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1.
Int J Biol Macromol ; 266(Pt 1): 131055, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38522681

RESUMO

The B-MYB gene encodes a transcription factor (B-MYB) that regulates cell growth and survival. Abnormal expression of B-MYB is frequently observed in lung cancer and poses challenges for targeted drug therapy. Oncogenes often contain DNA structures called G-quadruplexes (G4s) in their promoter regions, and B-MYB is no exception. These G4s play roles in genetic regulation and are potential cancer treatment targets. In this study, a probe was designed to specifically identify a G4 within the promoter region of the B-MYB gene. This probe combines an acridine derivative ligand with a DNA segment complementary to the target sequence, enabling it to hybridize with the adjacent sequence of the G4 being investigated. Biophysical studies demonstrated that the acridine derivative ligands C5NH2 and C8NH2 not only effectively stabilized the G4 structure but also exhibited moderate affinity. They were capable of altering the G4 topology and exhibited enhanced fluorescence emission in the presence of this quadruplex. Additionally, these ligands increased the number of G4s observed in cellular studies. Through various biophysical studies, the target sequence was shown to form a G4 structure, even with an extra nucleotide tail added to its flanking region. Cellular studies confirmed the co-localization between the target sequence and the developed probe.


Assuntos
Proteínas de Ciclo Celular , Corantes Fluorescentes , Quadruplex G , Humanos , Corantes Fluorescentes/química , Regiões Promotoras Genéticas , Proto-Oncogene Mas , Ligantes , Transativadores/genética , Transativadores/metabolismo , Transativadores/química , Acridinas/química , Acridinas/farmacologia
2.
Chemistry ; 30(22): e202400285, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38386665

RESUMO

The main goal of this work was to elucidate the potential relevance of (radio)metal chelates of 99mTc and Re targeting G-quadruplex structures for the design of new tools for cancer theranostics. 99mTc provides the complexes with the ability to perform single-photon-emission computed tomography imaging studies, while the Re complexes should act as anticancer agents upon interaction with specific G4 DNA or RNA structures present in tumor tissues. Towards this goal, we have developed isostructural 99mTc(I) and Re(I) tricarbonyl complexes anchored by a pyrazolyl-diamine (Pz) chelator carrying a pendant pyridostatin (PDS) fragment as the G4-binding motif. The interaction of the PDF-Pz-Re (8) complex with different G4-forming oligonucleotides was studied by circular dichroism, fluorescence spectroscopy and FRET-melting assays. The results showed that the Re complex retained the ability to bind and stabilize G4-structures from different DNA or RNA sequences, namely those present on the SRC proto-oncogene and telomeric RNA (TERRA sequence). PDF-Pz-Re (8) showed low to moderate cytotoxicity in PC3 and MCF-7 cancer cell lines, as typically observed for G4-binders. Biodistribution studies of the congener PDF-Pz-99mTc (12) in normal mice showed that the complex undergoes a fast blood clearance with a predominant hepatobiliary excretion, pointing also for a high in vitro stability.


Assuntos
Aminoquinolinas , Quadruplex G , Neoplasias , Ácidos Picolínicos , Rênio , Camundongos , Animais , Tecnécio/química , Distribuição Tecidual , DNA/química , Quelantes/química , Tomografia Computadorizada de Emissão de Fóton Único , RNA , Rênio/química , Compostos Radiofarmacêuticos/química
3.
Biomed Phys Eng Express ; 10(3)2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38417163

RESUMO

Radiometric surveys in radiotherapy bunkers have been carried out in Brazil for many years, both by the same radiotherapy facility for verification of shielding as by the regulatory agency for licensing and control purposes. In recent years, the Intensity Modulated Radiation Therapy (IMRT) technique has been gradually incorporated into many facilities. Therefore, it has been necessary to consider the increased leakage component that has an important impact on the secondary walls. For that, a radiometric survey method has been used that considers an increased 'time of beam-on' for the secondary walls. In this work we discuss two methods of doing this: the first considers that this 'time of beam-on' affects the sum of the two components, leakage and scattered. In another method it is considered that only the leakage component is affected by this extended 'time of beam-on'. We compare the methods and show that for secondary walls withU= 1 the first method overestimates dose rates by important percentages and for secondary walls withU< 1 it can both overestimate or underestimate the dose rates, depending on the parameters of the project. An optimized procedure is proposed, according to the use factor (U) of the secondary wall to be measured.


