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1.
Org Lett ; 23(13): 5098-5101, 2021 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-34124917

RESUMO

α-Haloketones are valuable intermediates in the synthesis of pharmaceuticals and natural products because they display two electrophiles. Although chemoselective additions to each of these functional groups are known, the use of fluorinated nucleophiles has not been characterized, except for the dimerization of fluorohalomethyl ketones. Our studies demonstrate the use of difluoroenolates to create difluorinated bromohydrins and chlorohydrins from α-haloketones without any cyclization or rearrangement due to the mild conditions.


Assuntos
Cloridrinas/síntese química , Cetonas/síntese química , Álcoois , Cloridrinas/química , Ciclização , Halogenação , Cetonas/química
2.
Methods Mol Biol ; 2266: 105-124, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33759123

RESUMO

Interactions between enzymes and small molecules lie in the center of many fundamental biochemical processes. Their analysis using molecular dynamics simulations have high computational demands, geometric approaches fail to consider chemical forces, and molecular docking offers only static information. Recently, we proposed to combine molecular docking and geometric approaches in an application called CaverDock. CaverDock is discretizing enzyme tunnel into discs, iteratively docking with restraints into one disc after another and searching for a trajectory of the ligand passing through the tunnel. Here, we focus on the practical side of its usage describing the whole method: from getting the application, and processing the data through a workflow, to interpreting the results. Moreover, we shared the best practices, recommended how to solve the most common issues, and demonstrated its application on three use cases.


Assuntos
Descoberta de Drogas/métodos , Simulação de Acoplamento Molecular/métodos , Proteínas/química , Ácido Araquidônico/química , Sítios de Ligação , Cloridrinas/química , Sistema Enzimático do Citocromo P-450/química , Desenho de Fármacos , Etanol/análogos & derivados , Etanol/química , Dibrometo de Etileno/química , Hidrolases/química , Ligantes , Simulação de Dinâmica Molecular , Ligação Proteica , Software , Relação Estrutura-Atividade , Termodinâmica
3.
Molecules ; 25(11)2020 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-32481583

RESUMO

Crude glycerol (C3H8O3) is a major by-product of biodiesel production from vegetable oils and animal fats. The increased biodiesel production in the last two decades has forced glycerol production up and prices down. However, crude glycerol from biodiesel production is not of adequate purity for industrial uses, including food, cosmetics and pharmaceuticals. The purification process of crude glycerol to reach the quality standards required by industry is expensive and dificult. Novel uses for crude glycerol can reduce the price of biodiesel and make it an economical alternative to diesel. Moreover, novel uses may improve environmental impact, since crude glycerol disposal is expensive and dificult. Glycerol is a versatile molecule with many potential applications in fermentation processes and synthetic chemistry. It serves as a glucose substitute in microbial growth media and as a precursor in the synthesis of a number of commercial intermediates or fine chemicals. Chlorinated derivatives of glycerol are an important class of such chemicals. The main focus of this review is the conversion of glycerol to chlorinated derivatives, such as epichlorohydrin and chlorohydrins, and their further use in the synthesis of additional downstream products. Downstream products include non-cyclic compounds with allyl, nitrile, azide and other functional groups, as well as oxazolidinones and triazoles, which are cyclic compounds derived from ephichlorohydrin and chlorohydrins. The polymers and ionic liquids, which use glycerol as an initial building block, are highlighted, as well.


Assuntos
Cloridrinas/química , Epicloroidrina/química , Glicerol/química
4.
World J Urol ; 38(3): 647-656, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30659302

RESUMO

PURPOSE: In this review, we summarize the importance of AR variants with a particular focus on clinically relevant members of this family. METHODS: A non-systematic literature review was performed based on Medline and PubMed. RESULTS: Endocrine therapy represents the central paradigm for the management of prostate cancer. Eventually, in response to androgen ablation therapy, several resistance mechanisms against the endocrine therapy might develop that can circumvent the therapy approaches. One specific resistance mechanism that has gained increasing attention is the generation of alternatively spliced variants of the androgen receptor, with AR-V7 being the most prominent. More broadly, AR-V7 is one member of a group of alternatively spliced AR variants that share a common feature, the missing ligand-binding domain. These ΔLBD androgen receptor variants have shown the capability to induce androgen receptor-mediated gene transcription even under conditions of androgen deprivation and to drive cancer progression. CONCLUSION: The methods used for detecting AR-Vs, at least on the mRNA level, are well-advanced and harbor the potential to be introduced into clinical diagnostics. It is important to note, that the testing, especially of AR-V7 has its limitations in predicting treatment response. More promising is the great number of active clinical trials aimed at reducing the AR-Vs, and using this to re-sensitize CRPC towards endocrine treatment might provide additional treatment options for CRPC patients in the future.


