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1.
J Clin Med ; 13(7)2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38610601

RESUMO

Objectives: To compare complications associated with percutaneous gastrostomies performed using PUSH and PULL techniques, whether endoscopic (PEG) or radiological (PRG), in a tertiary-level hospital. Methods: This was a prospective observational study. Adult patients who underwent percutaneous PULL or PUSH gastrostomy using PEG or PRG techniques at the Virgen del Rocio University Hospital and subsequently followed up in the Nutrition Unit between 2009-2020 were included. X2 tests or Fisher's test were used for the comparison of proportions when necessary. Univariate analysis was conducted to study risk factors for PRG-associated complications. Results: n = 423 (PULL = 181; PUSH = 242). The PULL technique was associated with a higher percentage of total complications (37.6% vs. 23.8%; p = 0.005), exudate (18.2% vs. 11.2%; p = 0.039), and irritation (3.3% vs. 0%; p = 0.006). In the total sample, there were 5 (1.1%) cases of peritonitis, 3 (0.7%) gastrocolic fistulas, and 1 (0.2%) death due to complications associated with gastrostomy. Gender, age, and different indications were not risk factors for a higher number of complications. The most common indications were neurological diseases (35.9%), head and neck cancer (29%), and amyotrophic lateral sclerosis (17.2%). Conclusions: The PULL technique was associated with more total complications than the PUSH technique, but both were shown to be safe techniques, as the majority of complications were minor.

2.
Front Med (Lausanne) ; 10: 1191204, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37915325

RESUMO

Objectives: To describe the complications associated with the different gastrostomy techniques [endoscopic (PEG), radiologic (PRG), and surgical (SG)] performed in the last 26 years in a terciary hospital. Methods: Retrospective observational study. Patients who underwent gastrostomy at the Virgen del Rocío University Hospital between 1995 and 2021 were included. For PEG, the PULL technique was performed until 2018 and subsequently the PUSH technique predominantly. For PRG, a pigtail catheter was used until 2003, a balloon catheter between 2003 and 2009, and a balloon catheter with gastropexy between 2015 and 2021. For SG, the conventional technique (CSG) was performed until 2009 and since then the laparoscopic assisted percutaneous gastrostomy (PLAG) technique. Descriptive analysis was performed obtaining the median and quartiles of the quantitative variables [P50 (P25-P75)] and the frequency for the qualitative variables [n (%)].The comparison of complications between patients who underwent different techniques was performed with Fisher's test. Results: n = 1,070 (PEG = 608, PRG = 344, SG = 118). The three most frequent indications were head and neck tumors, neurological diseases and gastroesophageal tumors. The percentage of patients who had any complication was 48.9% (PEG-PULL), 23.7% (PEG-PUSH), 38.5% (pigtail PRG), 39.2% (balloon PRG), 29.7% (balloon with gastropexy PRG), 87.3% (CSG), and 41.26% (PLAG). 2 (0.18%) patients died from gastrostomy-related complications. 18(1.68%) presented with peritonitis and 5 (0.4%) presented with gastrocolic fistula. The rest of the complications were minor. Conclusion: Gastrostomy in any of its modalities is currently a safe procedure with a low rate of complications, most of which are minor.

3.
Nutrients ; 14(22)2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36432521

RESUMO

OBJECTIVES: We aimed to describe and compare the complications associated with different percutaneous radiologic gastrostomy (PRG) techniques. METHODS: A retrospective and prospective observational study was conducted. Patients who underwent a PRG between 1995-2020 were included. TECHNIQUES: A pigtail catheter was used until 2003, a balloon catheter without pexy was used between 2003-2009 and a balloon catheter with gastropexy was used between 2015-2021. For the comparison of proportions, X2 tests or Fisher's test were used when necessary. Univariate analysis was performed to study the risk factors for PRG-associated complications. RESULTS: n = 330 (pigtail = 114, balloon-type without pexy = 28, balloon-type with pexy = 188). The most frequent indication was head and neck cancer. The number of patients with complications was 44 (38.5%), 11 (39.2%) and 54 (28,7%), respectively. There were seven (25%) cases of peritonitis in the balloon-type without-pexy group and 1 (0.5%) in the balloon-type with-pexy group, the latter being the only patient who died in the total number of patients (0.3%). Two (1%) patients of the balloon-type with-pexy group presented with gastrocolic fistula. The rest of the complications were minor. CONCLUSIONS: The most frequent complications associated with the administration of enteral nutrition through PRG were minor and the implementation of the balloon-type technique with pexy has led to a decrease in them.