Assuntos
Proteção Radiológica , Radioterapia de Intensidade Modulada , Proteção Radiológica/métodos , Radiometria/métodos , Radioterapia de Intensidade Modulada/métodos , Planejamento da Radioterapia Assistida por Computador/métodos
4.
Evid Based Dent ; 25(1): 49-50, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38273113

RESUMO

DATA SOURCES: Medline via EBSCOhost, PubMed, and Scopus up to February 2023. STUDY SELECTION: Observational studies in the English language published in peer-reviewed journals, encompassing children aged 0 to 6 years exposed to environmental tobacco smoke and passive smoking, with a focus on oral health conditions in deciduous dentition. DATA EXTRACTION AND SYNTHESIS: Data were extracted from 25 papers, encompassing study details, oral health, and smoking exposure. Confounding factors such as parental education, income, diet, fluoride exposure, gender, and oral hygiene practices were also identified. The risk of bias was assessed using the Newcastle-Ottawa Scale (NOS). Frequency effect size was calculated for health variables and smoking exposure. RESULTS: Most studies identified a correlation between passive smoking and an increased prevalence of dental caries. Environmental tobacco smoke exposure and dental caries risk were influenced by factors such as low parental education, socioeconomic status, dietary habits, oral hygiene, and gender. CONCLUSIONS: The results of this systematic review strongly indicate a significant association between dental caries in deciduous dentition and passive smoking.


Assuntos
Cárie Dentária , Poluição por Fumaça de Tabaco , Criança , Adulto , Pré-Escolar , Humanos , Cárie Dentária/epidemiologia , Cárie Dentária/etiologia , Saúde Bucal , Poluição por Fumaça de Tabaco/efeitos adversos , Suscetibilidade à Cárie Dentária , Dieta
5.
Funct Plant Biol ; 512024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38163648

RESUMO

Environments originating from banded iron formations, such as the canga , are important reference ecosystems for the recovery of degraded areas by mining. The objective of this work was to evaluate if the relationship between morphofunctional and photosynthetic attributes of native canga species from different functional group results in distinct responses when grown in iron mining tailings substrate. The experiment was carried out with species belonging to different functional groups: a widespread semi-deciduous tree-shrub, Myrcia splendens ; an endemic deciduous shrub, Jacaranda caroba ; and a nitrogen-fixing herbaceous species, Periandra mediterranea . The species were grown in two conditions, reference soil and iron ore tailing. Despite belonging to different functional groups when grown in tailings, the morphofunctional attributes presented similar responses between species. M. splendens was the species most affected by the conditions imposed by the iron ore mining tailings, with decreased light-use efficiency and electron transport. P. mediterranea had satisfactory growth and maintenance of photosynthetic attributes. J. caroba growing in the tailings increased the effective quantum yield of PSII. The photochemical and growth assessments were able to better explain the adaptive strategies developed by the species, guaranteeing a greater chance of success during the rehabilitation of mining substrates.


Assuntos
Ecossistema , Ferro , Plantas/metabolismo , Árvores/metabolismo , Mineração
6.
Int J Biol Macromol ; 259(Pt 2): 129157, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38199539

RESUMO

Oral cancer incidence and mortality are increasing over time. The most common therapies for oral cancers are surgery and radiotherapy, either used alone or combined, and immunotherapy can be also an option. Although there are several therapeutic options, none of them are completely effective, and in addition, there are numerous associated side effects. To overcome these limitations, researchers have been trying to reduce these drawbacks by using drug delivery systems that carry drugs for specific delivery to cancer cells. For that purpose, RNA-coated liposomes to selectively deliver the ligands C8 (acridine orange derivative) and dexamethasone to oral cancer cells were produced, characterized, and biologically evaluated. Firstly, the RNA structure and binding interaction with ligands (C8 and dexamethasone) were evaluated by circular dichroism (CD), thermal difference spectroscopy (TDS), nuclear magnetic resonance (NMR) and fluorescence titrations. The biophysical assays evidenced the formation of an RNA hairpin and duplex structure. Moreover, steady-state and time-resolved fluorescence intensity and anisotropy experiments show that C8 forms a complex with RNA and adopts an open conformation upon RNA binding. Then, RNA-coated liposomes were characterized by dynamic light scattering, and diameters near 160 nm were observed. Time-resolved anisotropy measurements of C8 loaded in RNA-functionalized liposomes indicate the co-existence of free C8 in solution (inside the liposome) and C8 bound to RNA at the external liposome surface. The RNA-functionalized liposomes loaded with C8 or dexamethasone mediated a significant reduction in the cell viability of malignant UPCI-SCC-154 cells while maintaining viable non-malignant NHDF cells. Additionally, the liposomes were able to internalize the cells, with higher uptake by the malignant cell line. Overall, the results obtained in this work can contribute to the development of new drug delivery systems based on RNA-coated liposomes.


