RESUMO
Breast tumours are embedded in a collagen I-rich extracellular matrix (ECM) network, where nutrients are scarce due to limited blood flow and elevated tumour growth. Metabolic adaptation is required for cancer cells to endure these conditions. Here, we demonstrated that the presence of ECM supported the growth of invasive breast cancer cells, but not non-transformed mammary epithelial cells, under amino acid starvation, through a mechanism that required macropinocytosis-dependent ECM uptake. Importantly, we showed that this behaviour was acquired during carcinoma progression. ECM internalisation, followed by lysosomal degradation, contributed to the up-regulation of the intracellular levels of several amino acids, most notably tyrosine and phenylalanine. This resulted in elevated tyrosine catabolism on ECM under starvation, leading to increased fumarate levels, potentially feeding into the tricarboxylic acid (TCA) cycle. Interestingly, this pathway was required for ECM-dependent cell growth and invasive cell migration under amino acid starvation, as the knockdown of p-hydroxyphenylpyruvate hydroxylase-like protein (HPDL), the third enzyme of the pathway, opposed cell growth and motility on ECM in both 2D and 3D systems, without affecting cell proliferation on plastic. Finally, high HPDL expression correlated with poor prognosis in breast cancer patients. Collectively, our results highlight that the ECM in the tumour microenvironment (TME) represents an alternative source of nutrients to support cancer cell growth by regulating phenylalanine and tyrosine metabolism.
Assuntos
Aminoácidos , Neoplasias da Mama , Humanos , Feminino , Aminoácidos/metabolismo , Neoplasias da Mama/metabolismo , Matriz Extracelular/metabolismo , Tirosina/metabolismo , Fenilalanina , Microambiente TumoralRESUMO
Plastic biodegradation by insects has made significant progress, opening up new avenues for the treatment of plastic waste. Wax moth larvae, for example, have attracted the attention of the scientific community because they are known to chew, ingest, and biodegrade natural polymer bee waxes. Despite this, we know very little about how these insects perform on manufactured plastics or how manufactured plastics affect insect metabolism. As a result, we studied the metabolism of greater wax moths (Galleria mellonella) fed on molasses-supplemented polylactic acid plastic (PLA) blocks. An analysis of the central carbon metabolism (CCM) metabolites was performed using liquid chromatography triple quadrupole mass spectrometry (LC-QQQ-MS), while an analysis of untargeted metabolites and lipids was conducted using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QToF-MS). In total, 169 targeted CCM metabolites, 222 untargeted polar metabolites, and 196 untargeted nonpolar lipids were identified within the insect samples. In contrast, compared to control larvae, PLA-fed larvae displayed significantly different levels of 97 CCM metabolites, 75 polar metabolites, and 57 lipids. Purine and pyrimidine metabolisms were affected by PLA feeding, as well as amino acid metabolism, carbohydrates, cofactors, vitamins, and related metabolisms. Additionally, PLA exposure disrupted insect energy metabolism and oxidative stress, among other metabolic disturbances. The larvae fed PLA have lower levels of several lipids, suggesting a reduction in lipid reserves, and ceramide levels are likely to have changed due to apoptosis and inflammation. The study indicates that G. mellonella larvae could ingest PLA but this process causes some metabolic stress for the host. Future studies of the molecular pathways of this biodegradation process might help to provide strategies for stress reduction that would speed up insect digestion of plastic.
