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1.
Transfus Med Rev ; 37(4): 150780, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37996288

RESUMO

In this review, we provide critical analysis of social science research into blood donation motivation and behavior. We first share an understanding of the existing literature and recommendations for future research collectively developed by members of the Working Group on Blood Donors and the Supply: Diversifying while Maintaining the Donor Pool, Donor Selection, and Optimizing Blood Availability and Safety, as part of the National Heart, Lung, and Blood Institute's 2022 State of the Science in Transfusion Medicine symposium. Then, rather than aim for a comprehensive treatment, we review 4 newer manuscripts that exemplify aspects of the group's recommendations and report results from countries where the blood supply is based on voluntary, nonremunerated donations. From the substantial existing literature, we selected: (1) a study that employed motivational interviewing techniques, thematic analysis, and surveys to link donation motivations and barriers reported by diverse young donors in the United States to actual donation behavior over a year of subsequent eligibility; (2) a survey regarding donation motivations and barriers and monetary amounts associated with willingness to participate in whole blood, plasma, or platelet collection; (3) a survey-based assessment of various emotional states reported by donors at 2 time points during donation and the relationship between emotional experience and subsequent vasovagal reactions; and (4) an interpretive discourse analysis of blood collection agency messaging to donors and the public in the beginning of the COVID-19 pandemic. We close by noting several challenges posed by the structure of the United States blood system and the current funding environment to conducting rigorous research and translating findings into practice.


Assuntos
Doação de Sangue , Motivação , Humanos , Pandemias , Doadores de Sangue , Inquéritos e Questionários
2.
Transfusion ; 63(5): 1074-1091, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37005871

RESUMO

BACKGROUND: State of the Science (SoS) meetings are used to define and highlight important unanswered scientific questions. The National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health, and the Office of the Assistant Secretary for Health (OASH), Department of Health and Human Services held a virtual SoS in transfusion medicine (TM) symposium. STUDY DESIGN AND METHODS: In advance of the symposium, six multidisciplinary working groups (WG) convened to define research priorities in the areas of: blood donors and the supply, optimizing transfusion outcomes for recipients, emerging infections, mechanistic aspects of components and transfusion, new computational methods in transfusion science, and impact of health disparities on donors and recipients. The overall objective was to identify key basic, translational, and clinical research questions that will help to increase and diversify the volunteer donor pool, ensure safe and effective transfusion strategies for recipients, and identify which blood products from which donors best meet the clinical needs of specific recipient populations. RESULTS: On August 29-30, 2022, over 400 researchers, clinicians, industry experts, government officials, community members, and patient advocates discussed the research priorities presented by each WG. Dialogue focused on the five highest priority research areas identified by each WG and included the rationale, proposed methodological approaches, feasibility, and barriers for success. DISCUSSION: This report summarizes the key ideas and research priorities identified during the NHLBI/OASH SoS in TM symposium. The report highlights major gaps in our current knowledge and provides a road map for TM research.


Assuntos
National Heart, Lung, and Blood Institute (U.S.) , Medicina Transfusional , Estados Unidos , Humanos , Transfusão de Sangue/métodos
3.
Transfusion ; 59(10): 3077-3083, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31490558