Assuntos
Gastrostomia , Radiologia , Humanos , Gastrostomia/efeitos adversos , Gastrostomia/métodos , Estudos Retrospectivos , Centros de Atenção Terciária , Radiografia Intervencionista/métodos
4.
EMBO Mol Med ; 14(7): e15203, 2022 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-35514210

RESUMO

The mitochondrial enzyme dihydroorotate dehydrogenase (DHODH) catalyzes one of the rate-limiting steps in de novo pyrimidine biosynthesis, a pathway that provides essential metabolic precursors for nucleic acids, glycoproteins, and phospholipids. DHODH inhibitors (DHODHi) are clinically used for autoimmune diseases and are emerging as a novel class of anticancer agents, especially in acute myeloid leukemia (AML) where pyrimidine starvation was recently shown to reverse the characteristic differentiation block in AML cells. Herein, we show that DHODH blockade rapidly shuts down protein translation in leukemic stem cells (LSCs) and has potent and selective activity against multiple AML subtypes. Moreover, we find that ablation of CDK5, a gene that is recurrently deleted in AML and related disorders, increases the sensitivity of AML cells to DHODHi. Our studies provide important molecular insights and identify a potential biomarker for an emerging strategy to target AML.


Assuntos
Leucemia Mieloide Aguda , Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Di-Hidro-Orotato Desidrogenase , Inibidores Enzimáticos/farmacologia , Humanos , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Biossíntese de Proteínas , Pirimidinas/farmacologia
5.
Cancer Discov ; 12(6): 1560-1579, 2022 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-35311997

RESUMO

Pharmacologic inhibition of epigenetic enzymes can have therapeutic benefit against hematologic malignancies. In addition to affecting tumor cell growth and proliferation, these epigenetic agents may induce antitumor immunity. Here, we discovered a novel immunoregulatory mechanism through inhibition of histone deacetylases (HDAC). In models of acute myeloid leukemia (AML), leukemia cell differentiation and therapeutic benefit mediated by the HDAC inhibitor (HDACi) panobinostat required activation of the type I interferon (IFN) pathway. Plasmacytoid dendritic cells (pDC) produced type I IFN after panobinostat treatment, through transcriptional activation of IFN genes concomitant with increased H3K27 acetylation at these loci. Depletion of pDCs abrogated panobinostat-mediated induction of type I IFN signaling in leukemia cells and impaired therapeutic efficacy, whereas combined treatment with panobinostat and IFNα improved outcomes in preclinical models. These discoveries offer a new therapeutic approach for AML and demonstrate that epigenetic rewiring of pDCs enhances antitumor immunity, opening the possibility of exploiting this approach for immunotherapies. SIGNIFICANCE: We demonstrate that HDACis induce terminal differentiation of AML through epigenetic remodeling of pDCs, resulting in production of type I IFN that is important for the therapeutic effects of HDACis. The study demonstrates the important functional interplay between the immune system and leukemias in response to HDAC inhibition. This article is highlighted in the In This Issue feature, p. 1397.


Assuntos
Leucemia Mieloide Aguda , Diferenciação Celular , Células Dendríticas , Epigênese Genética , Inibidores de Histona Desacetilases/farmacologia , Inibidores de Histona Desacetilases/uso terapêutico , Histona Desacetilases/genética , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Panobinostat/farmacologia
6.
Clin Cancer Res ; 27(22): 6222-6234, 2021 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-34475103

