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Cyclin-dependent kinase 9 (CDK9) promotes transcriptional elongation through RNAPII pause release. We now report that CDK9 is also essential for maintaining gene silencing at heterochromatic loci. Through a live cell drug screen with genetic confirmation, we discovered that CDK9 inhibition reactivates epigenetically silenced genes in cancer, leading to restored tumor suppressor gene expression, cell differentiation, and activation of endogenous retrovirus genes. CDK9 inhibition dephosphorylates the SWI/SNF protein BRG1, which contributes to gene reactivation. By optimization through gene expression, we developed a highly selective CDK9 inhibitor (MC180295, IC50 = 5 nM) that has broad anti-cancer activity in vitro and is effective in in vivo cancer models. Additionally, CDK9 inhibition sensitizes to the immune checkpoint inhibitor α-PD-1 in vivo, making it an excellent target for epigenetic therapy of cancer.
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Quinasa 9 Dependiente de la Ciclina/metabolismo , Animales , Línea Celular Tumoral , Quinasa 9 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 9 Dependiente de la Ciclina/genética , ADN Helicasas/genética , ADN Helicasas/metabolismo , Metilación de ADN , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Leucocitos Mononucleares/citología , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-myc/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Bibliotecas de Moléculas Pequeñas/química , Bibliotecas de Moléculas Pequeñas/farmacología , Relación Estructura-Actividad , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
ABSTRACT: Persisting alloreactive donor T cells in target tissues are a determinant of graft-versus-host disease (GVHD), but the transcriptional regulators that control the persistence and function of tissue-infiltrating T cells remain elusive. We demonstrate here that Id3, a DNA-binding inhibitor, is critical for sustaining T-cell responses in GVHD target tissues in mice, including the liver and intestine. Id3 loss results in aberrantly expressed PD-1 in polyfunctional T helper 1 (Th1) cells, decreased tissue-infiltrating PD-1+ polyfunctional Th1 cell numbers, impaired maintenance of liver TCF-1+ progenitor-like T cells, and inhibition of GVHD. PD-1 blockade restores the capacity of Id3-ablated donor T cells to mediate GVHD. Single-cell RNA-sequencing analysis revealed that Id3 loss leads to significantly decreased CD28- and PI3K/AKT-signaling activity in tissue-infiltrating polyfunctional Th1 cells, an indicator of active PD-1/PD-L1 effects. Id3 is also required for protecting CD8+ T cells from the PD-1 pathway-mediated suppression during GVHD. Genome-wide RNA-sequencing analysis reveals that Id3 represses transcription factors (e.g., Nfatc2, Fos, Jun, Ets1, and Prdm1) that are critical for PD-1 transcription, exuberant effector differentiation, and interferon responses and dysfunction of activated T cells. Id3 achieves these effects by restraining the chromatin accessibility for these transcription factors. Id3 ablation in donor T cells preserved their graft vs tumor effects in mice undergoing allogeneic hematopoietic stem cell transplantation. Furthermore, CRISPR/Cas9 knockout of ID3 in human CD19-directed chimeric antigen receptor T cells retained their antitumor activity in NOD/SCID/IL2Rg-/- mice early after administration. These findings identify that ID3 is an important target to reduce GVHD, and the gene-editing program of ID3 may have broad implications in T-cell-based immunotherapy.
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Enfermedad Injerto contra Huésped , Receptor de Muerte Celular Programada 1 , Ratones , Animales , Humanos , Receptor de Muerte Celular Programada 1/genética , Fosfatidilinositol 3-Quinasas , Ratones SCID , Ratones Endogámicos NOD , Enfermedad Injerto contra Huésped/prevención & control , Factores de Transcripción , ARNRESUMEN
CpG islands near promoters are normally unmethylated despite being surrounded by densely methylated regions. Aberrant hypermethylation of these CpG islands has been associated with the development of various human diseases. Although local genetic elements have been speculated to play a role in protecting promoters from methylation, only a limited number of methylation barriers have been identified. In this study, we conducted an integrated computational and experimental investigation of colorectal cancer methylomes. Our study revealed 610 genes with disrupted methylation barriers. Genomic sequences of these barriers shared a common 41-bp sequence motif (MB-41) that displayed homology to the chicken HS4 methylation barrier. Using the CDKN2A (P16) tumor suppressor gene promoter, we validated the protective function of MB-41 and showed that loss of such protection led to aberrant hypermethylation. Our findings highlight a novel sequence signature of cis-acting methylation barriers in the human genome that safeguard promoters from silencing.