Assuntos
Antagonistas de Androgênios/uso terapêutico , Antineoplásicos Hormonais/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Receptores Androgênicos/genética , Processamento Alternativo , Androstadienos/uso terapêutico , Benzamidas/uso terapêutico , Compostos Benzidrílicos/uso terapêutico , Benzimidazóis/uso terapêutico , Benzoquinonas/uso terapêutico , Sítios de Ligação/genética , Cloridrinas/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Humanos , Isoindóis/uso terapêutico , Isoxazóis/uso terapêutico , Lactamas Macrocíclicas/uso terapêutico , Masculino , Niclosamida/uso terapêutico , 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/genética , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas/antagonistas & inibidores , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores Androgênicos/metabolismo , Resorcinóis/uso terapêutico
5.
Biophys Chem ; 251: 106190, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31146215

RESUMO

In this review we discuss results from temperature and pressure dependent single-molecule Förster resonance energy transfer (smFRET) studies on nucleic acids in the presence of macromolecular crowders and organic osmolytes. As representative examples, we have chosen fragments of both DNAs and RNAs, i.e., a synthetic DNA hairpin, a human telomeric G-quadruplex and the microROSE RNA hairpin. To mimic the effects of intracellular components, our studies include the macromolecular crowding agent Ficoll, a copolymer of sucrose and epichlorohydrin, and the organic osmolytes trimethylamine N-oxide, urea and glycine as well as natural occurring osmolyte mixtures from deep sea organisms. Furthermore, the impact of mutations in an RNA sequence on the conformational dynamics is examined. Different from proteins, the effects of the osmolytes and crowding agents seem to strongly dependent on the structure and chemical make-up of the nucleic acid.


Assuntos
DNA/química , RNA/química , Temperatura , Cloridrinas/química , Transferência Ressonante de Energia de Fluorescência , Glicina/química , Humanos , Metilaminas/química , Conformação de Ácido Nucleico , Pressão , Sacarose/química , Ureia/química
6.
Prostate ; 79(2): 206-214, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30345525

RESUMO

INTRODUCTION AND OBJECTIVES: Multiple androgen receptor (AR)-dependent and -independent resistance mechanisms limit the efficacy of current castration-resistant prostate cancer (CRPC) treatment. Novel N-terminal domain (NTD) binding AR-targeting compounds, including EPI-001 (EPI), have the promising ability to block constitutively active splice variants, which represent a major resistance mechanism in CRPC. Autophagy is a conserved lysosomal degradation pathway that acts as survival mechanism in cells exposed to anticancer treatments. We hypothesized, that promising NTD-AR treatment may upregulate autophagy and that a combination of NTD-AR and autophagy inhibition might therefore increase antitumor effects. METHODS: AR-expressing prostate cancer cell lines (LNCaP, LNCaP-EnzR) were treated with different concentrations of EPI (10, 25, 50 µM) and in combination with the autophagy inhibitors chloroquine (CHQ, 20 µM) or 3-methyladenine (3-MA, 5 mM). Cell proliferation was assessed by WST-1-assays after 1 and 7 days. Ethidium bromide and Annexin V were used to measure viability and apoptosis on day 7 after treatment. Autophagosome formation was detected by AUTOdot staining. In addition, autophagic activity was monitored by immunocytochemistry and Western blot (WES) for the expression of ATG5, Beclin1, LC3-I/II and p62. RESULTS: Treatment with EPI resulted in a dose-dependent reduction of cell growth and increased apoptosis in both cancer cell lines on day 7. In addition, EPI treatment demonstrated an upregulated autophagosome formation in LNCaP and LNCaP-EnzR cells. Assessment of autophagic activity by immunocytochemistry and WES revealed an increase of ATG5 and LC3-II expression and a decreased p62 expression in all EPI-treated cells. A combined treatment of EPI with autophagy inhibitors led to a further significant reduction of cell viability in both cell lines. CONCLUSIONS: Our results demonstrate that NTD targeting AR inhibition using EPI leads to an increased autophagic activity in LNCaP and LNCaP-EnzR prostate cancer cells. A combination of NTD AR blockage with simultaneous autophagy inhibition increases the antitumor effect of EPI in prostate cancer cells. Double treatment may offer a promising strategy to overcome resistance mechanisms in advanced prostate cancer.


