Oncogenic Potential of Truncated-Gli3 via the Gsk3β/Gli3/AR-V7 Axis in Castration-Resistant Prostate Cancer
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ABSTRACT:
PROVIDER: PRJNA1075839 | ENA |
REPOSITORIES: ENA
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Project description:The functional activation of the androgen receptor (AR) and its interplay with the aberrant Hh/Gli cascade are pivotal in the progression of castration-resistant prostate cancer (CRPC) and resistance to AR-targeted therapies. Our study unveils a novel role of the truncated form of Gli (t-Gli3) in advancing CRPC. Investigation into Gli3 regulation revealed a Smo-independent mechanism for its activation. Despite lacking a transactivation domain, t-Gli3 relies on androgen receptor variant 7 (AR-V7) for its action. Mechanistically, Gsk3β activation leads to the t-Gli3 generation, and inhibition of Gsk3β supports the accumulation of full-length Gli3 through a non-canonical mechanism. Knockdown of Gsk3β (Gsk3β KD) reduces CRPC cell proliferation, induces apoptosis via mitochondrial fragmentation, and triggers metabolomic reprogramming. Orthotropic implantation of Gsk3β KD cells in the mouse prostate results in tumor growth retardation compared to scramble control cells. RNA-seq analysis of Gsk3β KD reveals upregulation of pathways associated with apoptosis, tumor suppressor pathway, and downregulation of oncogenic pathway relative to control. Furthermore, combinational use of a Gsk3β inhibitor with anti-Smo or Gli1 significantly inhibits the growth of CRPC cells, which are resistant to individual Smo or Gli1 inhibitor targeting. Intriguingly, solely targeting Gli3 proves effective in inhibiting CRPC cell growth. Overall, our study underscores the clinical significance of Gli3, emphasizing t-Gli3, and provides novel insights into the interplay of the Gsk3β/t-Gli3/AR-V7 axis in CRPC.
2025-01-15 | GSE255648 | GEO
Project description:In order to define the genes responsible for the growth and survival of a human castration-resistant prostate cancer cell line, a short term (doxycycline inducible) knockdown system was developed and utilized. Three independent 22Rv1 cell isolates were derived for each of the following doxycycline-inducible shRNAs (shGFP, shAR3, and shVav3) (AR3 = AR-V7). The cells were grown in androgen depleted conditions, plus or minus doxycycline, for three days. RNA from the 18 samples was then sent to the University of Miami Genetics Core for RNA Integrity Number (RIN) evaluation and microarray analysis. Genes differentially regulated by AR-V7 knock-down or VAV3 knock-down were explored as downstream targets of AR-V7 or VAV3, respectively.
2018-08-16 | GSE104572 | GEO
Project description:The constitutively active androgen receptor (AR) splice variant 7 (AR-V7) plays an important role in the progression of castration-resistant prostate cancer (CRPC). Although biomarker studies established the role of AR-V7 in resistance to AR-targeting therapies, how AR-V7 mediates genomic functions in CRPC remains largely unknown. Using a ChIP-exo approach, we show AR-V7 binds to distinct genomic regions and recognizes a full-length androgen-responsive element in CRPC cells and patient tissues. Remarkably, we find dramatic differences in AR-V7 cistromes across diverse CRPC cells and patient tissues, regulating different target gene sets involved in CRPC progression. Surprisingly, we discover that HoxB13 is universally required for and colocalizes with AR-V7 binding to open chromatin across CRPC genomes. HoxB13 pioneers AR-V7 binding through direct physical interaction, and collaborates with AR-V7 to up-regulate target oncogenes. Transcriptional coregulation by HoxB13 and AR-V7 was further supported by their coexpression in tumors and circulating tumor cells from CRPC patients. Importantly, HoxB13 silencing significantly decreases CRPC growth through inhibition of AR-V7 oncogenic function. These results identify HoxB13 as a pivotal upstream regulator of AR-V7-driven transcriptomes that are often cell context-dependent in CRPC, suggesting that HoxB13 may serve as a therapeutic target for AR-V7-driven prostate tumors.
2018-05-31 | GSE99378 | GEO
Project description:The purpose of this study was to characterize the downstream transcriptomic effects of ARVib-mediated degradation of AR/AR-V7, particularly in attenuating AR/AR-V7 target gene expression in prostate cancer cells. Towards this goal, next-generation sequencing (NGS)-based gene expression profiling (RNA-Sequencing; RNA-Seq) was performed on castration-resistant prostate cancer (CRPC) C4-2B MDVR cells that were treated with vehicle control or one of the AR/AR-V7 inhibitors (ARVib), ARVib-7 or ARVib-31.
