Hasil untuk "Diseases of the blood and blood-forming organs"

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arXiv Open Access 2025
Multi-models with averaging in feature domain for non-invasive blood glucose estimation

Yiting Wei, Bingo Wing-Kuen Ling, Qing Liu et al.

Diabetes is a serious chronic metabolic disease. In the recent years, more and more consumer technology enterprises focusing on human health are committed to implementing accurate and non-invasive blood glucose algorithm in their products. However, due to the interference from the external environment, these wearable non-invasive methods yield the low estimation accuracy. To address this issue, this paper employs different models based on different ranges of the blood glucose values for performing the blood glucose estimation. First the photoplethysmograms (PPGs) are acquired and they are denoised via the bit plane singular spectrum analysis (SSA) method. Second, the features are extracted. For the data in the training set, first the features are averaged across the measurements in the feature domain via the optimization approach. Second, the random forest is employed to sort the importance of each feature. Third, the training set is divided into three subsets according to the reference blood glucose values. Fourth, the feature vectors and the corresponding blood glucose values in the same group are employed to build an individual model. Fifth, for each feature, the average of the feature values for all the measurements in the same subset is computed. For the data in the test set, first, the sum of the weighted distances between the test feature values and the average values obtained in the above is computed for each model. Here, the weights are defined based on the importance sorted by the random forest obtained in the above. The model corresponding to the smallest sum is assigned. Finally, the blood glucose value is estimated based on the corresponding model. Compared to the state of arts methods, our proposed method can effectively improve the estimation accuracy.

arXiv Open Access 2025
An Integrated Open Source Software System for the Generation and Analysis of Subject-Specific Blood Flow Simulation Ensembles

Simon Leistikow, Thomas Miro, Adrian Kummerländer et al.

Background and Objective: Hemodynamic analysis of blood flow through arteries and veins is critical for diagnosing cardiovascular diseases, such as aneurysms and stenoses, and for investigating cardiovascular parameters, such as turbulence and wall shear stress. For subject-specific analyses, the anatomy and blood flow of the subject can be captured non-invasively using structural and 4D Magnetic Resonance Imaging (MRI). Computational Fluid Dynamics (CFD), on the other hand, can be used to generate blood flow simulations by solving the Navier-Stokes equations. To generate and analyze subject-specific blood flow simulations, MRI and CFD have to be brought together. Methods: We present an interactive, customizable, and user-oriented visual analysis tool that assists researchers in both medicine and numerical analysis. Our open-source tool is applicable to domains such as CFD and MRI, and it facilitates the analysis of simulation results and medical data, especially in hemodynamic studies. It enables the creation of simulation ensembles with a high variety of parameters. Furthermore, it allows for the visual and analytical examination of simulations and measurements through 2D embeddings of the similarity space. Results: To demonstrate the effectiveness of our tool, we applied it to three real-world use cases, showcasing its ability to configure simulation ensembles and analyse blood flow dynamics. We evaluated our example cases together with MRI and CFD experts to further enhance features and increase the usability. Conclusions: By combining the strengths of both CFD and MRI, our tool provides a more comprehensive understanding of hemodynamic parameters, facilitating more accurate analysis of hemodynamic biomarkers.

en physics.med-ph, cs.SE
DOAJ Open Access 2025
Intravascular Ultrasound-Guided Covered Endovascular Reconstruction of the Aortic Bifurcation for Acute Aortic Occlusion Concurrent with Severe Acute Necrotizing Pancreatitis: A Case Report

Diego Soto V, Paulo Cassis C, Cristian Marín O et al.

