Chromatin binding alteration after enzalutamide treatment
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ABSTRACT: In this study, we found the efficacy of AR-targeting drugs largely depended on the context of AR (Androgen Receptor) and ERα (Estrogen Receptor) status. Enzalutamide, an AR blocker, had a better inhibition effect on ER+ cells with lower AR expressed compared to cells expressed higher AR. To explore the mechanism of action of Enzalutamide, we performed ChIP-seq to illustrate the AR and ER genomic bindings after Enzalutamide treatment in both MCF7 and MCF7 with AR over expression (AROE) cells. Chromatin immunoprecipitation DNA-sequencing (ChIP-seq) for androgen receptor (AR) and Estrogen receptor (ER) after Enzalutamide treatment in MCF7 and MCF7 AROE cells
Project description:Prostate cancer is the most commonly diagnosed and second-most lethal cancer among men in the United States. The vast majority of prostate cancer deaths are due to castration-resistant prostate cancer (CRPC) â?? the lethal form of the disease that has progressed despite therapies that interfere with activation of androgen receptor (AR) signaling. One emergent resistance mechanism to medical castration is synthesis of intratumoral androgens that activate the AR. This insight led to the development of the AR antagonist enzalutamide. However, resistance to enzalutamide invariably develops, and disease progression is nearly universal. One mechanism of resistance to enzalutamide is an F877L mutation in the AR ligand-binding domain that can convert enzalutamide to an agonist of AR activity. However, mechanisms that contribute to the agonist switch had not been fully clarified, and there were no therapies to block AR F877L. Using cell line models of castration-resistant prostate cancer (CRPC), we determined that cellular androgen content influences enzalutamide agonism of mutant F877L AR. Further, enzalutamide treatment of AR F877L-expressing cell lines recapitulated the effects of androgen activation of F877L AR or wild-type AR. Because the BET bromodomain inhibitor JQ-1 was previously shown to block androgen activation of wild-type AR, we tested JQ-1 in AR F877L-expressing CRPC models. We determined that JQ-1 suppressed androgen or enzalutamide activation of mutant F877L AR and suppressed growth of mutant F877L AR CRPC tumors in vivo, demonstrating a new strategy to treat tumors harboring this mutation. RNA-seq profiles of prostate cancer cell lines to understand gene expression associated with enzalutamide treatment
Project description:Enzalutamide (formerly MDV3100 and available commercially as Xtandi), a novel androgen receptor (AR) signaling inhibitor, blocks the growth of castration-resistant prostate cancer (CRPC) in cellular model systems and was shown in a clinical study to increase survival in patients with metastatic CRPC. Enzalutamide inhibits multiple steps of AR signaling: (1) binding of androgens to AR, (2) AR nuclear translocation, and (3) association of AR with DNA. Here we used Affymetrix human genome microarray technology to investigate the global programme of gene expression of LNCaP cells in response to enzalutamide alone and in the context of DHT-stimulated androgen receptor gene expression. LNCaP cells were grown in RPMI 1640 supplemented with 5% hormone depleted FBS and treated with vehicle (control sample) , DHT (100 nM), enzalutamide (1 or 10 M-BM-5M) or DHT (100 nM) plus enzalutamide (1 or 10 M-BM-5M)for 16 hours for RNA extraction and hybridization. Each condition was done in triplicate.
Project description:Enzalutamide, a second-generation androgen receptor (AR) antagonist, has represented the association with improved overall survival in men with prostate cancer (PCa). However, PCa patients receiving enzalutamide will eventually develop resistance through various mechanisms without effective regimens. Here, we observed a higher level of formin-like 2 (FMNL2) in enzalutamide-resistant PCa cells. Functionally, FMNL2 knockdown partially re-sensitized enzalutamide-resistant PCa cells. Mechanistically, FMNL2 directly interacted with SRC kinase through FMNL2-FH1 and SRC-SH3 domain, which induced AR translocation from the cytoplasm to the nucleus, resulting in increased expression of the AR-targeted genes and leading to resistance to enzalutamide. Consistently, SRC inhibitor dasatinib rescued enzalutamide sensitivity and inhibited the proliferation of enzalutamide-resistant cancer cells. Taken together, our findings demonstrate a substantial role for FMNL2/SRC interaction in the regulation of AR translocation, suggesting that targeting FMNL2-mediated SRC activation might be a potential therapeutic strategy for enzalutamide-resistant PCa, and dasatinib could be an option.
Project description:Enzalutamide (formerly MDV3100 and available commercially as Xtandi), a novel androgen receptor (AR) signaling inhibitor, blocks the growth of castration-resistant prostate cancer (CRPC) in cellular model systems and was shown in a clinical study to increase survival in patients with metastatic CRPC. Enzalutamide inhibits multiple steps of AR signaling: (1) binding of androgens to AR, (2) AR nuclear translocation, and (3) association of AR with DNA. Here we used Affymetrix human genome microarray technology to investigate the global programme of gene expression of LNCaP cells in response to enzalutamide alone and in the context of DHT-stimulated androgen receptor gene expression.
