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IKZF1-deletions occur in 10-15% of patients with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) and predict a poor outcome. However, the impact of IKZF1-loss on sensitivity to drugs used in contemporary treatment protocols has remained underexplored. Here we show in experimental models and in patients that loss of IKZF1 promotes resistance to AraC, a key component of both upfront and relapsed treatment protocols. We attribute this resistance, in part, to diminished import and incorporation of cytarabine (AraC) due to reduced expression of the solute carrier hENT1. Moreover, we find elevated mRNA expression of Evi1, a known driver of therapy resistance in myeloid malignancies. Finally, a kinase directed CRISPR/Cas9-screen identified that inhibition of either mediator kinases CDK8/19 or casein kinase 2 can restore response to AraC. We conclude that this high-risk patient group could benefit from alternative antimetabolites, or targeted therapies that resensitize the cells to AraC.
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INTRODUCTION: Peripherally acting µ-opioid receptor antagonists (PAMORAs) are used in the treatment of opioid induced constipation without impacting the actions of opioid analgesics. Subcutaneous methylnaltrexone was one of the first PAMORAs approved in April 2008 for the treatment of opioid induced constipation in adult patients. The safety and effectiveness of methylnaltrexone has not been established in pediatric patients. In this study, the use of subcutaneous methylnaltrexone in pediatric patients is analyzed and reviewed. The primary outcome is occurrence of a bowel movement within 24 h after methylnaltrexone (MNTX) administration and the number of bowel movements following treatment with methylnaltrexone. Secondary outcomes include safety in this patient cohort. METHODS: This is a retrospective study of 79 pediatric patients with opioid induced constipation. Patients were administered methylnaltrexone during their inpatient stay. Data on bowel activity after methylnaltrexone was obtained from the hospital information system. RESULTS: Out of the 79 patients who received methylnaltrexone, there were seven patients from whom data could not be analyzed. Of the 72 patients whose data was available, 38% (N = 27) were documented as having a bowel movement, 62% (N = 45) did not have a bowel movement. Reported adverse events were minimal with nausea (N = 3), vomiting (N = 1), and flatulence (N = 6). CONCLUSION: Methylnaltrexone appears safe in the pediatric population and produces bowel movements in more than a third of pediatric patients. It is a feasible and safe option for opioid induced constipation in pediatric patients.
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Naltrexona/análogos & derivados , Neoplasias , Constipação Induzida por Opioides , Adulto , Humanos , Criança , Analgésicos Opioides/efeitos adversos , Constipação Induzida por Opioides/tratamento farmacológico , Estudos Retrospectivos , Constipação Intestinal/induzido quimicamente , Constipação Intestinal/tratamento farmacológico , Antagonistas de Entorpecentes/efeitos adversos , Neoplasias/tratamento farmacológico , Compostos de Amônio QuaternárioRESUMO
In pediatric acute lymphoblastic leukemia (ALL), mutations/deletions affecting the TP53 gene are rare at diagnosis. However, at relapse about 12% of patients show TP53 aberrations, which are predictive of a very poor outcome. Since p53-mediated apoptosis is an endpoint for many cytotoxic drugs, loss of p53 function frequently leads to therapy failure. In this study we show that CRISPR/Cas9-induced loss of TP53 drives resistance to a large majority of drugs used to treat relapsed ALL, including novel agents such as inotuzumab ozogamicin. Using a high-throughput drug screen, we identified the histone deacetylase inhibitor romidepsin as a potent sensitizer of drug responsiveness, improving sensitivity to all chemotherapies tested. In addition, romidepsin improved the response to cytarabine in TP53-deleted ALL cells in vivo. Together, these results indicate that the histone deacetylase inhibitor romidepsin can improve the efficacy of salvage therapies for relapsed TP53-mutated leukemia. Since romidepsin has been approved for clinical use in some adult malignancies, these findings may be rapidly translated to clinical practice.
