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1.
Nucleic Acids Res ; 51(1): 99-116, 2023 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-36535377

RESUMO

Numerous cancers, including prostate cancer (PCa), are addicted to transcription programs driven by specific genomic regions known as super-enhancers (SEs). The robust transcription of genes at such SEs is enabled by the formation of phase-separated condensates by transcription factors and coactivators with intrinsically disordered regions. The androgen receptor (AR), the main oncogenic driver in PCa, contains large disordered regions and is co-recruited with the transcriptional coactivator mediator complex subunit 1 (MED1) to SEs in androgen-dependent PCa cells, thereby promoting oncogenic transcriptional programs. In this work, we reveal that full-length AR forms foci with liquid-like properties in different PCa models. We demonstrate that foci formation correlates with AR transcriptional activity, as this activity can be modulated by changing cellular foci content chemically or by silencing MED1. AR ability to phase separate was also validated in vitro by using recombinant full-length AR protein. We also demonstrate that AR antagonists, which suppress transcriptional activity by targeting key regions for homotypic or heterotypic interactions of this receptor, hinder foci formation in PCa cells and phase separation in vitro. Our results suggest that enhanced compartmentalization of AR and coactivators may play an important role in the activation of oncogenic transcription programs in androgen-dependent PCa.


Assuntos
Neoplasias da Próstata , Receptores Androgênicos , Masculino , Humanos , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Androgênios , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Expressão Gênica , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica
2.
Int J Mol Sci ; 23(5)2022 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-35269731

RESUMO

The Myc family of transcription factors are involved in the development and progression of numerous cancers, including prostate cancer (PCa). Under the pressure of androgen receptor (AR)-directed therapies resistance can occur, leading to the lethal form of PCa known as neuroendocrine prostate cancer (NEPC), characterized among other features by N-Myc overexpression. There are no clinically approved treatments for NEPC, translating into poor patient prognosis and survival. Therefore, there is a pressing need to develop novel therapeutic avenues to treat NEPC patients. In this study, we investigate the N-Myc-Max DNA binding domain (DBD) as a potential target for small molecule inhibitors and utilize computer-aided drug design (CADD) approaches to discover prospective hits. Through further exploration and optimization, a compound, VPC-70619, was identified with notable anti-N-Myc potency and strong antiproliferative activity against numerous N-Myc expressing cell lines, including those representing NEPC.


Assuntos
Carcinoma Neuroendócrino , Neoplasias da Próstata , Carcinoma Neuroendócrino/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Estudos Prospectivos , Próstata/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo
3.
Int J Mol Sci ; 21(21)2020 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-33167327

RESUMO

Resistance to androgen-receptor (AR) directed therapies is, among other factors, associated with Myc transcription factors that are involved in development and progression of many cancers. Overexpression of N-Myc protein in prostate cancer (PCa) leads to its transformation to advanced neuroendocrine prostate cancer (NEPC) that currently has no approved treatments. N-Myc has a short half-life but acts as an NEPC stimulator when it is stabilized by forming a protective complex with Aurora A kinase (AURKA). Therefore, dual-inhibition of N-Myc and AURKA would be an attractive therapeutic avenue for NEPC. Following our computer-aided drug discovery approach, compounds exhibiting potent N-Myc specific inhibition and strong anti-proliferative activity against several N-Myc driven cell lines, were identified. Thereafter, we have developed dual inhibitors of N-Myc and AURKA through structure-based drug design approach by merging our novel N-Myc specific chemical scaffolds with fragments of known AURKA inhibitors. Favorable binding modes of the designed compounds to both N-Myc and AURKA target sites have been predicted by docking. A promising lead compound, 70812, demonstrated low-micromolar potency against both N-Myc and AURKA in vitro assays and effectively suppressed NEPC cell growth.