RESUMO

PURPOSE: In this article, we describe a combination chimeric antigen receptor (CAR) T-cell therapy that eradicated the majority of tumors in two immunocompetent murine pancreatic cancer models and a human pancreatic cancer xenograft model. EXPERIMENTAL DESIGN: We used a dual-specific murine CAR T cell that expresses a CAR against the Her2 tumor antigen, and a T-cell receptor (TCR) specific for gp100. As gp100 is also known as pMEL, the dual-specific CAR T cells are thus denoted as CARaMEL cells. A vaccine containing live vaccinia virus coding a gp100 minigene (VV-gp100) was administered to the recipient mice to stimulate CARaMEL cells. The treatment also included the histone deacetylase inhibitor panobinostat (Pano). RESULTS: The combination treatment enabled significant suppression of Her2+ pancreatic cancers leading to the eradication of the majority of the tumors. Besides inducing cancer cell apoptosis, Pano enhanced CAR T-cell gene accessibility and promoted CAR T-cell differentiation into central memory cells. To test the translational potential of this approach, we established a method to transduce human T cells with an anti-Her2 CAR and a gp100-TCR. The exposure of the human T cells to Pano promoted a T-cell central memory phenotype and the combination treatment of human CARaMEL cells and Pano eradicated human pancreatic cancer xenografts in mice. CONCLUSIONS: We propose that patients with pancreatic cancer could be treated using a scheme that contains dual-specific CAR T cells, a vaccine that activates the dual-specific CAR T cells through their TCR, and the administration of Pano.


Assuntos
Neoplasias Pancreáticas , Receptores de Antígenos Quiméricos , Animais , Linhagem Celular Tumoral , Inibidores de Histona Desacetilases/farmacologia , Humanos , Imunoterapia Adotiva/métodos , Camundongos , Neoplasias Pancreáticas/terapia , Panobinostat , Receptores de Antígenos de Linfócitos T/genética , Linfócitos T , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Cancer Discov ; 11(10): 2582-2601, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33990344

RESUMO

Pharmacologic inhibitors of cyclin-dependent kinases 4 and 6 (CDK4/6) are an approved treatment for hormone receptor-positive breast cancer and are currently under evaluation across hundreds of clinical trials for other cancer types. The clinical success of these inhibitors is largely attributed to well-defined tumor-intrinsic cytostatic mechanisms, whereas their emerging role as immunomodulatory agents is less understood. Using integrated epigenomic, transcriptomic, and proteomic analyses, we demonstrated a novel action of CDK4/6 inhibitors in promoting the phenotypic and functional acquisition of immunologic T-cell memory. Short-term priming with a CDK4/6 inhibitor promoted long-term endogenous antitumor T-cell immunity in mice, enhanced the persistence and therapeutic efficacy of chimeric antigen receptor T cells, and induced a retinoblastoma-dependent T-cell phenotype supportive of favorable responses to immune checkpoint blockade in patients with melanoma. Together, these mechanistic insights significantly broaden the prospective utility of CDK4/6 inhibitors as clinical tools to boost antitumor T-cell immunity. SIGNIFICANCE: Immunologic memory is critical for sustained antitumor immunity. Our discovery that CDK4/6 inhibitors drive T-cell memory fate commitment sheds new light on their clinical activity, which is essential for the design of clinical trial protocols incorporating these agents, particularly in combination with immunotherapy, for the treatment of cancer.This article is highlighted in the In This Issue feature, p. 2355.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Piperazinas/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Piridinas/uso terapêutico , Animais , Antineoplásicos/farmacologia , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Quinase 4 Dependente de Ciclina/antagonistas & inibidores , Quinase 6 Dependente de Ciclina/antagonistas & inibidores , Feminino , Humanos , Células T de Memória/efeitos dos fármacos , Camundongos , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Sci Adv ; 6(25): eaay5872, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32596441

RESUMO

The TET2 DNA hydroxymethyltransferase is frequently disrupted by somatic mutations in diffuse large B cell lymphomas (DLBCLs), a tumor that originates from germinal center (GC) B cells. Here, we show that TET2 deficiency leads to DNA hypermethylation of regulatory elements in GC B cells, associated with silencing of the respective genes. This hypermethylation affects the binding of transcription factors including those involved in exit from the GC reaction and involves pathways such as B cell receptor, antigen presentation, CD40, and others. Normal GC B cells manifest a typical hypomethylation signature, which is caused by AID, the enzyme that mediates somatic hypermutation. However, AID-induced demethylation is markedly impaired in TET2-deficient GC B cells, suggesting that AID epigenetic effects are partially dependent on TET2. Last, we find that TET2 mutant DLBCLs also manifest the aberrant TET2-deficient GC DNA methylation signature, suggesting that this epigenetic pattern is maintained during and contributes to lymphomagenesis.