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Depsipeptídeos , Inibidores de Histona Desacetilases , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Proteína Supressora de Tumor p53 , Humanos , Inibidores de Histona Desacetilases/uso terapêutico , Inibidores de Histona Desacetilases/farmacologia , Proteína Supressora de Tumor p53/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Depsipeptídeos/farmacologia , Depsipeptídeos/uso terapêutico , Camundongos , Animais , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Sistemas CRISPR-Cas , Ensaios Antitumorais Modelo de Xenoenxerto , Sinergismo FarmacológicoRESUMO
Tyrosine kinase 2 (TYK2) is a member of the Janus kinase/signal transducer and activator of transcription pathway, which is central in cytokine signaling. Previously, germline TYK2 mutations have been described in two patients developing de novo T-cell acute lymphoblastic leukemias (T-ALL) or precursor B-ALL. The mutations (P760L and G761V) are located within the regulatory pseudokinase domain and lead to constitutive activation of TYK2. We demonstrate the transformation capacity of TYK2 P760L in hematopoietic cell systems including primary bone marrow cells. In vivo engraftment of TYK2 P760L-expressing cell lines led to development of leukemia. A kinase inhibitor screen uncovered that oncogenic TYK2 acts synergistically with the PI3K/AKT/mTOR and CDK4/6 pathways. Accordingly, the TYK2-specific inhibitor deucravacitinib (BMS986165) reduces cell viability of TYK2 P760L-transformed cell models and ex vivo cultured TYK2 P760L-mutated patient- derived xenograft cells most efficiently when combined with mTOR or CDK4/6 inhibitors. Our study thereby pioneers novel treatment options for patients suffering from TYK2-driven acute leukemia.
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Leucemia-Linfoma Linfoblástico de Células T Precursoras , TYK2 Quinase , Humanos , Linhagem Celular , Quinase 4 Dependente de Ciclina , Fosfatidilinositol 3-Quinases , Serina-Treonina Quinases TOR , TYK2 Quinase/genética , TYK2 Quinase/metabolismoRESUMO
Although long-term survival in pediatric acute lymphoblastic leukemia (ALL) currently exceeds 90%, some subgroups, defined by specific genomic aberrations, respond poorly to treatment. We previously reported that leukemias harboring deletions or mutations affecting the B-cell transcription factor IKZF1 exhibit a tumor cell intrinsic resistance to glucocorticoids (GCs), one of the cornerstone drugs used in the treatment of ALL. Here, we identified increased activation of both AKT and ERK signaling pathways as drivers of GC resistance in IKZF1-deficient leukemic cells. Indeed, combined pharmacological inhibition of AKT and ERK signaling effectively reversed GC resistance in IKZF1-deficient leukemias. As inhibitors for both pathways are under clinical investigation, their combined use may enhance the efficacy of prednisolone-based therapy in this high-risk patient group.
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OBJECTIVES: We aimed to determine which factors influence recovery in stroke patients with pre-existing disability, as these patients are often excluded from acute treatment trials. MATERIALS AND METHODS: A prospective stroke center registry of admitted patients from 2019-2021 with acute stroke was queried for patients with pre-stroke modified Rankin Scale (mRS) of 0-4. Multivariable logistic regression was used to estimate odds of functional recovery at 90 days (mRS 0-2, or return to pre-stroke mRS). RESULTS: Of 1228 patients, 856 (70%) included patients had pre-stroke mRS 0-4 and 90-day follow-up mRS. The median age was 68y (IQR 59-78), with a median National Institutes of Health Stroke Scale (NIHSS) of 5 (IQR 2-17). Compared to those with mRS 0-1 (n = 596), patients with pre-stroke mRS of 2 (n = 126), 3 (n = 96), or 4 (n = 38) were less likely to achieve functional recovery in univariate analysis. After multivariable adjustment, odds of functional recovery were significantly lower for patients with pre-stroke mRS of 2 (adjusted odds ratio [ORadj] 0.45, 95% confidence interval [CI] 0.28-0.72), but not those with pre-stroke mRS of 3 (ORadj 1.14, 95%CI 0.66-1.97) or 4 (ORadj 0.50, 95%CI 0.21-1.19). Older age (ORadj per year 0.97, 95%CI 0.95-0.97) and higher NIHSS (ORadj per point 0.89, 95%CI 0.88-0.91) were associated with lower odds of functional recovery, while thrombolysis (ORadj 2.43, 95%CI 1.42-4.15) and a cryptogenic stroke mechanism (ORadj 1.57, 95%CI 1.07-2.31) were protective. CONCLUSIONS: Recovery of patients with pre-existing disability was driven by age and stroke severity. Thrombolysis remained predictive of recovery irrespective of age, stroke severity, and pre-stroke disability.