Assuntos
Lipossomos , Neoplasias Bucais , Humanos , Lipossomos/química , Sistemas de Liberação de Medicamentos , Linhagem Celular , Neoplasias Bucais/tratamento farmacológico , Dexametasona/farmacologia
7.
Biomed Phys Eng Express ; 10(2)2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38237176

RESUMO

To enhance the effect of radiation on the tumor without increasing the dose to the patient, the combination of high-Z nanoparticles with radiotherapy has been proposed. In this work, we investigate the effects of the physical parameters of nanoparticles (NPs) on the Dose Enhancement Factor (DEF), and on the Sensitive Enhancement Ratio (SER) by applying a version of the Linear Quadratic Model. A method for constructing voxelized realistic cell geometries in Monte Carlo simulations from confocal microscopy images was developed and applied to Gliobastoma Multiforme cell lines (U87 and U373). The comparison of simulations with realistic geometry and spherical geometry shows that there is significant impact on the survival curves obtained for the same irradiation conditions. Using this model, the DEF and the SER are determined as a function of the concentration, size and distribution of gold nanoparticles within the cell. For small NPs,dAuNP= 10 nm, no clear trend in the DEF and SER was observed when the number of NPs within the cell increases. Experimentally, the variable number of NPs measured inside the U373 cells (ranging between 1.48 × 105and 1.19 × 106) also did not influence much the observed cell survival upon irradiation of the cells with a Co-60 source. The same lack of trend is obtained when the Au content in the cell is kept constant, 0.897 mg/g, but the size of the NPs is changed. However, if the number of NPs is kept constant (7.91 × 105) and the size changes, there is a critical diameter above which the dose effect increases significantly. Using the realistic geometries, it was verified that the key parameter for the DEF and the SER enhancement is the volume fraction of Au in the cell, with NP size being a more important parameter than the number of NPs.


Assuntos
Nanopartículas Metálicas , Humanos , Dosagem Radioterapêutica , Ouro , Microscopia , Simulação por Computador
8.
Chemistry ; 30(13): e202303591, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38038361

RESUMO

Due to their favorable chemical features, Re and Tc complexes have been widely used for the development of new therapeutic agents and imaging probes to solve problems of biomedical relevance. This review provides an update of the most relevant research efforts towards the development of novel cancer theranostic agents using Re and Tc-based compounds interacting with specific DNA structures. This includes a variety of homometallic complexes, namely those containing M(CO)3 (M=Re, Tc) moieties, that exhibit different modes of interaction with DNA, such as covalent binding, intercalation, groove binding or G-quadruplex DNA binding. Additionally, heterometallic complexes, designed to potentiate synergistic effects of different metal centers to improve DNA-targeting, cytotoxicity and fluorescence properties, are also reviewed. Particular attention is also given to 99m Tc- and 188 Re-labeled oligonucleotides that have been widely explored to develop imaging and therapeutic radiopharmaceuticals through the in vivo hybridization with a specific complementary DNA or RNA target sequence to provide useful molecular tools in precision medicine for cancer diagnosis and treatment. Finally, the need for further improvement of DNA-targeted Re and Tc-based compounds as potential therapeutic and diagnostic agents is highlighted, and future directions are discussed.