RESUMO

BACKGROUND: Astronauts on exploration missions may be at risk for traumatic injury and medical conditions that lead to life threatening hemorrhage. Resuscitation protocols are limited by the austere conditions of spaceflight. Solutions may be found in low-resource terrestrial settings. The existing literature on alternative blood product administration and walking blood banks was evaluated for applicability to spaceflight. STUDY DESIGN AND METHODS: A literature review was done using PubMed and Google Scholar. References were crosschecked for additional publications not identified using the initial search terms. Twenty-seven articles were identified, including three controlled trials, six retrospective cohort analyses, 15 reviews, one case report, and two experimental studies. RESULTS: Solutions to blood transfusion in austere settings include lyophilized blood products, hemoglobin-based oxygen carriers (HBOCs), and fresh whole blood. Many of these products are investigational. Protocols for walking blood banks include methods for screening and activating donors, transfusion, and monitoring for adverse reactions. Microgravity and mission limitations create additional challenges for transfusion, including baseline physiologic changes, difficulty reconstituting lyophilized products, risk of air emboli during transfusion, equipment constraints, and limited evacuation and surgical options. CONCLUSION: Medical planning for space exploration should consider the possibility of acute blood loss. A model for "floating" blood banks based on terrestrial walking blood bank protocols from austere environments is presented, with suggestions for future development. Constraints on volume, mass, storage, and crew, present challenges to blood transfusion in space and must be weighed against the benefits of expanding medical capabilities.


Assuntos
Bancos de Sangue , Transfusão de Sangue , Hemorragia/terapia , Ressuscitação , Voo Espacial , Animais , Humanos
5.
Mil Med ; 183(suppl_2): 44-51, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-30189061

RESUMO

Whole blood is the preferred product for resuscitation of severe traumatic hemorrhage. It contains all the elements of blood that are necessary for oxygen delivery and hemostasis, in nearly physiologic ratios and concentrations. Group O whole blood that contains low titers of anti-A and anti-B antibodies (low titer group O whole blood) can be safely transfused as a universal blood product to patients of unknown blood group, facilitating rapid treatment of exsanguinating patients. Whole blood can be stored under refrigeration for up to 35 days, during which it retains acceptable hemostatic function, though supplementation with specific blood components, coagulation factors or other adjuncts may be necessary in some patients. Fresh whole blood can be collected from pre-screened donors in a walking blood bank to provide effective resuscitation when fully tested stored whole blood or blood components are unavailable and the need for transfusion is urgent. Available clinical data suggest that whole blood is at least equivalent if not superior to component therapy in the resuscitation of life-threatening hemorrhage. Low titer group O whole blood can be considered the standard of care in resuscitation of major hemorrhage.


Assuntos
Transfusão de Componentes Sanguíneos/normas , Transfusão de Sangue/métodos , Armazenamento de Sangue/métodos , Transfusão de Componentes Sanguíneos/métodos , Transfusão de Sangue/tendências , Hemorragia/terapia , Humanos , Militares , Ressuscitação/métodos
7.
Transfusion ; 57(10): 2440-2448, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28703859

RESUMO

BACKGROUND: Donor behaviors in STRIDE (Strategies to Reduce Iron Deficiency), a trial to reduce iron deficiency, were examined. STUDY DESIGN AND METHODS: Six hundred ninety-two frequent donors were randomized to receive either 19 or 38 mg iron for 60 days or an educational letter based on their predonation ferritin. Compliance with assigned pills, response to written recommendations, change in donation frequency, and future willingness to take iron supplements were examined. RESULTS: Donors who were randomized to receive iron pills had increased red blood cell donations and decreased hemoglobin deferrals compared with controls or with pre-STRIDE donations. Donors who were randomized to receive educational letters had fewer hemoglobin deferrals compared with controls. Of those who received a letter advising of low ferritin levels with recommendations to take iron supplements or delay future donations, 57% reported that they initiated iron supplementation, which was five times as many as those who received letters lacking a specific recommendation. The proportion reporting delayed donation was not statistically different (32% vs. 20%). Of donors who were assigned pills, 58% reported taking them "frequently," and forgetting was the primary reason for non-compliance. Approximately 80% of participants indicated that they would take iron supplements if provided by the center. CONCLUSIONS: Donors who were assigned iron pills had acceptable compliance, producing increased red blood cell donations and decreased low hemoglobin deferrals compared with controls or with pre-STRIDE rates. The majority of donors assigned to an educational letter took action after receiving a low ferritin result, with more donors choosing to take iron than delay donation. Providing donors with information on iron status with personalized recommendations was an effective alternative to directly providing iron supplements.