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Isquemia Encefálica , Acidente Vascular Cerebral , Idoso , Avaliação da Deficiência , Humanos , Fatores de Risco , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/terapia , Fatores de Tempo , Resultado do TratamentoRESUMO
INTRODUCTION: Ipsilateral nonstenotic (<50%) internal carotid artery (ICA) plaque, cardiac atriopathy, and patent foramen ovale (PFO) may account for a substantial proportion of embolic stroke of undetermined source (ESUS). METHODS: Consecutive stroke patients at our center (2019-2021) with unilateral, anterior circulation ESUS were categorized into the following mutually exclusive etiologies: (1) nonstenotic ipsilateral ICA plaque (NSP, ≥3mm in maximal axial diameter), (2) sex-adjusted mod-to-severe left atrial enlargement (LAE), (3) PFO, and (4) "occult ESUS" (patients who failed to meet criteria for these 3 groups). Descriptive statistics and multivariable logistic regression were used to model group characteristics. RESULTS: Of 132 included patients, the median age was 65 (IQR 56-73), 74 (56%) of whom were White, and 54 (41%) were female. Twenty-one patients (16%) had NSP proximal to the infarct territory, 17 (13%) had LAE, 9 (7%) had a PFO, and 85 (64%) had no other mechanism. Patients with LAE were older (p=0.004), and had more frequent intracranial occlusions of the internal carotid and proximal middle cerebral artery (p=0.048), while tobacco use was most commonly found among patients with NSP (75%) when compared to other ESUS groups (p=0.02). Five of 9 patients with LAE who underwent outpatient telemetry had paroxysmal atrial fibrillation (56%), while zero patients with PFO or NSP had paroxysmal atrial fibrillation (p=0.005). Older age (adjusted OR [aOR] 1.05, 95%CI 1.03-1.07), coronary artery disease (aOR 3.22, 95%CI 1.61-6.44) and hypertension (aOR 2.16, 95%CI 1.14-4.06) were independently associated with LAE, while only tobacco use was associated with NSP when compared to other ESUS subclassifiers (OR 3.18, 95%CI 1.08-0.42). Age and tobacco use were both inversely associated with PFO (aOR 0.93, 95%CI 0.88-0.98, and aOR 0.10, 95%CI 0.02-0.90, respectively). CONCLUSIONS: Certain clinical and radiographic features may be useful in predicting the proximal source of occult cerebral emboli, and can be used for cost-effective outpatient diagnostic testing.
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Fibrilação Atrial , AVC Embólico , Forame Oval Patente , Embolia Intracraniana , Placa Aterosclerótica , Acidente Vascular Cerebral , Idoso , Fibrilação Atrial/complicações , Feminino , Forame Oval Patente/complicações , Forame Oval Patente/diagnóstico por imagem , Humanos , Embolia Intracraniana/complicações , Embolia Intracraniana/etiologia , Masculino , Placa Aterosclerótica/complicações , Fatores de Risco , Acidente Vascular Cerebral/diagnósticoRESUMO
Asparaginase (ASNase) therapy has been a mainstay of acute lymphoblastic leukemia (ALL) protocols for decades and shows promise in the treatment of a variety of other cancers. To improve the efficacy of ASNase treatment, we used a CRISPR/Cas9-based screen to identify actionable signaling intermediates that improve the response to ASNase. Both genetic inactivation of Bruton's tyrosine kinase (BTK) and pharmacological inhibition by the BTK inhibitor ibrutinib strongly synergize with ASNase by inhibiting the amino acid response pathway, a mechanism involving c-Myc-mediated suppression of GCN2 activity. This synthetic lethal interaction was observed in 90% of patient-derived xenografts, regardless of the genomic subtype. Moreover, ibrutinib substantially improved ASNase treatment response in a murine PDX model. Hence, ibrutinib may be used to enhance the clinical efficacy of ASNase in ALL. This trial was registered at www.clinicaltrials.gov as # NCT02884453.
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Adenina/análogos & derivados , Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Aminoácidos/metabolismo , Antineoplásicos/uso terapêutico , Asparaginase/uso terapêutico , Piperidinas/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Adenina/farmacologia , Adenina/uso terapêutico , Tirosina Quinase da Agamaglobulinemia/metabolismo , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Asparaginase/farmacologia , Linhagem Celular Tumoral , Humanos , Camundongos , Piperidinas/farmacologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Targeting tumor cell metabolism is an attractive form of therapy, as it may enhance treatment response in therapy resistant cancers as well as mitigate treatment-related toxicities by reducing the need for genotoxic agents. To meet their increased demand for biomass accumulation and energy production and to maintain redox homeostasis, tumor cells undergo profound changes in their metabolism. In addition to the diversion of glucose metabolism, this is achieved by upregulation of amino acid metabolism. Interfering with amino acid availability can be selectively lethal to tumor cells and has proven to be a cancer specific Achilles' heel. Here we review the biology behind such cancer specific amino acid dependencies and discuss how these vulnerabilities can be exploited to improve cancer therapies.
