HDAC inhibition impedes epithelial–mesenchymal plasticity and suppresses metastatic, castration-resistant prostate cancer
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE67879 | GEO | 2015/10/12
SECONDARY ACCESSION(S): PRJNA281100
REPOSITORIES: GEO
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Project description:PI3K (phosphoinositide 3-kinase)/AKT and RAS/MAPK (mitogen-activated protein kinase) pathway coactivation in the prostate epithelium promotes both epithelial-mesenchymal transition (EMT) and metastatic castration-resistant prostate cancer (mCRPC), which is currently incurable. To study the dynamic regulation of the EMT process, we developed novel genetically defined cellular and in vivo model systems from which epithelial, EMT and mesenchymal-like tumor cells with Pten deletion and Kras activation can be isolated. When cultured individually, each population has the capacity to regenerate all three tumor cell populations, indicative of epithelial-mesenchymal plasticity. Despite harboring the same genetic alterations, mesenchymal-like tumor cells are resistant to PI3K and MAPK pathway inhibitors, suggesting that epigenetic mechanisms may regulate the EMT process, as well as dictate the heterogeneous responses of cancer cells to therapy. Among differentially expressed epigenetic regulators, the chromatin remodeling protein HMGA2 is significantly upregulated in EMT and mesenchymal-like tumors cells, as well as in human mCRPC. Knockdown of HMGA2, or suppressing HMGA2 expression with the histone deacetylase inhibitor LBH589, inhibits epithelial-mesenchymal plasticity and stemness activities in vitro and markedly reduces tumor growth and metastasis in vivo through successful targeting of EMT and mesenchymal-like tumor cells. Importantly, LBH589 treatment in combination with castration prevents mCRPC development and significantly prolongs survival following castration by enhancing p53 and androgen receptor acetylation and in turn sensitizing castration-resistant mesenchymal-like tumor cells to androgen deprivation therapy. Taken together, these findings demonstrate that cellular plasticity is regulated epigenetically, and that mesenchymal-like tumor cell populations in mCRPC that are resistant to conventional and targeted therapies can be effectively treated with the epigenetic inhibitor LBH589.
| S-EPMC4896852 | biostudies-literature
Project description:PI3K (phosphoinositide 3-kinase)/AKT and RAS/MAPK (mitogen-activated protein kinase) pathway coactivation in the prostate epithelium promotes both epithelial–mesenchymal transition (EMT) and metastatic castration-resistant prostate cancer (mCRPC), which is currently incurable. To study the dynamic regulation of the EMT process, we developed novel genetically defined cellular and in vivo model systems from which epithelial, EMT and mesenchymal-like tumor cells with Pten deletion and Kras activation can be isolated. When cultured individually, each population has the capacity to regenerate all three tumor cell populations, indicative of epithelial–mesenchymal plasticity. Despite harboring the same genetic alterations, mesenchymal-like tumor cells are resistant to PI3K and MAPK pathway inhibitors, suggesting that epigenetic mechanisms may regulate the EMT process, as well as dictate the heterogeneous responses of cancer cells to therapy. Among differentially expressed epigenetic regulators, the chromatin remodeling protein HMGA2 is significantly upregulated in EMT and mesenchymal-like tumors cells, as well as in human mCRPC. Knockdown of HMGA2, or suppressing HMGA2 expression with the histone deacetylase inhibitor LBH589, inhibits epithelial–mesenchymal plasticity and stemness activities in vitro and markedly reduces tumor growth and metastasis in vivo through successful targeting of EMT and mesenchymal-like tumor cells. Importantly, LBH589 treatment in combination with castration prevents mCRPC development and significantly prolongs survival following castration by enhancing p53 and androgen receptor acetylation and in turn sensitizing castration-resistant mesenchymal-like tumor cells to androgen deprivation therapy. Taken together, these findings demonstrate that cellular plasticity is regulated epigenetically, and that mesenchymal-like tumor cell populations in mCRPC that are resistant to conventional and targeted therapies can be effectively treated with the epigenetic inhibitor LBH589.