Assuntos
Doadores de Sangue/psicologia , Ferro/administração & dosagem , Correspondência como Assunto , Suplementos Nutricionais , Ferritinas/sangue , Fidelidade a Diretrizes , Hemoglobinas/análise , Humanos , Disseminação de Informação , Ferro/sangue
8.
Am J Hematol ; 92(9): 851-857, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28494509

RESUMO

Iron deficiency anemia is a common clinical condition often treated with tablets containing 65 mg of elemental iron. Such doses can elicit gastrointestinal side effects lowering patient compliance. Oral iron supplements also increase hepcidin production causing decreased fractional absorption of subsequent doses. Frequent blood donors often become iron deficient. Therefore, they were enrolled in a two-year study involving continued blood donations and randomization to receive no pill, placebo, 19, or 38 mg ferrous gluconate for 60 days. Total body iron (TBI) did not change for the subset of donors in the no pill and placebo groups who completed both enrollment and final visits (P = .21 and P = .28, respectively). However, repeated measures regression analysis on the complete dataset estimated a significant decrease in TBI of 52 mg/year for the placebo and no pill groups (P = .001). The effects of 19 and 38 mg iron supplementation on TBI were indistinguishable (P = .54). TBI increased by 229 mg after the initial 60 days of iron supplementation (P < .0001) and was maintained at this higher level with continued iron supplementation following each subsequent donation. The TBI increase was apportioned 51 mg to red cell iron (P < .0001) and 174 mg to storage iron (P < .0001). Changes in storage iron were negatively impacted by 57 mg due to concurrent antacid use (P = .04). These findings in blood donors suggest that much lower doses of iron than are currently used will be effective for clinical treatment of iron deficiency anemia.


Assuntos
Anemia Ferropriva , Compostos Ferrosos/administração & dosagem , Ferro/sangue , Flebotomia/efeitos adversos , Complicações Pós-Operatórias , Anemia Ferropriva/sangue , Anemia Ferropriva/tratamento farmacológico , Anemia Ferropriva/etiologia , Feminino , Humanos , Masculino , Complicações Pós-Operatórias/sangue , Complicações Pós-Operatórias/tratamento farmacológico
9.
Chest ; 152(3): 478-485, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28427966

RESUMO

BACKGROUND: Heparin-induced thrombocytopenia (HIT) complicated by severe thrombocytopenia and thrombosis can pose significant treatment challenges. Use of alternative anticoagulants in this setting may increase bleeding risks, especially in patients who have a protracted disease course. Additional therapies are lacking in this severely affected patient population. METHODS: We describe three patients with HIT who had severe thromboembolism and prolonged thrombocytopenia refractory to standard treatment but who achieved an immediate and sustained response to IVIg therapy. The mechanism of action of IVIg was evaluated in these patients and in five additional patients with severe HIT. The impact of a common polymorphism (H/R 131) in the platelet IgG receptor FcγRIIa on IVIg-mediated inhibition of platelet activation was also examined. RESULTS: At levels attained in vivo, IVIg inhibits HIT antibody-mediated platelet activation. The constant domain of IgG (Fc) but not the antigen-binding portion (Fab) is required for this effect. Consistent with this finding, IVIg had no effect on HIT antibody binding in a solid-phase HIT immunoassay (platelet factor 4 enzyme-linked immunoassay). The H/R131 polymorphism in FcγRIIa influences the susceptibility of platelets to IVIg treatment, with the HH131 genotype being most susceptible to IVIg-mediated inhibition of antibody-induced activation. However, at high doses of IVIg, activation of platelets of all FcγRIIa genotypes was significantly inhibited. All three patients did well on long-term anticoagulation therapy with direct oral anticoagulants. CONCLUSIONS: These studies suggest that IVIg treatment should be considered in patients with HIT who have severe disease that is refractory to standard therapies.