Assuntos
Mariposas , Animais , Abelhas , Larva/metabolismo , Mariposas/metabolismo , Poliésteres , Plásticos , Estresse Oxidativo , Ceras/metabolismo , LipídeosRESUMO
Post-translational modifications (PTMs) on intact histones play a major role in regulating chromatin dynamics and influence biological processes such as DNA transcription, replication, and repair. The nature and position of each histone PTM is crucial to decipher how this information is translated into biological response. In the present work, the potential of a novel tandem top-"double-down" approachâultraviolet photodissociation followed by mobility and mass-selected electron capture dissociation and mass spectrometry (UVPD-TIMS-q-ECD-ToF MS/MS)âis illustrated for the characterization of HeLa derived intact histone H4 proteoforms. The comparison between q-ECD-ToF MS/MS spectra and traditional Fourier-transform-ion cyclotron resonance-ECD MS/MS spectra of a H4 standard showed a similar sequence coverage (â¼75%) with significant faster data acquisition in the ToF MS/MS platform (â¼3 vs â¼15 min). Multiple mass shifts (e.g., 14 and 42 Da) were observed for the HeLa derived H4 proteoforms for which the top-down UVPD and ECD fragmentation analysis were consistent in detecting the presence of acetylated PTMs at the N-terminus and Lys5, Lys8, Lys12, and Lys16 residues, as well as methylated, dimethylated, and trimethylated PTMs at the Lys20 residue with a high sequence coverage (â¼90%). The presented top-down results are in good agreement with bottom-up TIMS ToF MS/MS experiments and allowed for additional description of PTMs at the N-terminus. The integration of a 213 nm UV laser in the present platform allowed for UVPD events prior to the ion mobility-mass precursor separation for collision-induced dissociation (CID)/ECD-ToF MS. Selected c305+ UVPD fragments, from different H4 proteoforms (e.g., Ac + Me2, 2Ac + Me2 and 3Ac + Me2), exhibited multiple IMS bands for which similar CID/ECD fragmentation patterns per IMS band pointed toward the presence of conformers, adopting the same PTM distribution, with a clear assignment of the PTM localization for each of the c305+ UVPD fragment H4 proteoforms. These results were consistent with the biological "zip" model, where acetylation proceeds in the Lys16 to Lys5 direction. This novel platform further enhances the structural toolbox with alternative fragmentation mechanisms (UVPD, CID, and ECD) in tandem with fast, high-resolution mobility separations and shows great promise for global proteoform analysis.
Assuntos
Histonas , Espectrometria de Massas em Tandem , Humanos , Histonas/química , Espectrometria de Massas em Tandem/métodos , Elétrons , Processamento de Proteína Pós-Traducional , Análise de FourierRESUMO
Human indoleamine 2,3-dioxygenase 1 (hIDO1) and human tryptophan dioxygenase (hTDO) are two important heme proteins that degrade the essential amino acid, l-tryptophan (Trp), along the kynurenine pathway. The two enzymes share a similar active site structure and an analogous catalytic mechanism, but they exhibit a variety of distinct functional properties. Here we used carbon monoxide (CO) as a structural probe to interrogate how the functionalities of the two enzymes are encoded in their structures. With X-ray crystallography, we detected an unexpected photochemical intermediate trapped in a crystal of the hIDO1-CO-Trp complex, where CO is photolyzed from the heme iron by X-rays at cryogenic temperatures (100 K). The CO photolysis triggers a large-scale migration of the substrate Trp, as well as the photolyzed CO, from the active site to a temporary binding site, Sa*. It is accompanied by a large conformational change to an active site loop, JK-LoopC, despite the severely restricted protein motion under the frozen conditions, which highlights the remarkable conformational plasticity of the hIDO1 protein. Comparative studies of a crystal of the hTDO-CO-Trp complex show that CO and Trp remain bound in the active site under comparable X-ray illumination, indicating a much more rigid protein architecture. The data offer important new insights into the structure and function relationships of the heme-based dioxygenases and provide new guidelines for structure-based design of inhibitors targeting them.
Assuntos
Dioxigenases/química , Heme/química , Domínio Catalítico , Cristalografia por Raios X , Dioxigenases/antagonistas & inibidores , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Processos Fotoquímicos , Conformação Proteica , Relação Estrutura-Atividade , Especificidade por SubstratoRESUMO
This study investigated the potential of red wine in modulating dental erosion kinetics in the presence or absence of salivary pellicle. Polished human enamel specimens were used in two conditions; presence or absence of acquired enamel pellicle; and subdivided according to exposure: red wine, orange juice, apple juice, or citric acid. The specimens were incubated in clarified whole human saliva (presence of acquired enamel pellicle) or in a humid chamber (absence of acquired enamel pellicle) for 2 h at 37°C, then in the test substances for 1 min, at 25°C, under shaking. This was repeated four times. Surface hardness was measured initially and after each cycle and surface reflection intensity was measured initially and after all cycles. In the presence of acquired enamel pellicle, red wine caused the least surface hardness loss, followed by orange juice, apple juice, and citric acid. Statistically significantly less surface reflection intensity loss was observed for red wine and orange juice than for apple juice and citric acid. In the absence of acquired enamel pellicle, red wine and orange juice caused less surface hardness loss than apple juice and citric acid. Orange juice showed the least surface reflection intensity loss, followed by red wine, citric acid, and apple juice. The polyphenol composition of these drinks can notably modulate the erosion kinetics.
