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OBJECTIVE: Adjuvant chemotherapy is often indicated in patients diagnosed with early breast cancer (EBC). Among others, weight gain is one of the observed side effects of both chemotherapy and other cancer treatments; however, the mechanism is not well-described. In this study, we aimed to assess thyroid function before and shortly after the course of chemotherapy for EBC. METHODS: This is a prospective cohort study of women diagnosed with EBC. The main outcome was the thyroid function and body weight before and after completing chemotherapy. Secondary outcomes were the presence of thyroid autoantibodies and treatment radiation dosage. We included 72 patients treated with adjuvant chemotherapy, whereas 59 patients also received supraclavicular locoregional radiotherapy. Triple-negative breast cancer (BC) patients receiving chemoimmunotherapy were excluded. RESULTS: After the chemotherapy, we observed an increase in thyroid-stimulating hormone (p = 0.03) and a decrease in free-thyroxine (p = 0.0006), with no significant weight change. The prevalence of autoimmune thyroiditis was low. On average 3 months post-chemo, we found no statistically significant difference in the thyroid function of women treated versus not treated with supraclavicular locoregional radiotherapy. CONCLUSIONS: Although statistically significant changes in thyroid hormones were observed, this study suggests no obvious clinically significant changes in thyroid function in women with early BC after the course of chemotherapy. The decrease in thyroid function was not related to autoimmunity, non-thyroidal illness, radiotherapy, or high-dose corticosteroids. Further studies with a longer follow-up of thyroid function after adjuvant chemotherapy and supraclavicular locoregional radiotherapy are needed.
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Neoplasias de la Mama , Posmenopausia , Glándula Tiroides , Humanos , Femenino , Neoplasias de la Mama/tratamiento farmacológico , Persona de Mediana Edad , Estudios Prospectivos , Glándula Tiroides/efectos de los fármacos , Glándula Tiroides/efectos de la radiación , Anciano , Quimioterapia Adyuvante/efectos adversos , Pruebas de Función de la Tiroides , Tirotropina/sangre , Tiroxina , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéuticoRESUMEN
High-resolution respirometry (HRR) can assess peripheral blood mononuclear cell (PBMC) bioenergetics, but no standardized medium for PBMC preparation and HRR analysis exist. Here, we study the effect of four different media (MiR05, PBS, RPMI, Plasmax) on the count, size, and HRR (Oxygraph-O2k) of intact PBMCs. Remarkably, the cell count was 21 % higher when PBMCs were resuspended in MiR05 than in PBS or Plasmax, causing O2 flux underestimation during HRR due to inherent adjustments. Moreover, smaller cell size and cell aggregation was observed in MiR05. Based on our findings, we propose that Plasmax, PBS or RPMI is more suitable than MiR05 for HRR of intact PBMCs. We provide oxygen solubility factors for Plasmax and PBS and encourage further optimization of a standardized HRR protocol for intact PBMCs.
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Tamaño de la Célula , Medios de Cultivo , Leucocitos Mononucleares , Leucocitos Mononucleares/metabolismo , Humanos , Medios de Cultivo/química , Respiración de la CélulaRESUMEN
BACKGROUND: Breast cancer survivors are a growing population due to improved treatment. It is known that postmenopausal women treated for breast cancer may experience weight gain and increased insulin resistance, but detailed knowledge on how chemotherapy impact metabolic and endocrine mechanisms remain unknown. OBJECTIVES: We performed a thorough, preliminary study to elucidate the differing mechanisms of postprandial absorption and metabolism in postmenopausal early breast cancer (EBC) patients treated with adjuvant chemotherapy compared to healthy controls. We hypothesize that chemotherapy has a negative impact on metabolism in EBC patients. METHODS: We examined four postmenopausal women shortly after treatment with chemotherapy for EBC and four age-matched healthy women who served as controls using isotopic tracers during a mixed meal-test. Blood was sampled during the 240 min meal-test to examine postprandial absorption and endogenous synthesis of lipid and carbohydrate metabolites. RESULTS: We found that insulin concentrations were numerically higher before the meal-test in the EBC patients compared to controls (76.3 pmol/L vs 37.0 pmol/L; P = 0.06). Glucose kinetics was increased postprandial (most pronounced at 30 min, 9.46 mmol/L vs 7.33 mmol/L; P = 0.51), with no difference between the groups regarding liver glucose output. Fatty acid kinetics showed a numeric increase in oleic acid rate of appearance in BC patients, but only during the first hour after the mixed meal. There was no significant difference in VLDL-TAG synthesis between the two groups. CONCLUSIONS: This preliminary study is unique in using advanced tracer methods to investigate in vivo metabolism of EBC patients after chemotherapy although no statistical differences in glucose and fatty acid kinetics was seen compared to controls. However, during the first two postprandial hours, oral glucose and oleic acid appearance in the systematic circulation was elevated in the EBC patients. This could be due to changes in gastrointestinal uptake and further studies with altered set-up could provide valuable insights.