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Aminoácidos , Neoplasias , Aminoácidos/metabolismo , Humanos , Neoplasias/terapia , OxirreduçãoRESUMO
AIMS: Apolipoprotein D (ApoD) is a protein that is regulated by androgen and oestrogen, and is a major constituent of breast cysts. Although ApoD has been reported to be a marker of breast cancer, its prognostic importance in invasive breast cancer is unclear. The aim of this study was to investigate the relationship between ApoD protein expression, oestrogen receptor-α (ERα) expression and androgen receptor (AR) expression in predicting breast cancer outcome. METHODS AND RESULTS: ApoD levels were measured by the use of immunohistochemistry and video image analysis on tissue sections from a breast cancer cohort (n = 214). We assessed the associations of ApoD expression with disease-free survival (DFS), metastasis-free survival (MFS), and overall survival (OS). We also assessed the relationship between ApoD expression, AR expression and ERα expression in predicting OS. ApoD expression (>1% ApoD positivity) was found in 72% (154/214) of tissues. High ApoD positivity (≥20.7%, fourth quartile) was an independent predictor of MFS and OS, and conferred a 2.2-fold increased risk of developing metastatic disease and a 2.1-fold increased risk of breast cancer-related death. ApoD positivity was not associated with AR or ERα nuclear positivity. However, patients with (≥1%) ERα-positive cancers with low (<20.7%) ApoD positivity, or those showing high (≥78%) AR positivity and low (<20.7%) ApoD positivity had better OS than other patient groups. CONCLUSIONS: ApoD expression could be used to predict breast cancer prognosis independently of ERα and AR expression.
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Apolipoproteínas D/metabolismo , Biomarcadores Tumorais/análise , Neoplasias da Mama/patologia , Adulto , Apolipoproteínas D/análise , Feminino , Humanos , Pessoa de Meia-Idade , Prognóstico , Resultado do TratamentoRESUMO
Acute myeloid leukaemia (AML) is a heterogeneous disease characterized by transcriptional dysregulation that results in a block in differentiation and increased malignant self-renewal. Various epigenetic therapies aimed at reversing these hallmarks of AML have progressed into clinical trials, but most show only modest efficacy owing to an inability to effectively eradicate leukaemia stem cells (LSCs)1. Here, to specifically identify novel dependencies in LSCs, we screened a bespoke library of small hairpin RNAs that target chromatin regulators in a unique ex vivo mouse model of LSCs. We identify the MYST acetyltransferase HBO1 (also known as KAT7 or MYST2) and several known members of the HBO1 protein complex as critical regulators of LSC maintenance. Using CRISPR domain screening and quantitative mass spectrometry, we identified the histone acetyltransferase domain of HBO1 as being essential in the acetylation of histone H3 at K14. H3 acetylated at K14 (H3K14ac) facilitates the processivity of RNA polymerase II to maintain the high expression of key genes (including Hoxa9 and Hoxa10) that help to sustain the functional properties of LSCs. To leverage this dependency therapeutically, we developed a highly potent small-molecule inhibitor of HBO1 and demonstrate its mode of activity as a competitive analogue of acetyl-CoA. Inhibition of HBO1 phenocopied our genetic data and showed efficacy in a broad range of human cell lines and primary AML cells from patients. These biological, structural and chemical insights into a therapeutic target in AML will enable the clinical translation of these findings.