Assuntos
Antineoplásicos/isolamento & purificação , Aurora Quinase A/antagonistas & inibidores , Carcinoma Neuroendócrino/tratamento farmacológico , Proteína Proto-Oncogênica N-Myc/antagonistas & inibidores , Neoplasias da Próstata/tratamento farmacológico , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Células Cultivadas , Descoberta de Drogas/métodos , Ensaios de Seleção de Medicamentos Antitumorais , Drogas em Investigação/química , Drogas em Investigação/isolamento & purificação , Drogas em Investigação/farmacologia , Humanos , Masculino , Modelos Moleculares , Simulação de Acoplamento Molecular , Terapia de Alvo Molecular , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/isolamento & purificação , Inibidores de Proteínas Quinases/farmacologia , Receptores Androgênicos/metabolismo
4.
BMC Infect Dis ; 19(1): 820, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31533648

RESUMO

BACKGROUND: The aim of this study was to establish the prevalence of lipodystrophy and its association to cumulative exposure to antiretroviral drugs. METHOD: We conducted a cross sectional study in all HIV- infected patients attending the HIV clinic in the Centre hospitalier universitaire de Montréal (CHUM) with DEXA scan. Lipodystrophy was defined as a trunk/limb fat ratio ≥ 1.5. Association between cumulative exposure to antiretroviral (measured in years of use) with trunk/limb fat ratio (coded as a continuous variable) was assessed using univariate and multivariate linear regression for each antiretroviral drug with at least 40 exposed patients. RESULTS: One hundred sixty-six patients were included. Seventy-five percent were male, median age was 56 years, 67% were Caucasian. Overall, prevalence of lipodystrophy was 47%, with a mean trunk/limb fat ratio of 1.87, SD = 1.03, min = 0.6 and max = 5.87. Each 10-year increase in age and HIV infection duration was associated with an average increase of 0.24 and 0.34 for the trunk/limb fat ratio respectively. (p = 0.003, p = 0.002, respectively) Patients classified as lipodystrophic were more likely to be diabetic (50 vs. 28%, p = 0.07) and to have dyslipidemia (47 vs. 19%, p = 0.01). According to viral load at DEXA test, each one log increase was associated with less probability (0.7) of lipodystrophy. (p = 0.01) Among ARV drugs tested, there was an association between years of use of d4T, ritonavir and raltegravir and higher trunk/limb fat ratio (indicating more lipodystrophy) (p < 0.05). CONCLUSION: Lipodystrophy is very common in HIV infected patients and is correlated with duration of some new antiretroviral drugs.


Assuntos
Antirretrovirais/uso terapêutico , Infecções por HIV/tratamento farmacológico , Síndrome de Lipodistrofia Associada ao HIV/diagnóstico , Absorciometria de Fóton , Adulto , Idoso , Estudos Transversais , Dislipidemias/diagnóstico , Dislipidemias/etiologia , Feminino , Síndrome de Lipodistrofia Associada ao HIV/epidemiologia , Síndrome de Lipodistrofia Associada ao HIV/etiologia , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Carga Viral
5.
Molecules ; 24(4)2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30791548

RESUMO

The heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) is a versatile RNA-binding protein playing a critical role in alternative pre-mRNA splicing regulation in cancer. Emerging data have implicated hnRNP A1 as a central player in a splicing regulatory circuit involving its direct transcriptional control by c-Myc oncoprotein and the production of the constitutively active ligand-independent alternative splice variant of androgen receptor, AR-V7, which promotes castration-resistant prostate cancer (CRPC). As there is an urgent need for effective CRPC drugs, targeting hnRNP A1 could, therefore, serve a dual purpose of preventing AR-V7 generation as well as reducing c-Myc transcriptional output. Herein, we report compound VPC-80051 as the first small molecule inhibitor of hnRNP A1 splicing activity discovered to date by using a computer-aided drug discovery approach. The inhibitor was developed to target the RNA-binding domain (RBD) of hnRNP A1. Further experimental evaluation demonstrated that VPC-80051 interacts directly with hnRNP A1 RBD and reduces AR-V7 messenger levels in 22Rv1 CRPC cell line. This study lays the groundwork for future structure-based development of more potent and selective small molecule inhibitors of hnRNP A1⁻RNA interactions aimed at altering the production of cancer-specific alternative splice isoforms.