Assuntos
Neoplasias , Rênio , Humanos , Tecnécio/química , Compostos Radiofarmacêuticos/química , Diagnóstico por Imagem , DNA , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Rênio/química
9.
Mol Pharm ; 21(1): 216-233, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37992229

RESUMO

Nuclear DNA is the canonical target for biological damage induced by Auger electrons (AE) in the context of targeted radionuclide therapy (TRT) of cancer, but other subcellular components might also be relevant for this purpose, such as the energized mitochondria of tumor cells. Having this in mind, we have synthesized novel DOTA-based chelators carrying a prostate-specific membrane antigen (PSMA) inhibitor and a triphenyl phosphonium (TPP) group that were used to obtain dual-targeted 111In-radioconjugates ([111In]In-TPP-DOTAGA-PSMA and [111In]In-TPP-DOTAGA-G3-PSMA), aiming to promote a selective uptake of an AE-emitter radiometal (111In) by PSMA+ prostate cancer (PCa) cells and an enhanced accumulation in the mitochondria. These dual-targeted 111In-radiocomplexes are highly stable under physiological conditions and in cell culture media. The complexes showed relatively similar binding affinities toward the PSMA compared to the reference tracer [111In]In-PSMA-617, in line with their high cellular uptake and internalization in PSMA+ PCa cells. The complexes compromised cell survival in a dose-dependent manner and in the case of [111In]In-TPP-DOTAGA-G3-PSMA to a higher extent than observed for the single-targeted congener [111In]In-PSMA-617. µSPECT imaging studies in PSMA+ PCa xenografts showed that the TPP pharmacophore did not interfere with the excellent in vivo tumor uptake of the "golden standard" [111In]In-PSMA-617, although it led to a higher kidney retention. Such kidney retention does not necessarily compromise their usefulness as radiotherapeutics due to the short tissue range of the Auger/conversion electrons emitted by 111In. Overall, our results provide valuable insights into the potential use of mitochondrial targeting by PSMA-based radiocomplexes for efficient use of AE-emitting radionuclides in TRT, giving impetus to extend the studies to other AE-emitting trivalent radiometals (e.g., 161Tb or 165Er) and to further optimize the designed dual-targeting constructs.


Assuntos
Neoplasias da Próstata , Masculino , Humanos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/metabolismo , Glutamato Carboxipeptidase II/metabolismo , Antígenos de Superfície/metabolismo , Radioisótopos , Compostos Radiofarmacêuticos , Mitocôndrias/metabolismo , Linhagem Celular Tumoral
10.
Braz. oral res. (Online) ; 38: e013, 2024. tab, graf
Artigo em Inglês | LILACS-Express | LILACS, BBO | ID: biblio-1528146

RESUMO

Abstract This study aimed to develop and validate a self-administered questionnaire in Brazilian Portuguese to verify the level of knowledge of orthodontists in the care of pregnant, lactating, and postmenopausal women, named "Considerations on Orthodontic Treatment during Pregnancy, Lactation, and Postmenopausal Periods." The development and validation of the questionnaire consisted of the following steps: a) item generation; b) item reduction; c) questionnaire design; and d) validity and reliability tests in a cross-sectional study with 258 orthodontists working in the field from different Brazilian states. A total of 60 orthodontists participated in test-retest over a mean period of 45 days. The preliminary questionnaire consisted of a total of 60 questions. After item reduction, 40 questions were selected for the final version of the questionnaire, with eight questions about pregnant women; six about lactating women; 18 about postmenopausal women, and eight about general knowledge in dentistry. Each item had three response options in the Likert scale format. Face and content validity analysis, reliability assessment through internal consistency (Cronbach's alpha and McDonald's omega), and test-retest reliability through the intraclass correlation coefficient (ICC) and Spearman's correlation coefficient were performed. Face and content validity indicated that the questionnaire was considered valid, objective, and easily understandable. The questionnaire had good internal consistency (Cronbach's alpha = 0.77; McDonald's omega = 0.78) and good test-retest reliability (ICC = 0.71; Spearman's correlation coefficient = 0.51). The questionnaire was considered valid and reliable to assess the level of knowledge of orthodontists in the care of pregnant, lactating, and postmenopausal women.