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Histona Acetiltransferases/metabolismo , Leucemia Mieloide Aguda/metabolismo , Células-Tronco Neoplásicas/metabolismo , Animais , Linhagem Celular Tumoral , Histona Acetiltransferases/química , Histona Acetiltransferases/genética , Humanos , Leucemia Mieloide Aguda/genética , Camundongos , Camundongos Endogâmicos C57BL , Modelos Moleculares , Estrutura Terciária de ProteínaRESUMO
Genomic alterations involving translocations of the ETS-related gene ERG occur in approximately half of prostate cancer cases. These alterations result in aberrant, androgen-regulated production of ERG protein variants that directly contribute to disease development and progression. This study describes the discovery and characterization of a new class of small molecule ERG antagonists identified through rational in silico methods. These antagonists are designed to sterically block DNA binding by the ETS domain of ERG and thereby disrupt transcriptional activity. We confirmed the direct binding of a lead compound, VPC-18005, with the ERG-ETS domain using biophysical approaches. We then demonstrated VPC-18005 reduced migration and invasion rates of ERG expressing prostate cancer cells, and reduced metastasis in a zebrafish xenograft model. These results demonstrate proof-of-principal that small molecule targeting of the ERG-ETS domain can suppress transcriptional activity and reverse transformed characteristics of prostate cancers aberrantly expressing ERG. Clinical advancement of the developed small molecule inhibitors may provide new therapeutic agents for use as alternatives to, or in combination with, current therapies for men with ERG-expressing metastatic castration-resistant prostate cancer.
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Antineoplásicos/química , Antineoplásicos/farmacologia , Descoberta de Drogas , Motivo ETS , Neoplasias da Próstata/metabolismo , Domínios e Motivos de Interação entre Proteínas , Regulador Transcricional ERG/química , Regulador Transcricional ERG/metabolismo , Animais , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Descoberta de Drogas/métodos , Regulação Neoplásica da Expressão Gênica , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Modelos Moleculares , Conformação Molecular , Proteínas de Fusão Oncogênica/química , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Ligação Proteica , Relação Estrutura-Atividade , Regulador Transcricional ERG/genética , Peixe-ZebraRESUMO
Treatment-induced neuroendocrine transdifferentiation (NEtD) complicates therapies for metastatic prostate cancer (PCa). Based on evidence that PCa cells can transdifferentiate to other neuroectodermally-derived cell lineages in vitro, we proposed that NEtD requires first an intermediary reprogramming to metastable cancer stem-like cells (CSCs) of a neural class and we demonstrate that several different AR+/PSA+ PCa cell lines were efficiently reprogrammed to, maintained and propagated as CSCs by growth in androgen-free neural/neural crest (N/NC) stem medium. Such reprogrammed cells lost features of prostate differentiation; gained features of N/NC stem cells and tumor-initiating potential; were resistant to androgen signaling inhibition; and acquired an invasive phenotype in vitro and in vivo. When placed back into serum-containing mediums, reprogrammed cells could be re-differentiated to N-/NC-derived cell lineages or return back to an AR+ prostate-like state. Once returned, the AR+ cells were resistant to androgen signaling inhibition. Acute androgen deprivation or anti-androgen treatment in serum-containing medium led to the transient appearance of a sub-population of cells with similar characteristics. Finally, a 132 gene signature derived from reprogrammed PCa cell lines distinguished tumors from PCa patients with adverse outcomes. This model may explain neural manifestations of PCa associated with lethal disease. The metastable nature of the reprogrammed stem-like PCa cells suggests that cycles of PCa cell reprogramming followed by re-differentiation may support disease progression and therapeutic resistance. The ability of a gene signature from reprogrammed PCa cells to identify tumors from patients with metastasis or PCa-specific mortality implies that developmental reprogramming is linked to aggressive tumor behaviors.
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Transdiferenciação Celular/fisiologia , Reprogramação Celular/fisiologia , Resistencia a Medicamentos Antineoplásicos/fisiologia , Células-Tronco Neoplásicas/patologia , Neoplasias da Próstata/patologia , Animais , Western Blotting , Progressão da Doença , Citometria de Fluxo , Imunofluorescência , Xenoenxertos , Humanos , Masculino , Camundongos , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase em Tempo Real , Peixe-ZebraRESUMO
Small glutamine-rich tetratricopeptide repeat-containing protein α (SGTA) has been implicated as a co-chaperone and regulator of androgen and growth hormone receptor (AR, GHR) signalling. We investigated the functional consequences of partial and full Sgta ablation in vivo using Cre-lox Sgta-null mice. Sgta(+/-) breeders generated viable Sgta(-/-) offspring, but at less than Mendelian expectancy. Sgta(-/-) breeders were subfertile with small litters and higher neonatal death (P < 0.02). Body size was significantly and proportionately smaller in male and female Sgta(-/-) (vs WT, Sgta(+/-) P < 0.001) from d19. Serum IGF-1 levels were genotype- and sex-dependent. Food intake, muscle and bone mass and adiposity were unchanged in Sgta(-/-). Vital and sex organs had normal relative weight, morphology and histology, although certain androgen-sensitive measures such as penis and preputial size, and testis descent, were greater in Sgta(-/-). Expression of AR and its targets remained largely unchanged, although AR localisation was genotype- and tissue-dependent. Generally expression of other TPR-containing proteins was unchanged. In conclusion, this thorough investigation of SGTA-null mutation reports a mild phenotype of reduced body size. The model's full potential likely will be realised by genetic crosses with other models to interrogate the role of SGTA in the many diseases in which it has been implicated.