Assuntos
Antagonistas de Receptores de Andrógenos/farmacologia , Compostos Benzidrílicos/farmacologia , Cloridrinas/farmacologia , Feniltioidantoína/análogos & derivados , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Receptores Androgênicos/metabolismo , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Proteína 5 Relacionada à Autofagia/biossíntese , Proteína 5 Relacionada à Autofagia/genética , Benzamidas , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Técnicas de Silenciamento de Genes , Humanos , Masculino , Proteínas Associadas aos Microtúbulos/biossíntese , Proteínas Associadas aos Microtúbulos/genética , Nitrilas , Células PC-3 , Feniltioidantoína/farmacologia , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/metabolismo , Neoplasias de Próstata Resistentes à Castração/patologia
7.
Environ Sci Technol ; 53(3): 1217-1224, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30387352

RESUMO

Washing with chlorine bleach leads to high mixing ratios of gas-phase HOCl. Using two methods that are sensitive to surface film composition-attenuated total reflection fourier transform infrared (ATR-FTIR) spectroscopy and direct analysis in real time mass spectrometry (DART-MS)-we present the first study of the chlorination chemistry that occurs when gaseous HOCl reacts with thin films of squalene and oleic acid. At mixing ratios of 600 ppbv, HOCl forms chlorohydrins by adding across carbon-carbon double bonds without breaking the carbon backbone. The initial uptake of one HOCl molecule occurs on the time scale of a few minutes at these mixing ratios. For oleic acid, ester formation proceeds immediately thereafter, leading to dimeric and trimeric chlorinated products. For squalene, subsequent HOCl uptake occurs until all six of its carbon-carbon double bonds become chlorinated within 1-2 h. These results indicate that chlorination of skin oil, which contains substantial carbon unsaturation, is likely to occur rapidly under common cleaning conditions, potentially leading to the irritation associated with chlorinated bleach. This chemistry will likely also proceed with cooking oils, in the human respiratory system which has unsaturated surfactants as important components of lung fluid, and with organic components of the sea surface microlayer.


Assuntos
Cloridrinas , Ácido Oleico , Halogenação , Humanos , Ácido Hipocloroso , Esqualeno
8.
Exp Cell Res ; 359(1): 215-225, 2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-28736082

RESUMO

Prostate cancer (PC) is one of the leading causes of cancer death in men. It commonly develops in older males, but the number of younger men diagnosed with the disease has increased in recent years. Hormone therapies, such as chemical and surgical methods that inhibit androgen synthesis or androgen receptor (AR) activation, have been used for advanced disease. However, castration-resistant PC (CRPC), which exhibits androgen-independent mechanisms for activating AR, develops after a few years of such treatment and no therapy is available. In this study, we examined differences in the proteomes associated with the androgen-dependent (DHT treatment) and -independent (FSK, forskolin treatment) AR signaling conditions in LNCaP prostate cancer cells. Moreover, we used EPI-001, which inhibits AR-mediated transcriptional activity, to examine whether the observed differences in protein expression were directly affected by AR-mediated mechanisms. A total of 213 protein spots were matched in our 2-dimensional gel electrophoresis (2DE) analysis and 8 proteins with significant expression changes in our 5 different treatment groups were identified by mass spectrometry. Among these proteins, expression levels of PEPCK-M, catalase, tubulin alpha chain, alpha-enolase, and endoplasmic reticulum resident protein 29 were significantly altered by DHT and the levels of HSP 90 and EF-Tu were changed by FSK. These changes were blocked by EPI-001 in DHT-regulated proteins, PEPCK-M, catalase, and tubulin alpha chain and FSK-regulated EF-Tu protein. The results from our immunohistochemical analysis using in vivo xenograft models were consistent with the 2DE data. We therefore report the first identification of differences in proteins that are significantly regulated under androgen-dependent and -independent AR signaling conditions. Our findings could suggest a possible molecular mechanism through which AR is activated in the absence and/or presence of androgen, and might help explain the inhibitory action of EPI-001 on CRPC.