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Neoplasias Colorrectales , Metilación de ADN , Regiones Promotoras Genéticas , Animales , Humanos , Línea Celular Tumoral , Neoplasias Colorrectales/genética , Islas de CpG , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Genoma Humano , Motivos de Nucleótidos , Pollos , Estudio de Asociación del Genoma CompletoRESUMEN
BACKGROUND & AIMS: Aberrant DNA methylation is frequent in colorectal cancer (CRC), but underlying mechanisms and pathologic consequences are poorly understood. METHODS: We disrupted active DNA demethylation genes Tet1 and/or Tdg from ApcMin mice and characterized the methylome and transcriptome of colonic adenomas. Data were compared to human colonic adenocarcinomas (COAD) in The Cancer Genome Atlas. RESULTS: There were increased numbers of small intestinal adenomas in ApcMin mice expressing the TdgN151A allele, whereas Tet1-deficient and Tet1/TdgN151A-double heterozygous ApcMin colonic adenomas were larger with features of erosion and invasion. We detected reduction in global DNA hypomethylation in colonic adenomas from Tet1- and Tdg-mutant ApcMin mice and hypermethylation of CpG islands in Tet1-mutant ApcMin adenomas. Up-regulation of inflammatory, immune, and interferon response genes was present in Tet1- and Tdg-mutant colonic adenomas compared to control ApcMin adenomas. This up-regulation was also seen in murine colonic organoids and human CRC lines infected with lentiviruses expressing TET1 or TDG short hairpin RNA. A 127-gene inflammatory signature separated colonic adenocarcinomas into 4 groups, closely aligned with their microsatellite or chromosomal instability and characterized by different levels of DNA methylation and DNMT1 expression that anticorrelated with TET1 expression. Tumors with the CpG island methylator phenotype (CIMP) had concerted high DNMT1/low TET1 expression. TET1 or TDG knockdown in CRC lines enhanced killing by natural killer cells. CONCLUSIONS: Our findings reveal a novel epigenetic regulation, linked to the type of genomic instability, by which TET1/TDG-mediated DNA demethylation decreases methylation levels and inflammatory/interferon/immune responses. CIMP in CRC is triggered by an imbalance of methylating activities over demethylating activities. These mice represent a model of CIMP CRC.
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Adenocarcinoma , Adenoma , Neoplasias del Colon , Neoplasias Colorrectales , Animales , Humanos , Ratones , Adenocarcinoma/genética , Adenocarcinoma/patología , Adenoma/genética , Adenoma/patología , Carcinogénesis/genética , Transformación Celular Neoplásica/genética , Neoplasias del Colon/genética , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Islas de CpG/genética , Metilación de ADN , Proteínas de Unión al ADN/genética , Epigénesis Genética , Oxigenasas de Función Mixta/genética , Fenotipo , Proteínas Proto-Oncogénicas/genéticaRESUMEN
BACKGROUND: Systemic primary carnitine deficiency (PCD) is characterized by cardiomyopathy and arrhythmia. Without carnitine supplementation, progression is usually towards fatal cardiac decompensation. While the cardiomyopathy is most likely secondary to energy deficiency, the mechanism of arrhythmia is unclear, and may be related to a short QT interval. OBJECTIVE: We aim to describe rhythmic manifestations at diagnosis and with carnitine supplementation. METHODS: French patients diagnosed for PCD were retrospectively included. Clinical and para clinical data at diagnosis and during follow-up were collected. Electrocardiograms with QT interval measurements were blinded reviewed by two paediatric cardiologists. RESULTS: Nineteen patients (median age at diagnosis 2.3 years (extremes 0.3-28.9)) followed in 8 French centres were included. At diagnosis, 21% of patients (4/19) had arrhythmia (2 ventricular fibrillations, 1 ventricular tachycardia and 1 sudden death), and 84% (16/19) had cardiomyopathy. Six electrocardiograms before treatment out of 11 available displayed a short QT (QTc < 340 ms). Median corrected QTc after carnitine supplementation was 404 ms (extremes 341-447) versus 350 ms (extremes 282-421) before treatment (p < 0.001). The whole QTc was prolonged, and no patient reached the criterion of short QT syndrome with carnitine supplementation. Three patients died, probably from rhythmic cause without carnitine supplementation (two extra-hospital sudden deaths and one non-recoverable rhythmic storm before carnitine supplementation), whereas no rhythmic complication occurred in patients with carnitine supplementation. CONCLUSION: PCD is associated with shortening of the QT interval inducing severe arrhythmia. A potential explanation would be a toxic effect of accumulated fatty acid and metabolites on ionic channels embedded in the cell membrane. Carnitine supplementation normalizes the QTc and prevents arrhythmia. Newborn screening of primary carnitine deficiency would prevent avoidable deaths.