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Chaperonas Moleculares/metabolismo , Animais , Tamanho Corporal , Feminino , Masculino , Camundongos , Camundongos Knockout , Chaperonas Moleculares/genética , Análise de SobrevidaRESUMO
INTRODUCTION: Current approaches to inhibit oestrogen receptor-alpha (ERα) are focused on targeting its hormone-binding pocket and have limitations. Thus, we propose that inhibitors that bind to a coactivator-binding pocket on ERα, called activation function 2 (AF2), might overcome some of these limitations. METHODS: In silico virtual screening was used to identify small-molecule ERα AF2 inhibitors. These compounds were screened for inhibition of ERα transcriptional activity using stably transfected T47D-KBluc cell line. A direct physical interaction between the AF2 binders and the ERα protein was measured using biolayer interferometry (BLI) and an ERα coactivator displacement assay. Cell viability was assessed by MTS assay in ERα-positive MCF7 cells, tamoxifen-resistant (TamR) cell lines TamR3 and TamR6, and ERα-negative MDA-MB-453 and HeLa cell lines. In addition, ERα inhibition in TamR cells and the effect of compounds on mRNA and protein expression of oestrogen-dependent genes, pS2, cathepsin D and cell division cycle 2 (CDC2) were determined. RESULTS: Fifteen inhibitors from two chemical classes, derivatives of pyrazolidine-3,5-dione and carbohydrazide, were identified. In a series of in vitro assays, VPC-16230 of the carbohydrazide chemical class emerged as a lead ERα AF2 inhibitor that significantly downregulated ERα transcriptional activity (half-maximal inhibitory concentration = 5.81 µM). By directly binding to the ERα protein, as confirmed by BLI, VPC-16230 effectively displaced coactivator peptides from the AF2 pocket, confirming its site-specific action. VPC-16230 selectively suppressed the growth of ERα-positive breast cancer cells. Furthermore, it significantly inhibited ERα mediated transcription in TamR cells. More importantly, it reduced mRNA and protein levels of pS2, cathepsin D and CDC2, validating its ER-directed activity. CONCLUSION: We identified VPC-16230 as an ERα AF2-specific inhibitor that demonstrated promising antiproliferative effects in breast cancer cell lines, including TamR cells. VPC-16230 reduced the expression of ERα-inducible genes, including CDC2, which is involved in cell division. We anticipate that the application of ERα AF2 inhibitors will provide a novel approach that can act as a complementary therapeutic to treat ERα-positive, tamoxifen-resistant and metastatic breast cancers.
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Antineoplásicos/química , Domínio Catalítico , Descoberta de Drogas , Moduladores de Receptor Estrogênico/química , Receptor alfa de Estrogênio/química , Antineoplásicos/farmacologia , Sítios de Ligação , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Simulação por Computador , Descoberta de Drogas/métodos , Resistencia a Medicamentos Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Estradiol/metabolismo , Moduladores de Receptor Estrogênico/farmacologia , Receptor alfa de Estrogênio/antagonistas & inibidores , Receptor alfa de Estrogênio/genética , Estrogênios/metabolismo , Feminino , Humanos , Ligantes , Células MCF-7 , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Reprodutibilidade dos Testes , Bibliotecas de Moléculas Pequenas , Transcrição Gênica/efeitos dos fármacosRESUMO
Nuclear receptors (NRs), a family of 48 transcriptional factors, have been studied intensively for their roles in cancer development and progression. The presence of distinctive ligand binding sites capable of interacting with small molecules has made NRs attractive targets for developing cancer therapeutics. In particular, a number of drugs have been developed over the years to target human androgen- and estrogen receptors for the treatment of prostate cancer and breast cancer. In contrast, orphan nuclear receptors (ONRs), which in many cases lack known biological functions or ligands, are still largely under investigated. This review is a summary on ONRs that have been implicated in prostate and breast cancers, specifically retinoic acid-receptor-related orphan receptors (RORs), liver X receptors (LXRs), chicken ovalbumin upstream promoter transcription factors (COUP-TFs), estrogen related receptors (ERRs), nerve growth factor 1B-like receptors, and ''dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1'' (DAX1). Discovery and development of small molecules that can bind at various functional sites on these ONRs will help determine their biological functions. In addition, these molecules have the potential to act as prototypes for future drug development. Ultimately, the therapeutic value of targeting the ONRs may go well beyond prostate and breast cancers.