Assuntos
Biologia Computacional , Descoberta de Drogas , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Ribonucleoproteína Nuclear Heterogênea A1/genética , Neoplasias de Próstata Resistentes à Castração/genética , Splicing de RNA/efeitos dos fármacos , Sítios de Ligação , Linhagem Celular Tumoral , Biologia Computacional/métodos , Simulação por Computador , Descoberta de Drogas/métodos , Ribonucleoproteína Nuclear Heterogênea A1/química , Humanos , Masculino , Modelos Moleculares , Conformação Molecular , Relação Estrutura-Atividade
6.
Clin Immunol ; 177: 87-94, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-26387630

RESUMO

Blood samples from 32 patients with severe Traumatic brain injury (TBI) were studied and compared with 11 cardiac surgery patients, and 29 healthy controls. A dramatic decreased expression of HLA class I molecules on monocytes was associated with increased KIR+ NK cell frequency in TBI patients. Overall, the phenotype of TBI NK cells marked by KIR and CD57 expression and lower level of NKp46 and DNAM-1 reflected a differentiated state. The NK-cell response to missing self was marked by lower degranulation and lower IFN-γ production after stimulation with HLA class I deficient cell line. In contrast, the NK-cell ADCC was not altered. IL-12 was able to restore both IFN-γ production and the cytotoxicity capacities of NK cells. This study provides the first extensive description of the phenotype and functions of NK cells in TBI patients. Further evaluation of IL-12 treatment to overcome immunosuppression-induced nosocomial infections is warranted.


Assuntos
Lesões Encefálicas Traumáticas/imunologia , Interleucina-12/imunologia , Células Matadoras Naturais/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Degranulação Celular/imunologia , Feminino , Genes MHC Classe I , Genes MHC da Classe II , Humanos , Interferon gama/imunologia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
7.
Mol Inform ; 42(8-9): e2300026, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37193651

RESUMO

Androgen receptor (AR) inhibition remains the primary strategy to combat the progression of prostate cancer (PC). However, all clinically used AR inhibitors target the ligand-binding domain (LBD), which is highly susceptible to truncations through splicing or mutations that confer drug resistance. Thus, there exists an urgent need for AR inhibitors with novel modes of action. We thus launched a virtual screening of an ultra-large chemical library to find novel inhibitors of the AR DNA-binding domain (DBD) at two sites: protein-DNA interface (P-box) and dimerization site (D-box). The compounds selected through vigorous computational filtering were then experimentally validated. We identified several novel chemotypes that effectively suppress transcriptional activity of AR and its splice variant V7. The identified compounds represent previously unexplored chemical scaffolds with a mechanism of action that evades the conventional drug resistance manifested through LBD mutations. Additionally, we describe the binding features required to inhibit AR DBD at both P-box and D-box target sites.


Assuntos
Neoplasias da Próstata , Receptores Androgênicos , Masculino , Humanos , Receptores Androgênicos/metabolismo , Androgênios , Antagonistas de Receptores de Andrógenos/farmacologia , Antagonistas de Receptores de Andrógenos/química , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , DNA
8.
Cells ; 11(18)2022 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-36139361

RESUMO

The mutation-driven transformation of clinical anti-androgen drugs into agonists of the human androgen receptor (AR) represents a major challenge for the treatment of prostate cancer patients. To address this challenge, we have developed a novel class of inhibitors targeting the DNA-binding domain (DBD) of the receptor, which is distanced from the androgen binding site (ABS) targeted by all conventional anti-AR drugs and prone to resistant mutations. While many members of the developed 4-(4-phenylthiazol-2-yl)morpholine series of AR-DBD inhibitors demonstrated the effective suppression of wild-type AR, a few represented by 4-(4-(3-fluoro-2-methoxyphenyl)thiazol-2-yl)morpholine (VPC14368) exhibited a partial agonistic effect toward the mutated T878A form of the receptor, implying their cross-interaction with the AR ABS. To study the molecular basis of the observed cross-reactivity, we co-crystallized the T878A mutated form of the AR ligand binding domain (LBD) with a bound VPC14368 molecule. Computational modelling revealed that helix 12 of AR undergoes a characteristic shift upon VPC14368 binding causing the agonistic behaviour. Based on the obtained structural data we then designed derivatives of VPC14368 to successfully eliminate the cross-reactivity towards the AR ABS, while maintaining significant anti-AR DBD potency.