9.
Dig Dis ; 37(6): 498-508, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31067534

RESUMO

BACKGROUND/AIMS: One hallmark of chronic liver disease in patients with portal hypertension is the formation of portal-systemic collaterals in which angiogenesis has a fundamental role. We studied patients with chronic liver disease undergoing liver transplantation to correlate levels of circulating angiogenic factors in portal and peripheral circulation with portal pressure and portal-systemic collaterals. METHODS: Sixteen patients who underwent liver transplantation were enrolled. During transplant surgery, we determined portal venous pressure and portal-systemic collateral formation. We determined angiogenics mediator levels in systemic and portal plasma. Peripheral plasma from healthy donors was measured as controls. RESULTS: Vascular endothelial growth factor (VEGF)-R1 and 2, Ang-1 and 2, Tie2, FGF- 1 and 2, CD163, PDGFR-ß, PDGFsRα, PDGF-AB and BB, CD163, TGF-ß VASH-1 levels were significantly different in the controls in comparison to cases. Significantly decreased portal venous levels of Ang-1, FGF-1, PDGF-AB/BB, and CC were observed in patients with higher portal pressure. Peripheral VEGF, Ang-1, pPDGF-AB, BB, and CC were significantly decreased in patients with more severe collateral formation. While peripheral VEGF-R1 was higher in patients with severe collateral formation. For portal circulation, VEGF, Ang-1, -pPDGF-AB, BB, and CC were significantly decreased in patients with more severe collateral formation Conclusions: Angiogenesis factors correlated with portal pressure and collateral formation and different patterns of circulating angiogenesis mediators were found in peripheral and portal blood of patients with chronic liver disease. These results support the importance of angiogenic pathways in cirrhosis and portal hypertension and highlight areas for further study to identify clinically useful noninvasive markers of portal pressure and collateral formation.


Assuntos
Circulação Colateral , Hepatopatias/fisiopatologia , Neovascularização Patológica/patologia , Pressão na Veia Porta , Adulto , Idoso , Animais , Doença Crônica , Feminino , Humanos , Fígado/patologia , Transplante de Fígado , Masculino , Pessoa de Meia-Idade , Neovascularização Patológica/fisiopatologia , Doadores de Tecidos
10.
Cancer Discov ; 8(12): 1632-1653, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30274972

RESUMO

TET2 somatic mutations occur in ∼10% of diffuse large B-cell lymphomas (DLBCL) but are of unknown significance. Herein, we show that TET2 is required for the humoral immune response and is a DLBCL tumor suppressor. TET2 loss of function disrupts transit of B cells through germinal centers (GC), causing GC hyperplasia, impaired class switch recombination, blockade of plasma cell differentiation, and a preneoplastic phenotype. TET2 loss was linked to focal loss of enhancer hydroxymethylation and transcriptional repression of genes that mediate GC exit, such as PRDM1. Notably, these enhancers and genes are also repressed in CREBBP-mutant DLBCLs. Accordingly, TET2 mutation in patients yields a CREBBP-mutant gene-expression signature, CREBBP and TET2 mutations are generally mutually exclusive, and hydroxymethylation loss caused by TET2 deficiency impairs enhancer H3K27 acetylation. Hence, TET2 plays a critical role in the GC reaction, and its loss of function results in lymphomagenesis through failure to activate genes linked to GC exit signals. SIGNIFICANCE: We show that TET2 is required for exit of the GC, B-cell differentiation, and is a tumor suppressor for mature B cells. Loss of TET2 phenocopies CREBBP somatic mutation. These results advocate for sequencing TET2 in patients with lymphoma and for the testing of epigenetic therapies to treat these tumors.See related commentary by Shingleton and Dave, p. 1515.This article is highlighted in the In This Issue feature, p. 1494.