Assuntos
Erosão Dentária , Vinho , Esmalte Dentário , Película Dentária , Humanos , Cinética , SalivaRESUMO
BACKGROUND: The objective of this study is to investigate the accuracy of the 3D Endo software, cone-beam computed tomography (CBCT) software, and the electronic apex locator (EAL) in endodontic length determination. METHODS: 302 root canals in 111 human extracted molars were chosen. Access cavity was performed, and root canal lengths were measured with a digital caliper for actual length (AL) and EAL for electronic length. Teeth were then scanned using CBCT device at voxel size of 0.10 mm. It measured root canal lengths using the CBCT (Romexis Viewer), 3D Endo for proposed length (3D-PL) and correct length (3D-CL). Mean differences between the four methods with the AL were calculated and compared. Fisher's exact test, paired t-test, Bland-Altman plot were used to test the differences among the experimental modalities in working length determination at the significance of 0.05. RESULTS: The accuracy in the range of ± 0.5 mm of the EAL ProPex II was highest among the experimental modalities, however this method disagreed with the actual length. CONCLUSIONS: The correct working length after adjustment from the semi-automatically length by the 3D Endo software and Romexis Viewer measurements agreed with the AL.
Assuntos
Cavidade Pulpar , Ápice Dentário , Tomografia Computadorizada de Feixe Cônico , Cavidade Pulpar/diagnóstico por imagem , Eletrônica , Humanos , Odontometria , Ápice Dentário/diagnóstico por imagemRESUMO
BACKGROUND: The transformation temperatures were important values, influencing the mechanical properties and clinical performance of nickel-titanium instruments. The aim of this study was to determine the transformation temperatures of three rotary nickel-titanium (NiTi) instruments: Reciproc, HyFlex CM Pro, and Neoniti before and after simulated clinical uses. METHODS: Ninety new NiTi instruments of three single-file instruments: Reciproc, HyFlex CM Pro, and Neoniti were divided into three groups. Thirty instruments of each group were divided into 3 subgroups (10 instruments for each subgroup): new, one-time simulated clinical used and sterilised, and three times simulated clinical used and sterilized subgroups. The instruments were in the as-received condition for the new subgroups, one time used in the plastic endo-training blocks and sterilised for the one-time subgroups, and three times used in the plastic endo-training blocks and sterilised for the three times subgroups. Each instrument in subgroups was cut into four small segments of 4-5 mm. All segments of instruments were analysed using Differential Scanning Calorimetry (DSC). Data was collected and analysed using SPSS version 20.0 with ANOVA test or Kruskal-Wallis test at the significant level of 0.05. RESULTS: There was not significant difference between before and after simulated clinical use with sterilised procedure in three NiTi instrument systems. The austenite-finish (Af) temperatures of three instrument systems were higher than that of the human body (37 °C), of these, the Af temperature of Neoniti was highest and that of HyFlex CM Pro was lowest. CONCLUSIONS: The austenite-finish (Af) temperatures of three NiTi instruments were higher than that of human body temperature, therefore, material was in the phase transformation from martensite to austenite, gives the instruments more flexibility when used in the clinical situation.
Assuntos
Níquel , Titânio , Varredura Diferencial de Calorimetria , Humanos , Preparo de Canal Radicular , TemperaturaRESUMO
BACKGROUND: The present study aims to evaluate the effectiveness of mineral trioxide aggregate (MTA) application in treating dens evaginatus affected teeth with apical lesions and open apices using haemostatic collagen membrane to prevent the apical extrusion of MTA. METHODS: Twelve patients with 14 dens evaginatus affected teeth with apical lesions and open apices were treated with MTA apical plug and haemostatic collagen membrane. Clinical symptoms of subjective pain, pain of palpation, percussion, sinus tract, and the apical lesions' radiographic parameter were recorded at every 3-month interval up to 9 months after treatment. Paired t-test or Wilcoxon signed-rank test was used for statistical analysis with P < 0.05 as the threshold for considering results to be statistically significant. RESULTS: No patient experienced clinical symptoms 3 months after endodontic treatment. In addition, there was a significant difference in the dimensions of the apical lesions' before compared to 3 months after endodontic treatment. CONCLUSIONS: The combination of MTA apical plug and haemostatic collagen membrane effectively treated dens evaginatus affected teeth with apical lesions, and open apices.