Assuntos
Antagonistas de Receptores de Andrógenos , Receptores Androgênicos , Antagonistas de Androgênios , Antagonistas de Receptores de Andrógenos/farmacologia , DNA , Humanos , Ligantes , Masculino , Morfolinas , Receptores Androgênicos/metabolismo
9.
Cancers (Basel) ; 13(12)2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34208290

RESUMO

Resistance to drug treatments is common in prostate cancer (PCa), and the gain-of-function mutations in human androgen receptor (AR) represent one of the most dominant drivers of progression to resistance to AR pathway inhibitors (ARPI). Previously, we evaluated the in vitro response of 24 AR mutations, identified in men with castration-resistant PCa, to five AR antagonists. In the current work, we evaluated 44 additional PCa-associated AR mutants, reported in the literature, and thus expanded the study of the effect of darolutamide to a total of 68 AR mutants. Unlike other AR antagonists, we demonstrate that darolutamide exhibits consistent efficiency against all characterized gain-of-function mutations in a full-length AR. Additionally, the response of the AR mutants to clinically used bicalutamide and enzalutamide, as well as to major endogenous steroids (DHT, estradiol, progesterone and hydrocortisone), was also investigated. As genomic profiling of PCa patients becomes increasingly feasible, the developed "AR functional encyclopedia" could provide decision-makers with a tool to guide the treatment choice for PCa patients based on their AR mutation status.

10.
Eur J Cardiothorac Surg ; 60(4): 874-879, 2021 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-33724380

RESUMO

OBJECTIVES: The carotid approach for transcatheter aortic valve replacement (TAVR) has been shown to be feasible and safe. The goal of this study was to compare the 30-day outcomes of trans-carotid (TC) and transfemoral (TF) TAVR. METHODS: This retrospective study enrolled 500 consecutive patients treated by TC-TAVR (n = 100) or TF-TAVR (n = 400) with percutaneous closure between January 2018 and January 2020 at the Nantes University Hospital. The primary end-point was the occurrence of cardiovascular death and cerebrovascular events at 30 days. RESULTS: The mean age was 79.9 ± 8.1 in the TC group and 81.3 ± 6.9 (P = 0.069) in the TF group. The TC group had more men (69% vs 50.5%; P = 0.001) and more patients with peripheral vascular disease (86% vs 14.8%; P < 0.0001). Cardiac characteristics were similar between the groups, and the EuroSCORE II was 3.8 ± 2.6% vs 4.6 ± 6.0%, respectively (P = 0.443). The 30-day mortality was 2% in the TC group versus 1% in the TF group (P = 0.345). TC-TAVR was not associated with an increased risk of stroke (2% vs 2.5%; P = 0.999) or major vascular complications (2% vs 4%; P = 0.548). More permanent pacemakers were implanted in the TF group (14.9% vs 5.6%; P = 0.015), and no moderate or severe aortic regurgitation was observed in the TC group (0 vs 3.3%; P = 0.08). TC-TAVR was not associated with an increased risk of mortality or stroke at 30 days (odds ratio 1.32; 95% confidence interval 0.42-4.21; P = 0.63) in the multivariable analysis. CONCLUSIONS: No statistically significant differences between TC-TAVR and TF-TAVR were observed; therefore, TC-TAVR should be the first alternative in patients with anatomical contraindications to the femoral route.


Assuntos
Estenose da Valva Aórtica , Substituição da Valva Aórtica Transcateter , Idoso , Idoso de 80 Anos ou mais , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgia , Artéria Femoral/cirurgia , Humanos , Masculino , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Substituição da Valva Aórtica Transcateter/efeitos adversos , Resultado do Tratamento
11.
Minerva Anestesiol ; 87(11): 1191-1199, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34102807