Assuntos
Diferenciação Celular/genética , Proteínas de Ligação a DNA/genética , Centro Germinativo/metabolismo , Linfoma Difuso de Grandes Células B/genética , Plasmócitos/metabolismo , Proteínas Proto-Oncogênicas/genética , Animais , Proteína de Ligação a CREB/genética , Proteína de Ligação a CREB/metabolismo , Proteínas de Ligação a DNA/metabolismo , Dioxigenases , Epigênese Genética/genética , Perfilação da Expressão Gênica/métodos , Centro Germinativo/patologia , Células-Tronco Hematopoéticas/metabolismo , Humanos , Hiperplasia , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/patologia , Camundongos Knockout , Camundongos Transgênicos , Mutação , Plasmócitos/patologia , Fator 1 de Ligação ao Domínio I Regulador Positivo/genética , Fator 1 de Ligação ao Domínio I Regulador Positivo/metabolismo , Proteínas Proto-Oncogênicas/metabolismo
11.
Blood ; 132(7): e13-e23, 2018 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-29967128

RESUMO

The biological role of extracellular vesicles (EVs) in diffuse large B-cell lymphoma (DLBCL) initiation and progression remains largely unknown. We characterized EVs secreted by 5 DLBCL cell lines, a primary DLBCL tumor, and a normal control B-cell sample, optimized their purification, and analyzed their content. We found that DLBCLs secreted large quantities of CD63, Alix, TSG101, and CD81 EVs, which can be extracted using an ultracentrifugation-based method and traced by their cell of origin surface markers. We also showed that tumor-derived EVs can be exchanged between lymphoma cells, normal tonsillar cells, and HK stromal cells. We then examined the content of EVs, focusing on isolation of high-quality total RNA. We sequenced the total RNA and analyzed the nature of RNA species, including coding and noncoding RNAs. We compared whole-cell and EV-derived RNA composition in benign and malignant B cells and discovered that transcripts from EVs were involved in many critical cellular functions. Finally, we performed mutational analysis and found that mutations detected in EVs exquisitely represented mutations in the cell of origin. These results enhance our understanding and enable future studies of the role that EVs may play in the pathogenesis of DLBCL, particularly with regards to the exchange of genomic information. Current findings open a new strategy for liquid biopsy approaches in disease monitoring.


Assuntos
Vesículas Extracelulares/metabolismo , Linfoma Difuso de Grandes Células B/metabolismo , Proteínas de Neoplasias/metabolismo , RNA Neoplásico/metabolismo , Linhagem Celular Tumoral , Vesículas Extracelulares/genética , Vesículas Extracelulares/patologia , Humanos , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia , Proteínas de Neoplasias/genética , RNA Neoplásico/genética
12.
Mol Cell Biol ; 38(10)2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29507185

RESUMO

The liver X receptors (LXRs) are ligand-activated nuclear receptors with established roles in the maintenance of lipid homeostasis in multiple tissues. LXRs exert additional biological functions as negative regulators of inflammation, particularly in macrophages. However, the transcriptional responses controlled by LXRs in other myeloid cells, such as dendritic cells (DCs), are still poorly understood. Here we used gain- and loss-of-function models to characterize the impact of LXR deficiency on DC activation programs. Our results identified an LXR-dependent pathway that is important for DC chemotaxis. LXR-deficient mature DCs are defective in stimulus-induced migration in vitro and in vivo Mechanistically, we show that LXRs facilitate DC chemotactic signaling by regulating the expression of CD38, an ectoenzyme important for leukocyte trafficking. Pharmacological or genetic inactivation of CD38 activity abolished the LXR-dependent induction of DC chemotaxis. Using the low-density lipoprotein receptor-deficient (LDLR-/-) LDLR-/- mouse model of atherosclerosis, we also demonstrated that hematopoietic CD38 expression is important for the accumulation of lipid-laden myeloid cells in lesions, suggesting that CD38 is a key factor in leukocyte migration during atherogenesis. Collectively, our results demonstrate that LXRs are required for the efficient emigration of DCs in response to chemotactic signals during inflammation.