Acute aortic occlusion (AAO) is a high-mortality condition, and its occurrence during severe acute necrotizing pancreatitis (SANP) is rare. A 62-year-old male with SANP developed AAO. Urgent hybrid revascularization—including thrombectomy and the covered endovascular reconstruction of the aortic bifurcation (CERAB) technique guided by intravascular ultrasound (IVUS)—was performed. The patient recovered bilateral lower limb perfusion and distal pulses without requiring further vascular reinterventions or other major surgical procedures. However, he developed severe medical complications during the postoperative period, including pelvic infections and acute renal failure. Nonetheless, the patient recovered and was discharged on postoperative day 64. A hybrid approach—combining thrombectomy with IVUS-guided CERAB—appears technically feasible as an urgent revascularization strategy for AAO. However, despite procedural feasibility of a hybrid approach, the combination of AAO and severe SANP-related medical complications is associated with an elevated risk of short-term morbidity and mortality.

Diseases of the blood and blood-forming organs, Diseases of the circulatory (Cardiovascular) system
DOAJ Open Access 2025
Pharmacological activity of OST-01, a natural product from baccharis coridifolia, on breast cancer cells

HyunJun Kang, Dinh Hoa Hoang, Melissa Valerio et al.

Abstract Natural products have long been a viable source of therapeutic agents, providing unique structures and mechanisms that may be beneficial for cancer treatment. Herein we first report on the anticancer activity OST-01, a natural product from Baccharis Coridifolia, on breast cancer cells, including triple-negative breast cancer (TNBC). OST-01 significantly inhibited cell proliferation and oncogenic activities of TNBC cells in vitro. OST-01 also markedly inhibited TNBC tumor growth in vivo, with > 50% reduction in tumor size compared to vehicle control treatment in different in vivo models, i.e., cell line-derived (CDX), patient-derived (PDX), and mammary fat pad xenografts. Mechanistically, OST-01 induces ferroptosis by downregulating LRP8-regulated selenoproteins, i.e., GPX4. A shift from a basal-mesenchymal to a luminal-epithelial state of breast cancer stem cells (BCSCs) as supported by the downregulation of stemness (e.g., CD44) and mesenchymal (e.g., FN1 and vimentin) markers, along with the upregulation of differentiation markers (e.g., CD24) and luminal-epithelial markers (e.g., CK19), was also observed.

Diseases of the blood and blood-forming organs, Neoplasms. Tumors. Oncology. Including cancer and carcinogens
arXiv Open Access 2024
Multimodal Analysis of White Blood Cell Differentiation in Acute Myeloid Leukemia Patients using a β-Variational Autoencoder

Gizem Mert, Ario Sadafi, Raheleh Salehi et al.

Biomedical imaging and RNA sequencing with single-cell resolution improves our understanding of white blood cell diseases like leukemia. By combining morphological and transcriptomic data, we can gain insights into cellular functions and trajectoriess involved in blood cell differentiation. However, existing methodologies struggle with integrating morphological and transcriptomic data, leaving a significant research gap in comprehensively understanding the dynamics of cell differentiation. Here, we introduce an unsupervised method that explores and reconstructs these two modalities and uncovers the relationship between different subtypes of white blood cells from human peripheral blood smears in terms of morphology and their corresponding transcriptome. Our method is based on a beta-variational autoencoder (ß-VAE) with a customized loss function, incorporating a R-CNN architecture to distinguish single-cell from background and to minimize any interference from artifacts. This implementation of ß-VAE shows good reconstruction capability along with continuous latent embeddings, while maintaining clear differentiation between single-cell classes. Our novel approach is especially helpful to uncover the correlation of two latent features in complex biological processes such as formation of granules in the cell (granulopoiesis) with gene expression patterns. It thus provides a unique tool to improve the understanding of white blood cell maturation for biomedicine and diagnostics.

en cs.CV, cs.LG
arXiv Open Access 2024
Predicting Progression Events in Multiple Myeloma from Routine Blood Work

Maximilian Ferle, Nora Grieb, Markus Kreuz et al.