Assuntos
Anticoagulantes/efeitos adversos , Heparina/efeitos adversos , Imunoglobulinas Intravenosas/uso terapêutico , Fatores Imunológicos/uso terapêutico , Trombocitopenia/induzido quimicamente , Trombocitopenia/tratamento farmacológico , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Receptores de IgG , Trombocitopenia/diagnóstico
10.
Transfusion ; 57(4): 946-951, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28164344

RESUMO

BACKGROUND: Pica, the compulsive consumption of ice or other nonnutritious substances, is associated with iron deficiency, a common negative consequence of frequent blood donation. Because of this, blood donors, such as those participating in the Strategies to Reduce Iron Deficiency (STRIDE) study, are an ideal population to explore pica and iron deficiency. STUDY DESIGN AND METHODS: STRIDE was a 2-year intervention trial to assess the effectiveness of iron supplementation for mitigating iron deficiency in frequent blood donors. Subjects completed baseline and follow-up questionnaires that included questions about pica symptoms. In-depth telephone interviews were conducted with 14 of these subjects reporting pica symptoms and eight presumed controls (casual ice chewers) to gain a deeper understanding of pica symptoms and their impact on daily life and to make a final determination on the presence of pica. RESULTS: Pica was confirmed in five of the 14 subjects reporting symptoms and in two of eight controls. Outcome misclassification based on the questionnaire was attributed to inadequate assessment of several pica symptoms identified during the interview. Comparison of subjects' repeated quantitative iron measurements taken throughout STRIDE with subjects' final adjudicated pica status revealed a positive relationship between development of pica and worsening iron status; the opposite was found in those whose pica symptoms resolved. CONCLUSION: Continued refinement of pica symptom questions will allow for rapid and accurate detection of pica in frequent blood donors and confirmation of successful treatment with iron supplements.


Assuntos
Doadores de Sangue , Suplementos Nutricionais , Ferro/administração & dosagem , Pica , Estudos de Coortes , Feminino , Humanos , Gelo , Ferro/sangue , Masculino , Pica/sangue , Pica/tratamento farmacológico , Pica/epidemiologia , Pica/etiologia , Fatores de Tempo
11.
PLoS One ; 11(11): e0166438, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27875550

RESUMO

Chromatin immunoprecipitation and DNA sequencing (ChIP-seq) has been instrumental in inferring the roles of histone post-translational modifications in the regulation of transcription, chromatin compaction and other cellular processes that require modulation of chromatin structure. However, analysis of ChIP-seq data is challenging when the manipulation of a chromatin-modifying enzyme significantly affects global levels of histone post-translational modifications. For example, small molecule inhibition of the methyltransferase EZH2 reduces global levels of histone H3 lysine 27 trimethylation (H3K27me3). However, standard ChIP-seq normalization and analysis methods fail to detect a decrease upon EZH2 inhibitor treatment. We overcome this challenge by employing an alternative normalization approach that is based on the addition of Drosophila melanogaster chromatin and a D. melanogaster-specific antibody into standard ChIP reactions. Specifically, the use of an antibody that exclusively recognizes the D. melanogaster histone variant H2Av enables precipitation of D. melanogaster chromatin as a minor fraction of the total ChIP DNA. The D. melanogaster ChIP-seq tags are used to normalize the human ChIP-seq data from DMSO and EZH2 inhibitor-treated samples. Employing this strategy, a substantial reduction in H3K27me3 signal is now observed in ChIP-seq data from EZH2 inhibitor treated samples.