Assuntos
Androgênios/farmacologia , Neoplasias da Próstata/metabolismo , Proteoma/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Compostos Benzidrílicos/farmacologia , Linhagem Celular Tumoral , Cloridrinas/farmacologia , Colforsina/farmacologia , Di-Hidrotestosterona/farmacologia , Eletroforese em Gel Bidimensional , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Fator Tu de Elongação de Peptídeos/metabolismo , Fosfoenolpiruvato Carboxiquinase (ATP)/metabolismo , Neoplasias da Próstata/patologia , Proteômica , Espectrometria de Massas em Tandem , Tubulina (Proteína)/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Chem Commun (Camb) ; 53(25): 3579-3582, 2017 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-28289745

RESUMO

Artificial enzymes are required to catalyse non-natural reactions. Here, a hybrid catalyst was developed by embedding a novel Ru complex in the transport protein NikA. The protein scaffold activates the bound Ru complex to produce a catalyst with high regio- and stereo-selectivity. The hybrid efficiently and stably produced α-hydroxy-ß-chloro chlorohydrins from alkenes (up to 180 TON with a TOF of 1050 h-1).


Assuntos
Alcenos/química , Cloridrinas/química , Rutênio/química , Catálise , Complexos de Coordenação/química , Conformação Molecular , Espectroscopia de Infravermelho com Transformada de Fourier , Estereoisomerismo
10.
J Chromatogr A ; 1490: 74-79, 2017 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-28238325

RESUMO

A novel base treatment followed by liquid-liquid extraction was developed to remove the interference of excess derivatization reagent BSTFA [N,O-Bis(trimethylsilyl)trifluoroacetamide] and its byproducts for trace determination of 1-chloro-2-propanol and 2-chloro-1-propanol in a food additive. The corresponding trimethylsilyl derivatives were analyzed by gas chromatography mass spectrometry (GC/MS) detection in selective ion monitoring mode. Due to a large volume splitless injection needed for achieving the required sensitivity, excess BSTFA in the derivatization sample solution interfered with the trimethylsilyl derivatives of the analytes of interest, making their quantitation not attainable. Efforts were made to decompose BSTFA while keeping the trimethylsilyl derivatives intact. Water or aqueous sulfuric acid treatment converted BSTFA into mainly N-trimethylsilyltrifluoroacetamide, which partitions between aqueous and organic layers. In contrast, aqueous sodium hydroxide decomposed BSTFA into trifluoroacetic acid, which went entirely into the aqueous layer. No BSTFA or its byproduct N-trimethylsilyltrifluoroacetamide or trifluroacetamide was found in the organic layer where the derivatized alcohols existed, which in turn completely eliminated their interference, enabling accurate and precise determination of parts per billion of the short-chain alcohols in the food additive. Contrary to the conventional wisdom that a trimethylsilyl derivative is susceptible to hydrolysis, the derivatized short-chain alcohols were found stable even in the presence of 0.17N aqueous sodium hydroxide as the improved GC/MS method was validated successfully, with a satisfactory linearity response in the concentration range of 10-400ng/g (regression coefficient greater than 0.999), good method precision (<4%), good recovery (90-98%), and excellent limit of detection (3ng/g) and limit of quantitation (10ng/g).


Assuntos
Acetamidas/química , Cloridrinas/análise , Aditivos Alimentares/isolamento & purificação , Extração Líquido-Líquido/métodos , Compostos de Trimetilsilil/química , Aditivos Alimentares/química , Cromatografia Gasosa-Espectrometria de Massas
11.
Mar Drugs ; 15(1)2017 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-28124983

RESUMO

Pericosine E (6), a metabolite of Periconia byssoides OUPS-N133 was originally isolated from the sea hare Aplysia kurodai, which exists as an enantiomeric mixture in nature. The enantiospecific syntheses of both enantiomers of Periconia byssoides OUPS-N133 has been achieved, along with six stereoisomers, using a common simple synthetic strategy. For these efficient syntheses, highly regio- and steroselective processes for the preparation of bromohydrin and anti-epoxide intermediates were applied. In order to access the unique O-linked carbadisaccharide structure, coupling of chlorohydrin as a donor and anti-epoxide as an acceptor was achieved using catalytic BF3·Et2O. Most of the synthesized compounds exhibited selectively significant inhibitory activity against α-glycosidase derived from yeast. The strongest analog showed almost 50 times the activity of the positive control, deoxynojirimycin.