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Cardiomiopatías , Síndrome de QT Prolongado , Recién Nacido , Niño , Humanos , Preescolar , Muerte Súbita Cardíaca/etiología , Muerte Súbita Cardíaca/prevención & control , Estudios Retrospectivos , Arritmias Cardíacas/complicaciones , Cardiomiopatías/complicaciones , Carnitina/metabolismo , Electrocardiografía/efectos adversosRESUMEN
Maternal history for sporadic Alzheimer's disease (AD) predisposes the offspring to the disease later in life. However, the mechanisms behind this phenomenon are still unknown. Lifestyle and nutrition can directly modulate susceptibility to AD. Herein we investigated whether gestational high fat diet influences the offspring susceptibility to AD later in life. Triple transgenic dams were administered high fat diet or regular chow throughout 3 weeks gestation. Offspring were fed regular chow throughout their life and tested for spatial learning and memory, brain amyloidosis, tau pathology, and synaptic function. Gestational high fat diet attenuated memory decline, synaptic dysfunction, amyloid-ß and tau neuropathology in the offspring by transcriptional regulation of BACE-1, CDK5, and tau gene expression via the upregulation of FOXP2 repressor. Gestational high fat diet protects offspring against the development of the AD phenotype. In utero dietary intervention could be implemented as preventative strategy against AD.
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Enfermedad de Alzheimer , Dieta Alta en Grasa , Trastornos de la Memoria , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/fisiopatología , Enfermedad de Alzheimer/prevención & control , Péptidos beta-Amiloides/genética , Péptidos beta-Amiloides/metabolismo , Amiloidosis/genética , Amiloidosis/metabolismo , Amiloidosis/fisiopatología , Amiloidosis/prevención & control , Animales , Encéfalo/metabolismo , Encéfalo/fisiopatología , Encefalopatías/genética , Encefalopatías/metabolismo , Encefalopatías/fisiopatología , Encefalopatías/prevención & control , Modelos Animales de Enfermedad , Femenino , Factores de Transcripción Forkhead/genética , Predisposición Genética a la Enfermedad/prevención & control , Trastornos de la Memoria/genética , Trastornos de la Memoria/metabolismo , Trastornos de la Memoria/fisiopatología , Trastornos de la Memoria/prevención & control , Ratones , Ratones Transgénicos , Embarazo/genética , Embarazo/metabolismo , Proteínas Represoras/genética , Sinapsis/genética , Sinapsis/metabolismo , Transcripción Genética , Regulación hacia Arriba , Proteínas tau/genética , Proteínas tau/metabolismoRESUMEN
Next-generation sequencing has revealed that more than 50% of human cancers harbour mutations in enzymes that are involved in chromatin organization. Tumour cells not only are activated by genetic and epigenetic alterations, but also routinely use epigenetic processes to ensure their escape from chemotherapy and host immune surveillance. Hence, a growing emphasis of recent drug discovery efforts has been on targeting the epigenome, including DNA methylation and histone modifications, with several new drugs being tested and some already approved by the US Food and Drug Administration (FDA). The future will see the increasing success of combining epigenetic drugs with other therapies. As epigenetic drugs target the epigenome as a whole, these true 'genomic medicines' lessen the need for precision approaches to individualized therapies.