Assuntos
Proteínas de Drosophila/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Histonas/metabolismo , Animais , Imunoprecipitação da Cromatina , Proteínas de Drosophila/genética , Drosophila melanogaster , Proteína Potenciadora do Homólogo 2 de Zeste/antagonistas & inibidores , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Inibidores Enzimáticos/farmacologia , Estudo de Associação Genômica Ampla , Histonas/genética , Humanos , Metilação/efeitos dos fármacos , Análise de Sequência de DNA
13.
Clin Cancer Res ; 22(16): 4259-70, 2016 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-27169995

RESUMO

PURPOSE: The initiation, progression, and maintenance of pancreatic ductal adenocarcinoma (PDAC) results from the interplay of genetic and epigenetic events. While the genetic alterations of PDAC have been well characterized, epigenetic pathways regulating PDAC remain, for the most part, elusive. The goal of this study was to identify novel epigenetic regulators contributing to the biology of PDAC. EXPERIMENTAL DESIGN: In vivo pooled shRNA screens targeting 118 epigenetic proteins were performed in two orthotopic PDAC xenograft models. Candidate genes were characterized in 19 human PDAC cell lines, heterotopic xenograft tumor models, and a genetically engineered mouse (GEM) model of PDAC. Gene expression, IHC, and immunoprecipitation experiments were performed to analyze the pathways by which candidate genes contribute to PDAC. RESULTS: In vivo shRNA screens identified BRD2 and BRD3, members of the BET family of chromatin adaptors, as key regulators of PDAC tumor growth. Pharmacologic inhibition of BET bromodomains enhanced survival in a PDAC GEM model and inhibited growth of human-derived xenograft tumors. BET proteins contribute to PDAC cell growth through direct interaction with members of the GLI family of transcription factors and modulating their activity. Within cancer cells, BET bromodomain inhibition results in downregulation of SHH, a key mediator of the tumor microenvironment and canonical activator of GLI. Consistent with this, inhibition of BET bromodomains decreases cancer-associated fibroblast content of tumors in both GEM and xenograft tumor models. CONCLUSIONS: Therapeutic inhibition of BET proteins offers a novel mechanism to target both the neoplastic and stromal components of PDAC. Clin Cancer Res; 22(16); 4259-70. ©2016 AACR.


Assuntos
Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Proteínas de Ligação a RNA/metabolismo , Microambiente Tumoral , Proteína GLI1 em Dedos de Zinco/metabolismo , Animais , Antineoplásicos/farmacologia , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Genes myc , Proteínas Hedgehog/metabolismo , Xenoenxertos , Humanos , Camundongos , Neoplasias Pancreáticas/genética , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Interferência de RNA , Proteínas de Ligação a RNA/antagonistas & inibidores , Proteínas de Ligação a RNA/química , Transdução de Sinais , Carga Tumoral , Microambiente Tumoral/genética
14.
J Biol Chem ; 291(25): 13014-27, 2016 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-27056325

RESUMO

Covalent modification of histones is a fundamental mechanism of regulated gene expression in eukaryotes, and interpretation of histone modifications is an essential feature of epigenetic control. Bromodomains are specialized binding modules that interact with acetylated histones, linking chromatin recognition to gene transcription. Because of their ability to function in a domain-specific fashion, selective disruption of bromodomain:acetylated histone interactions with chemical probes serves as a powerful means for understanding biological processes regulated by these chromatin adaptors. Here we describe the discovery and characterization of potent and selective small molecule inhibitors for the bromodomains of CREBBP/EP300 that engage their target in cellular assays. We use these tools to demonstrate a critical role for CREBBP/EP300 bromodomains in regulatory T cell biology. Because regulatory T cell recruitment to tumors is a major mechanism of immune evasion by cancer cells, our data highlight the importance of CREBBP/EP300 bromodomain inhibition as a novel, small molecule-based approach for cancer immunotherapy.