The ability to accurately predict disease progression is paramount for optimizing multiple myeloma patient care. This study introduces a hybrid neural network architecture, combining Long Short-Term Memory networks with a Conditional Restricted Boltzmann Machine, to predict future blood work of affected patients from a series of historical laboratory results. We demonstrate that our model can replicate the statistical moments of the time series ($0.95~\pm~0.01~\geq~R^2~\geq~0.83~\pm~0.03$) and forecast future blood work features with high correlation to actual patient data ($0.92\pm0.02~\geq~r~\geq~0.52~\pm~0.09$). Subsequently, a second Long Short-Term Memory network is employed to detect and annotate disease progression events within the forecasted blood work time series. We show that these annotations enable the prediction of progression events with significant reliability (AUROC$~=~0.88~\pm~0.01$), up to 12 months in advance (AUROC($t+12~$mos)$~=0.65~\pm~0.01$). Our system is designed in a modular fashion, featuring separate entities for forecasting and progression event annotation. This structure not only enhances interpretability but also facilitates the integration of additional modules to perform subsequent operations on the generated outputs. Our approach utilizes a minimal set of routine blood work measurements, which avoids the need for expensive or resource-intensive tests and ensures accessibility of the system in clinical routine. This capability allows for individualized risk assessment and making informed treatment decisions tailored to a patient's unique disease kinetics. The represented approach contributes to the development of a scalable and cost-effective virtual human twin system for optimized healthcare resource utilization and improved patient outcomes in multiple myeloma care.

en stat.AP, q-bio.QM
DOAJ Open Access 2024
PREVALÊNCIA DE ALOIMUNIZACÃO EM PACIENTES COM DOENÇA FALCIFORME ATENDIDOS NO HEMOCENTRO DO ACRE

RCA Carvalho, DC Smielewski, BC Almeida et al.

Objetivo: Determinar a prevalência de anticorpos antieritrocitários em pacientes com doença falciforme (DF) que realizaram transfusão nos hospitais do Acre. Material e métodos: Trata-se de um estudo observacional retrospectivo, realizado de 01/09/17 a 01/07/24, abrangendo 84 pacientes com DF que receberam hemocomponentes no período. As investigações imunohematológicas se inciaram com a Pesquisa de Anticorpos Irregulares (PAI). Amostras positivas para a PAI foram submetidas a um painel com 11 hemácias de fenótipo conhecido para identificação de anticorpos irregulares utilizando o método Gel Centrifugação em cartão de Liss/Coombs. Todos os estudos imunohematológicos do Acre são realizados no hemocentro coordenador do estado. Resultados: Dos 84 pacientes com DF que receberam concentrado de hemácias, 14 (16,7%) apresentaram PAI positivo, dos quais 8 (57%) apresentaram anticorpos únicos e 6 (43%) apresentaram múltiplos anticorpos. Foram identificados 22 anticorpos, com as seguintes prevalências de especificidade: Anti-E 10 (45,4%), Anti-C 3 (13,6%), Anti-c 3 (13,6%), Anti-Kell 2 (9,1%), Anti-M 1 (4,5%), Anti-D 1 (4,5%), Anti-S 1 (4,5%) e Anti-Jkb 1 (4,5%). Discussão: Estudos com pacientes com DF no Brasil mostram prevalências variáveis de aloimunização. Em São Paulo, 22,6% dos pacientes com DF desenvolveram anticorpos irregulares, sendo o anti-Kell o mais frequente. Em Salvador, a taxa foi de 51,9%, sendo o anti-E, o aloanticorpo mais prevalente. Em Alagoas, a aloimunização foi de 12,7%, com 70% dos anticorpos pertencentes aos sistemas Rh e Kell. O desenvolvimento de aloanticorpos pode causar reações transfusionais, sejam elas agudas ou tardias. Além disso, sua ocorrência dificulta a disponibilização de hemácias compatíveis em futuras transfusões. O risco de aloimunização depende da imunogenicidade do antígeno, da resposta imune do receptor, da diferença no padrão antigênico do doador e do receptor e da frequência de transfusões. Pacientes com DF homozigotos frequentemente necessitam de múltiplas transfusões de concentrado de hemácias, expondo-os a diversos antígenos eritrocitários. Embora seja difícil estimar a prevalência de aloimunização na população geral que já recebeu transfusão, espera-se que pacientes com DF tenham prevalências mais altas, devido às transfusões frequentes. Em Rio Branco, a prevalência de aloimunização está dentro da descrita nacionalmente, sendo o Anti-E o mais prevalente, assim como em Salvador. Além do grupo E, foram encontradas altas prevalências para os anticorpos Anti-C e Anti-c. Anticorpos Anti-E, Anti-c, Anti-Kell, Anti-D e Anti-S estão associados a reações transfusionais hemolíticas tardias. O grupo E é considerado altamente imunogênico e relevante clinicamente, embora não seja comum na população em geral. Devido ao surgimento desses anticorpos nos pacientes com DF, seriam necessários mais estudos sobre o padrão fenotípico dos doadores do Acre, para melhor caracterização das idiossincrasias fenotípicas regionais e melhor manejo de hemocomponentes para os pacientes com DF. Conclusão: Embora a prevalência de aloimunização varie no Brasil, o Hemocentro do Acre apresenta dados que se alinham com os extremos registrados no país. A preocupação com aloimunizações é relevante para reduzir as reações transfusionais, melhorar o manejo dos hemocomponentes e proporcionar um tratamento de melhor qualidade para esses pacientes.