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Neoplasias de la Mama , Glucosa , Humanos , Femenino , Neoplasias de la Mama/tratamiento farmacológico , Ácido Oléico , Posmenopausia , Datos Preliminares , Glucemia/metabolismo , Insulina , Ácidos Grasos , Periodo Posprandial , TriglicéridosRESUMEN
The KN Motif and AnKyrin Repeat Domain 1 (KANK1) is proposed as a tumour suppressor gene, as its expression is reduced or absent in several types of tumour tissue, and over-expressing the protein inhibited the proliferation of tumour cells in solid cancer models. We report a novel germline loss of heterozygosity mutation encompassing the KANK1 gene in a young patient diagnosed with myelodysplastic neoplasm (MDS) with no additional disease-related genomic aberrations. To study the potential role of KANK1 in haematopoiesis, we generated a new transgenic mouse model with a confirmed loss of KANK1 expression. KANK1 knockout mice did not develop any haematological abnormalities; however, the loss of its expression led to alteration in the colony forming and proliferative potential of bone marrow (BM) cells and a decrease in hematopoietic stem and progenitor cells (HSPCs) population frequency. A comprehensive marker expression analysis of lineage cell populations indicated a role for Kank1 in lymphoid cell development, and total protein analysis suggests the involvement of Kank1 in BM cells' cytoskeleton formation and mobility.
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Proteínas Adaptadoras Transductoras de Señales , Neoplasias , Animales , Humanos , Ratones , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Repetición de Anquirina/genética , Proteínas del Citoesqueleto/metabolismo , Modelos Animales de EnfermedadRESUMEN
BACKGROUND: Adjuvant chemo- and radiotherapy cause cellular damage to tumorous and healthy dividing cells. Chemotherapy has been shown to cause mitochondrial respiratory dysfunction in non-tumorous tissues, but the effects on human peripheral blood mononuclear cells (PBMCs) remain unknown. AIM: We aimed to investigate mitochondrial respiration of PBMCs before and after adjuvant chemo- and radiotherapy in postmenopausal patients with early breast cancer (EBC) and relate these to metabolic parameters of the patients. METHODS: Twenty-three postmenopausal women diagnosed with EBC were examined before and shortly after chemotherapy with (n = 18) or without (n = 5) radiotherapy. Respiration (O2 flux per million PBMCs) was assessed by high-resolution respirometry of intact and permeabilized PBMCs. Clinical metabolic characteristics and mitochondrial DNA (mtDNA) content of PBMCs (mtDN relative to nuclear DNA) were furthermore assessed. RESULTS: Respiration of intact and permeabilized PBMCs from EBC patients significantly increased with adjuvant chemo- and radiotherapy (p = 6 × 10-5 and p = 1 × 10-7 , respectively). The oxygen flux attributed to specific mitochondrial complexes and respiratory states increased by 17-43% compared to before therapy initiation. Similarly, PBMC mtDNA content increased by 40% (p = 0.002). Leukocytes (p = 0.0001), hemoglobin (p = 0.0003), and HDL cholesterol (p = 0.003) concentrations decreased whereas triglyceride (p = 0.01) and LDL (p = 0.02) concentrations increased after treatment suggesting a worsened metabolic state. None of the metabolic parameters or the mtDNA content of PBMCs correlated significantly with PBMC respiration. CONCLUSION: This study shows that mitochondrial respiration and mtDNA content in circulating PBMCs increase after adjuvant chemo- and radiotherapy in postmenopausal patients with EBC. Besides the increased mtDNA content, a shift in PBMC subpopulation proportions towards cells relying on oxidative phosphorylation, who may be less sensitive to chemotherapy, might influence the increased mitochondrial respiration observed iafter chemotherapy.