Assuntos
Proteína de Ligação a CREB/antagonistas & inibidores , Proteína p300 Associada a E1A/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Linfócitos T Reguladores/efeitos dos fármacos , Acetilação/efeitos dos fármacos , Proteína de Ligação a CREB/química , Proteína de Ligação a CREB/metabolismo , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Células Cultivadas , Proteína p300 Associada a E1A/química , Proteína p300 Associada a E1A/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Histonas/metabolismo , Humanos , Simulação de Acoplamento Molecular , Estrutura Terciária de Proteína/efeitos dos fármacos , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/metabolismo , Transcriptoma/efeitos dos fármacos
15.
Cancer Res ; 76(7): 1975-88, 2016 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-26837761

RESUMO

Lysine-specific demethylase 1 (KDM1A) is a transcriptional coregulator that can function in both the activation and repression of gene expression, depending upon context. KDM1A plays an important role in hematopoiesis and was identified as a dependency factor in leukemia stem cell populations. Therefore, we investigated the consequences of inhibiting KDM1A in a panel of cell lines representing all acute myelogenous leukemia (AML) subtypes using selective, reversible and irreversible KDM1A small-molecule inhibitors. Cell models of AML, CML, and T-ALL were potently affected by KDM1A inhibition, and cells bearing RUNX1-RUNX1T1 (AML1-ETO) translocations were especially among the most sensitive. RNAi-mediated silencing of KDM1A also effectively suppressed growth of RUNX1-RUNX1T1-containing cell lines. Furthermore, pharmacologic inhibition of KDM1A resulted in complete abrogation of tumor growth in an AML xenograft model harboring RUNX1-RUNX1T1 translocations. We unexpectedly found that KDM1A-targeting compounds not only inhibited the catalytic activity of the enzyme, but evicted KDM1A from target genes. Accordingly, compound-mediated KDM1A eviction was associated with elevated levels of local histone H3 lysine 4 dimethylation, and increased target gene expression, which was further accompanied by cellular differentiation and induction of cell death. Finally, our finding that KDM1A inhibitors effectively synergize with multiple conventional as well as candidate anti-AML agents affords a framework for potential future clinical application. Cancer Res; 76(7); 1975-88. ©2016 AACR.


Assuntos
Histona Desmetilases/metabolismo , Leucemia Mieloide Aguda/genética , Linhagem Celular Tumoral , Histona Desmetilases/genética , Humanos , Processamento de Proteína Pós-Traducional , Transfecção
16.
Transfusion ; 56(6 Pt 2): 1588-97, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26813849

RESUMO

BACKGROUND: The historical approach of offering dietary advice to donors with low hemoglobin (Hb) is ineffective for preventing iron deficiency in frequent donors. Alternative approaches to maintaining donor iron status were explored. STUDY DESIGN AND METHODS: Frequent blood donors were randomly assigned into five arms for 2 years of follow-up. Three double-blinded arms provided 60 once-daily pills after each donation (38, 19, or 0 mg of iron). Two single-blinded arms provided iron status (ferritin) or no information letters after each donation. Ferritin, soluble transferrin receptor, and complete blood count were measured at each donation. RESULTS: There were 692 subjects enrolled and 393 completed the study. Subjects in pill groups deenrolled more than those in letter groups (39% vs. 7%). Adverse events occurred equally in subjects receiving iron or placebo pills. Of those completing the study, the prevalence of ferritin of less than 12 or less than 26 ng/mL declined by more than 50% and was statistically indistinguishable in the three intervention groups (19 or 38 mg of iron; iron status letter). Longitudinal analyses of all subjects showed improved iron status in iron pill groups and worsening iron status in control groups (placebo; no information letter). The iron pill groups experienced a net increase of approximately 0.6 g/dL Hb compared to control groups. The iron status letter group had little change in Hb. CONCLUSION: Providing 19 or 38 mg of daily iron or iron status information were effective and mostly equivalent interventions for mitigating iron deficiency in regular donors when compared at the end of the 2-year longitudinal phase of the study. Donors without intervention had worsened iron deficiency with continued donation.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Doadores de Sangue/educação , Ferro/administração & dosagem , Adulto , Anemia Ferropriva/sangue , Contagem de Células Sanguíneas , Suplementos Nutricionais , Método Duplo-Cego , Feminino , Ferritinas/sangue , Humanos , Ferro/efeitos adversos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Receptores da Transferrina/análise , Método Simples-Cego , Resultado do Tratamento
17.
Elife ; 52016 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-26731516