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Neoplasias da Mama/tratamento farmacológico , Terapia de Alvo Molecular/métodos , Receptores Nucleares Órfãos/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Antineoplásicos/farmacologia , Neoplasias da Mama/metabolismo , Fator I de Transcrição COUP/metabolismo , Fatores de Transcrição COUP/metabolismo , Receptor Nuclear Órfão DAX-1/metabolismo , Feminino , Humanos , Receptores X do Fígado , Masculino , Proteínas de Membrana Transportadoras/metabolismo , Membro 1 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Neoplasias da Próstata/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologiaRESUMO
Small glutamine-rich tetratricopeptide repeat-containing protein α (SGTA) is a steroid receptor molecular co-chaperone that may substantially influence hormone action and, consequently, hormone-mediated carcinogenesis. To date, published studies describe SGTA as a protein that is potentially critical in a range of biological processes, including viral infection, cell division, mitosis, and cell cycle checkpoint activation. SGTA interacts with the molecular chaperones, heat shock protein 70 (HSP70) and HSP90, and with steroid receptor complexes, including those containing the androgen receptor. Steroid receptors are critical for maintaining cell growth and differentiation in hormonally regulated tissues, such as male and female reproductive tissues, and also play a role in disease states involving these tissues. There is growing evidence that, through its interactions with chaperones and steroid receptors, SGTA may be a key player in the pathogenesis of hormonally influenced disease states, including prostate cancer and polycystic ovary syndrome. Research into the function of SGTA has been conducted in several model organisms and cell types, with these studies showing that SGTA functionality is cell-specific and tissue-specific. However, very few studies have been replicated in multiple cell types or experimental systems. Although a broad range of functions have been attributed to SGTA, there is a serious lack of mechanistic information to describe how SGTA acts. In this review, published evidence linking SGTA with hormonally regulated disease states is summarized and discussed, highlighting the need for future research to more clearly define the biological function(s) of this potentially important co-chaperone.
Assuntos
Proteínas de Transporte/metabolismo , Síndrome do Ovário Policístico/metabolismo , Neoplasias da Próstata/metabolismo , Animais , Feminino , Humanos , Masculino , Modelos Animais , Chaperonas Moleculares , Dobramento de Proteína , Esteroides/metabolismoRESUMO
OBJECTIVE: To evaluate the expression and function of small glutamine-rich tetratricopeptide repeat-containing protein alpha (SGTA), an androgen receptor (AR) molecular chaperone, in human ovarian tissues. DESIGN: Examine the effect of SGTA on AR subcellular localization in granulosa tumor cells (KGN) and SGTA expression in ovarian tissues. SETTING: University-based research laboratory. PATIENT(S): Archived tissues from premenopausal women and granulosa cells from infertile women receiving assisted reproduction. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): AR subcellular localization and SGTA protein or mRNA levels. RESULT(S): SGTA and AR proteins were expressed in the cytoplasm of KGN cells and exposure to androgen stimulated AR nuclear localization. SGTA protein knockdown increased AR nuclear localization at low (0-0.1 nmol/L) but not high (1-10 nmol/L) concentrations of androgen hormone. In ovarian tissues, SGTA was localized to the cytoplasm of granulosa cells at all stages of folliculogenesis and in thecal cells of antral follicles. SGTA protein levels were similar when comparing primordial and primary follicles within core biopsies (n = 40) from women with and without polycystic ovary syndrome (PCOS). Likewise, SGTA mRNA levels were not significantly different in granulosa cells from preovulatory follicles after hyperstimulation of women with and without PCOS. CONCLUSION(S): SGTA is present in human ovaries and has the potential to modulate AR signalling, but it may not be differentially expressed in PCOS.