Assuntos
Quimiotaxia/fisiologia , Células Dendríticas/fisiologia , Receptores X do Fígado/fisiologia , ADP-Ribosil Ciclase 1/metabolismo , Animais , Células Cultivadas , Células Dendríticas/citologia , Inflamação , Metabolismo dos Lipídeos , Receptores X do Fígado/genética , Macrófagos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores Nucleares Órfãos , Receptores Citoplasmáticos e Nucleares , Transdução de Sinais
13.
Nat Commun ; 9(1): 222, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-29335468

RESUMO

Epigenetic heterogeneity is emerging as a feature of tumors. In diffuse large B-cell lymphoma (DLBCL), increased cytosine methylation heterogeneity is associated with poor clinical outcome, yet the underlying mechanisms remain unclear. Activation-induced cytidine deaminase (AICDA), an enzyme that mediates affinity maturation and facilitates DNA demethylation in germinal center (GC) B cells, is required for DLBCL pathogenesis and linked to inferior outcome. Here we show that AICDA overexpression causes more aggressive disease in BCL2-driven murine lymphomas. This phenotype is associated with increased cytosine methylation heterogeneity, but not with increased AICDA-mediated somatic mutation burden. Reciprocally, the cytosine methylation heterogeneity characteristic of normal GC B cells is lost upon AICDA depletion. These observations are relevant to human patients, since DLBCLs with high AICDA expression manifest increased methylation heterogeneity vs. AICDA-low DLBCLs. Our results identify AICDA as a driver of epigenetic heterogeneity in B-cell lymphomas with potential significance for other tumors with aberrant expression of cytidine deaminases.


Assuntos
Citidina Desaminase/genética , Epigênese Genética , Centro Germinativo/metabolismo , Linfoma Difuso de Grandes Células B/genética , Animais , Linfócitos B/metabolismo , Linfócitos B/patologia , Citidina Desaminase/metabolismo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Linfoma Difuso de Grandes Células B/enzimologia , Linfoma Difuso de Grandes Células B/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Mutação
14.
Curr Opin Hematol ; 24(4): 402-408, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28375986

RESUMO

PURPOSE OF REVIEW: There is mounting evidence that heterogeneity of the epigenome is a feature of many cancers, including B-cell lymphomas, and presents important clinical implications. The purpose of this review is to explain the biological and clinical relevance of this epigenetic phenomenon in B-cell neoplasms. RECENT FINDINGS: Here, we summarize new findings demonstrating that B-cell lymphomas display increased DNA methylation heterogeneity compared to their normal counterparts. This plasticity of cytosine methylation manifests both as intertumor and intratumor heterogeneity and is associated with worse prognosis and poor clinical outcome in lymphoma patients. Recent studies of different subtypes of B-cell lymphomas have revealed that epigenetic aberrations and heterogeneous cytosine methylation patterning are common features of all neoplasms derived from B-lymphocytes, irrespective of maturation stage. With regard to mechanisms driving this process, recent reports suggest that cytosine methylation heterogeneity arises through passive and active processes. One factor implicated in active generation of cytosine methylation heterogeneity is activation-induced cytidine deaminase, which mediates DNA methylation changes and introduces epigenetic heterogeneity in normal germinal center B cells, the cells of origin of mature B-cell neoplasms such as diffuse large B-cell lymphoma and follicular lymphoma. SUMMARY: Understanding the scope and mechanism of epigenetic heterogeneity in cancer is of paramount importance to our understanding of clonal plasticity and treatment responses in B-cell lymphomas.


Assuntos
Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Heterogeneidade Genética , Leucemia de Células B/genética , Linfoma de Células B/genética , Animais , Metilação de DNA , Centro Germinativo/metabolismo , Humanos , Leucemia de Células B/diagnóstico , Leucemia de Células B/metabolismo , Linfoma de Células B/diagnóstico , Linfoma de Células B/metabolismo , Transdução de Sinais
15.
Curr Opin Hematol ; 23(4): 377-84, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27055146