Assuntos
Materiais Restauradores do Canal Radicular , Compostos de Alumínio/uso terapêutico , Compostos de Cálcio/uso terapêutico , Combinação de Medicamentos , Humanos , Óxidos/uso terapêutico , Materiais Restauradores do Canal Radicular/uso terapêutico , Silicatos/uso terapêutico , Ápice Dentário/diagnóstico por imagemRESUMO
BACKGROUND: To introduce a new method for measurement of surface roughness of the endodontic instrument, before and after instrumentation, using the Field Emission Scanning Electronic Microscope (FE-SEM) combined with the ImageJ software. METHODS: Twenty J-shape resin blocks were divided into two groups, ten blocks of each group. Simulated root canal inside the resin block was 16 mm length, 600 angle of curvature, and radius of 4.5 mm. Ten WaveOne Gold Primary and 10 Reciproc Blue R25 instruments were used for root canal instrumentation. The instruments were scanned before and after instrumentation with special molds made to ensure the same areas at the point located 3 mm from the tips of the instruments using the FE-SEM. These scanned images were analyzed using the ImageJ. The arithmetical mean roughness (Ra), root mean square roughness (Rq), and the average distance between the highest peak and lowest valley in each sampling length (Rz) were calculated by ImageJ for quantitative analyses. The paired-t test was performed to analyze the data using the SPSS 22.0 at the significance of .05. RESULTS: Almost all surface roughness values were decreased. However, these decreases were not statistically significant (P > .05). CONCLUSIONS: The FE-SEM combined with the ImageJ was the reliable and appropriate modality for measurement surface roughness of instruments.
Assuntos
Níquel , Titânio , Ligas Dentárias , Instrumentos Odontológicos , Eletrônica , Desenho de Equipamento , Teste de Materiais , Preparo de Canal RadicularRESUMO
The targeting of glutamine metabolism specifically via pharmacological inhibition of glutaminase 1 (GLS1) has been translated into clinical trials as a novel therapy for several cancers. The results, though encouraging, show room for improvement in terms of tumor reduction. In this study, the glutaminase II pathway is found to be upregulated for glutamate production upon GLS1 inhibition in pancreatic tumors. Moreover, genetic suppression of glutamine transaminase K (GTK), a key enzyme of the glutaminase II pathway, leads to the complete inhibition of pancreatic tumorigenesis in vivo unveiling GTK as a new metabolic target for cancer therapy. These results suggest that current trials using GLS1 inhibition as a therapeutic approach targeting glutamine metabolism in cancer should take into account the upregulation of other metabolic pathways that can lead to glutamate production; one such pathway is the glutaminase II pathway via GTK.
Assuntos
Inibidores Enzimáticos/farmacologia , Glutaminase/genética , Liases/genética , Neoplasias Pancreáticas/tratamento farmacológico , Transaminases/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Ácido Glutâmico/metabolismo , Glutaminase/antagonistas & inibidores , Glutamina/genética , Glutamina/metabolismo , Humanos , Liases/antagonistas & inibidores , Redes e Vias Metabólicas/efeitos dos fármacos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Transaminases/antagonistas & inibidoresRESUMO
Indoleamine 2,3-dioxygenase 1 (hIDO1) and tryptophan dioxygenase (hTDO) are two of the only three heme-based dioxygenases in humans. They have recently been identified as key cancer immunotherapeutic drug targets. While structures of hIDO1 in complex with inhibitors have been documented, so far there are no structures of hTDO-inhibitor complexes available. Here we use PF-06840003 (IPD), a hIDO1-selective inhibitor in clinical trials, as a structural probe to elucidate inhibitor-selectivity in hIDO1 versus hTDO. Spectroscopic studies show that IPD exhibits 400-fold higher inhibition activity toward hIDO1 with respect to hTDO. Crystallographic structures reveal that the binding pocket of IPD in the active site in hIDO1 is much more flexible as compared to that in hTDO, which offers a molecular explanation for the superior inhibition activity of IPD in hIDO1 with respect to hTDO. In addition to the IPD bound in the active site, a second IPD molecule was identified in an inhibitory site on the proximal side of the heme in hIDO1 and in an exosite that is â¼40 Å away from the active site in hTDO. Taken together the data provide new insights into structure-based design of mono and dual inhibitors targeting hIDO1 and/or hTDO.
Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Triptofano Oxigenase/antagonistas & inibidores , Cristalografia por Raios X , Inibidores Enzimáticos/metabolismo , Heme/metabolismo , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/química , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Modelos Moleculares , Domínios Proteicos , Especificidade por Substrato , Triptofano Oxigenase/química , Triptofano Oxigenase/metabolismoRESUMO
Human indoleamine 2,3-dioxygenase 1 (hIDO1) is an important heme-containing enzyme that is a key drug target for cancer immunotherapy. Several hIDO1 inhibitors have entered clinical trials, among which BMS-986205 (BMS) stands out as the only suicide inhibitor. Despite its "best-in-class" activity, the action mechanism of BMS remains elusive. Here, we report three crystal structures of hIDO1-BMS complexes that define the complete binding trajectory of the inhibitor. BMS first binds in a solvent exposed surface cleft near the active site in an extended conformation. The initial binding partially unfolds the active site, which triggers heme release, thereby exposing a new binding pocket. The inhibitor then undergoes a large scale movement to this new binding pocket, where it binds by adopting a high energy kinked conformation. Finally, the inhibitor relaxes to a bent conformation, via an additional large scale rearrangement, culminating in the energy minimum state. The structural data offer a molecular explanation for the remarkable efficacy and suicide inhibition activity of the inhibitor. They also suggest a novel strategy that can be applied for drug development targeting hIDO1 and related enzymes.
Assuntos
Acetamidas/farmacologia , Inibidores Enzimáticos/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Quinolinas/farmacologia , Acetamidas/química , Sítios de Ligação/efeitos dos fármacos , Inibidores Enzimáticos/química , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Modelos Moleculares , Estrutura Molecular , Quinolinas/químicaRESUMO
Globular proteins, such as cytochrome c (cyt c), display an organized native conformation, maintained by a hydrogen bond interaction network. In the present work, the structural interrogation of kinetically trapped intermediates of cyt c was performed by correlating the ion-neutral collision cross section (CCS) and charge state with the starting solution conditions and time after desolvation using collision induced activation (CIA), time-resolved hydrogen/deuterium back exchange (HDX) and trapped ion mobility spectrometry-mass spectrometry (TIMS-MS). The high ion mobility resolving power of the TIMS analyzer allowed the identification of new ion mobility bands, yielding a total of 63 mobility bands over the +6 to +21 charge states and 20 mobility bands over the -5 to -10 charge states. Mobility selected HDX rates showed that for the same charge state, conformers with larger CCS present faster HDX rates in both positive and negative ion mode, suggesting that the charge sites and neighboring exchange sites on the accessible surface area define the exchange rate regardless of the charge state. Complementary molecular dynamic simulations permitted the generation of candidate structures and a mechanistic model of the folding transitions from native (N) to molten globule (MG) to kinetic intermediates (U) pathways. Our results suggest that cyt c major structural unfolding is associated with the distancing of the N- and C-terminal helices and subsequent solvent exposure of the hydrophobic, heme-containing cavity.