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Neoplasias de la Mama , Leucocitos Mononucleares , Humanos , Femenino , Leucocitos Mononucleares/metabolismo , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Neoplasias de la Mama/radioterapia , Mitocondrias/metabolismo , ADN Mitocondrial/genética , ADN Mitocondrial/metabolismo , RespiraciónRESUMEN
BACKGROUND: Idiopathic non-clonal cytopenia (ICUS) and clonal cytopenia (CCUS) are common in the elderly population. While these entities have similar clinical presentations with peripheral blood cytopenia and less than 10% bone marrow dysplasia, their malignant potential is different and the biological relationship between these disorders and myeloid neoplasms such as myelodysplastic syndrome (MDS) is not fully understood. Aberrant DNA methylation has previously been described to play a vital role in MDS and acute myeloid leukemia (AML) pathogenesis. In addition, obesity confers a poorer prognosis in MDS with inferior overall survival and a higher rate of AML transformation. In this study, we measured DNA methylation of the promoter for the obesity-regulated gene LEP, encoding leptin, in hematopoietic cells from ICUS, CCUS and MDS patients and healthy controls. We investigated whether LEP promoter methylation is an early event in the development of myeloid neoplasms and whether it is associated with clinical outcome. RESULTS: We found that blood cells of patients with ICUS, CCUS and MDS all have a significantly hypermethylated LEP promoter compared to healthy controls and that LEP hypermethylation is associated with anemia, increased bone marrow blast percentage, and lower plasma leptin levels. MDS patients with a high LEP promoter methylation have a higher risk of progression, shorter progression-free survival, and inferior overall survival. Furthermore, LEP promoter methylation was an independent risk factor for the progression of MDS in a multivariate Cox regression analysis. CONCLUSION: In conclusion, hypermethylation of the LEP promoter is an early and frequent event in myeloid neoplasms and is associated with a worse prognosis.
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Anemia , Leptina , Leucemia Mieloide Aguda , Síndromes Mielodisplásicos , Anciano , Humanos , Anemia/genética , Hematopoyesis Clonal , Metilación de ADN , Leptina/genética , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicos/genética , Síndromes Mielodisplásicos/patología , Obesidad/genéticaRESUMEN
Dysregulation of circulating lipids is a central element for the metabolic syndrome. However, it is not well established whether human subcutaneous adipose tissue is affected by or affect circulating lipids through epigenetic mechanisms. Hence, our aim was to investigate the association between circulating lipids and DNA methylation levels in human adipose tissue. DNA methylation and gene expression were analysed genome-wide in subcutaneous adipose tissue from two different cohorts, including 85 men and 93 women, respectively. Associations between DNA methylation and circulating levels of triglycerides, low-density lipoprotein, high-density lipoprotein and total cholesterol were analysed. Causal mediation analyses tested if adipose tissue DNA methylation mediates the effects of triglycerides on gene expression or insulin resistance. We found 115 novel associations between triglycerides and adipose tissue DNA methylation, e.g. in the promoter of RFS1, ARID2 and HOXA5 in the male cohort (P ≤ 1.1 × 10-7), and 63 associations, e.g. within the gene body of PTPRN2 and COL6A3 in the female cohort. We further connected these findings to altered mRNA expression levels in adipose tissue (e.g. HOXA5, IL11 and FAM45B). Interestingly, there was no overlap between methylation sites associated with triglycerides in men and the sites found in women, which points towards sex-specific effects of triglycerides on the epigenome. Finally, a causal mediation analysis provided support for adipose tissue DNA methylation as a partial mediating factor between circulating triglycerides and insulin resistance. This study identified novel epigenetic alterations in adipose tissue associated with circulating lipids. Identified epigenetic changes seem to mediate effects of triglycerides on insulin resistance.
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Metilación de ADN , Resistencia a la Insulina , Humanos , Masculino , Femenino , Metilación de ADN/genética , Triglicéridos/genética , Triglicéridos/metabolismo , Resistencia a la Insulina/genética , Epigénesis Genética/genética , Tejido Adiposo/metabolismoRESUMEN
INTRODUCTION: Breast cancer (BC) is a common type of cancer in women. Advances in therapy options have resulted in higher overall survival rates but side effects of cancer treatment are increasingly in the spotlight. The beneficial effects of anti-oestrogen therapy with tamoxifen and letrozole in the prevention of BC recurrence are well documented. While the most common side-effects of this therapy are well-defined, less is known about its effects on thyroid function. In women treated for early BC, an average of 1-5 kg weight gain has been observed after treatment with chemotherapy/anti-oestrogens. We aim to evaluate the current knowledge on the side effects of tamoxifen and letrozole treatments on thyroid function, followed by its potential influence on the observed weight gain. METHODS: We searched PubMed and found 16 publications on thyroid function and tamoxifen treatment in pre- and post-menopausal women with early- and advanced BC, whereas five publications on letrozole treatment in post-menopausal women with advanced BC. RESULTS: According to the current literature, there is an overall tendency towards a mild and transient thyroid dysfunction, that is, subclinical hypothyroidism in tamoxifen-treated patients. Only one publication reported further significant changes in thyroid hormones beyond one year of tamoxifen treatment. No significant changes in thyroid function have been observed among letrozole-treated patients. CONCLUSION: Tamoxifen-treated patients can develop mild and transient thyroid dysfunction within the first 12 months, yet further significant changes in thyroid function beyond one year of tamoxifen treatment have been reported in a single study. There is no evidence of thyroid dysfunction in letrozole-treated patients. Current literature does not focus on subclinical hypothyroidism as a possible cause of weight gain in patients with BC. Subgrouping of BC patients and studies with a longer observation of thyroid hormones and weight changes during and after anti-oestrogen treatment are needed to further elucidate how anti-oestrogens affect thyroid function.