2015-10-07 | GSE67681 | GEO
Project description:PI3K (phosphoinositide 3-kinase)/AKT and RAS/MAPK (mitogen-activated protein kinase) pathway coactivation in the prostate epithelium promotes both epithelial–mesenchymal transition (EMT) and metastatic castration-resistant prostate cancer (mCRPC), which is currently incurable. To study the dynamic regulation of the EMT process, we developed novel genetically defined cellular and in vivo model systems from which epithelial, EMT and mesenchymal-like tumor cells with Pten deletion and Kras activation can be isolated. When cultured individually, each population has the capacity to regenerate all three tumor cell populations, indicative of epithelial–mesenchymal plasticity. Despite harboring the same genetic alterations, mesenchymal-like tumor cells are resistant to PI3K and MAPK pathway inhibitors, suggesting that epigenetic mechanisms may regulate the EMT process, as well as dictate the heterogeneous responses of cancer cells to therapy. Among differentially expressed epigenetic regulators, the chromatin remodeling protein HMGA2 is significantly upregulated in EMT and mesenchymal-like tumors cells, as well as in human mCRPC. Knockdown of HMGA2, or suppressing HMGA2 expression with the histone deacetylase inhibitor LBH589, inhibits epithelial–mesenchymal plasticity and stemness activities in vitro and markedly reduces tumor growth and metastasis in vivo through successful targeting of EMT and mesenchymal-like tumor cells. Importantly, LBH589 treatment in combination with castration prevents mCRPC development and significantly prolongs survival following castration by enhancing p53 and androgen receptor acetylation and in turn sensitizing castration-resistant mesenchymal-like tumor cells to androgen deprivation therapy. Taken together, these findings demonstrate that cellular plasticity is regulated epigenetically, and that mesenchymal-like tumor cell populations in mCRPC that are resistant to conventional and targeted therapies can be effectively treated with the epigenetic inhibitor LBH589.
2015-10-12 | GSE67872 | GEO
Project description:Metastatic castration-resistant prostate cancer (CRPC) is a fatal disease, primarily resulting from the transcriptional addiction driven by androgen receptor (AR). First-line CRPC treatments typically target AR signaling, but are rapidly bypassed, resulting in only a modest survival benefit with antiandrogens. Therapeutic approaches that more effectively block the AR-transcriptional axis are urgently needed. Here, we investigated the molecular mechanism underlying the association between the transcriptional coactivator MED1 and AR as a vulnerability in AR-driven CRPC. MED1 undergoes CDK7-dependent phosphorylation at T1457 and physically engages AR at superenhancer sites, and is essential for AR-mediated transcription. In addition, a CDK7-specific inhibitor, THZ1, blunts AR-dependent neoplastic growth by blocking AR/MED1 corecruitment genome-wide, as well as reverses the hyperphosphorylated MED1-associated enzalutamide-resistant phenotype. In vivo, THZ1 induces tumor regression of AR-amplified human CRPC in a xenograft mouse model. Together, we demonstrate that CDK7 inhibition selectively targets MED1-mediated, AR-dependent oncogenic transcriptional amplification, thus representing a potential new approach for the treatment of CRPC. SIGNIFICANCE: Potent inhibition of AR signaling is critical to treat CRPC. This study uncovers a driver role for CDK7 in regulating AR-mediated transcription through phosphorylation of MED1, thus revealing a therapeutically targetable potential vulnerability in AR-addicted CRPC.See related commentary by Russo et al., p. 1490.This article is highlighted in the In This Issue feature, p. 1469.
| S-EPMC7202356 | biostudies-literature
Project description:Disease progression and therapeutic resistance of prostate cancer (PC) are linked to multiple molecular events that promote survival and plasticity. We previously showed that heat shock protein 27 (HSP27) acted as a driver of castration-resistant phenotype (CRPC) and developed an oligonucleotides antisense (ASO) against HSP27 with evidence of anti-cancer activity in men with CRPC. Here, we show that the tumor suppressor Menin (MEN1) is highly regulated by HSP27. Menin is overexpressed in high-grade PC and CRPC. High MEN1 mRNA expression is associated with decreased biochemical relapse-free and overall survival. Silencing Menin with ASO technology inhibits CRPC cell proliferation, tumor growth, and restores chemotherapeutic sensitivity. ChIP-seq analysis revealed differential DNA binding sites of Menin in various prostatic cells, suggesting a switch from tumor suppressor to oncogenic functions in CRPC. These data support the evaluation of ASO against Menin for CRPC.