11.
Braz Dent J ; 34(6): 100-109, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38133084

RESUMO

This study aimed to analyze the 100 most-cited papers in Dentistry, with a focus on female leadership in dental research. Papers were retrieved from the Web of Science Core Collection (WoS- CC) in the category 'Dentistry, Oral Surgery & Medicine'. Gender was assessed through WoS-CC, Scopus, ResearchGate, social media, institutional websites, and software that assigns gender according to first names (https://genderapi.io). Characteristics of authors in leadership roles were retrieved, such as affiliation, publication history, citations, H factor, and i500. The 100 most-cited papers in Dentistry were authored by 394 researchers, 326 (82.7%) men, and 68 (17.3%) women - there were 4.8 male authors for each female. Among the lead authors, there were 11.3 males for each female. Among female senior authors, there were 7 males for each female. Among lead/senior authors of the 100 most-cited papers (first and last authors, respectively), 18 were women. There was an increase in the participation of women in the top cited papers regardless of authorship role across the six decades, with a peak of two female authors in the first decade of the 21st century. For female authors in leadership roles, their publication history shows the time between their first and last papers in WoS-CC ranged from 4 to 42 years for lead authors and 1 to 39 years for senior authors. Women were found to be largely underrepresented as leaders of the 100 most-cited papers, highlighting pervasive gender inequalities in dental research publications.


Assuntos
Pesquisa em Odontologia , Cirurgia Bucal , Humanos , Masculino , Feminino , Liderança , Bibliometria , Autoria
12.
Sensors (Basel) ; 23(22)2023 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-38005657

RESUMO

The field of organic-borne biomarkers has been gaining relevance due to its suitability for diagnosing pathologies and health conditions in a rapid, accurate, non-invasive, painless and low-cost way. Due to the lack of analytical techniques with features capable of analysing such a complex matrix as the human breath, the academic community has focused on developing electronic noses based on arrays of gas sensors. These sensors are assembled considering the excitability, sensitivity and sensing capacities of a specific nanocomposite, graphene. In this way, graphene-based sensors can be employed for a vast range of applications that vary from environmental to medical applications. This review work aims to gather the most relevant published papers under the scope of "Graphene sensors" and "Biomarkers" in order to assess the state of the art in the field of graphene sensors for the purposes of biomarker identification. During the bibliographic search, a total of six pathologies were identified as the focus of the work. They were lung cancer, gastric cancer, chronic kidney diseases, respiratory diseases that involve inflammatory processes of the airways, like asthma and chronic obstructive pulmonary disease, sleep apnoea and diabetes. The achieved results, current development of the sensing sensors, and main limitations or challenges of the field of graphene sensors are discussed throughout the paper, as well as the features of the experiments addressed.


Assuntos
Asma , Grafite , Neoplasias Pulmonares , Doença Pulmonar Obstrutiva Crônica , Humanos , Asma/diagnóstico , Biomarcadores , Testes Respiratórios/métodos
13.
Dalton Trans ; 52(43): 15757-15766, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37846621

RESUMO

The pursuit of molecular imaging for tumors has led to endeavors focused on targeting epidermal growth factor receptors (EGFR) through monoclonal antibodies or radionuclide-labelled EGF analogs with 99mTc, 111In, or 131I. In this context, various 99mTc-labeled EGFR inhibitors using quinazoline structures have been reported based on the so-called pendant approach and on two types of complexes and labelling strategies: "4 + 1" mixed ligand complexes and fac-tricarbonyl complexes. Apart from this approach, which alters lead structures by linking pharmacophores to chelator frameworks through different connectors, the integrated incorporation of topoisomerase and tyrosine kinase inhibitors into Re and 99mTc complexes has not been explored. Here we present [M(η6-inhibitor)2]+ (M = Re, 99mTc) and [Re(η6-bz)(η6-inhibitor)]+ complexes, where the core structure of an EGFR tyrosine kinase inhibitor binds directly to the metal center. These complexes exhibit potential for tumor imaging: initial biological investigations highlight the influence of one versus two bound inhibitors on the metal center.