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Neoplasias de la Mama , Hipotiroidismo , Humanos , Femenino , Letrozol/efectos adversos , Tamoxifeno/efectos adversos , Inhibidores de la Aromatasa/uso terapéutico , Nitrilos/efectos adversos , Triazoles/efectos adversos , Recurrencia Local de Neoplasia/tratamiento farmacológico , Estrógenos , Hipotiroidismo/inducido químicamente , Antineoplásicos Hormonales/efectos adversos , Quimioterapia AdyuvanteRESUMEN
Studies in genetically 'identical' individuals indicate that as much as 50% of complex trait variation cannot be traced to genetics or to the environment. The mechanisms that generate this 'unexplained' phenotypic variation (UPV) remain largely unknown. Here, we identify neuronatin (NNAT) as a conserved factor that buffers against UPV. We find that Nnat deficiency in isogenic mice triggers the emergence of a bi-stable polyphenism, where littermates emerge into adulthood either 'normal' or 'overgrown'. Mechanistically, this is mediated by an insulin-dependent overgrowth that arises from histone deacetylase (HDAC)-dependent ß-cell hyperproliferation. A multi-dimensional analysis of monozygotic twin discordance reveals the existence of two patterns of human UPV, one of which (Type B) phenocopies the NNAT-buffered polyphenism identified in mice. Specifically, Type-B monozygotic co-twins exhibit coordinated increases in fat and lean mass across the body; decreased NNAT expression; increased HDAC-responsive gene signatures; and clinical outcomes linked to insulinemia. Critically, the Type-B UPV signature stratifies both childhood and adult cohorts into four metabolic states, including two phenotypically and molecularly distinct types of obesity.
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Proteínas de la Membrana , Proteínas del Tejido Nervioso , Adaptación Fisiológica , Adulto , Animales , Niño , Histona Desacetilasas , Humanos , Insulina , Proteínas de la Membrana/metabolismo , Ratones , Proteínas del Tejido Nervioso/genética , Obesidad/genética , Obesidad/metabolismoRESUMEN
Mutations in the epigenetic modifier TET2 are frequent in myeloid malignancies and clonal hematopoiesis of indeterminate potential (CHIP) and clonal cytopenia of undetermined significance (CCUS). Here, we investigate associations between TET2 mutations and DNA methylation in whole blood in 305 elderly twins, 15 patients with CCUS and 18 healthy controls. We find that TET2 mutations are associated with DNA hypermethylation at enhancer sites in whole blood in CHIP and in both granulocytes and mononuclear cells in CCUS. These hypermethylated sites are associated with leukocyte function and immune response and ETS-related and C/EBP-related transcription factor motifs. While the majority of TET2-associated hypermethylation sites are shared between CHIP and in AML, we find a set of AML-specific hypermethylated loci at active enhancer elements in hematopoietic stem cells. In summary, we show that TET2 mutations is associated with hypermethylated enhancers involved in myeloid differentiation in both CHIP, CCUS and AML patients.