RESUMO

PURPOSE OF REVIEW: Perturbation of the epigenome is emerging as a central driving force in the pathogenesis of diffuse large B-cell lymphomas (DLBCL) and follicular lymphoma. The purpose of this review is to explain how alteration of different layers of the epigenome contributes to the biology and clinical features of these tumors. RECENT FINDINGS: Key new findings implicate DNA methylation heterogeneity as a core feature of DLBCL. Epigenetic diversity is linked to unfavorable clinical outcomes, clonal selection at relapse, and is driven at least in part because of the actions of activation-induced cytosine deaminase, which is a unique feature of B-cell lymphomas. Somatic mutations in histone modifier genes drive lymphomagenesis through the establishment of aberrant gene-specific histone modification signatures. For example, EZH2 somatic mutations drive silencing of bivalent gene promoters through histone 3 lysine 27 trimethylation, whereas KMT2D (MLL2) mutations disrupt specific sets of enhancers through depletion of histone 3 lysine 4 mono and dimethylation (H3K4me1/me2). SUMMARY: Appreciation of the epigenome in determining lymphoma clonal heterogeneity and in driving lymphoma phenotypes through altered promoter and enhancer histone modification profiles is leading to a paradigm shift in how we understand and design therapies for DLBCL and follicular lymphoma.


Assuntos
Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Linfoma de Células B/genética , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Cromatina/genética , Cromatina/metabolismo , Evolução Clonal/genética , Citosina/metabolismo , Metilação de DNA , Proteínas de Ligação a DNA/metabolismo , Dioxigenases , Elementos Facilitadores Genéticos , Inativação Gênica , Genes Supressores de Tumor , Centro Germinativo/metabolismo , Centro Germinativo/patologia , Histona Metiltransferases , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Linfoma de Células B/metabolismo , Linfoma de Células B/mortalidade , Linfoma de Células B/terapia , Linfoma Folicular/genética , Linfoma Folicular/metabolismo , Linfoma Folicular/mortalidade , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/mortalidade , Mutação , Prognóstico , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas/metabolismo , Transdução de Sinais
17.
Support Care Cancer ; 24(1): 93-101, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25935657

RESUMO

PURPOSE: Use of peripherally inserted central catheters (PICCs) has markedly increased during the last decade. However, there are few studies on use of PICCs in patients with haematological malignancies (HM) receiving intensive chemotherapy. Preliminary data suggest a higher rate of PICC-related complications in these high-risk patients. This prospective observational single-centre study aimed to investigate PICC-related complications after implementation of a multidisciplinary approach to PICC care and compared it with previous literature. METHODS: A total of 44 PICCs were inserted in 36 patients (27.3%, thrombocytopenia <50 × 10(9)/L at insertion) over 5045 PICC days (median duration, 114.5 days). RESULTS: No major insertion-related complications were observed. Major late complications were obstruction in 13.6% (1.19/1000 PICC days) of patients, catheter-related bloodstream infection in 6.8% (0.59/1000 PICC days), and catheter-related thrombosis in 4.5% (0.39/1000 PICC days). Premature PICC removal occurred in 34% (2.97/1000 PICC days) of patients. The overall rate of potentially major dangerous complications was particularly low (11.36%, 0.99/1000 PICC days) compared with previous studies. CONCLUSIONS: This study highlights the utility of a multidisciplinary approach for PICC care in adults with HM receiving intensive chemotherapy. We provide further data to support use of PICCs in such patient populations.


Assuntos
Infecções Relacionadas a Cateter/etiologia , Cateterismo Venoso Central/efeitos adversos , Cateterismo Periférico/efeitos adversos , Doenças Hematológicas/etiologia , Trombose/etiologia , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Adulto Jovem
18.
Rev. méd. Chile ; 142(10): 1229-1237, oct. 2014. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-731653

RESUMO

Background: Preservation solutions are critical for organ transplantation. In liver transplant (LT), the solution developed by the University Of Wisconsin (UW) is the gold-standard to perfuse deceased brain death donor (DBD) grafts. Histidine-Tryptophan-Ketoglutarate (HTK), formerly a cardioplegic infusion, has been also used in solid organ transplantation. Aim: To compare the outcomes of LT in our center using either HTK or UW solution. Patients and Methods: Retrospective study including 93 LT DBD liver grafts in 89 patients transplanted between March 1994 and July 2010. Forty-eight grafts were preserved with UW and 45 with HTK. Donor and recipient demographics, total infused volume, cold ischemia time, post-reperfusion biopsy, liver function tests, incidence of biliary complications, acute rejection and 12-month graft and patient survival were assessed. Preservation solution costs per liver graft were also recorded. Results: Donor and recipient demographics were similar. When comparing UW and HTK, no differences were observed in cold ischemia time (9.6 ± 3 and 8.7 ± 2 h respectively, p = 0.23), biliary complications, the incidence of acute rejection, primary or delayed graft dysfunction. Histology on post-reperfusion biopsies revealed no differences between groups. The infused volume was significantly higher with HTK than with UW (9 (5-16) and 6 (3-11) l, p < 0.001). The cost per procurement was remarkably lower using HTK. Conclusions: Perfusion of DBD liver grafts with HTK is clinically equivalent to UW, with a significant cost reduction.