Assuntos
Radioisótopos , Rênio , Radioisótopos/química , Receptores ErbB/metabolismo , Quelantes/química , Diagnóstico por Imagem , Rênio/química , Tecnécio/química , Compostos Radiofarmacêuticos/química
14.
Pharmaceuticals (Basel) ; 16(10)2023 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-37895872

RESUMO

Ascidians are marine invertebrates that synthesize sulfated glycosaminoglycans (GAGs) within their viscera. Ascidian GAGs are considered analogues of mammalian GAGs and possess great potential as bioactive compounds, presenting antitumoral and anticoagulant activity. Due to its worldwide occurrence and, therefore, being a suitable organism for large-scale mariculture in many marine environments, our main objectives are to study Microcosmus exasperatus GAGs regarding composition, structure, and biological activity. We also aim to develop efficient protocols for sulfated polysaccharides extraction and purification for large-scale production and clinical applications. GAGs derived from M. exasperatus viscera were extracted by proteolytic digestion, purified by ion-exchange liquid chromatography, and characterized by agarose gel electrophoresis and enzymatic treatments. Anticoagulant activity was evaluated by APTT assays. Antitumoral activity was assessed in an in vitro model of tumor cell culture using MTT, clonogenic, and wound healing assays, respectively. Our results show that M. exasperatus presents three distinct polysaccharides; among them, two were identified: a dermatan sulfate and a fucosylated dermatan sulfate. Antitumoral activity was confirmed for the total polysaccharides (TP). While short-term incubation does not affect tumor cell viability at low concentrations, long-term TP incubation decreases LLC tumor cell growth/proliferation at different concentrations. In addition, TP decreased tumor cell migration at different concentrations. In conclusion, we state that M. exasperatus presents great potential as an alternative GAG source, producing compounds with antitumoral properties at low concentrations that do not possess anticoagulant activity and do not enhance other aspects of malignancy, such as tumor cell migration. Our perspectives are to apply these molecules in future preclinical studies for cancer treatment as antitumoral agents to be combined with current treatments to potentiate therapeutic efficacy.

15.
J Nucl Med ; 64(9): 1344-1351, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37591544

RESUMO

Auger electron (AE) radiopharmaceutical therapy (RPT) may have the same therapeutic efficacy as α-particles for oncologic small disease, with lower risks of normal-tissue toxicity. The seeds of using AE emitters for RPT were planted several decades ago. Much knowledge has been gathered about the potency of the biologic effects caused by the intense shower of these low-energy AEs. Given their short range, AEs deposit much of their energy in the immediate vicinity of their site of decay. However, the promise of AE RPT has not yet been realized, with few agents evaluated in clinical trials and none becoming part of routine treatment so far. Instigated by the 2022 "Technical Meeting on Auger Electron Emitters for Radiopharmaceutical Developments" at the International Atomic Energy Agency, this review presents the current status of AE RPT based on the discussions by experts in the field. A scoring system was applied to illustrate hurdles in the development of AE RPT, and we present a selected list of well-studied and emerging AE-emitting radionuclides. Based on the number of AEs and other emissions, physical half-life, radionuclide production, radiochemical approaches, dosimetry, and vector availability, recommendations are put forward to enhance and impact future efforts in AE RPT research.


Assuntos
Elétrons , Compostos Radiofarmacêuticos , Compostos Radiofarmacêuticos/efeitos adversos , Partículas alfa/uso terapêutico , Meia-Vida , Agências Internacionais
16.
Chemistry ; 29(39): e202301181, 2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37115041

RESUMO

The structural determinants of the interaction of the G-quadruplex (G4) motif found in precursor miRNA 149 (rG4) with the acridine orange derivative C8 , a G4 ligand stabilizer possessing anticancer activity, and the protein nucleolin (overexpressed in cancer cells) were investigated by Nuclear Magnetic Resonance (NMR) spectroscopy. For the rG4/C8 complex, the results revealed a strong stabilizing interaction between the aromatic core and the iodinated ring of the C8 ligand with the rG4 structure. The NMR study revealed also different interaction patterns between nucleolin and rG4 and nucleolin and rG4/C8 complex. In the absence of the ligand, rG4 establishes interactions with polar residues of the protein while for the rG4/C8 complex, these contacts are mainly established with amino acids that have hydrophobic side chains. However, nucleolin chemical shift perturbation studies in the presence of rG4 or rG4/C8 reveal the same location between domains 1 and 2 of the protein, which suggests that the rG4 and rG4/C8 complex bind in this region. This puzzling structural study opens a new framework to study rG4/ligand/nucleolin complexes that might impact the biogenesis of miRNA 149.


