Project description:Advanced bladder cancer is treated mainly with gemcitabine and cisplatin, but most patients eventually become resistance to these chemotherapeutic agents. Androgen receptor (AR) signaling has been implicated in bladder cancer as well as other types of cancer including prostate cancer. In the present study, we showed the expression and role of AR in gemcitabine-resistant bladder cancer cells and examined the potential of enzalutamide, an AR inhibitor, as a therapeutic for the chemoresistance. First of all, we established gemcitabine-resistant T24 cells (T24GR) from T24 bladder cancer cells and performed gene expression profiling and network analysis, which revealed increased AR expression and AR-related gene network in T24GR cells. Quantitative RT-PCR and Western blot analysis confirmed increased expression of AR in T24GR cells compared with parental T24 cells, which was associated with more potent transcriptional activity of AR in T24GR cells. The number of AR gene copy in T24GR cells was twice as many as that of T24 cells. Knockdown of AR expression by siRNA resulted in inhibition of proliferation of T24GR cells. Cell culture in charcoal-stripped serum and treatment with enzalutamide also inhibited growth of T24GR cells, which was accompanied by cell cycle arrest. Lastly, the AR transcriptional activity was found to be reduced in T24GR cells by enzalutamide treatment. Our results suggest that blockade of AR signaling by enzalutamide might be effective for patients with advanced gemcitabine-resistant bladder cancer with increased AR expression.
Project description:Prostate cancer is a leading cause of cancer-related death among men globally. It often develops resistance to standard androgen deprivation therapy and androgen receptor (AR) pathway inhibitors such as enzalutamide. This resistance highlights the urgent need for novel therapeutic strategies. ADA-308 emerges as a promising candidate, demonstrating potent inhibition of both AR-sensitive adenocarcinoma as well as enzalutamide-resistant prostate cancer cell lines. Our studies reveal that ADA-308 effectively blocks AR activity, including nuclear localization, and inhibits cell proliferation in vitro. Furthermore, ADA-308 demonstrates remarkable efficacy in vivo, showcasing a robust antitumor response in enzalutamide-resistant models. These findings establish ADA-308’s role as a potent AR inhibitor that overcomes resistance to AR-targeted therapies and highlight its potential as a novel therapeutic approach in advanced prostate cancer management.
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:Prostate cancer is the second leading cause of cancer death among men in the United States. The Androgen receptor (AR) antagonist Enzalutamide is a FDA approved therapy for treatment of late stage prostate cancer patients and is currently under clinical study for early stage prostate cancer treatment. After a short positive response period, patients will develop drug resistance. In this study we used RNA-sequencing and bioinformatics analysis to identify Notch signaling pathway as a deregulated pathway in Enzalutamide-resistant cells. NOTCH2 and c-MYC positively correlated with AR expression in patients' samples mimicking cells with Enzalutamide-resistance. In Enzalutamide-resistant cells, MR49F and C4-2R, we found that cleaved-NOTCH1, HES1 and c-MYC protein expression are significantly elevated indicating an activated NOTCH1 pathway in those cells. In addition, ADAM10 and ADAM17 had a higher expression in Enzalutamide-resistant cells, suggesting a role for S2 cleavage in the increased cleaved NOTCH1 expression. Furthermore, treatment of Enzalutamide-resistant cells with PF-03084014 in combination with Enzalutamide increased cell death, decreased colony formation ability and re-sensitized Enzalutamide-resistant cells to Enzalutamide. Knockdown of NOTCH1 in C4-2R increases Enzalutamide sensitivity by decreasing cell proliferation and increasing cell death. In a 22RV1 xenograft model, PF-03084014 and Enzalutamide induced a decrease in tumor growth through a reduced cell proliferation and increased apoptosis. These results indicate that Notch1 signaling can contribute to Enzalutamide-resistance in Prostate cancer and inhibition of this pathway can re-sensitize resistant cells to Enzalutamide.