Assuntos
Dissacarídeos/química , Inibidores de Glicosídeo Hidrolases/química , Ácido Chiquímico/análogos & derivados , alfa-Glucosidases/química , 1-Desoxinojirimicina/química , Álcoois/química , Ascomicetos/química , Cloridrinas/química , Compostos de Epóxi/química , Glucosamina/análogos & derivados , Glucosamina/química , Ácido Chiquímico/química , Estereoisomerismo , Leveduras/química
12.
Expert Opin Drug Metab Toxicol ; 13(5): 513-524, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27936967

RESUMO

INTRODUCTION: Adverse drug reactions (ADRs) pose a significant health problem and are generally attributed to reactive metabolites. Olefinic moieties in drugs can undergo cytochrome P450-mediated bioactivation to produce reactive metabolites but myeloperoxidase (MPO)-mediated bioactivation of these moieties has not been reported. Thus, small molecules of alkene hydrocarbons are used as model compounds to characterize the MPO-mediated metabolism. Areas covered: The authors focus on MPO-mediated metabolism of alkene hydrocarbons to form chlorohydrins and the potential role of chlorohydrins in alkene toxicity and carcinogenicity. A case study is presented, in which a carcinogenic alkene, 1,3-butadiene, is demonstrated to form 1-chloro-2-hydroxy-3-butene (CHB) through the MPO-mediated pathway. Further bioactivation of CHB yields a cross-linking metabolite, 1-chloro-3-buten-2-one (CBO), which is highly reactive toward glutathione, proteins, nucleosides, and DNA. Toxicity and mutagenicity of CHB and CBO are also presented. Expert opinion: Alkene hydrocarbons readily undergo MPO-mediated bioactivation to form chlorohydrins, which can further be biotransformed into proteins/DNA-modifying reactive metabolites. Therefore, chlorohydrin formation may play an important role in alkene toxicity and carcinogenicity. Olefinic moieties in drugs are expected to undergo similar bioactivation, which may contribute to ADRs. Studies to investigate the roles of MPO and chlorohydrin formation in ADRs are thus warranted.


Assuntos
Alcenos/metabolismo , Ácido Hipocloroso/metabolismo , Peroxidase/metabolismo , Alcenos/efeitos adversos , Alcenos/química , Animais , Butadienos/metabolismo , Butadienos/toxicidade , Carcinógenos/metabolismo , Carcinógenos/toxicidade , Cloridrinas/efeitos adversos , Cloridrinas/química , Cloridrinas/metabolismo , Humanos , Hidrocarbonetos/efeitos adversos , Hidrocarbonetos/química , Hidrocarbonetos/metabolismo
13.
Oncologist ; 21(12): 1427-1435, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27628492

RESUMO

: Despite the recent approval and widespread use of abiraterone acetate and enzalutamide for the treatment of castration-resistant prostate cancer (CRPC), this disease still poses significant management challenges because of various tumor escape mechanisms, including those that allow androgen receptor (AR) signaling to remain active. These AR-related resistance mechanisms include AR gene amplification or overexpression, constitutively active ligand-independent AR splice variants, and gain-of-function mutations involving the AR ligand-binding domain (LBD), among others. Therefore, the development of AR-targeted therapies that function independently of the LBD represents an unmet medical need and has the potential to overcome many of these resistance mechanisms. This article discusses N-terminal domain (NTD) inhibition as a novel concept in the field of AR-directed therapies for prostate cancer. AR NTD-targeting agents have the potential to overcome shortcomings of current hormonal therapies by inhibiting all forms of AR-mediated transcriptional activity, and as a result, may affect a broader AR population including mutational and splice variant ARs. Indeed, the first clinical trial of an AR NTD inhibitor is now underway. IMPLICATIONS FOR PRACTICE: Because of emerging resistance mechanisms that involve the ligand-binding domain of the androgen receptor (AR), there is currently no effective treatment addressing tumor escape mechanisms related to current AR-targeted therapies. Many patients still demonstrate limited clinical response to current hormonal agents, and castration-resistant prostate cancer remains a lethal disease. Intense research efforts are under way to develop therapies to target resistance mechanisms, including those directed at other parts of the AR molecule. A novel small-molecule agent, EPI-506, represents a new pharmaceutical class, AR N-terminal domain inhibitors, and shows preclinical promise to overcome many known resistance mechanisms related to novel hormonal therapies.