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Metilación de ADN/efectos de los fármacos , Epigenómica/métodos , Inhibidores de Histona Desacetilasas/farmacología , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Epigénesis Genética , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Histonas/metabolismo , HumanosRESUMEN
BACKGROUND: DNA methylation alterations have similar patterns in normal aging tissue and in cancer. In this study, we investigated breast tissue-specific age-related DNA methylation alterations and used those methylation sites to identify individuals with outlier phenotypes. Outlier phenotype is identified by unsupervised anomaly detection algorithms and is defined by individuals who have normal tissue age-dependent DNA methylation levels that vary dramatically from the population mean. METHODS: We generated whole-genome DNA methylation profiles (GSE160233) on purified epithelial cells and used publicly available Infinium HumanMethylation 450K array datasets (TCGA, GSE88883, GSE69914, GSE101961, and GSE74214) for discovery and validation. RESULTS: We found that hypermethylation in normal breast tissue is the best predictor of hypermethylation in cancer. Using unsupervised anomaly detection approaches, we found that about 10% of the individuals (39/427) were outliers for DNA methylation from 6 DNA methylation datasets. We also found that there were significantly more outlier samples in normal-adjacent to cancer (24/139, 17.3%) than in normal samples (15/228, 5.2%). Additionally, we found significant differences between the predicted ages based on DNA methylation and the chronological ages among outliers and not-outliers. Additionally, we found that accelerated outliers (older predicted age) were more frequent in normal-adjacent to cancer (14/17, 82%) compared to normal samples from individuals without cancer (3/17, 18%). Furthermore, in matched samples, we found that the epigenome of the outliers in the pre-malignant tissue was as severely altered as in cancer. CONCLUSIONS: A subset of patients with breast cancer has severely altered epigenomes which are characterized by accelerated aging in their normal-appearing tissue. In the future, these DNA methylation sites should be studied further such as in cell-free DNA to determine their potential use as biomarkers for early detection of malignant transformation and preventive intervention in breast cancer.
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Envejecimiento/patología , Neoplasias de la Mama/patología , Mama/patología , Envejecimiento/genética , Envejecimiento/metabolismo , Mama/metabolismo , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Islas de CpG , Metilación de ADN , Epigenoma , Femenino , Humanos , FenotipoRESUMEN
Nerve injury-induced hyperactivity of primary sensory neurons in the dorsal root ganglion (DRG) contributes to chronic pain development, but the underlying epigenetic mechanisms remain poorly understood. Here we determined genome-wide changes in DNA methylation in the nervous system in neuropathic pain. Spinal nerve ligation (SNL), but not paclitaxel treatment, in male Sprague Dawley rats induced a consistent low-level hypomethylation in the CpG sites in the DRG during the acute and chronic phases of neuropathic pain. DNA methylation remodeling in the DRG occurred early after SNL and persisted for at least 3 weeks. SNL caused DNA methylation changes at 8% of CpG sites with prevailing hypomethylation outside of CpG islands, in introns, intergenic regions, and repetitive sequences. In contrast, SNL caused more gains of methylation in the spinal cord and prefrontal cortex. The DNA methylation changes in the injured DRGs recapitulated developmental reprogramming at the neonatal stage. Methylation reprogramming was correlated with increased gene expression variability. A diet deficient in methyl donors induced hypomethylation and pain hypersensitivity. Intrathecal administration of the DNA methyltransferase inhibitor RG108 caused long-lasting pain hypersensitivity. DNA methylation reprogramming in the DRG thus contributes to nerve injury-induced chronic pain. Restoring DNA methylation may represent a new therapeutic approach to treat neuropathic pain.SIGNIFICANCE STATEMENT Epigenetic mechanisms are critically involved in the transition from acute to chronic pain after nerve injury. However, genome-wide changes in DNA methylation in the nervous system and their roles in neuropathic pain development remain unclear. Here we used digital restriction enzyme analysis of methylation to quantitatively determine genome-wide DNA methylation changes caused by nerve injury. We showed that nerve injury caused DNA methylation changes at 8% of CpG sites with prevailing hypomethylation outside of CpG islands in the dorsal root ganglion. Reducing DNA methylation induced pain hypersensitivity, whereas increasing DNA methylation attenuated neuropathic pain. These findings extend our understanding of the epigenetic mechanism of chronic neuropathic pain and suggest new strategies to treat nerve injury-induced chronic pain.