Assuntos
Proteínas de Transporte/metabolismo , Tumor de Células da Granulosa/metabolismo , Ovário/metabolismo , Síndrome do Ovário Policístico/metabolismo , Adulto , Proteínas de Transporte/genética , Estudos de Casos e Controles , Linhagem Celular Tumoral , China , Di-Hidrotestosterona/farmacologia , Feminino , Tumor de Células da Granulosa/genética , Tumor de Células da Granulosa/patologia , Humanos , Pessoa de Meia-Idade , Chaperonas Moleculares , Ovário/efeitos dos fármacos , Ovário/patologia , Síndrome do Ovário Policístico/genética , Síndrome do Ovário Policístico/patologia , Transporte Proteico , Interferência de RNA , RNA Mensageiro/metabolismo , Receptores Androgênicos/efeitos dos fármacos , Receptores Androgênicos/metabolismo , Austrália do Sul , TransfecçãoRESUMO
The androgen receptor (AR) is expressed in a majority of ovarian carcinomas, but its role in disease development remains unclear. In this study, AR and a novel AR molecular chaperone called small glutamine-rich tetratricopeptide repeat-containing protein alpha (SGTA) were investigated to assess their potential role in ovarian carcinogenesis. First, an AR and SGTA-positive ovarian cancer cell line was identified to examine whether SGTA influenced AR subcellular localization. Next, relative protein levels of AR and SGTA were measured in two sets of clinical samples: (1) 46 serous ovarian carcinomas (stages I-IV), 9 serous borderline tumors, and 11 benign ovarian tumors; and (2) 24 patient-matched stage III primary and metastatic serous ovarian tumors. Ablation of SGTA protein in OVCAR3 cells significantly increased AR nuclear localization under basal (p ≤ 0.001) and androgen-stimulated (p ≤ 0.001) conditions. In the first clinical set, AR levels were significantly lower in early- (I/II) and late-stage (III/IV) cancers compared with benign (p ≤ 0.001) but not borderline ovarian tumors. SGTA alone did not discriminate between groups but the AR/SGTA ratio was significantly lower in carcinomas and borderline tumors compared with benign tumors (p ≤ 0.001 and 0.015, respectively). In the second clinical set, matched primary and metastatic serous ovarian cancers did not significantly differ for any parameter measured. Collectively, our results suggest that SGTA can influence AR signaling in ovarian cancer cells and that AR signaling capacity may be reduced with the development but not metastatic progression of serous ovarian cancer.
Assuntos
Carcinoma/genética , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Receptores Androgênicos/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma/patologia , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Progressão da Doença , Feminino , Humanos , Pessoa de Meia-Idade , Chaperonas Moleculares , Metástase Neoplásica/genética , Metástase Neoplásica/patologia , Estadiamento de Neoplasias , Neoplasias Ovarianas/metabolismo , Receptores Androgênicos/metabolismo , Transdução de SinaisRESUMO
ZNF652, a DNA binding transcription factor, was previously suggested to be differentially expressed in prostate cancer. This study investigated if the expressions of ZNF652 and androgen receptor (AR) in prostate cancer are associated with prostate specific antigen (PSA) defined relapse. ZNF652 and AR immunoreactivity were evaluated in prostate tissues from a cohort of 121 patients with prostate cancer and associations with disease outcome determined. To assess if ZNF652 can influence AR expression, or vice versa, levels of expression of ZNF652, AR and PSA were determined in the prostate cell line LNCaP following induction of AR activity by 5alpha-dihydrotestosterone, or knockdown of ZNF652 expression. Two thirds of prostate tumors retained high levels of ZNF652 (71/109 cases) and 50% of tumors high levels of AR (57/113). There was a significant decrease (p=0.005) in relapse-free survival of patients with high expression levels of both ZNF652 and AR and this was independent of preoperative PSA and seminal vesicle involvement. Modulation of either AR or ZNF652 expression levels in LNCaP cells was not associated with any corresponding changes to the levels of either ZNF652 or AR, respectively. High levels of expression of both AR and ZNF652 in clinically organ-defined prostate cancer are associated with a statistically increased risk of relapse. The ZNF652 and AR transcription factors are acting independently and it is proposed that the continued maintenance of expression of ZNF652 in AR positive cells results in a gene expression pattern that contributes to the relapse.