Assuntos
Antagonistas de Androgênios/uso terapêutico , Compostos Benzidrílicos/uso terapêutico , Cloridrinas/uso terapêutico , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Receptores Androgênicos/química , Humanos , Masculino , Domínios Proteicos , Receptores Androgênicos/fisiologia , Estudos Retrospectivos , Transdução de Sinais , Esteroide 17-alfa-Hidroxilase/antagonistas & inibidores
14.
ACS Chem Biol ; 11(9): 2499-505, 2016 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-27356095

RESUMO

Castration-resistant prostate cancer is the lethal condition suffered by prostate cancer patients that become refractory to androgen deprivation therapy. EPI-001 is a recently identified compound active against this condition that modulates the activity of the androgen receptor, a nuclear receptor that is essential for disease progression. The mechanism by which this compound exerts its inhibitory activity is however not yet fully understood. Here we show, by using high resolution solution nuclear magnetic resonance spectroscopy, that EPI-001 selectively interacts with a partially folded region of the transactivation domain of the androgen receptor, known as transactivation unit 5, that is key for the ability of prostate cells to proliferate in the absence of androgens, a distinctive feature of castration-resistant prostate cancer. Our results can contribute to the development of more potent and less toxic novel androgen receptor antagonists for treating this disease.


Assuntos
Compostos Benzidrílicos/farmacologia , Cloridrinas/farmacologia , Orquiectomia , Neoplasias da Próstata/tratamento farmacológico , Receptores Androgênicos/metabolismo , Compostos Benzidrílicos/uso terapêutico , Cloridrinas/uso terapêutico , Humanos , Masculino , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Ativação Transcricional
15.
Clin Cancer Res ; 22(17): 4466-77, 2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-27140928

RESUMO

PURPOSE: Persistent androgen receptor (AR) transcriptional activity is clinically evident in castration-resistant prostate cancer (CRPC). Therefore, AR remains as a viable therapeutic target for CRPC. All current hormonal therapies target the C-terminus ligand-binding domain (LBD) of AR. By using EPI to target AR activation function-1 (AF-1), in the N-terminal domain that is essential for AR transactivation, we evaluate the ability of EPI to overcome several clinically relevant AR-related mechanisms of resistance. EXPERIMENTAL DESIGN: To study the effect of EPI on AR transcriptional activity against overexpressed coactivators, such as SRC1-3 and p300, luciferase reporter assays were performed using LNCaP cells. AR-negative COS-1 cells were employed for reporter assays to examine whether the length of polyglutamine tract affects inhibition by EPI. The effect of EPI on constitutively active AR splice variants was studied in LNCaP95 cells, which express AR-V7 variant. To evaluate the effect of EPI on the proliferation of LNCaP95 cells, we performed in vitro BrdUrd incorporation assay and in vivo studies using xenografts in mice. RESULTS: EPI effectively overcame several molecular alterations underlying aberrant AR activity, including overexpressed coactivators, AR gain-of-function mutations, and constitutively active AR-V7. EPI inhibited AR transcriptional activity regardless of the length of polyglutamine tract. Importantly, EPI significantly inhibited the in vitro and in vivo proliferation of LNCaP95 prostate cancer cells, which are androgen independent and enzalutamide resistant. CONCLUSIONS: These findings support EPI as a promising therapeutic agent to treat CRPC, particularly against tumors driven by constitutively active AR splice variants that are resistant to LBD-targeting drugs. Clin Cancer Res; 22(17); 4466-77. ©2016 AACRSee related commentary by Sharp et al., p. 4280.


Assuntos
Antagonistas de Receptores de Andrógenos/farmacologia , Compostos Benzidrílicos/farmacologia , Cloridrinas/farmacologia , Resistencia a Medicamentos Antineoplásicos , Neoplasias de Próstata Resistentes à Castração/metabolismo , Receptores Androgênicos/metabolismo , Animais , Apoptose/efeitos dos fármacos , Células COS , Linhagem Celular Tumoral , Chlorocebus aethiops , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos , Mutação , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/genética , Ligação Proteica , Splicing de RNA , Receptores Androgênicos/genética , Transdução de Sinais/efeitos dos fármacos , Ativação Transcricional , Ensaios Antitumorais Modelo de Xenoenxerto
16.
J Toxicol Sci ; 41(1): 91-104, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26763396