Assuntos
Quadruplex G , MicroRNAs , Humanos , Ligantes , Fosfoproteínas/química , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Carcinogênese , Nucleolina
17.
Arch Biochem Biophys ; 738: 109557, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36878339

RESUMO

Integrins are a family of heterodimeric transmembrane receptors which link the extracellular matrix to the cell cytoskeleton. These receptors play a role in many cellular processes: adhesion, proliferation, migration, apoptosis, and platelet aggregation, thus modulating a wide range of scenarios in health and disease. Therefore, integrins have been the target of new antithrombotic drugs. Disintegrins from snake venoms are recognized by the ability to modulate the activity of integrins, such as integrin αIIbß3, a fundamental platelet glycoprotein, and αvß3 expressed on tumor cells. For this reason, disintegrins are unique and potential tools for examining integrin-matrix interaction and the development of novel antithrombotic agents. The present study aims to obtain the recombinant form of jararacin and evaluate the secondary structure and its effects on hemostasis and thrombosis. rJararacin was expressed in the Pichia pastoris (P. pastoris) expression system and purified the recombinant protein with a yield of 40 mg/L of culture. The molecular mass (7722 Da) and internal sequence were confirmed by mass spectrometry. Structure and folding analysis were obtained by Circular Dichroism and 1H Nuclear Magnetic Resonance spectra. Disintegrin structure reveals properly folded with the presence of ß-sheet structure. rJararacin significantly demonstrated inhibition of the adhesion of B16F10 cells and platelets to the fibronectin matrix under static conditions. rJararacin inhibited platelet aggregation induced by ADP (IC50 95 nM), collagen (IC50 57 nM), and thrombin (IC50 22 nM) in a dose-dependent manner. This disintegrin also inhibited 81% and 94% of the adhesion of platelets to fibrinogen and collagen under continuous flow, respectively. In addition, rjararacin efficaciously prevents platelet aggregation in vitro and ex vivo with rat platelets and thrombus occlusion at an effective dose (5 mg/kg). The data here provides evidence that rjararacin possesses the potential as an αIIbß3 antagonist, capable of preventing arterial thrombosis.


Assuntos
Venenos de Crotalídeos , Trombose , Ratos , Animais , Desintegrinas/farmacologia , Desintegrinas/química , Desintegrinas/metabolismo , Inibidores da Agregação Plaquetária/farmacologia , Inibidores da Agregação Plaquetária/química , Venenos de Crotalídeos/química , Venenos de Crotalídeos/farmacologia , Agregação Plaquetária , Hemostasia , Integrinas/metabolismo , Trombose/tratamento farmacológico
18.
Nanotheranostics ; 7(1): 22-40, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36593794

RESUMO

Over the last decades, gold nanoparticles (AuNPs) have proven to be remarkable tools for drug delivery and theranostic applications in cancer treatment. On the other hand, Pt(IV) prodrugs have been employed as an interesting alternative to the more common Pt(II) complexes, such as cisplatin, for cancer chemotherapy. Searching to design an image-guided nanocarrier to deliver selectively Pt(IV) prodrugs to tumors expressing the gastrin releasing peptide receptor (GRPR), we have synthesized small core AuNPs carrying a thiolated DOTA derivative, a GRPR-targeting bombesin analog (BBN[7-14]) and a Pt(IV) prodrug attached to the AuNPs without (AuNP-BBN-Pt1) or with a PEGylated linker (AuNP-BBN-Pt2 and AuNP-BBN-Pt3). In the GRPR+ prostate cancer PC3 cell line, the cytotoxic activity of the designed AuNP-BBN-Pt nanoparticles is strongly influenced by the presence of the PEGylated linker. Thus, AuNP-BBN-Pt1 displayed the lowest IC50 value (9.3 ± 2.3 µM of Pt), which is comparable to that exhibited by cisplatin in the same cell line. In contrast, AuNP-BBN-Pt1 showed an IC50 value of 97 ± 18 µM of Pt in the non-tumoral RWPE-1 prostate cells with a much higher selective index (SI) towards PC3 cells (SI = 10) when compared with cisplatin (SI = 1.3). The AuNPs were also successfully labeled with 67Ga and the resulting 67Ga-AuNP-BBN-Pt were used to assess their cellular uptake in PC3 cells, with AuNP-BBN-Pt1 also displaying the highest cellular internalization. Finally, intratumoral administration of 67Ga-AuNP-BBN-Pt1 in a PC3 tumor-bearing mice showed a prolonged retention of the nanoparticle compared to that of cisplatin, with optimal in vivo stability and 20% of the injected platinum remaining in the tumor after 72 h post-injection. Furthermore, microSPECT imaging studies confirmed the uptake and considerable retention of the 67Ga-labeled AuNPs in the tumors. Overall, these results show the potential of these targeted AuNPs loaded with Pt(IV) prodrugs for prostate cancer theranostics.