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Dolor Crónico/metabolismo , Metilación de ADN/fisiología , Ganglios Espinales/metabolismo , Neuralgia/metabolismo , Animales , Dolor Crónico/genética , Epigénesis Genética/genética , Ganglios Espinales/lesiones , Masculino , Neuralgia/genética , Ratas , Ratas Sprague-DawleyAsunto(s)
Azacitidina , Leucemia Mieloide Aguda , Antimetabolitos Antineoplásicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Azacitidina/uso terapéutico , Decitabina/efectos adversos , Humanos , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/etiología , Resultado del TratamientoRESUMEN
TET1 oxidizes methylated cytosine into 5-hydroxymethylcytosine (5hmC), resulting in regulation of DNA methylation and gene expression. Full length TET1 (TET1FL) has a CXXC domain that binds to unmethylated CpG islands (CGIs). This CXXC domain allows TET1 to protect CGIs from aberrant methylation, but it also limits its ability to regulate genes outside of CGIs. Here, we report a novel isoform of TET1 (TET1ALT) that has a unique transcription start site from an alternate promoter in intron 2, yielding a protein with a unique translation start site. Importantly, TET1ALT lacks the CXXC domain but retains the catalytic domain. TET1ALT is repressed in embryonic stem cells (ESCs) but becomes activated in embryonic and adult tissues while TET1FL is expressed in ESCs, but repressed in adult tissues. Overexpression of TET1ALT shows production of 5hmC with distinct (and weaker) effects on DNA methylation or gene expression when compared to TET1FL. TET1ALT is aberrantly activated in multiple cancer types including breast, uterine and glioblastoma, and TET1 activation is associated with a worse overall survival in breast, uterine and ovarian cancers. Our data suggest that the predominantly activated isoform of TET1 in cancer cells does not protect from CGI methylation and likely mediates dynamic site-specific demethylation outside of CGIs.
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Regulación Neoplásica de la Expresión Génica , Oxigenasas de Función Mixta/genética , Neoplasias/genética , Proteínas Proto-Oncogénicas/genética , Animales , Sitios de Unión/genética , Western Blotting , Línea Celular , Línea Celular Tumoral , Islas de CpG/genética , Metilación de ADN , Células Madre Embrionarias/metabolismo , Células HEK293 , Células HeLa , Humanos , Células K562 , Células MCF-7 , Masculino , Ratones Endogámicos C57BL , Oxigenasas de Función Mixta/metabolismo , Neoplasias/metabolismo , Neoplasias/patología , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Proto-Oncogénicas/metabolismoRESUMEN
The interaction between the (epi)genetic makeup of an individual and his/her environmental exposure record (exposome) is accepted as a determinant factor for a significant proportion of human malignancies. Recent evidence has highlighted the key role of epigenetic mechanisms in mediating gene-environment interactions and translating exposures into tumorigenesis. There is also growing evidence that epigenetic changes may be risk factor-specific ("fingerprints") that should prove instrumental in the discovery of new biomarkers in cancer. Here, we review the state of the science of epigenetics associated with environmental stimuli and cancer risk, highlighting key developments in the field. Critical knowledge gaps and research needs are discussed and advances in epigenomics that may help in understanding the functional relevance of epigenetic alterations. Key elements required for causality inferences linking epigenetic changes to exposure and cancer are discussed and how these alterations can be incorporated in carcinogen evaluation and in understanding mechanisms underlying epigenome deregulation by the environment.
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Exposición a Riesgos Ambientales/efectos adversos , Epigénesis Genética , Epigenómica , Interacción Gen-Ambiente , Neoplasias/etiología , Animales , Metilación de ADN , Humanos , Neoplasias/patología , Factores de RiesgoRESUMEN
BACKGROUND: Outcomes for patients with relapsed or refractory acute myeloid leukemia (AML) are poor. Guadecitabine, a next-generation hypomethylating agent, could be useful in treating such patients. METHODS: In this multicenter, open-label, phase 2 dose-expansion study, AML patients from 10 North American medical centers were first randomized (1:1) to receive subcutaneous guadecitabine at 60 or 90 mg/m2 on 5 consecutive days in each 28-day cycle (5-day regimen). Subsequently, another cohort was treated for 10 days with 60 mg/m2 (10-day regimen). RESULTS: Between June 15, 2012, and August 19, 2013, 108 patients with previously treated AML consented to enroll in the study, and 103 of these patients were treated; 5 patients did not receive the study treatment. A total of 103 patients were included in the safety and efficacy analyses (24 and 26 patients who were randomly assigned to 60 and 90 mg/m2 /d, respectively [5-day regimen] and 53 patients who were assigned to 60 mg/m2 /d [10-day regimen]). The 90 mg/m2 dose showed no benefit in clinical outcomes in comparison with 60 mg/m2 in the randomized cohort. Composite complete response (CRc) and complete response (CR) rates were higher with the 10-day regimen versus the 5-day regimen (CRc, 30.2% vs 16.0%; P = .1061; CR, 18.9% vs 8%; P = .15). Adverse events (grade ≥ 3) were mainly hematologic, with a higher incidence on the 10-day regimen. Early all-cause mortality was low and similar between regimens. Twenty patients (8 on the 5-day regimen and 12 on the 10-day regimen) were bridged to hematopoietic cell transplantation. CONCLUSIONS: Guadecitabine has promising clinical activity and an acceptable safety profile and thus warrants further development in this population. Cancer 2018;124:325-34. © 2017 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