RESUMO

BACKGROUND: The standardized management of anticoagulation during the cardiopulmonary bypass seems inaccurate because of patients and surgeries variability. This study evaluates if an individualized management of heparin and protamine guided by the HMS Plus system during cardiopulmonary bypass could reduce postoperative blood loss. METHODS: We conducted a prospective, controlled, unblinded, single-center study. One-hundred and eighthy-eight patients operated for cardiac surgery were included. Patients were divided in ACT Plus group (standardized approach) and HMS Plus group (individualized approach). The primary outcome was blood-loss volume during the first 24 postoperative hours. The main secondary outcomes were the need for allogeneic blood transfusions and the final protamine/heparin ratio. RESULTS: There was no difference between the two groups for baseline characteristics. Medium blood-loss volume in the ACT Plus group was 522±260 mL vs. 527±255 mL in the HMS Plus group (P=0.58). The final protamine/heparin ratio in the ACT Plus group was 0.94±0.1 vs. 0.58±0.1 in the HMS Plus group (P<0.0001). The transfusion rate during surgery in the ACT Plus group was 25% vs. 14% in the HMS Plus group (P=0.09). CONCLUSIONS: HMS Plus did not reduce the mean blood-loss volume during the first 24 postoperative hours compared with ACT Plus. Its utility for potential transfusion rate reduction remains to be proven.


Assuntos
Anticoagulantes , Procedimentos Cirúrgicos Cardíacos , Anticoagulantes/uso terapêutico , Heparina/uso terapêutico , Humanos , Hemorragia Pós-Operatória/epidemiologia , Hemorragia Pós-Operatória/prevenção & controle , Estudos Prospectivos
12.
Cancers (Basel) ; 13(14)2021 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-34298700

RESUMO

Prostate cancer patients undergoing androgen deprivation therapy almost invariably develop castration-resistant prostate cancer. Resistance can occur when mutations in the androgen receptor (AR) render anti-androgen drugs ineffective or through the expression of constitutively active splice variants lacking the androgen binding domain entirely (e.g., ARV7). In this study, we are reporting the discovery of a novel AR-NTD covalent inhibitor 1-chloro-3-[(5-([(2S)-3-chloro-2-hydroxypropyl]amino)naphthalen-1-yl)amino]propan-2-ol (VPC-220010) targeting the AR-N-terminal Domain (AR-NTD). VPC-220010 inhibits AR-mediated transcription of full length and truncated variant ARV7, downregulates AR response genes, and selectively reduces the growth of both full-length AR- and truncated AR-dependent prostate cancer cell lines. We show that VPC-220010 disrupts interactions between AR and known coactivators and coregulatory proteins, such as CHD4, FOXA1, ZMIZ1, and several SWI/SNF complex proteins. Taken together, our data suggest that VPC-220010 is a promising small molecule that can be further optimized into effective AR-NTD inhibitor for the treatment of CRPC.

13.
J Med Chem ; 64(20): 14968-14982, 2021 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-34661404

RESUMO

Prostate cancer (PCa) patients undergoing androgen deprivation therapy almost invariably develop castration-resistant prostate cancer (CRPC). Targeting the androgen receptor (AR) Binding Function-3 (BF3) site offers a promising option to treat CRPC. However, BF3 inhibitors have been limited by poor potency or inadequate metabolic stability. Through extensive medicinal chemistry, molecular modeling, and biochemistry, we identified 2-(5,6,7-trifluoro-1H-Indol-3-yl)-quinoline-5-carboxamide (VPC-13789), a potent AR BF3 antagonist with markedly improved pharmacokinetic properties. We demonstrate that VPC-13789 suppresses AR-mediated transcription, chromatin binding, and recruitment of coregulatory proteins. This novel AR antagonist selectively reduces the growth of both androgen-dependent and enzalutamide-resistant PCa cell lines. Having demonstrated in vitro efficacy, we developed an orally bioavailable prodrug that reduced PSA production and tumor volume in animal models of CRPC with no observed toxicity. VPC-13789 is a potent, selective, and orally bioavailable antiandrogen with a distinct mode of action that has a potential as novel CRPC therapeutics.