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Metilación de ADN , Proteínas de Unión al ADN/genética , Dioxigenasas/genética , Elementos de Facilitación Genéticos , Hematopoyesis/genética , Mutación , ADN (Citosina-5-)-Metiltransferasas/genética , ADN Metiltransferasa 3A , Células Madre Hematopoyéticas , Humanos , Trastornos Mieloproliferativos/genética , Factores de Transcripción/genéticaRESUMEN
The role of vitamin C in the treatment of cancer has been subject to controversy for decades. Within the past 10 years, mechanistic insight into the importance of vitamin C in epigenetic regulation has provided a new rationale for its potential anti-cancer effects. At physiological concentrations, vitamin C is a potent antioxidant and thereby co-factor for a range of enzymes including the Fe(II)- and α-ketoglutarate-dependent dioxygenases that represent some of the most important epigenetic regulators; the ten-eleven translocation (TET) methylcytosine dioxygenases and the Jumonji-C domain-containing histone demethylases. Epigenetic deregulation is a hallmark of many cancers and reduced activity of these enzymes or somatic loss-of-function mutations in the genes encoding them, are observed in many cancer types. The present review outlines the growing literature on the role of vitamin C in epigenetic therapy of cancer. In the vast majority of in vitro, animal and clinical studies included in this review, vitamin C showed ability across cancer types to increase the hydroxylation of 5-methylcytosine to 5-hydroxymethylcytosine catalyzed by the TET enzymes - the first step in DNA demethylation. Most consistently, vitamin C in combination with the class of epigenetic drugs, DNA methyltransferase inhibitors, has demonstrated efficacy in the treatment of hematological malignancies in both preclinical and the limited number of available clinical studies. Yet, the pertinent question of what is the optimal dose of vitamin C in cancer studies remains to be answered. High-quality randomized placebo-controlled trials are needed to determine whether supplementation with vitamin C may benefit subgroups of patients with (pre-)cancer.
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Dioxigenasas , Neoplasias , Animales , Antioxidantes , Ácido Ascórbico , Metilación de ADN , Dioxigenasas/genética , Dioxigenasas/metabolismo , Epigénesis Genética , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/genética , VitaminasRESUMEN
The extent to which reduced insulin secretion during prolonged fasting reflects failure to compensate for whole body insulin resistance or a normal adjustment to potentially increased hepatic insulin action is unknown. We examined the effects of 36- versus 12-h fasting on insulin secretion and whole body versus hepatic insulin action in 13 healthy young males. Hepatic glucose production and insulin action were studied using stable isotopes, whereas whole body insulin action and insulin secretion were studied using an intravenous glucose tolerance test (IVGTT) and minimal modeling. Insulin, glucose, and lipid profiles were subsequently measured during a refeeding meal test. Prolonged fasting caused a minor reduction of first-phase insulin secretion in a context of improved hepatic insulin action, contrasting an increase in whole body insulin resistance. Accordingly, prolonged fasting was associated with opposite-directed effects on hepatic versus whole body insulin secretion disposition indices. Thirty-six-hour fasting compared with 12-h fasting was associated with increased serum insulin levels during the refeeding meal test. In conclusion, reduced insulin secretion during prolonged fasting may represent a healthy response to improved hepatic insulin action. Use of insulin secretion disposition indices without taking organ-specific insulin action into account may lead to erroneous conclusions.NEW & NOTEWORTHY Thirty-six-hour prolonged, compared with 12-h overnight fasting, is associated with slightly reduced first-phase insulin secretion in the face of opposite-directed changes in hepatic versus whole body insulin action in healthy young males. The paradoxical finding of increased hepatic versus decreased whole body insulin secretion disposition indices during prolonged fasting challenges the physiological understanding and validity of insulin secretion disposition indices not taking organ-specific insulin action into account.
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Ayuno/metabolismo , Privación de Alimentos/fisiología , Secreción de Insulina , Insulina/metabolismo , Hígado/metabolismo , Adulto , Glucemia/metabolismo , Dinamarca , Prueba de Tolerancia a la Glucosa , Indicadores de Salud , Humanos , Resistencia a la Insulina/fisiología , Masculino , Factores de Tiempo , Adulto JovenRESUMEN
The DNA methyltransferase inhibitors (DNMTi) 5-azacytidine and 5-aza-2-deoxycytidine have been approved for the treatment of different types of hematologic malignancies. However, only about 50% of patients respond to treatment. Therefore, a more comprehensive understanding of the molecular changes in patients treated with DNMTi is needed. Here, we examined gene expression profiles in a total of 150 RNA samples from two adult cohorts and one pediatric cohort with hematologic cancers taken before, during, and after treatment with 5-azacytidine (40 patients; 15 nonresponders, 25 responders). Using each patient as their own control, malignant cells showed preferential activation of a subset of evolutionarily young transposable elements (TE), including endogenous retroviral long terminal repeats (LTR), short and long interspersed nuclear elements (SINE and LINE), and the type I IFN pathway in responders, all independent of disease classification. Transfection of eight upregulated LTRs into recipient human cells in culture showed robust and heterogenous activation of six genes in the type I IFN pathway. These results, obtained in diverse hematologic disease entities, show that common targets (TE) activated by the same drug (5-azacytidine) elicit an immune response, which may be important for patient's responses to DNMTi. SIGNIFICANCE: Activation of specific classes of evolutionarily young transposable elements can lead to activation of the innate immune system.