Assuntos
Nanopartículas Metálicas , Pró-Fármacos , Neoplasias da Próstata , Humanos , Masculino , Animais , Camundongos , Pró-Fármacos/farmacologia , Ouro , Cisplatino/farmacologia , Nanopartículas Metálicas/química , Receptores da Bombesina/metabolismo , Neoplasias da Próstata/metabolismo , Polietilenoglicóis
19.
J Inorg Biochem ; 240: 112091, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36527994

RESUMO

Gallium and indium octahedral complexes with isoniazid derivative ligands were successfully prepared. The ligands, isonicotinoyl benzoylacetone (H2L1) and 4-chlorobenzoylacetone isonicotinoyl hydrazone (H2L2), and their respective coordination compounds with gallium and indium [GaL1(HL1)] (GaL1), [GaL2(HL2)] (GaL2), [InL1(HL1)] (InL1) and [InL2(HL2)] (InL2) were investigated by NMR, ESI-MS, UV-Vis, IR, single-crystal X-ray diffraction and elemental analysis. In vitro interaction studies with human serum albumin (HSA) evidenced a moderate affinity of all complexes with HSA through spontaneous hydrophobic interactions. The greatest suppression of HSA fluorescence was caused by GaL2 and InL2, which was associated to the higher lipophilicity of H2L2. In vitro interaction studies with CT-DNA indicated weak interactions of the biomolecule with all complexes. Cytotoxicity assays with MCF-7 (breast carcinoma), PC-3 (prostate carcinoma) and RWPE-1 (healthy human prostate epithelial) cell lines showed that complexes with H2L2 are more active and selective against MCF-7, with the greatest cytotoxicity observed for InL2 (IC50 = 10.34 ± 1.69 µM). H2L1 and H2L2 were labelled with gallium-67, and it was verified that 67GaL2 has a greater lipophilicity than 67GaL1, as well as higher stability in human serum or in the presence of apo-transferrin. Cellular uptake assays with 67GaL1 and 67GaL2 evidenced that the H2L2-containing radiocomplex has a higher accumulation in MCF-7 and PC-3 cells than the non-halogenated congener 67GaL1. The anti-Mycobacterium tuberculosis assays revealed that both ligands and metal complexes are potent growth inhibitors, with MIC90 (µg mL-1) values observed from 0.419 ± 0.05 to 1.378 ± 0.21.


Assuntos
Antineoplásicos , Complexos de Coordenação , Gálio , Mycobacterium tuberculosis , Neoplasias , Tuberculose , Masculino , Humanos , Isoniazida/farmacologia , Índio/farmacologia , Gálio/farmacologia , Gálio/química , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Ligantes , Antineoplásicos/farmacologia , Antineoplásicos/química
20.
An. bras. dermatol ; 98(6): 814-836, 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1520040

RESUMO

Abstract This publication is an update of the "Consensus on the therapeutic management of atopic dermatitis - Brazilian Society of Dermatology" published in 2019, considering the novel, targeted-oriented systemic therapies for atopic dermatitis. The initial recommendations of the current consensus for systemic treatment of patients with atopic dermatitis were based on a recent review of scientific published data and a consensus was reached after voting. The Brazilian Society of Dermatology invited 31 experts from all regions of Brazil and 2 international experts on atopic dermatitis who fully contributed to the process. The methods included an e-Delphi study to avoid bias, a literature search and a final consensus meeting. The authors added novel approved drugs in Brazil and the indication for phototherapy and systemic therapy for AD. The therapeutical response to systemic treatment is hereby reported in a suitable form for clinical practice and is also part of this updated manuscript.

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