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Azacitidina/análogos & derivados , Leucemia Mieloide Aguda/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Azacitidina/administración & dosificación , Azacitidina/efectos adversos , Azacitidina/farmacología , Esquema de Medicación , Femenino , Trasplante de Células Madre Hematopoyéticas , Humanos , Leucemia Mieloide Aguda/mortalidad , Masculino , Persona de Mediana Edad , RecurrenciaRESUMEN
BACKGROUND: The hypomethylating drugs azacitidine and decitabine have shown efficacy in myelodysplastic syndromes and acute myeloid leukaemia, but complete tumour responses are infrequent and of short duration, possibly because of the short half-lives and suboptimal bone marrow exposure of the drugs. Guadecitabine, a next-generation hypomethylating drug, has a longer half-life and exposure than its active metabolite decitabine. A phase 1 study established 60 mg/m2 guadecitabine for 5 days as an effective treatment schedule. In this phase 2 study, we aimed to assess the safety and activity of two doses and schedules of guadecitabine in older (≥65 years) patients with treatment-naive acute myeloid leukaemia who were not candidates for intensive chemotherapy. METHODS: We did a multicentre, randomised, open-label, phase 1/2 study of guadecitabine in cohorts of patients with treatment-naive acute myeloid leukaemia, relapsed or refractory acute myeloid leukaemia, and myelodysplastic syndromes; here we report the phase 2 results from the cohort of treatment-naive patients with acute myeloid leukaemia. We included patients aged at least 65 years from 14 US medical centres (hospitals and specialist cancer clinics) who were not candidates for intensive chemotherapy and randomly assigned them (1:1) using a computer algorithm (for dynamic randomisation) to guadecitabine 60 or 90 mg/m2 on days 1-5 (5-day schedule) of a 28-day treatment cycle. Treatment allocation was not masked. We also assigned additional patients to guadecitabine 60 mg/m2 in a 10-day schedule in a 28-day treatment cycle after a protocol amendment. The primary endpoint was composite complete response (complete response, complete response with incomplete platelet recovery, or complete response with incomplete neutrophil recovery regardless of platelets). Response was assessed in all patients (as-treated) who received at least one dose of guadecitabine. We present the final analysis, although at the time of the database lock, 15 patients were still in follow-up for overall survival. This study is registered with ClinicalTrials.gov, number NCT01261312. FINDINGS: Between Aug 24, 2012, and Sept 15, 2014, 107 patients were enrolled: 54 on the 5-day schedule (26 randomly assigned to 60 mg/m2 and 28 to 90 mg/m2) and 53 were assigned to the 10-day schedule. Median age was 77 years (range 62-92), and median follow-up was 953 days (IQR 721-1040). All treated patients were assessable for a response. The number of patients who achieved a composite complete response did not differ between dose groups or schedules (13 [54%, 95% CI 32·8-74·4] with 60 mg/m2 on the 5-day schedule; 16 [59%; 38·8-77·6] with 90 mg/m2 on the 5-day schedule; and 26 [50%, 35·8-64·2] with 60 mg/m2 on the 10-day schedule). The most frequent grade 3 or worse adverse events, regardless of relationship to treatment, were febrile neutropenia (31 [61%] of 51 patients on the 5-day schedule vs 36 [69%] of 52 patients on the 10-day schedule), thrombocytopenia (25 [49%] vs 22 [42%]), neutropenia (20 [39%] vs 18 [35%]), pneumonia (15 [29%] vs 19 [37%]), anaemia (15 [29%] vs 12 [23%]), and sepsis (eight [16%] vs 14 [27%]). The most common serious adverse events, regardless of relationship to treatment, for the 5-day and 10-day schedules, respectively, were febrile neutropenia (27 [53%] vs 25 [48%]), pneumonia (14 [27%] vs 16 [31%]), and sepsis (eight [16%] vs 14 [27%]). 23 (22%) patients died because of adverse events (mainly from sepsis, eight [8%]; and pneumonia, five [5%]); four deaths were from adverse events deemed treatment-related (pneumonia, two [2%]; multiorgan failure, one [1%]; and sepsis, one [1%], all in the 10-day cohort). INTERPRETATION: More than half of older treatment-naive patients with acute myeloid leukaemia achieved a composite complete response with guadecitabine at all drug doses and schedules investigated, with tolerable toxicity. The recommended guadecitabine regimen for this population is 60 mg/m2 in a 5-day schedule. A phase 3 study in this patient population is ongoing (NCT02348489) to assess guadecitabine 60 mg/m2 in a 5-day schedule versus standard of care. FUNDING: Astex Pharmaceuticals and Stand Up To Cancer.