RESUMO

We previously reported that 28-day exposure to hepatocarcinogens that facilitate cell proliferation specifically alters the expression of G1/S checkpoint-related genes and proteins, induces aberrant early expression of ubiquitin D (UBD) at the G2 phase, and increases apoptosis in the rat liver, indicating G1/S and spindle checkpoint dysfunction. The present study aimed to determine the time of onset of carcinogen-specific cell-cycle disruption after repeated administration of renal carcinogens for up to 28 days. Rats were orally administered the renal carcinogens nitrofurantoin (NFT), 1-amino-2,4-dibromoantraquinone (ADAQ), and 1,2,3-trichloropropane (TCP) or the non-carcinogenic renal toxicants 1-chloro-2-propanol, triamterene, and carboxin for 3, 7 or 28 days. Both immunohistochemical single-molecule analysis and real-time RT-PCR analysis revealed that carcinogen-specific expression changes were not observed after 28 days of administration. However, the renal carcinogens ADAQ and TCP specifically reduced the number of cells expressing phosphorylated-histone H3 at Ser10 in both UBD(+) cells and proliferating cells, suggestive of insufficient UBD expression at the M phase and early transition of proliferating cells from the M phase, without increasing apoptosis, after 28 days of administration. In contrast, NFT, which has marginal carcinogenic potential, did not induce such cellular responses. These results suggest that it may take 28 days to induce spindle checkpoint dysfunction by renal carcinogens; however, induction of apoptosis may not be essential. Thus, induction of spindle checkpoint dysfunction may be dependent on carcinogenic potential of carcinogen examined, and marginal carcinogens may not exert sufficient responses even after 28 days of administration.


Assuntos
Antraquinonas/administração & dosagem , Antraquinonas/toxicidade , Rim/citologia , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Nitrofurantoína/administração & dosagem , Nitrofurantoína/toxicidade , Propano/análogos & derivados , Animais , Peso Corporal/efeitos dos fármacos , Carboxina/administração & dosagem , Carboxina/toxicidade , Proliferação de Células/efeitos dos fármacos , Cloridrinas/administração & dosagem , Cloridrinas/toxicidade , Histonas/metabolismo , Rim/efeitos dos fármacos , Masculino , Tamanho do Órgão/efeitos dos fármacos , Propano/administração & dosagem , Propano/toxicidade , Ratos Endogâmicos F344 , Fatores de Tempo , Triantereno/administração & dosagem , Triantereno/toxicidade , Ubiquitinas/metabolismo
17.
J Biosci Bioeng ; 122(2): 246-51, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26822095

RESUMO

Chloropropanol fatty acid esters (CPFAEs) are well-known contaminants in refined oils and fats, and several research groups have studied their formation. However, the results obtained in these studies were not satisfactory because the CPFAEs were not analyzed comprehensively. Thus, in the present study, a comprehensive analysis was performed to obtain new details about CPFAE formation. Each lipid (monopalmitin, dipalmitin, tripalmitin, monoolein, diolein, triolein, and crude palm oil) was heated at 250°C for 90 min, and the CPFAEs were analyzed using supercritical fluid chromatography/tandem mass spectrometry. It was found that CP fatty acid monoesters were formed from monoacylglycerols and diacylglycerols after heating in the presence of a chlorine compound. In addition, CP fatty acid diesters were formed from diacylglycerols and triacylglycerols under the same conditions. In the case of crude palm oil, only CP fatty acid diesters were formed. Therefore, these results indicated that CPFAEs in refined palm oil were formed mainly from triacylglycerols.


Assuntos
Cloridrinas/metabolismo , Ésteres/metabolismo , Ácidos Graxos/biossíntese , Cromatografia com Fluido Supercrítico , Ácidos Graxos/metabolismo , Glicerídeos/química , Glicerídeos/metabolismo , Temperatura Alta , Óleo de Palmeira , Óleos Vegetais/química , Óleos Vegetais/metabolismo , Espectrometria de Massas em Tandem
18.
Oxid Med Cell Longev ; 2016: 8386362, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28090245

RESUMO

Chlorinated phospholipids are formed by the reaction of hypochlorous acid (HOCl), generated by the enzyme myeloperoxidase under inflammatory conditions, and the unsaturated fatty acyl residues or the head group. In the first case the generated chlorohydrins are both proinflammatory and cytotoxic, thus having a significant impact on the structures of biomembranes. The latter case leads to chloramines, the properties of which are by far less well understood. Since HOCl is also widely used as a disinfecting and antibacterial agent in medicinal, industrial, and domestic applications, it may represent an additional source of danger in the case of abuse or mishandling. This review discusses the reaction behavior of in vivo generated HOCl and biomolecules like DNA, proteins, and carbohydrates but will focus on phospholipids. Not only the beneficial and pathological (toxic) effects of chlorinated lipids but also the importance of these chlorinated species is discussed. Some selected cleavage products of (chlorinated) phospholipids and plasmalogens such as lysophospholipids, (chlorinated) free fatty acids and α-chloro fatty aldehydes, which are all well known to massively contribute to inflammatory diseases associated with oxidative stress, will be also discussed. Finally, common analytical methods to study these compounds will be reviewed with focus on mass spectrometric techniques.