RESUMO

Pharmacological inhibition of chromatin co-regulatory factors represents a clinically validated strategy to modulate oncogenic signaling through selective attenuation of gene expression. Here, we demonstrate that CBP/EP300 bromodomain inhibition preferentially abrogates the viability of multiple myeloma cell lines. Selective targeting of multiple myeloma cell lines through CBP/EP300 bromodomain inhibition is the result of direct transcriptional suppression of the lymphocyte-specific transcription factor IRF4, which is essential for the viability of myeloma cells, and the concomitant repression of the IRF4 target gene c-MYC. Ectopic expression of either IRF4 or MYC antagonizes the phenotypic and transcriptional effects of CBP/EP300 bromodomain inhibition, highlighting the IRF4/MYC axis as a key component of its mechanism of action. These findings suggest that CBP/EP300 bromodomain inhibition represents a viable therapeutic strategy for targeting multiple myeloma and other lymphoid malignancies dependent on the IRF4 network.


Assuntos
Antineoplásicos/farmacologia , Proteína p300 Associada a E1A/antagonistas & inibidores , Fatores Reguladores de Interferon/metabolismo , Mieloma Múltiplo/fisiopatologia , Fragmentos de Peptídeos/antagonistas & inibidores , Sialoglicoproteínas/antagonistas & inibidores , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos
18.
Cancer Res ; 76(6): 1313-9, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26759243

RESUMO

Small-molecule inhibitors of the bromodomain and extraterminal (BET) family of proteins are being tested in clinical trials for a variety of cancers, but patient selection strategies remain limited. This challenge is partly attributed to the heterogeneous responses elicited by BET inhibition (BETi), including cellular differentiation, senescence, and death. In this study, we performed phenotypic and gene-expression analyses of treatment-naive and engineered tolerant cell lines representing human melanoma and leukemia to elucidate the dominant features defining response to BETi. We found that de novo and acquired tolerance to BETi is driven by the robustness of the apoptotic response, and that genetic or pharmacologic manipulation of the apoptotic signaling network can modify the phenotypic response to BETi. We further reveal that the expression signatures of the apoptotic genes BCL2, BCL2L1, and BAD significantly predict response to BETi. Taken together, our findings highlight the apoptotic program as a determinant of response to BETi, and provide a molecular basis for patient stratification and combination therapy development.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Proteínas Reguladoras de Apoptose/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HCT116 , Células HL-60 , Células HT29 , Humanos , Células K562 , Leucemia/tratamento farmacológico , Leucemia/metabolismo , Melanoma/tratamento farmacológico , Melanoma/metabolismo , Transdução de Sinais/efeitos dos fármacos
19.
Bioorg Med Chem Lett ; 25(9): 1842-8, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25851940

RESUMO

In this report we detail the evolution of our previously reported thiophene isoxazole BET inhibitor chemotype exemplified by CPI-3 to a novel bromodomain selective chemotype (the methyl isoxazoleazepine chemotype) exemplified by carboxamide 23. The methyl isoxazoleazepine chemotype provides potent inhibition of the bromodomains of the BET family, excellent in vivo PK across species, low unbound clearance, and target engagement in a MYC PK-PD model.


Assuntos
Azepinas/farmacologia , Desenho de Fármacos , Proteínas Nucleares/antagonistas & inibidores , Oxazóis/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas de Ligação a RNA/antagonistas & inibidores , Fatores de Transcrição/antagonistas & inibidores , Azepinas/síntese química , Azepinas/química , Proteínas de Ciclo Celular , Relação Dose-Resposta a Droga , Humanos , Modelos Moleculares , Estrutura Molecular , Oxazóis/síntese química , Oxazóis/química , Relação Estrutura-Atividade
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