Project description:Prostate cancer is the most commonly diagnosed and second-most lethal cancer among men in the United States. The vast majority of prostate cancer deaths are due to castration-resistant prostate cancer (CRPC) – the lethal form of the disease that has progressed despite therapies that interfere with activation of androgen receptor (AR) signaling. One emergent resistance mechanism to medical castration is synthesis of intratumoral androgens that activate the AR. This insight led to the development of the AR antagonist enzalutamide. However, resistance to enzalutamide invariably develops, and disease progression is nearly universal. One mechanism of resistance to enzalutamide is an F877L mutation in the AR ligand-binding domain that can convert enzalutamide to an agonist of AR activity. However, mechanisms that contribute to the agonist switch had not been fully clarified, and there were no therapies to block AR F877L. Using cell line models of castration-resistant prostate cancer (CRPC), we determined that cellular androgen content influences enzalutamide agonism of mutant F877L AR. Further, enzalutamide treatment of AR F877L-expressing cell lines recapitulated the effects of androgen activation of F877L AR or wild-type AR. Because the BET bromodomain inhibitor JQ-1 was previously shown to block androgen activation of wild-type AR, we tested JQ-1 in AR F877L-expressing CRPC models. We determined that JQ-1 suppressed androgen or enzalutamide activation of mutant F877L AR and suppressed growth of mutant F877L AR CRPC tumors in vivo, demonstrating a new strategy to treat tumors harboring this mutation.
Project description:To explore the mechanism of action of Enzalutamide, we performed RNA-seq to investigate gene expression difference after Enzalutamide treatment in both MCF7 and MCF7 with AR over expression (AROE) cells. RNA-sequencing (RNA-seq) of MCF7 and MCF7 AROE cells with DMSO or Enzalutamide treatment
Project description:Enzalutamide, a second-generation androgen receptor (AR) antagonist, has demonstrated clinical benefit in men with prostate cancer. However, it only provides a temporary response and modest increase in survival, indicating a rapid evolution of resistance. Previous studies suggest that enzalutamide may function as a partial transcriptional agonist, but the underlying mechanisms for enzalutamide-induced transcription remain poorly understood. Here, we show that enzalutamide stimulates expression of a novel subset of genes distinct from androgen-responsive genes. Treatment of prostate cancer cells with enzalutamide enhances recruitment of pioneer factor GATA2, AR, Mediator subunits MED1 and MED14, and RNA Pol II to regulatory elements of enzalutamide-responsive genes. Mechanistically, GATA2 functions in directing AR, Mediator and Pol II loading to enzalutamide-responsive gene loci. Importantly, the GATA2 inhibitor K7174 inhibits enzalutamide-induced transcription by decreasing binding of the GATA2/AR/Mediator/Pol II transcriptional complex, contributing to sensitization of prostate cancer cells to enzalutamide treatment. Our findings provide mechanistic insight into the future combination of GATA2 inhibitors and enzalutamide for improved AR-targeted therapy.
Project description:Molecular mechanisms underlying resistance to androgen deprivation therapy (ADT) and, in particular, to antiandrogen Enzalutamide, in treating castration-resistant prostate cancer (CRPC), remain incompletely understood. Through screening >120 CRPC patient samples, we observed 3 expression patterns of androgen receptor (AR) protein: primarily nuclear (nuc-AR), mixed nuclear/cytoplasmic expression (nuc/cyto-AR), and low/no expression (AR-/lo). Xenograft CRPC modeling in 4 models (i.e., LNCaP, VCaP, LAPC4, and LAPC9) recapitulated the 3 AR expression patterns in castration-resistant tumors developed from parental androgen-dependent tumors. Strikingly, although the 3 CRPC models that retained AR expression (LNCaP, VCaP, and LAPC4) responded, to different levels and in different kinetics, to Enzalutamide, the AR-/lo LAPC9 CRPC was completely refractory to Enzalutamide. By combining whole-genome RNA-Seq and biochemical analyses together with experimental combinatorial therapy in the LNCaP and LAPC9 models, we identified BCL-2 as a critical therapeutic target in both AR+/hi and AR-/lo, Enzalutamide-resistant CRPC models.
Project description:Castration resistant prostate cancer (CRPC) develops resistance to antiandrogens affecting Androgen Receptor (AR) signaling through a variety of mechanism. Because of this, the efficacy of androgen receptor targeted therapy remains limited for many patients with CRPC. We developed LNCaP-enzalutamide (ENZU) and resistance cells to study changes in transcriptomic profile compared to parental cells.
Project description:Endocrine therapy is the most important treatment modality of breast cancer patients whose tumors express the estrogen receptor (ER). The androgen receptor (AR) is also expressed in the vast majority (80-90%) of ER-positive tumors. However, AR-targeting drugs are not used in clinical practice, but have been evaluated in multiple trials and preclinical studies. We performed a genome-wide study to identify genetic context-dependent AR signaling induced by either AR agonist (dihydrotestosterone [DHT]), or AR antagonist (enzalutamide [Enz]), known as pharmacogenomic expression quantitative expression loci (PGx-eQTLs), utilizing a previously well characterized lymphoblastic cell line panel.