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Antimetabolitos Antineoplásicos/farmacología , Azacitidina/farmacología , Elementos Transponibles de ADN/efectos de los fármacos , Neoplasias Hematológicas/tratamiento farmacológico , Inmunidad Innata/genética , Anciano , Anciano de 80 o más Años , Antimetabolitos Antineoplásicos/uso terapéutico , Azacitidina/uso terapéutico , Estudios de Cohortes , Elementos Transponibles de ADN/genética , Resistencia a Antineoplásicos/genética , Resistencia a Antineoplásicos/inmunología , Retrovirus Endógenos/genética , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/inmunología , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/inmunología , Humanos , Inmunidad Innata/efectos de los fármacos , Interferón Tipo I/metabolismo , Masculino , Persona de Mediana Edad , Imitación Molecular/inmunología , RNA-Seq , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Transducción de Señal/inmunología , Regulación hacia Arriba/efectos de los fármacosRESUMEN
Patients with recurrent glioblastoma achieving response to bevacizumab combined with chemotherapy have clinical improvement and prolonged survival. High gene expression of angiotensinogen (AGT) is associated with a poor bevacizumab response. Because AGT expression is epigenetically regulated, we aimed to investigate whether AGT promoter methylation in tumor tissue predicts response to bevacizumab combination therapy in patients with recurrent glioblastoma. The study included 159 patients with recurrent glioblastoma, treated with bevacizumab combination treatment (training cohort, n = 77; validation cohort, n = 82). All patients could be evaluated for treatment response and biomarkers. DNA methylation of 4 CpG sites in the AGT promoter was measured using pyrosequencing. A model for nonresponse was established using logistic regression analysis. In the training cohort, lower methylation of each of the four CpG sites in the AGT promoter was significantly associated with nonresponse (all P < 0.05). Moreover, the mean methylation level of all four CpG sites was associated with an increased likelihood of not achieving response to bevacizumab combination therapy (twofold decrease: odds ratio = 3.01; 95% confidence interval: 1.41-6.44; P = 0.004). We developed a model for nonresponse in the training cohort, where a threshold of mean AGT promoter methylation levels was set to below 12%. The model could predict bevacizumab nonresponse with 96% specificity. Importantly, this predictor was also significantly associated with nonresponse in the validation cohort (P = 0.037). Taken together, our findings suggest that low AGT promoter methylation in tumor tissue predicts nonresponse to bevacizumab combination treatment in patients with recurrent glioblastoma. We have, thus, established and successfully validated a predictor for nonresponse that can be used to identify patients who will not benefit from bevacizumab combination therapy.
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Angiotensinógeno/genética , Angiotensinógeno/metabolismo , Antineoplásicos Inmunológicos/uso terapéutico , Bevacizumab/uso terapéutico , Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Recurrencia Local de Neoplasia/metabolismo , Sistema Renina-Angiotensina/genética , Adulto , Anciano , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Estudios de Cohortes , Islas de CpG , Metilación de ADN , Femenino , Glioblastoma/tratamiento farmacológico , Glioblastoma/genética , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/prevención & control , Regiones Promotoras GenéticasRESUMEN
Background: Being born with low birth weight (LBW) is a risk factor for muscle insulin resistance and type 2 diabetes (T2D), which may be mediated by epigenetic mechanisms programmed by the intrauterine environment. Epigenetic mechanisms exert their prime effects in developing cells. We hypothesized that muscle insulin resistance in LBW subjects may be due to early differential epigenomic and transcriptomic alterations in their immature muscle progenitor cells.Results: Muscle progenitor cells were obtained from 23 healthy young adult men born at term with LBW, and 15 BMI-matched normal birth weight (NBW) controls. The cells were subsequently cultured and differentiated into myotubes. DNA and RNA were harvested before and after differentiation for genome-wide DNA methylation and RNA expression measurements.After correcting for multiple comparisons (q ≤ 0.05), 56 CpG sites were found to be significantly, differentially methylated in myoblasts from LBW compared with NBW men, of which the top five gene-annotated CpG sites (SKI, ARMCX3, NR5A2, NEUROG, ESRRG) previously have been associated to regulation of cholesterol, fatty acid and glucose metabolism and muscle development or hypertrophy. LBW men displayed markedly decreased myotube gene expression levels of the AMPK-repressing tyrosine kinase gene FYN and the histone deacetylase gene HDAC7. Silencing of FYN and HDAC7 was associated with impaired myotube formation, which for HDAC7 reduced muscle glucose uptake.Conclusions: The data provides evidence of impaired muscle development predisposing LBW individuals to T2D is linked to and potentially caused by distinct DNA methylation and transcriptional changes including down regulation of HDAC7 and FYN in their immature myoblast stem cells.