Diseases of the blood and blood-forming organs
DOAJ Open Access 2024
POTENCIAL IMUNOMODULADOR DO EXTRATO DE PELARGONIUM SIDOIDES EM LINFÓCITOS T CD8 EM PACIENTES COM LEUCEMIA LINFOCÍTICA CRÔNICA

SR Oliveira, TH Luizete, LR Soares et al.

Introdução: A leucemia linfocítica crônica (LLC) promove uma disfunção do sistema imunológico, que se manifesta principalmente no estado de imunodeficiência humoral e celular e em uma alta incidência de doenças autoimunes, infecções e malignidades secundárias. A presença de comorbidades e a condição geral dos pacientes também influenciam a suscetibilidade a infecções, sendo associada a defeitos nas células citotóxicas afetando suas funções normais. As terapias complementares para o tratamento do câncer em geral, incluindo o uso de produtos naturais como os fitoterápicos, estão sendo cada vez mais utilizadas como terapias complementares aos tratamentos convencionais. O extrato de Pelargonium sidoides, comercialmente disponível como EPs® 7630, apresenta metabólitos secundários como polifenólicos e cumarina, com potenciais propriedades anticancerígenas e estudos indicam que atua como um fármaco capaz de estimular a resposta imunológica. Objetivo: Este estudo teve como objetivo avaliar o potencial do EPs® 7630 na imunomodulação relacionada à produção de perforina e granzima B por linfócitos T CD8 em pacientes com LLC. Materiais e métodos: Inicialmente, foi realizada coleta e separação de células mononucleares do sangue periférico (PBMCs) de oito pacientes com LLC atendidos no Hospital das Clínicas da Universidade Federal do Triângulo Mineiro (UFTM). Em seguida, foi realizado o tratamento das células PBMCs com extrato EPs® 7630 (Kaloba®, Takeda Pharma Ltda) nas concentrações de 10 e 100 μg/mL, em triplicatas. Foram mantidas em incubadora com a atmosfera de CO2 de 5% a 37°C por 72 horas. Após o período de incubação, foi realizada a análise por citometria de fluxo com as marcações anti-CD3 (BV450), anti-CD8 (APC-H7), anti-perforina clone DG9 (PE), anti-perforina clone BD48 (PerCP) e anti-granzima B (FITC). As células T CD8 foram identificadas a partir da marcação positiva para CD3 e CD8. Resultados: O tratamento com o extrato de P. sidoides na concentração de 100 μg/mL promoveu uma maior quantidade de células T CD8 que expressavam perforina inativa, comparada às que não receberam tratamento (48,27% vs. 42,38%, p = 0,0142) e àquelas que foram tratadas com a concentração 10 μg/mL do extrato (48,27% vs. 43,24%, p = 0,0372). A expressão de perforina ativada e granzima B não diferiu entre os tratamentos. Discussão: Esses achados sugerem que o EPs® 7630 pode modular a resposta imune por meio da regulação da expressão de proteínas envolvidas na citotoxicidade mediada por células T CD8. A capacidade do extrato de promover a expressão da perforina inativa pode ter implicações no controle da resposta imune contra células tumorais, indicando um potencial papel terapêutico na LLC e em outras neoplasias hematológicas. Conclusão: O estudo mostrou o potencial imunomodulador do EPs® 7630 em pacientes com LLC, evidenciando um aumento na produção de perforina em células T CD8. Investigações adicionais in vitro e in vivo poderão contribuir para uma melhor compreensão do potencial terapêutico do extrato na resposta imune em neoplasias hematológicas.