Assuntos
Citocromos c/química , Animais , Medição da Troca de Deutério , Cavalos , Espectrometria de Mobilidade Iônica/métodos , Espectrometria de Massas/métodos , Simulação de Dinâmica Molecular , Conformação Proteica , Desdobramento de ProteínaRESUMO
KChIP3 (potassium channel interacting protein 3) is a calcium-binding protein that binds at the N terminus of the Kv4 voltage-gated potassium channel through interactions at two contact sites and has been shown to regulate potassium current gating kinetics as well as channel trafficking in cardiac and neuronal cells. Using fluorescence spectroscopy, isothermal calorimetry, and docking simulations we show that the novel potassium current activator, NS5806, binds at a hydrophobic site on the C terminus of KChIP3 in a calcium-dependent manner, with an equilibrium dissociation constant of 2-5 µM in the calcium-bound form. We further determined that the association between KChIP3 and the hydrophobic N terminus of Kv4.3 is calcium-dependent, with an equilibrium dissociation constant in the apo-state of 70 ± 3 µM and 2.7 ± 0.1 µM in the calcium-bound form. NS5806 increases the affinity between KChIP3 and the N terminus of Kv4.3 (Kd = 1.9 ± 0.1 µM) in the presence and absence of calcium. Mutation of Tyr-174 or Phe-218 on KChIP3 abolished the enhancement of Kv4.3 site 1 binding in the apo-state, highlighting the role of these residues in drug and K4.3 binding. Kinetic studies show that NS5806 decreases the rate of dissociation between KChIP3 and the N terminus of KV4.3. Overall, these studies support the idea that NS5806 directly interacts with KChIP3 and modulates the interactions between this calcium-binding protein and the T1 domain of the Kv4.3 channels through reorientation of helix 10 on KChIP3.
Assuntos
Proteínas Interatuantes com Canais de Kv/metabolismo , Compostos de Fenilureia/química , Proteínas Repressoras/metabolismo , Canais de Potássio Shal/metabolismo , Tetrazóis/química , Animais , Anisotropia , Sítios de Ligação , Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Calorimetria , Transferência Ressonante de Energia de Fluorescência , Magnésio/química , Camundongos , Modelos Moleculares , Simulação de Dinâmica Molecular , Ligação Proteica , Estrutura Terciária de Proteína , Espectrometria de FluorescênciaRESUMO
Among the natural tetramic acids with a decalinoyl part, signermycin B is unique because it contains a cis-decalin. In this paper, we demonstrate that the cis-decalin section of signermycin B can be accessed by an anionic oxy-Cope rearrangement. The substrate, a tricyclic dienol was prepared by an intramolecular Diels-Alder reaction of a masked ortho-benzoquinone, generated by oxidation of an α-methoxyphenol in presence of cis-2-hexenol. After a superfluous bromine on the cycloadduct was removed, reaction of the tricyclic ketone with isopropenylmagnesium bromide led to the tricyclic trienol that underwent the oxy-Cope rearrangement to a cis-decalinone. While we could show, that introduction of the 4-ethyl substituent (signermycin B numbering) is possible by enolate alkylation, the 4-epi-isomer was formed.
RESUMO
The pathobiology of tau is of great importance for understanding the mechanisms of neurodegeneration in aging and age-associated disorders such as Alzheimer disease (AD) and frontotemporal dementias. It is critical to identify neuronal populations and brain regions that are vulnerable or resistant to tau pathological changes. Pick disease (PiD) is a three-repeat (3R) tauopathy that belongs to the group of frontotemporal lobar degenerations. The neuropathologic changes of PiD are characterized by globular tau-positive neuronal intracytoplasmic inclusions, called Pick bodies, in the granule cells of the dentate gyrus and frontal and temporal neocortices, and ballooned neurons, named Pick neurons, in the neocortex. In the present study, we examined 13 autopsy-confirmed cases of PiD. Using immunohistochemistry for phospho-tau (AT8) and 3R tau isoform, all PiD cases demonstrated extensive lesions involving the hippocampus and neocortex. However, the lateral geniculate body (LGB) is spared of significant tau lesions in contrast to the neighboring hippocampus and other thalamic nuclei. Only 1 PiD case (7.7%) had tau-positive neurons, and 4 cases had tau-positive neurites (31%) in the LGB. By contrast, the LGB does consistently harbor tau lesions in other tauopathies including progressive supranuclear palsy, corticobasal degeneration, and AD.
Assuntos
Doença de Alzheimer , Neocórtex , Doença de Pick , Tauopatias , Humanos , Doença de Pick/patologia , Proteínas tau/metabolismo , Corpos Geniculados/metabolismo , Corpos Geniculados/patologia , Tauopatias/patologia , Neocórtex/patologiaRESUMO
The transformation of a benign phyllodes tumor (PT) into a malignant PT and/or carcinoma is extremely uncommon. We present a case of a 66-year-old female with a huge mass on the left breast which was successfully removed by surgical resection. The pathological diagnosis was infiltrating lobular carcinoma with pure rhabdoid features and the malignant transformation of a benign phyllodes tumor. The first time this rare case was reported, it is demonstrated a special phenomenon through the synchronous transformation of PT grades and the carcinomatous transformation of PT.