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Regulación hacia Abajo/genética , Epigenoma/genética , Recién Nacido de Bajo Peso , Fibras Musculares Esqueléticas/metabolismo , Mioblastos/metabolismo , Transcriptoma/genética , Adulto , Humanos , Masculino , Adulto JovenRESUMEN
BACKGROUND: Patients with haematological malignancies are often vitamin C deficient, and vitamin C is essential for the TET-induced conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), the first step in active DNA demethylation. Here, we investigate whether oral vitamin C supplementation can correct vitamin C deficiency and affect the 5hmC/5mC ratio in patients with myeloid cancers treated with DNA methyltransferase inhibitors (DNMTis). RESULTS: We conducted a randomized, double-blinded, placebo-controlled pilot trial (NCT02877277) in Danish patients with myeloid cancers performed during 3 cycles of DNMTi-treatment (5-azacytidine, 100 mg/m2/d for 5 days in 28-day cycles) supplemented by oral dose of 500 mg vitamin C (n = 10) or placebo (n = 10) daily during the last 2 cycles. Fourteen patients (70%) were deficient in plasma vitamin C (< 23 µM) and four of the remaining six patients were taking vitamin supplements at inclusion. Global DNA methylation was significantly higher in patients with severe vitamin C deficiency (< 11.4 µM; 4.997 vs 4.656% 5mC relative to deoxyguanosine, 95% CI [0.126, 0.556], P = 0.004). Oral supplementation restored plasma vitamin C levels to the normal range in all patients in the vitamin C arm (mean increase 34.85 ± 7.94 µM, P = 0.0004). We show for the first time that global 5hmC/5mC levels were significantly increased in mononuclear myeloid cells from patients receiving oral vitamin C compared to placebo (0.037% vs - 0.029%, 95% CI [- 0.129, - 0.003], P = 0.041). CONCLUSIONS: Normalization of plasma vitamin C by oral supplementation leads to an increase in the 5hmC/5mC ratio compared to placebo-treated patients and may enhance the biological effects of DNMTis. The clinical efficacy of oral vitamin C supplementation to DNMTis should be investigated in a large randomized, placebo-controlled clinical trial. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02877277 . Registered on 9 August 2016, retrospectively registered.
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Ácido Ascórbico/administración & dosificación , Azacitidina/administración & dosificación , Metilación de ADN/efectos de los fármacos , Leucemia Mieloide/terapia , Síndromes Mielodisplásicos/terapia , Administración Oral , Anciano , Anciano de 80 o más Años , Ácido Ascórbico/sangre , Ácido Ascórbico/farmacología , Azacitidina/farmacología , Islas de CpG/efectos de los fármacos , Dinamarca , Método Doble Ciego , Epigénesis Genética/efectos de los fármacos , Femenino , Humanos , Leucemia Mieloide/sangre , Leucemia Mieloide/genética , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/sangre , Síndromes Mielodisplásicos/genética , Proyectos PilotoRESUMEN
BACKGROUND: Individuals born with low birth weight (LBW) have an increased risk of metabolic diseases when exposed to diets rich in calories and fat but may respond to fasting in a metabolically preferential manner. We hypothesized that impaired foetal growth is associated with differential regulation of gene expression and epigenetics in metabolic tissues in response to fasting in young adulthood. METHODS: Genome-wide expression and DNA methylation were analysed in subcutaneous adipose tissue (SAT) and skeletal muscle from LBW and normal birth weight (NBW) men after 36â¯h fasting and after an isocaloric control study using microarrays. FINDINGS: Transcriptome analyses revealed that expression of genes involved in oxidative phosphorylation (OXPHOS) and other key metabolic pathways were lower in SAT from LBW vs NBW men after the control study, but paradoxically higher in LBW vs NBW men after 36â¯h fasting. Thus, fasting was associated with downregulated OXPHOS and metabolic gene sets in NBW men only. Likewise, in skeletal muscle only NBW men downregulated OXPHOS genes with fasting. Few epigenetic changes were observed in SAT and muscle between the groups. INTERPRETATION: Our results provide insights into the molecular mechanisms in muscle and adipose tissue governing a differential metabolic response in subjects with impaired foetal growth when exposed to fasting in adulthood. The results support the concept of developmental programming of metabolic diseases including type 2 diabetes. FUND: The Swedish Research Council, the Danish Council for Strategic Research, the Novo Nordisk foundation, the Swedish Foundation for Strategic Research, The European Foundation for the Study of Diabetes, The EU 6th Framework EXGENESIS grant and Rigshospitalet.