Diseases of the blood and blood-forming organs
arXiv Open Access 2023
Predicting blood pressure under circumstances of missing data: An analysis of missing data patterns and imputation methods using NHANES

Harish Chauhan, Nikunj Gupta, Zoe Haskell-Craig

The World Health Organization defines cardio-vascular disease (CVD) as "a group of disorders of the heart and blood vessels," including coronary heart disease and stroke (WHO 21). CVD is affected by "intermediate risk factors" such as raised blood pressure, raised blood glucose, raised blood lipids, and obesity. These are predominantly influenced by lifestyle and behaviour, including physical inactivity, unhealthy diets, high intake of salt, and tobacco and alcohol use. However, genetics and social/environmental factors such as poverty, stress, and racism also play an important role. Researchers studying the behavioural and environmental factors associated with these "intermediate risk factors" need access to high quality and detailed information on diet and physical activity. However, missing data are a pervasive problem in clinical and public health research, affecting both randomized trials and observational studies. Reasons for missing data can vary substantially across studies because of loss to follow-up, missed study visits, refusal to answer survey questions, or an unrecorded measurement during an office visit. One method of handling missing values is to simply delete observations for which there is missingness (called Complete Case Analysis). This is rarely used as deleting the data point containing missing data (List wise deletion) results in a smaller number of samples and thus affects accuracy. Additional methods of handling missing data exists, such as summarizing the variables with its observed values (Available Case Analysis). Motivated by the pervasiveness of missing data in the NHANES dataset, we will conduct an analysis of imputation methods under different simulated patterns of missing data. We will then apply these imputation methods to create a complete dataset upon which we can use ordinary least squares to predict blood pressure from diet and physical activity.

en cs.LG, stat.ME
DOAJ Open Access 2023
AVALIAÇÃO DO USO DE ESTROGÊNIOS CONJUGADOS PARA O TRATAMENTO DE HEMORRAGIA DIGESTIVA BAIXA POR ANGIODISPLASIA: RELATO DE CASO

EGRA Câmara, CSSD Paiva, LJV Rodrigues et al.