Assuntos
Antagonistas de Androgênios/farmacologia , Antineoplásicos/farmacologia , Desenvolvimento de Medicamentos , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Quinolinas/farmacologia , Receptores Androgênicos/metabolismo , Administração Oral , Antagonistas de Androgênios/administração & dosagem , Antagonistas de Androgênios/química , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Disponibilidade Biológica , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Masculino , Modelos Moleculares , Estrutura Molecular , Neoplasias de Próstata Resistentes à Castração/metabolismo , Neoplasias de Próstata Resistentes à Castração/patologia , Quinolinas/administração & dosagem , Quinolinas/química , Relação Estrutura-Atividade
14.
Mol Inform ; 37(9-10): e1800043, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29733509

RESUMO

Androgen receptor (AR) is a master regulator of prostate cancer (PCa), and therefore is a pivotal drug target for the treatment of PCa including its castration-resistance form (CRPC). The development of acquired resistance is a major challenge in the use of the current antiandrogens. The recent advancements in inhibiting AR activity with small molecules specifically designed to target areas distinct from the receptor's androgen binding site are carefully discussed. Our new classes of AR inhibitors of AF2 and BF3 functional sites and DBD domains designed using cheminformatics techniques are promising to circumvent various AR-dependent resistance mechanisms.


Assuntos
Antagonistas de Receptores de Andrógenos/farmacologia , Antineoplásicos/farmacologia , Descoberta de Drogas/métodos , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Relação Quantitativa Estrutura-Atividade , Antagonistas de Receptores de Andrógenos/química , Antineoplásicos/química , Ensaios de Triagem em Larga Escala/métodos , Humanos , Masculino
15.
Eur J Med Chem ; 160: 108-119, 2018 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-30326371

RESUMO

While Myc is an essential regulator of growth in normal cells, it is also frequently associated with cancer progression, therapy-resistance and lethal outcomes in most human cancers. In prostate cancer (PCa), Myc transcription factors are implicated in the pathogenesis and progression of the full spectrum of PCa, from adenocarcinoma to advanced castration-resistant and neuroendocrine phenotypes. Though a high-value therapeutic target, clinically approved anti-Myc drugs have yet to be discovered. To elicit its oncogenic effects, Myc must form a heterodimer with its partner Max, which together bind DNA and activate transcription of a spectrum of target genes that promote cell growth, proliferation, metabolism, and apoptosis while blocking differentiation. In this study, we identified a binding site on the DNA-binding domain of the structurally ordered Myc-Max complex and employed a computer-aided rational drug discovery approach to identify small molecules that effectively inhibit Myc-Max functionality. A large-scale virtual screening protocol implementing structure-based methodologies was utilized to select a set of top-ranked compounds that were subsequently evaluated experimentally and characterized mechanistically for their ability to inhibit Myc-Max transcriptional activity and subsequent downstream functions, to reduce viability in PCa cell lines, disrupt protein-DNA interactions and to induce apoptosis as their mechanism of action. Among compounds identified that effectively inhibit Myc-Max activity with low to mid-micromolar range potency and no or minimal generic cytotoxicity, VPC-70067, a close analog of the previously identified Myc inhibitor 10058-F4, served as proof-of-concept that our in silico drug discovery strategy performed as expected. Compound VPC-70063, of a chemically different scaffold, was the best performer in a panel of in vitro assays, and the forerunner for future hit-to-lead optimization efforts. These findings lay a foundation for developing more potent, specific and clinically optimized Myc-Max inhibitors that may serve as promising therapeutics, alone or in combination with current anti-cancer treatments, for treatment of specific phenotypes or heterogeneous tumors.


Assuntos
Antineoplásicos/farmacologia , Desenho Assistido por Computador , Descoberta de Drogas , Neoplasias da Próstata/tratamento farmacológico , Proteínas Proto-Oncogênicas c-myc/antagonistas & inibidores , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Masculino , Estrutura Molecular , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Proteínas Proto-Oncogênicas c-myc/isolamento & purificação , Proteínas Proto-Oncogênicas c-myc/metabolismo , Relação Estrutura-Atividade , Células Tumorais Cultivadas
16.
Eur J Med Chem ; 157: 1164-1173, 2018 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-30193215