2021-08-22 | GSE158556 | GEO
Project description:Although AR-V7 has been intensively studied, it remains unclear whether AR-V7 can specifically activate a distinctive transcriptional program from the full-length AR (AR-FL), and whether AR-V7 may play a role in accelerating the metastatic progression of castration-resistant PCa (CRPC). In this study, we hypothesize that AR-V7 can drive a distinct transcription program from AR-FL in CRPC condition. To test this, we used LNCaP model with inducible overexpression of AR-V7 or AR-FL to examine the effects of AR-V7 overexpression or AR-FL overexpression stimulated with DHT for 4 hours on AR-V7 or AR-FL cistromes. We also studied the effects of AR-V7 on cistromes of pioneer factor FOXA1 and active histone marker H3K27ac, and the function of phosphorylation at Ser81 on AR-V7 function in CRPC.
2024-06-05 | GSE221140 | GEO
Project description:Liquid biopsies have demonstrated that the constitutively active androgen receptor splice variant-7 (AR-V7) associates with reduced response and overall survival (OS) from endocrine therapies in castration resistant prostate cancer (CRPC). However, these studies provide little information pertaining to AR-V7 biology and expression in prostate cancer (PC) tissue. Following generation and validation of a novel AR-V7 antibody for immunohistochemistry (IHC); nuclear AR-V7 protein expression was determined for 358 primary prostate samples (358 patients) and 293 metastatic biopsies (194 patients). Associations with disease progression, nuclear AR full length (AR-FL) expression, response to abiraterone and/or enzalutamide, and gene signatures (from three independent cohorts) was determined.
2018-10-19 | GSE118435 | GEO
Project description:Although AR-V7 has been intensively studied, it remains unclear whether AR-V7 and other AR splicing variants can specifically activate a distinctive transcriptional program from the full-length AR (AR-FL), and whether AR-V7 may play a role in accelerating the metastatic progression of castration-resistant PCa (CRPC). In this study, we hypothesize that AR-V7 can drive a distinct transcription program from AR-FL in CRPC condition. To test this, we used LNCaP model with inducible overexpression of AR-V7 or AR-V7-S81A to examine the transcriptional function of AR-V7 and the role of S81 phosphorylation on AR-V7 transcriptome. We also studied the endogenous AR-V7 transcriptome in CWR-22Rv1 cells using siRNA against AR-V7. Lastly, we used LNCaP model with inducible overexpression of AR-V567es to examine the AR-V567es transcriptome.
2024-06-05 | GSE221141 | GEO
Project description:Although AR-V7 has been intensively studied, it remains unclear whether AR-V7 and other AR splicing variants can specifically activate a distinctive transcriptional program from the full-length AR (AR-FL), and whether AR-V7 may play a role in accelerating the metastatic progression of castration-resistant PCa (CRPC). In this study, we hypothesize that AR-V7 can drive a distinct transcription program from AR-FL in CRPC condition. To test this, we performed ATAC-seq using LNCaP model with inducible overexpression of AR-V7 to examine the function of AR-V7. We demonstrated that AR-V7 has “pioneer factor-like” activities to access the androgen-responsive elements (AREs) located at compact chromatin regions. More importantly, we found that SOX9, a critical metastasis driver gene, was a direct target and downstream effector of AR-V7, and its protein expression was dramatically upregulated at AR-V7-induced bone lesions.
2024-06-05 | GSE221137 | GEO
Project description:Androgen Receptor splice variant V7 (AR-V7) mediates AR signalling in castration resistant prostate cancer (CRPC)
| PRJNA602078 | ENA
Project description:CRPC remains AR dependent. There are multiple mechanisms for reactivation of AR including expression of constitutively active AR splices variant AR-V7 (AR3). Earlier studies suggest that though the variants regulate many of the same genes as AR, they also have unique targets. Another argument is that the variant is a “weak” AR. We have used an LNCaP cell line that expresses AR-V7 in response to doxycycline (LNCaP AR-V7) to compare the activities of the two isoforms and to identify differential regulation of target genes. We also used VCaP cell line that expresses AR-V7 in response to doxycycline (VCaP AR-V7) to validate the activities of the two isoforms in an alternative prostate cancer cell line. The transcriptomes for AR and AR-V7 in these cell lines were identified using RNA-Seq.
2021-01-21 | GSE143905 | GEO