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Tejido Adiposo/metabolismo , Metabolismo Energético/genética , Ayuno , Regulación de la Expresión Génica , Músculo Esquelético/metabolismo , Adulto , Sitios de Unión , Biomarcadores , Peso al Nacer , Metilación de ADN , Perfilación de la Expresión Génica , Estudio de Asociación del Genoma Completo , Humanos , Masculino , Modelos Biológicos , Motivos de Nucleótidos , Unión Proteica , Factores Sexuales , Factores de Transcripción , Transcripción Genética , Adulto JovenRESUMEN
Aim: The TCF7L2 gene variant rs7903146 has the largest effect on type 2 diabetes risk reported in genome-wide association studies, however its role in adipose tissue development and function is unknown. We investigate the association between gene variant rs7903146 and metabolic parameters and examine in vitro and ex vivo gene expression of TCF7L2 in human adipose tissue and progenitor cells from two independent populations of young healthy men with increased risk of type 2 diabetes due to low birth weight (LBW). Design: Adipose tissue biopsies were excised from 40 healthy young men with low and normal birth weights (NBW) after a control and 5-day high-fat overfeeding diet. In another cohort including 13 LBW and 13 NBW men, adipocyte progenitor cells were isolated and cultivated. Transcriptome-wide expression was performed on RNA extracted from biopsies or cell cultures. Results: Diet-induced peripheral insulin resistance is more pronounced in carriers of the T-risk allele rs7903146, whereas no association with hepatic insulin resistance was shown. TCF7L2 expression increased during adipogenesis in isolated preadipocytes from both LBW and NBW men (p < 0.001) and correlated positively with markers of progenitor cell proliferation and maturation capacity. In the mature adipose tissue, LBW men had lower expression of TCF7L2 compared to NBW men at baseline (p = 0.03) and TCF7L2 expression was suppressed by short-term overfeeding in NBW men (p = 0.005). Conclusions: The results suggest a regulation of TCF7L2 expression during adipogenesis and in mature adipose tissue upon overfeeding, and further that young men exposed to an adverse intrauterine environment have reduced mature adipose tissue TCF7L2 expression.
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Adipogénesis/fisiología , Tejido Adiposo/metabolismo , Diferenciación Celular/fisiología , Dieta Alta en Grasa , Proteína 2 Similar al Factor de Transcripción 7/metabolismo , Adulto , Alelos , Estudios Cruzados , Diabetes Mellitus Tipo 2/genética , Humanos , Recién Nacido de Bajo Peso , Resistencia a la Insulina/fisiología , Masculino , Proteína 2 Similar al Factor de Transcripción 7/genética , Adulto JovenRESUMEN
The ADAMTS9 rs4607103 C allele is one of the few gene variants proposed to increase the risk of type 2 diabetes through an impairment of insulin sensitivity. We show that the variant is associated with increased expression of the secreted ADAMTS9 and decreased insulin sensitivity and signaling in human skeletal muscle. In line with this, mice lacking Adamts9 selectively in skeletal muscle have improved insulin sensitivity. The molecular link between ADAMTS9 and insulin signaling was characterized further in a model where ADAMTS9 was overexpressed in skeletal muscle. This selective overexpression resulted in decreased insulin signaling presumably mediated through alterations of the integrin ß1 signaling pathway and disruption of the intracellular cytoskeletal organization. Furthermore, this led to impaired mitochondrial function in mouse muscle-an observation found to be of translational character because humans carrying the ADAMTS9 risk allele have decreased expression of mitochondrial markers. Finally, we found that the link between ADAMTS9 overexpression and impaired insulin signaling could be due to accumulation of harmful lipid intermediates. Our findings contribute to the understanding of the molecular mechanisms underlying insulin resistance and type 2 diabetes and point to inhibition of ADAMTS9 as a potential novel mode of treating insulin resistance.