RESUMO

The androgen receptor (AR) is a hormone-activated transcription factor that regulates the development and progression of prostate cancer (PCa) and represents one of the most well-established drug targets. Currently clinically approved small molecule inhibitors of AR, such as enzalutamide, are built upon a common chemical scaffold that interacts with the AR by the same mechanism of action. These inhibitors eventually fail due to the emergence of drug-resistance in the form of AR mutations and expression of truncated AR splice variants (e.g. AR-V7) that are constitutively active, signalling the progression of the castration-resistant state of the disease. The urgent need therefore continues for novel classes of AR inhibitors that can overcome drug resistance, especially since AR signalling remains important even in late-stage advanced PCa. Previously, we identified a collection of 10-benzylidene-10H-anthracen-9-ones that effectively inhibit AR transcriptional activity, induce AR degradation and display some ability to block recruitment of hormones to the receptor. In the current work, we extended the analysis of the lead compounds, and used methods of both ligand- and structure-based drug design to develop a panel of novel 10-benzylidene-10H-anthracen-9-one derivatives capable of suppressing transcriptional activity and protein expression levels of both full length- and AR-V7 truncated forms of human androgen receptor. Importantly, the developed compounds efficiently inhibited the growth of AR-V7 dependent prostate cancer cell-lines which are completely resistant to all current anti-androgens.


Assuntos
Antagonistas de Androgênios/farmacologia , Variação Genética/genética , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Antagonistas de Androgênios/síntese química , Antagonistas de Androgênios/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Modelos Moleculares , Estrutura Molecular , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/química , Relação Estrutura-Atividade
17.
Cancer Lett ; 437: 35-43, 2018 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-30165195

RESUMO

Prostate cancer (PCa) is a leading cause of death for men in North America. The androgen receptor (AR) - a hormone inducible transcription factor - drives expression of tumor promoting genes and represents an important therapeutic target in PCa. The AR is activated by steroid recruitment to its ligand binding domain (LBD), followed by receptor nuclear translocation and dimerization via the DNA binding domain (DBD). Clinically used small molecules interfere with steroid recruitment and prevent AR-driven tumor growth, but are rendered ineffective by emergence of LBD mutations or expression of constitutively active variants, such as ARV7, that lack the LBD. Both drug-resistance mechanisms confound treatment of this 'castration resistant' stage of PCa (CRPC), characterized by return of AR signalling. Here, we employ computer-aided drug-design to develop small molecules that block the AR-DBD dimerization interface, an attractive target given its role in AR activation and independence from the LBD. Virtual screening on the AR-DBD structure led to development of prototypical compounds that block AR dimerization, inhibiting AR-transcriptional activity through a LBD-independent mechanism. Such inhibitors may potentially circumvent AR-dependent resistance mechanisms and directly target CRPC tumor growth.


Assuntos
Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Multimerização Proteica/efeitos dos fármacos , Receptores Androgênicos/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Sequência de Aminoácidos , Sítios de Ligação/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Humanos , Imidazóis/metabolismo , Imidazóis/farmacologia , Masculino , Mutação , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/metabolismo , Domínios Proteicos , Receptores Androgênicos/química , Receptores Androgênicos/genética , Homologia de Sequência de Aminoácidos , Bibliotecas de Moléculas Pequenas/metabolismo , Tiazóis/metabolismo , Tiazóis/farmacologia
18.
J Biotechnol ; 128(2): 423-34, 2007 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-17126944

RESUMO

Papaya mosaic virus (PapMV) like particles (VLPs) were used as a platform for fusion of affinity peptides binding to resting spores of Plasmodiophora brassicae-a major pathogen of crucifers. Three peptides with specific affinity to the target were isolated and cloned at the C-terminus of the PapMV coat protein (CP), generating three different high avidity VLPs. The peptides were exposed at the surface of the VLPs and their avidity to resting spores of P. brassicae was measured by flow cytometry. NLP-A, with the peptide DPAPRPR, showed the highest avidity. The binding avidity of NLP-A to P. brassicae spores was comparable to that of a polyclonal antibody. NLP-A was also shown to be more specific than the antibody. Fusion of the affinity peptide to a monomeric form (mCP) of the CP [Lecours, K., Tremblay, M.-H., Laliberté Gagné, M.-E., Gagné, S.M., Leclerc, D., 2006. Purification and biochemical characterization of a monomeric form of papaya mosaic potexvirus coat protein. Protein Express. Purific. 47, 273-280] generated a fusion protein that was unable to assemble into VLPs, and mCP-A fusions failed to bind resting spores. The avidity of VLP-A was increased by adding a glycine spacer between the C-terminus of the PapMV CP and the peptide, and improved even further by using a duplicated A peptide in the fusion protein. The use of high avidity VLPs has advantages over polyclonal antibodies because of target specificity. VLPs offers the specificity of monoclonal antibodies but can be more easily generated using the powerful selection of phage display.