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Azacitidina/análogos & derivados , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/mortalidad , Seguridad del Paciente/estadística & datos numéricos , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Azacitidina/efectos adversos , Azacitidina/uso terapéutico , Supervivencia sin Enfermedad , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Humanos , Infusiones Intravenosas , Estimación de Kaplan-Meier , Leucemia Mieloide Aguda/diagnóstico , Dosis Máxima Tolerada , Persona de Mediana Edad , Invasividad Neoplásica/patología , Estadificación de Neoplasias , Pronóstico , Estudios Prospectivos , Inducción de Remisión , Medición de Riesgo , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
The myelodysplastic syndrome (MDS) is a clonal hematologic disorder that frequently evolves to acute myeloid leukemia (AML). Its pathogenesis remains unclear, but mutations in epigenetic modifiers are common and the disease often responds to DNA methylation inhibitors. We analyzed DNA methylation in the bone marrow and spleen in two mouse models of MDS/AML, the NUP98-HOXD13 (NHD13) mouse and the RUNX1 mutant mouse model. Methylation array analysis showed an average of 512/3445 (14.9%) genes hypermethylated in NHD13 MDS, and 331 (9.6%) genes hypermethylated in RUNX1 MDS. Thirty-two percent of genes in common between the two models (2/3 NHD13 mice and 2/3 RUNX1 mice) were also hypermethylated in at least two of 19 human MDS samples. Detailed analysis of 41 genes in mice showed progressive drift in DNA methylation from young to old normal bone marrow and spleen; to MDS, where we detected accelerated age-related methylation; and finally to AML, which markedly extends DNA methylation abnormalities. Most of these genes showed similar patterns in human MDS and AML. Repeat element hypomethylation was rare in MDS but marked the transition to AML in some cases. Our data show consistency in patterns of aberrant DNA methylation in human and mouse MDS and suggest that epigenetically, MDS displays an accelerated aging phenotype.
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Metilación de ADN/genética , Epigénesis Genética/genética , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicos/genética , Animales , Células de la Médula Ósea , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Modelos Animales de Enfermedad , Humanos , Leucemia Mieloide Aguda/patología , Ratones , Síndromes Mielodisplásicos/patología , Proteínas de Complejo Poro Nuclear/genéticaRESUMEN
The search for a connection between diet and human cancer has a long history in cancer research, as has interest in the mechanisms by which dietary factors might increase or decrease cancer risk. The realization that altering diet can alter the epigenetic state of genes and that these epigenetic alterations might increase or decrease cancer risk is a more modern notion, driven largely by studies in animal models. The connections between diet and epigenetic alterations, on the one hand, and between epigenetic alterations and cancer, on the other, are supported by both observational studies in humans as well as animal models. However, the conclusion that diet is linked directly to epigenetic alterations and that these epigenetic alterations directly increase or decrease the risk of human cancer is much less certain. We suggest that true and measurable effects of diet or dietary supplements on epigenotype and cancer risk are most likely to be observed in longitudinal studies and at the extremes of the intersection of dietary risk factors and human population variability. Careful analysis of such outlier populations is most likely to shed light on the molecular mechanisms by which suspected environmental risk factors drive the process of carcinogenesis.
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Envejecimiento , Dieta Saludable , Epigénesis Genética , Medicina Basada en la Evidencia , Neoplasias/prevención & control , Estado Nutricional , Animales , Investigación Biomédica/métodos , Investigación Biomédica/tendencias , Suplementos Dietéticos , Epigenómica/métodos , Epigenómica/tendencias , Humanos , Neoplasias/genética , Neoplasias/inmunología , Neoplasias/metabolismo , Nutrigenómica/métodos , Nutrigenómica/tendencias , Ciencias de la Nutrición/métodos , Ciencias de la Nutrición/tendenciasRESUMEN
Epigenetics refers to stable alterations in gene expression with no underlying modifications in the genetic sequence and is best exemplified by differentiation, in which multiple cell types diverge physiologically despite a common genetic code. Interest in this area of science has grown over the past decades, especially since it was found to play a major role in physiologic phenomena such as embryogenesis, imprinting, and X chromosome inactivation, and in disease states such as cancer. The latter had been previously thought of as a disease with an exclusive genetic etiology. However, recent data have demonstrated that the complexity of human carcinogenesis cannot be accounted for by genetic alterations alone, but also involves epigenetic changes in processes such as DNA methylation, histone modifications, and microRNA expression. In turn, these molecular alterations lead to permanent changes in the expression of genes that regulate the neoplastic phenotype, such as cellular growth and invasiveness. Targeting epigenetic modifiers has been referred to as epigenetic therapy. The success of this approach in hematopoietic malignancies validates the importance of epigenetic alterations in cancer, not only at the therapeutic level but also with regard to prevention, diagnosis, risk stratification, and prognosis.