Introdução: As Angiodisplasias Gastrointestinais (AG) são malformações vasculares que acometem mais comumente o cólon, predispondo à ocorrência de Hemorragia Digestiva Baixa (HDB) em até 40% dos casos. As modalidades terapêuticas incluem a terapia endoscópica, arteriografia com angioembolização e, em casos refratários, a ressecção cirúrgica do segmento acometido. O manejo medicamentoso, por sua vez, é reservado aos doentes com lesões múltiplas, inacessíveis via endoscopia, com falha ou contraindicação às terapias invasivas. O tratamento hormonal baseado no uso de estrogênio, com ou sem progesterona, constitui uma alternativa terapêutica para os pacientes com telangiectasia hemorrágica hereditária, doença renal terminal ou doença de Von Willebrand, tendo sua eficácia questionável nos casos de AG esporádica. Objetivo: Relatar caso de AG hemorrágica não hereditária refratária tratada com Estrogênios Conjugados (EC). Relato de caso: Paciente do sexo masculino, 55 anos, hipertenso e portador de diverticulose, deu entrada em hospital de referência com quadro de lipotímia, sudorese e melena 3 dias antes da admissão. Iniciada investigação por endoscopia digestiva alta e colonoscopia, ambas sem evidência de foco hemorrágico. Devido à persistência do sangramento e piora do estado geral, foi realizada laparotomia exploradora, com enterotomia duodenal e esclerose endoscópica de telangiectasia. Após 10 dias, na ausência de melhora clínica, optado por proceder arteriografia com embolização dos ramos das artérias jejunoileais e introdução de EC 0,625 mg via oral 8/8h, evoluindo após 3 dias com choque hemorrágico e necessidade de hemotransfusão. No quinto dia pós-operatório, foi realizada angiotomografia com presença de sangue em ampola retal e mantido tratamento clínico, evoluindo após o oitavo dia com recuperação do estado geral e melhora dos índices hematimétricos. Discussão: O efeito pró-trombótico dos EC é documentado devido estímulo ao aumento dos níveis plasmáticos dos fatores II, VII, VIII, X, Fibrinogênio e do Fator de Von Willebrand, tendo seu pico de ação no 7° dia de uso. Apesar da ação anti-hemorrágica, seu benefício em casos de AG ainda não é bem documentado. Nesse relato, é possível avaliar paciente refratário às medidas protocolares com melhora clínica e laboratorial após 8 dias da introdução do hormônio conjugado. Conclusão: O uso de EC como terapia medicamentosa pode ser benéfico em casos de angiodisplasia sangrante refratária à terapia de primeira linha devido ao seu efeito pró-coagulante. Entretanto, ainda são necessários estudos complementares para esclarecer a repercussão dessa abordagem terapêutica no tempo de internação e no desfecho clínico desse grupo de pacientes.

Diseases of the blood and blood-forming organs
arXiv Open Access 2021
Vortical flow structures induced by red blood cells in capillaries

François Yaya, Johannes Römer, Achim Guckenberger et al.

Knowledge about the flow field of the plasma around the red blood cells in capillary flow is important for a physical understanding of blood flow and the transport of micro- and nanoparticles and molecules in the flowing plasma. We conduct an experimental study on the flow field around red blood cells in capillary flow that are complemented by simulations of vortical flow between red blood cells. Red blood cells were injected in a 10x12 micrometer rectangular microchannel at a low hematocrit and the flow field around a single or two cells have been characterized thanks to a highspeed camera and by tracking 250 nm nanoparticles in flow behaving as tracers. While the flow field around a steady croissant shape is found to be relatively similar to that of a rigid sphere, the flow field around a slipper shape exhibits a small vortex at the rear of the red blood cell. Even more pronounced are vortex-like structures observed in the central region between two neighboring croissants. Conclusions: The rotation frequency of the vortices is to a good approximation, inversely proportional to the distance between the cells. Our experimental data are confirmed and complemented by numerical simulations.

en physics.bio-ph, physics.flu-dyn
arXiv Open Access 2021
Ambulatory blood pressure monitoring versus office blood pressure measurement: Are there sex differences?

Aleksandar Miladinović, Miloš Ajčević, Giulia Siveri et al.

The accurate measurement of blood pressure (BP) is an important prerequisite for the reliable diagnosis and efficient management of hypertension and other medical conditions. Office Blood Pressure Measurement (OBP) is a technique performed in-office with the sphygmomanometer, while Ambulatory Blood Pressure Monitoring (ABPM) is a technique that measures blood pressure during 24h. The BP fluctuations also depend on other factors such as physical activity, temperature, mood, age, sex, any pathologies, a hormonal activity that may intrinsically influence the differences between OBP and ABPM. The aim of this study is to examine the possible influence of sex on the discrepancies between OBP and ABPM in 872 subjects with known or suspected hypertension. A significant correlation was observed between OBP and ABPM mean values calculated during the day, night and 24h (ABPMday, ABPMnight, ABPM24h) in both groups (p<0.0001). The main finding of this study is that no difference between sexes was observed in the relation between OBP and mean ABMP values except between systolic OBP and systolic ABPM during the night. In addition, this study showed a moderate correlation between BPs obtained with the two approaches with a great dispersion around the regression line which suggests that the two approaches cannot be used interchangeably.

en eess.SP, cs.LG
DOAJ Open Access 2021
Colony-stimulating factor 3 receptor (CSF3R) M696T mutation does not impact on clinical outcomes of a Ph+ acute lymphoblastic leukemia patient

Xin Chen, Bichen Wang, Aiming Pang et al.