Assuntos
Proteínas do Capsídeo/química , Carica/microbiologia , Fungos/metabolismo , Potexvirus/metabolismo , Animais , Proteínas do Capsídeo/biossíntese , Proteínas do Capsídeo/genética , Carica/virologia , Biblioteca de Peptídeos , Ligação Proteica , Solo/análise , Microbiologia do Solo , Esporos/metabolismo , Montagem de Vírus
19.
FEBS J ; 273(1): 14-25, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16367744

RESUMO

Papaya mosaic potexvirus (PapMV) coat protein (CP) was expressed (CPdeltaN5) in Escherichia coli and showed to self assemble into nucleocapsid like particles (NLPs). Twenty per cent of the purified protein was found as NLPs of 50 nm in length and 80% was found as a multimer of 450 kDa (20 subunits) arranged in a disk. Two mutants in the RNA binding domain of the PapMV CP, K97A and E128A showed interesting properties. The proteins of both mutants could be easily purified and CD spectra of these proteins showed secondary and tertiary structures similar to the WT protein. The mutant K97A was unable to self assemble and bind RNA. On the contrary, the mutant E128A showed an improved affinity for RNA and self assembled more efficiently in NLPs. E128A NLPs were longer (150 nm) than the recombinant CPdeltaN5 and 100% percent of the protein was found as NLPs in bacteria. E128A NLPs were more resistant to digestion by trypsin than the CPdeltaN5 but were more sensitive to denaturation by heat. We discuss the possible role of K97 and E128 in the assembly of PapMV.


Assuntos
Proteínas do Capsídeo/genética , Vírus do Mosaico/genética , Mutação , Potexvirus/genética , RNA Viral/metabolismo , Montagem de Vírus/genética , Sequência de Aminoácidos , Sítios de Ligação , Cromatografia em Gel , Dicroísmo Circular , Escherichia coli/genética , Escherichia coli/metabolismo , Imuno-Histoquímica , Dados de Sequência Molecular , Vírus do Mosaico/metabolismo , Vírus do Mosaico/fisiologia , Nucleocapsídeo/química , Nucleocapsídeo/genética , Nucleocapsídeo/metabolismo , Potexvirus/fisiologia , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Alinhamento de Sequência , Temperatura , Tripsina/metabolismo , Montagem de Vírus/fisiologia
20.
Methods Mol Biol ; 1443: 31-54, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27246333

RESUMO

The androgen receptor (AR) is an important regulator of genes responsible for the development and recurrence of prostate cancer. Current therapies for this disease rely on small-molecule inhibitors that block the transcriptional activity of the AR. Recently, major advances in the development of novel AR inhibitors resulted from X-ray crystallographic information on the receptor and utilization of in silico drug design synergized with rigorous experimental testing.Herein, we describe a drug-discovery pipeline for in silico screening for small molecules that target an allosteric region on the AR termed the binding-function 3 (BF3) site. Following the identification of potential candidates, the compounds are tested in cell culture and biochemical assays for their ability to interact with and inhibit the AR. The described pipeline is readily accessible and could be applied in drug design efforts toward any surface-exposed region on the AR or other related steroid nuclear receptor.


Assuntos
Antagonistas de Receptores de Andrógenos/farmacologia , Biologia Computacional/métodos , Descoberta de Drogas/métodos , Ensaios de Triagem em Larga Escala/métodos , Neoplasias da Próstata/tratamento farmacológico , Receptores Androgênicos/química , Antagonistas de Receptores de Andrógenos/química , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Proteínas de Fluorescência Verde/metabolismo , Humanos , Masculino , Regiões Promotoras Genéticas , Neoplasias da Próstata/metabolismo , Conformação Proteica , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Ativação Transcricional , Células Tumorais Cultivadas
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