acute lineage conversion from ARPC to NEPC which should inform future therapeutic development. Further, we distinguished the activities of ASCL1 and NeuroD1 from the inactivation of RE-1 silencing transcription factor (REST), a master suppressor of a major neuronal gene program, in establishing a NEPC lineage state and in modulating the expression of genes associated with major histocompatibility complex class I (MHC I) antigen processing and presentation.
Project description:Neuroendocrine prostate cancer (NEPC) arises primarily through neuroendocrine transdifferentiation (NEtD) as an adaptive mechanism of therapeutic resistance. Models to define the functional effects of putative drivers of this process on androgen receptor (AR) signaling and NE cancer lineage programs are lacking. We adapted a genetically defined strategy from the field of cellular reprogramming to directly convert AR-active prostate cancer (ARPC) to AR-independent NEPC using candidate factors. We delineated critical roles of the pioneer factors ASCL1 and NeuroD1 in NEtD and uncovered their abilities to silence AR expression and signaling by remodeling chromatin at the somatically acquired AR enhancer and global AR binding sites with enhancer activity. We also elucidated the dynamic temporal changes in the transcriptomic and epigenomic landscapes of cells undergoing acute lineage conversion from ARPC to NEPC which should inform future therapeutic development. Further, we distinguished the activities of ASCL1 and NeuroD1 from the inactivation of RE-1 silencing transcription factor (REST), a master suppressor of a major neuronal gene program, in establishing a NEPC lineage state and in modulating the expression of genes associated with major histocompatibility complex class I (MHC I) antigen processing and presentation.
Project description:Metastatic and locally advanced prostate cancer is treated by pharmacological targeting of androgen synthesis and androgen response via androgen signaling inhibitors (ASI), most of which target the androgen receptor (AR). However, ASI therapy invariably fails after 1-2 years. Emerging clinical evidence indicates that in response to ASI therapy, the AR-positive prostatic adenocarcinoma can transdifferentiate into AR-negative neuroendocrine prostate cancer (NEPC) in 17-25% treated patients, likely through a process called neuroendocrine differentiation (NED). Despite high clinical incidence, the epigenetic pathways underlying NED and ASI therapy-induced NED remain unclear. By utilizing a combinatorial single cell and bulk mRNA sequencing workflow, we demonstrate in a time-resolved manner that following AR inhibition with enzalutamide, prostate cancer cells exhibit immediate loss of canonical AR signaling activity and simultaneous morphological change from epithelial to NE-like (NEL) morphology, followed by activation of specific neuroendocrine (NE)-associated transcriptional programs. Additionally, we observed that activation of NE-associated pathways occurs prior to complete repression of epithelial or canonical AR pathways, a phenomenon also observed clinically via heterogenous AR status in clinical samples. Our model indicates that, mechanistically, ASI therapy induces NED with initial morphological change followed by deactivation of canonical AR target genes and subsequent de-repression of NE-associated target genes, while retaining AR expression and transcriptional shift towards non-canonical AR activity. Coupled with scRNA-seq and CUT&RUN analysis, our model system can provide a platform for screening of potential therapeutic agents that may prevent ASI-induced NED or reverse the NED process.