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Epigénesis Genética , Neoplasias/genética , Animales , Biomarcadores de Tumor/genética , Ciclo Celular/genética , Transformación Celular Neoplásica/genética , Metilación de ADN , Histonas/genética , Humanos , MicroARNs/genética , Invasividad Neoplásica/genética , Neoplasias/clasificación , Neoplasias/diagnóstico , Neoplasias/metabolismo , Neoplasias/prevención & control , Neoplasias/terapia , Pronóstico , Medición de RiesgoRESUMEN
Modified epigenetic programming early in life is proposed to underlie the development of an adverse adult phenotype, known as the Developmental Origins of Health and Disease (DOHaD) concept. Several environmental contaminants have been implicated as modifying factors of the developing epigenome. This underlines the need to investigate this newly recognized toxicological risk and systematically screen for the epigenome modifying potential of compounds. In this study, we examined the applicability of the zebrafish embryo as a screening model for DNA methylation modifications. Embryos were exposed from 0 to 72 h post fertilization (hpf) to bisphenol-A (BPA), diethylstilbestrol, 17α-ethynylestradiol, nickel, cadmium, tributyltin, arsenite, perfluoroctanoic acid, valproic acid, flusilazole, 5-azacytidine (5AC) in subtoxic concentrations. Both global and site-specific methylation was examined. Global methylation was only affected by 5AC. Genome wide locus-specific analysis was performed for BPA exposed embryos using Digital Restriction Enzyme Analysis of Methylation (DREAM), which showed minimal wide scale effects on the genome, whereas potential informative markers were not confirmed by pyrosequencing. Site-specific methylation was examined in the promoter regions of three selected genes vasa, vtg1 and cyp19a2, of which vasa (ddx4) was the most responsive. This analysis distinguished estrogenic compounds from metals by direction and sensitivity of the effect compared to embryotoxicity. In conclusion, the zebrafish embryo is a potential screening tool to examine DNA methylation modifications after xenobiotic exposure. The next step is to examine the adult phenotype of exposed embryos and to analyze molecular mechanisms that potentially link epigenetic effects and altered phenotypes, to support the DOHaD hypothesis.
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Metilación de ADN/efectos de los fármacos , Proteínas de Pez Cebra/genética , Pez Cebra/embriología , Pez Cebra/genética , Animales , Compuestos de Bencidrilo/toxicidad , Metilación de ADN/fisiología , Evaluación Preclínica de Medicamentos/métodos , Embrión no Mamífero , Epigénesis Genética/efectos de los fármacos , Epigénesis Genética/fisiología , Metales Pesados/toxicidad , Fenoles/toxicidad , Esteroides/toxicidad , Pez Cebra/metabolismo , Proteínas de Pez Cebra/biosíntesisRESUMEN
TET1 is a 5-methylcytosine dioxygenase and its DNA demethylating activity has been implicated in pluripotency and reprogramming. However, the precise role of TET1 in DNA methylation regulation outside of developmental reprogramming is still unclear. Here, we show that overexpression of the TET1 catalytic domain but not full length TET1 (TET1-FL) induces massive global DNA demethylation in differentiated cells. Genome-wide mapping reveals that 5-hydroxymethylcytosine production by TET1-FL is inhibited as DNA methylation increases, which can be explained by the preferential binding of TET1-FL to unmethylated CpG islands (CGIs) through its CXXC domain. TET1-FL specifically accumulates 5-hydroxymethylcytosine at the edges of hypomethylated CGIs, while knockdown of endogenous TET1 induces methylation spreading from methylated edges into hypomethylated CGIs. We also found that gene expression changes after TET1-FL overexpression are relatively small and independent of its dioxygenase function. Thus, our results identify TET1 as a maintenance DNA demethylase that does not purposely decrease methylation levels, but specifically prevents aberrant methylation spreading into CGIs in differentiated cells.