Assuntos
Cloridrinas/análise , Ácidos Graxos/metabolismo , Fosfolipídeos/metabolismo , Ácidos Graxos/química , Cromatografia Gasosa-Espectrometria de Massas , Halogenação , Humanos , Ácido Hipocloroso/química , Ácido Hipocloroso/metabolismo , Inflamação/metabolismo , Inflamação/patologia , Peroxidase/metabolismo , Fosfolipídeos/química , Espécies Reativas de Oxigênio/química , Espécies Reativas de Oxigênio/metabolismo
19.
J Chromatogr A ; 1439: 89-96, 2016 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-26700153

RESUMO

Reactive oxygen species (ROS) play important physiological roles and are of particular relevance in the pathogenesis of inflammatory diseases. At inflammatory conditions, the enzyme myeloperoxidase generates hypochlorous acid (HOCl) which adds to the double bonds of fatty acyl residues of (phospho)lipids under the formation of chlorohydrins. This may lead to the development of many inflammatory diseases, such as atherosclerosis or arthritis, if the ROS generation exceeds a certain extent. Using oleic acid as the simplest unsaturated fatty acid which contains just a single double bond, as a model system, we investigated all products - including the chlorohydrin - after its reaction with HOCl by a combination of thin-layer chromatography and electrospray ionization mass spectrometry. Unlike the general acceptance, the reaction of oleic acid and HOCl leads not exclusively to the formation of chlorohydrin (isomers) but is much more complex: there are also considerable amounts of dimeric and (to a minor extent) trimeric products which can be assigned to isomeric ethers and esters. The obtained products after oleic acid chlorination were also compared with the reaction products of 1-palmitoyl-2-oleoyl-sn-phosphatidylcholine (POPC) and HOCl. The reasons why different products are obtained will be discussed and the involvement of the carboxylic acid emphasized.


Assuntos
Ácido Hipocloroso/química , Ácido Oleico/química , Cloridrinas/química , Cromatografia em Camada Delgada , Dimerização , Ésteres , Halogenação , Isomerismo , Oxirredução , Fosfatidilcolinas/química , Espectrometria de Massas por Ionização por Electrospray
20.
J AOAC Int ; 98(5): 1423-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26525262

RESUMO

A novel analytical approach involving solvent extraction with methyl tert-butyl ether (MTBE) followed by GC was developed to quantify residues that result from the postharvest fumigation of almonds and walnuts with propylene oxide (PPO). Verification and quantification of PPO, propylene chlorohydrin (PCH) [1-chloropropan-2-ol (PCH-1) and 2-chloropropan-1-ol (PCH-2)], and propylene bromohydrin (PBH) [1-bromopropan-2-ol (PBH-1) and 2-bromopropan-1-ol (PBH-2)] was accomplished with a combination of electron impact ionization MS (EIMS), negative ion chemical ionization MS (NCIMS), and electron capture detection (ECD). Respective GC/EIMS LOQs for PPO, PCH-1, PCH-2, PBH-1, and PBH-2 in MTBE extracts were [ppm (µg/g nut)] 0.9, 2.1, 2.5, 30.3, and 50.0 for almonds and 0.8, 2.2, 2.02, 41.6, and 45.7 for walnuts. Relative to GC/EIMS, GC-ECD analyses resulted in no detection of PPO, similar detector responses for PCH isomers, and >100-fold more sensitive detection of PBH isomers. NCIMS did not enhance detection of PBH isomers relative to EIMS and was, respectively, approximately 20-, 5-, and 10-fold less sensitive to PPO, PCH-1, and PCH-2. MTBE extraction efficiencies were >90% for all analytes. The 10-fold concentration of MTBE extracts yielded recoveries of 85-105% for the PBH isomers and a concomitant decrease in LODs and LOQs across detector types. The recoveries of PCH isomers and PPO in the MTBE concentrate were relatively low (approximately 50 to 75%), which confound improvements in LODs and LOQs regardless of detector type.


Assuntos
Cloridrinas/isolamento & purificação , Elétrons , Compostos de Epóxi/química , Juglans/química , Propanóis/isolamento & purificação , Prunus dulcis/química , Compostos de Epóxi/farmacologia , Fumigação , Cromatografia Gasosa-Espectrometria de Massas/métodos , Juglans/efeitos dos fármacos , Limite de Detecção , Éteres Metílicos/química , Prunus dulcis/efeitos dos fármacos , Solventes/química
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