| S-EPMC8724010 | biostudies-literature
Project description:The management of men with metastatic castration-resistant prostate cancer (CRPC) has taken several leaps forward in the last 2 years, with the demonstration of improved overall survival with three novel agents (sipuleucel-T, cabazitaxel, and abiraterone acetate), and a significant delay in skeletal-related events observed with denosumab. The pipeline of systemic therapies in prostate cancer remains strong, as multiple agents with a diverse array of mechanisms of action are demonstrating preliminary signs of clinical benefit, leading to more definitive phase III confirmatory trials. In this review, we will discuss the evolving landscape of treatment options for men with CRPC, with a particular focus on currently approved and emerging treatment options for these patients. Knowledge of these evolving standards will help to optimize delivery of care and long term outcomes in men with advanced CRPC.
| S-EPMC3685202 | biostudies-literature
Project description:We performed RNA-seq and ChIP-seq in three prostate cell lines (VCaP, LNCaP and DU145) to ascertain the role of the mediator complex MED1 in AR signaling. Upon androgen stimulation, MED1 undergoes phosphorylation by CDK7 and physically engages with AR at super-enhancer sites, which is essential for AR-mediated transcription. The CDK7 specific inhibitor THZ1 blunts AR-dependent neoplastic growth by preventing the co-recruitment of AR/MED1 in a genome-wide fashion, and reverts the enzalutamide resistance characterized by hyper-phosphorylated MED1. The effect of THZ1 phenocopies that for MED1 and CDK7 knockdown.
2019-08-20 | GSE125245 | GEO
Project description:MicroRNAs (miRs) are small, endogenous, non-coding RNAs that regulate the stability and/or translation of complementary mRNA targets. MiRs have emerged not only as critical modulators of normal physiologic processes, but their deregulation may significantly impact prostate and other cancers. The expression of miR-23b and miR-27b, which are encoded by the same miR cluster (miR-23b/-27b), are downregulated in metastatic, castration-resistant tumors compared to primary prostate cancer and benign tissue; however, their possible role in prostate cancer progression is unknown. We found that ectopic expression of miR-23b/-27b in two independent castration-resistant prostate cancer cell lines resulted in suppression of invasion and migration, as well as reduced survival in soft agar (a measure of anoikis). However, there was no effect of miR-23b/-27b on cell proliferation suggesting that these miRs function as metastasis (but not growth) suppressors in prostate cancer. Conversely, inhibition of miR-23b/-27b in the less aggressive androgen-dependent LNCaP prostate cancer cell line resulted in enhanced invasion and migration also without affecting proliferation. Mechanistically, we found that introduction of miR-23b/-27b in metastatic, castration-resistant prostate cancer cell lines resulted in a significant attenuation of Rac1 activity without affecting total Rac1 levels and caused increased levels of the tumor suppressor E-cadherin. Inhibition of these miRs had the opposite effect in androgen-dependent LNCaP cells. These results suggest that miR-23b/-27b are metastasis suppressors that might serve as novel biomarkers and therapeutic agents for castration-resistant disease.
| S-EPMC3530545 | biostudies-literature
Project description:The arrival of several new agents--cabazitaxel, abiraterone acetate, enzalutamide, and radium-223--is changing the treatment options and management of patients with metastatic castration-resistant prostate cancer (mCRPC). Many other novel agents are also being investigated. As new drugs become approved, new treatment strategies and markers to best select which patients will best respond to which drug are needed. This review article is a summary of a European Treatment Practices Meeting, which was convened to discuss these latest data on novel agents and current treatment strategies in the mCRPC setting.
| S-EPMC3662847 | biostudies-other
Project description:To review and evaluate current literature on the US Food and Drug Administration (FDA)-approved drug enzalutamide (XTANDI(®)) in metastatic castration-resistant prostate cancer.Literature search was done through PubMed using the terms enzalutamide, MDV3100, abiraterone, and castration-resistant prostate cancer. Data from FDA product labels were also used.Recent and relevant studies were included in the review. Collected clinical trials were screened and evaluated.Enzalutamide is an androgen receptor (AR) inhibitor with high selectivity and affinity to the AR. It was approved by the FDA to treat metastatic castration-resistant prostate cancer in patients previously treated with docetaxel, after a Phase III trial (AFFIRM) that showed a 4.8-month survival benefit in this population. Recently, the FDA expanded the approval of enzalutamide as first-line therapy for metastatic castration-resistant prostate cancer (mCRPC) who did not receive chemotherapy. Moreover, enzalutamide is shown to be associated with an acceptable safety profile.Enzalutamide has been shown to be both safe and effective in improving overall survival in metastatic castration-resistant prostate cancer postchemotherapy with docetaxel and as a first line treatment before initiation of chemotherapy. However, additional studies and head-to-head trials are needed.
| S-EPMC4407758 | biostudies-other