Assuntos
Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fígado , Transplante de Fígado/métodos , Soluções para Preservação de Órgãos , Preservação de Órgãos/instrumentação , Adenosina , Alopurinol , Morte Encefálica , Glucose , Glutationa , Sobrevivência de Enxerto/efeitos dos fármacos , Sobrevivência de Enxerto/fisiologia , Insulina , Falência Hepática/patologia , Manitol , Cloreto de Potássio , Procaína , Rafinose , Estudos Retrospectivos , Doadores de Tecidos
19.
Front Immunol ; 5: 642, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25566255

RESUMO

Activation-induced cytidine deaminase (AID) is essential for somatic hypermutation and class switch recombination of immunoglobulin (Ig) genes during B cell maturation and immune response. Expression of AID is tightly regulated due to its mutagenic and recombinogenic potential, which is known to target not only Ig genes, but also non-Ig genes, contributing to lymphomagenesis. In recent years, a new epigenetic function of AID and its link to DNA demethylation came to light in several developmental systems. In this review, we summarize existing evidence linking deamination of unmodified and modified cytidine by AID to base-excision repair and mismatch repair machinery resulting in passive or active removal of DNA methylation mark, with the focus on B cell biology. We also discuss potential contribution of AID-dependent DNA hypomethylation to lymphomagenesis.

20.
Rev Med Chil ; 142(10): 1229-37, 2014 Oct.
Artigo em Espanhol | MEDLINE | ID: mdl-25601106

RESUMO

BACKGROUND: Preservation solutions are critical for organ transplantation. In liver transplant (LT), the solution developed by the University Of Wisconsin (UW) is the gold-standard to perfuse deceased brain death donor (DBD) grafts. Histidine-Tryptophan-Ketoglutarate (HTK), formerly a cardioplegic infusion, has been also used in solid organ transplantation. AIM: To compare the outcomes of LT in our center using either HTK or UW solution. PATIENTS AND METHODS: Retrospective study including 93 LT DBD liver grafts in 89 patients transplanted between March 1994 and July 2010. Forty-eight grafts were preserved with UW and 45 with HTK. Donor and recipient demographics, total infused volume, cold ischemia time, post-reperfusion biopsy, liver function tests, incidence of biliary complications, acute rejection and 12-month graft and patient survival were assessed. Preservation solution costs per liver graft were also recorded. RESULTS: Donor and recipient demographics were similar. When comparing UW and HTK, no differences were observed in cold ischemia time (9.6 ± 3 and 8.7 ± 2 h respectively, p = 0.23), biliary complications, the incidence of acute rejection, primary or delayed graft dysfunction. Histology on post-reperfusion biopsies revealed no differences between groups. The infused volume was significantly higher with HTK than with UW (9 (5-16) and 6 (3-11) l, p < 0.001). The cost per procurement was remarkably lower using HTK. CONCLUSIONS: Perfusion of DBD liver grafts with HTK is clinically equivalent to UW, with a significant cost reduction.


Assuntos
Transplante de Fígado/métodos , Fígado , Soluções para Preservação de Órgãos , Preservação de Órgãos/instrumentação , Adenosina , Adulto , Alopurinol , Morte Encefálica , Feminino , Glucose , Glutationa , Sobrevivência de Enxerto/efeitos dos fármacos , Sobrevivência de Enxerto/fisiologia , Humanos , Insulina , Falência Hepática/patologia , Masculino , Manitol , Pessoa de Meia-Idade , Cloreto de Potássio , Procaína , Rafinose , Estudos Retrospectivos , Doadores de Tecidos
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