RESUMO
Human tryptophan dioxygenase (TDO) and indoleamine 2,3-dioxygenase (IDO) are two important targets in cancer immunotherapy. Extensive research has led to a large number of potent IDO inhibitors; in addition, 52 structures of IDO in complex with inhibitors with a wide array of chemical scaffolds have been documented. In contrast, progress in the development of TDO inhibitors has been limited. Only four structures of TDO in complex with competitive inhibitors that compete with the substrate L-tryptophan for binding to the active site have been reported to date. Here we systematically evaluated the structures of TDO in complex with competitive inhibitors with three types of pharmacophores, imidazo-isoindole, indole-tetrazole, and indole-benzotriazole. The comparative assessment of the protein-inhibitor interactions sheds new light into the structure-based design of enzyme-selective inhibitors.
Assuntos
Inibidores Enzimáticos , Indolamina-Pirrol 2,3,-Dioxigenase , Triptofano Oxigenase , Humanos , Triptofano Oxigenase/antagonistas & inibidores , Triptofano Oxigenase/metabolismo , Triptofano Oxigenase/química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/química , Relação Estrutura-Atividade , Indóis/química , Indóis/farmacologia , Indóis/metabolismo , Modelos Moleculares , Tetrazóis/química , Tetrazóis/farmacologia , Tetrazóis/metabolismo , Triptofano/química , Triptofano/metabolismo , Imidazóis/química , Imidazóis/farmacologia , Imidazóis/metabolismo , Ligação ProteicaRESUMO
The purpose of this study was to assess the effect of a calcium silicate-based sealers (CeraSeal) and an epoxy resin-based sealer (AH Plus) on cytotoxicity and cell migration of stem cell from the human apical papilla (hSCAPs) by using the Alamar Blue, Annexin V-FICT and wound healing assays. In Alamar Blue assay, hSCAPs exposed to undiluted CeraSeal extract had significantly higher cell viability compared with that observed when cells were treated with AH Plus in all experimental period (p < 0.001). The flow cytometry analysis confirmed the comparison on viable cells and indicated that AH Plus increased apoptosis compared to CeraSeal and the control groups (p < 0.001). Additionally, AH Plus exhibited significantly lower level of cell migration than CeraSeal and the control for up to 48 h observation (p < 0.01). In summary, calcium silicate-based sealer (CeraSeal) is less cytotoxic and more biocompatible than epoxy resin-based sealer (AH Plus).
Assuntos
Resinas Epóxi , Materiais Restauradores do Canal Radicular , Humanos , Resinas Epóxi/toxicidade , Materiais Restauradores do Canal Radicular/toxicidade , Cavidade Pulpar , Teste de Materiais , Compostos de Cálcio/toxicidade , Silicatos/toxicidade , Células-Tronco , Movimento CelularRESUMO
INTRODUCTION AND IMPORTANCE: Papillary thyroid carcinoma is the most common type of malignancy in endocrine tumor. Women with breast cancer have an increased risk of developing thyroid cancer. Especially, patients with BRCA1 germline variants, which belong to the DNA DSB repair system, there may be a genetic susceptibility to thyroid cancer. CASE PRESENTATION: This study investigated a 47-year-old Vietnamese female patient with BRCA1 mutation, namely NM_007294.3 (BRCA1): c.4998insA (p. Tyr1666Terfs), who developed PTC after one year of breast cancer treatment. CLINICAL DISCUSSION: Factors that are thought to increase the risk of thyroid cancer after breast cancer treatment include treatment methods, hormonal factors, genetic susceptibility, and others. A hypothesis is breast cancer with BRCA1 mutation increases the risk of thyroid cancer. CONCLUSION: Understanding the relationship between breast and thyroid cancer helps clinicians for well management of both diseases and also contributes to the development of new preventive strategies, diagnostics and therapeutics as so as a new research direction.