Abstract. Colony-stimulating factor 3 receptor (CSF3R) mutations have been identified in a variety of myeloid disorders. Although CSF3R point mutations (eg, T618I) are emerging as key players in chronic neutrophilic leukemia/atypical chronic myelogenous leukemia , the significance of rarer CSF3R mutations is unknown. Here, we report a 32-year-old female who was diagnosed as Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) with the CSF3R M696T mutation and was undergone unrelated donor hematopoietic stem cell transplantation. The patient achieved complete remission with chemotherapy in combination with tyrosine kinase inhibitor (TKI) and long-term survival by unrelated donor transplantation. Meanwhile, we performed a series of experiments using murine interleukin 3 (IL-3)-dependent Ba/F3 cell line to evaluate the transforming capacity of the CSF3R M696T mutation. We confirmed the presence of a CSF3R M696T germline mutation in this patient which was inherited from her mother. The in vitro experiment results showed that the CSF3R M696T mutation contributes marginally to the tumor transformation of Ba/F3 cells, indicating that CSF3R M696T mutation was neutral in tumor transformation ability. We concluded that TKI is effective in patients with the CSF3R M696T mutation in Ph+ ALL and donors with CSF3R M696T mutation might still be selected as the candidate for transplantation.

Diseases of the blood and blood-forming organs
DOAJ Open Access 2021
MODULAÇÃO EPIGENÉTICA DE EHMT1/EHMT2 EM LINHAGENS DE MELANOMA E CARCINOMA DE PULMÃO

LDC Filiú-Braga, FAR Neves, F Saldanha-Araujo

Objetivos: Modificações epigenéticas, incluindo metilação de DNA e modificação de histonas, controlam as expressões gênicas e desempenham um papel crucial durante a tumorigênese. A família histona metiltransferase de EHMT composta por EHMT1 e EHMT2 estão desregulados em vários tipos de câncer, onde essas enzimas parecem desempenhar funções centrais em processos oncogênicos importantes. Nesse trabalho, investigamos a ação da inibição de EHMT1 e EHMT2 por UNC-0646 - um potente inibidor seletivo dessas enzimas - na proliferação e viabilidade celular, morte celular e disfunção mitocondrial em duas linhagens humanas de câncer, uma de melanoma (MEWO) e a outra de carcinoma de pulmão (A549). Material e método: Para isso, usamos UNC0646 nas linhagens, MEWO e A549, por ensaio de MTT para avaliação da proliferação e viabilidade celular. Em seguida, considerando o IC50 e IC75, a morte celular foi determinada por coloração com Anexina V/PI e para avaliação do potencial de membrana mitocondrial foi usado a sonda Rodamina 123. Em ambas as marcações usamos citometria de fluxo. Resultados: A inibição das enzimas EHMT1/EHMT2 demonstrou uma diminuição significativamente na viabilidade das células, Mewo e A549, de uma maneira dependente da dose. Concordante, observamos que a inibição também promoveu despolarização do potencial de membrana mitocondrial e consequentemente a morte celular em ambas as linhagens. Discussão: Corroborando com os achados observados, alguns trabalhos mostraram que a modulação direcionado de EHMT1/EHMT2 levaram também a promoção do apoptose celular para outros tipos de câncer, incluindo câncer de mama, glioblastoma, LLC, LLA e câncer de bexiga. Conclusão: Sendo assim, estes resultados indicam claramente que a inibição de EHMT1/EHMT2 promove a morte celular de células cancerígenas. Indicando que essas histonas metiltransferases podem ser um alvo epigenético para o tratamento do carcinoma de pulmão e melanoma maligno.

Diseases of the blood and blood-forming organs

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