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:Androgen receptor (AR)-targeting prostate cancer drugs, which are predominantly competitive ligand binding domain (LBD)-binding antagonists, are inactivated by common resistance -mechanisms. It is important to develop next-generation mechanistically-distinct drugs to treat castration- and drug- resistant prostate cancers. Here, we describe a second-generation AR pan-antagonist (UT-34) that degrades the AR and AR splice variants. UT-34 inhibits the wild-type and LBD mutant ARs comparably and inhibits the in vitro proliferation and in vivo growth of enzalutamide-sensitive and resistant prostate cancer xenografts. In preclinical models, UT-34 induced the regression of enzalutamide-resistant tumors at doses when the AR is degraded; but, at lower doses when the AR is just antagonized, it inhibits, without shrinking, the tumors. This indicates that degradation might be a prerequisite for tumor regression. Mechanistically, UT-34 promotes a conformation that is distinct from the LBD-binding competitive antagonist, enzalutamide, and degrades the AR through the ubiquitin proteasome mechanism. UT-34 has a broad safety margin and exhibits no cross-reactivity with G-Protein Coupled Receptor, kinase, and nuclear receptor family members. Collectively, UT-34 exhibits the properties necessary for a next-generation prostate cancer drug. MR49F cells (n=3-4/group) were maintained in charcoal-stripped serum containing medium for 48 hours and treated with vehicle, 0.1 nM R1881, or 10 uM of UT-34 in combination with 0.1 nM R1881. Twenty four hours after treatment, the cells were harvested, RNA was isolated and expression of genes was measured using microarray (Affymetrix Clarion S) UT-34 is a selective androgen receptor degrader that degrades and antagonizes the AR. UT-34 binds to the AF-1 domain of the AR and degrades the AR through ubiquitin proteasome pathways. The transcriptome study was performed to evaluate the ability of UT-34 to antagonize the enzalutamide-resistant AR function.
Project description:The treatment of advanced prostate cancer has been transformed by novel antiandrogen therapies such as enzalutamide. Using the LnCaP/AR xenograft model, we identified induction of glucocorticoid receptor (GR) expression as a common feature of drug resistant tumors. From a resistant xenograft tumor, we derived a GR expressing resistant subline called LREX' which maintains the resistant phenotype. mRNA expression was used to characterize resistant tissues. LnCaP/AR cells were injected into castrate mice and tumors were established. Mice were then treated with vehicle (Con), 4 days of anti-androgen (ARN-509 10mgkg), or were maintained on anti-androgen (10mg/kg ARN-509 or enzalutamide) until emergence of resistance. Resistant tissues continued to be exposed to anti-androgen through time of harvest. LREX' (LnCaP/AR Resistant to Enzalutamide Xenograft Derived) was derived from an enzalutamide resistant xenograft and was re-injected into castrate mice undergoing continual treatment with enzalutamide. The GR probe on the Illumina array failed to detect GR expression. Therefore, GR expression as determined by qPCR is annotated separately. Of the 10 control tissues, 8 were analyzed twice (technical duplicates annotated as A and B).
Project description:The goal of this study was to determine how androgen receptor inhibition alters transcriptional programs in castration-resistant prostate cancer cells. 16D castration-resistant prostate cancer cells were grown in the presence of 10 micromolar enzalutamide for 24, 48, 96, 144 hours or for more than 2 months (long-term). Analysis shows that androgen receptor target genes are reduced with enzalutamide while metabolic genes are also differentially expressed.
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:Posttranslational modifications of histones such as methylation regulate chromatin structure and gene expression. Methylation of histone lysine residues is generally performed by SET domain methyltransferases. Here, we identify the heterodimeric C21orf127/TRMT112 complex as a specific histone methyltransferase. Assembly of the seven-b-strand protein C21orf127 (also named Hemk2, N6amt1 or PrmC) with TRMT112 is essential to form an active enzyme, hereafter named KMT9 that writes the histone mark H4K12me1 in vitro and in vivo. The H4K12me1 mark is enriched at promoters of KMT9 target genes and co-localises with the active histone mark H4K12ac. By controlling expression of genes involved in energy metabolism, KMT9 regulates oxidative phosphorylation in androgen receptor-dependent and -independent prostate tumour cells. Importantly, KMT9 depletion severely affects proliferation of castration and enzalutamide-resistant prostate cancer cells and xenograft tumours. Together, our data link the writing of the H4K12me1 histone mark by KMT9 with KMT9-dependent gene expression, which in consequence regulates energy metabolism and proliferation. KMT9 executes these functions independently of androgen receptor and androgen signalling thus, providing a promising paradigm for the treatment of castration resistant prostate cancer.