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1.
Mol Cell ; 82(21): 4080-4098.e12, 2022 11 03.
Artículo en Inglés | MEDLINE | ID: mdl-36272410

RESUMEN

Growing evidence suggests prevalence of transcriptional condensates on chromatin, yet their mechanisms of formation and functional significance remain largely unclear. In human cancer, a series of mutations in the histone acetylation reader ENL create gain-of-function mutants with increased transcriptional activation ability. Here, we show that these mutations, clustered in ENL's structured acetyl-reading YEATS domain, trigger aberrant condensates at native genomic targets through multivalent homotypic and heterotypic interactions. Mechanistically, mutation-induced structural changes in the YEATS domain, ENL's two disordered regions of opposing charges, and the incorporation of extrinsic elongation factors are all required for ENL condensate formation. Extensive mutagenesis establishes condensate formation as a driver of oncogenic gene activation. Furthermore, expression of ENL mutants beyond the endogenous level leads to non-functional condensates. Our findings provide new mechanistic and functional insights into cancer-associated condensates and support condensate dysregulation as an oncogenic mechanism.


Asunto(s)
Neoplasias , Cuerpos Nucleares , Humanos , Dominios Proteicos , Cromatina/genética , Mutación , Neoplasias/genética
2.
Brief Bioinform ; 24(6)2023 09 22.
Artículo en Inglés | MEDLINE | ID: mdl-37985455

RESUMEN

DNA methylation is a fundamental epigenetic modification involved in various biological processes and diseases. Analysis of DNA methylation data at a genome-wide and high-throughput level can provide insights into diseases influenced by epigenetics, such as cancer. Recent technological advances have led to the development of high-throughput approaches, such as genome-scale profiling, that allow for computational analysis of epigenetics. Deep learning (DL) methods are essential in facilitating computational studies in epigenetics for DNA methylation analysis. In this systematic review, we assessed the various applications of DL applied to DNA methylation data or multi-omics data to discover cancer biomarkers, perform classification, imputation and survival analysis. The review first introduces state-of-the-art DL architectures and highlights their usefulness in addressing challenges related to cancer epigenetics. Finally, the review discusses potential limitations and future research directions in this field.


Asunto(s)
Aprendizaje Profundo , Neoplasias , Humanos , Metilación de ADN , Epigénesis Genética , Genoma , Neoplasias/genética
3.
Int J Mol Sci ; 25(13)2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-39000010

RESUMEN

Histone lysine demethylases (KDMs) play an essential role in biological processes such as transcription regulation, RNA maturation, transposable element control, and genome damage sensing and repair. In most cases, their action requires catalytic activities, but non-catalytic functions have also been shown in some KDMs. Indeed, some strictly KDM-related proteins and some KDM isoforms do not act as histone demethylase but show other enzymatic activities or relevant non-enzymatic functions in different cell types. Moreover, many studies have reported on functions potentially supported by catalytically dead mutant KDMs. This is probably due to the versatility of the catalytical core, which can adapt to assume different molecular functions, and to the complex multi-domain structure of these proteins which encompasses functional modules for targeting histone modifications, promoting protein-protein interactions, or recognizing nucleic acid structural motifs. This rich modularity and the availability of multiple isoforms in the various classes produced variants with enzymatic functions aside from histone demethylation or variants with non-catalytical functions during the evolution. In this review we will catalog the proteins with null or questionable demethylase activity and predicted or validated inactive isoforms, summarizing what is known about their alternative functions. We will then go through some experimental evidence for the non-catalytical functions of active KDMs.


Asunto(s)
Histona Demetilasas , Histona Demetilasas/metabolismo , Histona Demetilasas/genética , Histona Demetilasas/química , Humanos , Animales , Histonas/metabolismo
4.
Semin Cancer Biol ; 83: 166-176, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-33220458

RESUMEN

Both genetic and epigenetic mechanisms intimately regulate cancer development and chemoresistance. Different genetic alterations are observed in multiple genes, and most are irreversible. Aside from genetic alterations, epigenetic alterations play a crucial role in cancer. The reversible nature of epigenetic modifications makes them an attractive target for cancer prevention and therapy. Specific epigenetic alteration is also being investigated as a potential biomarker in multiple cancers. c-MYC is one of the most important transcription factors that are centrally implicated in multiple types of cancer cells reprogramming, proliferation, and chemoresistance. c-MYC shows not only genetic alterations but epigenetic changes in multiple cancers. It has been observed that epigenome aberrations can reversibly alter the expression of c-MYC, both transcriptional and translational levels. Understanding the underlying mechanism of the epigenetic alterations of c-MYC, that has its role in multiple levels of cancer pathogenesis, can give a better understanding of various unresolved questions regarding cancer. Recently, some researchers reported that targeting the epigenetic modifiers of c-MYC can successfully inhibit cancer cell proliferation, sensitize the chemoresistant cells, and increase the patient survival rate. As c-MYC is an important transcription factor, epigenetic therapy might be one of the best alternatives for the conventional therapies that assumes the "one-size-fits-all" role. It can also increase the precision of targeting and enhance the effectiveness of treatments among various cancer subtypes. In this review, we highlighted the role of epigenetically modified c-MYC in cancer cell reprogramming, progression, and chemoresistance. We also summarize the potential therapeutic approaches to target these modifications for the prevention of cancer development and chemoresistant phenotypes.


Asunto(s)
Reprogramación Celular , Neoplasias , Reprogramación Celular/genética , Resistencia a Antineoplásicos/genética , Epigénesis Genética , Genes myc , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Neoplasias/patología , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Factores de Transcripción/genética
5.
Semin Cancer Biol ; 83: 335-352, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-33453404

RESUMEN

In-depth insights in cancer biology over the past decades have highlighted the important roles of epigenetic mechanisms in the initiation and progression of tumorigenesis. The cancer epigenome usually experiences multiple alternations, including genome-wide DNA hypomethylation and site-specific DNA hypermethylation, various histone posttranslational modifications, and dysregulation of non-coding RNAs (ncRNAs). These epigenetic changes are plastic and reversible, and could potentially occur in the early stage of carcinogenesis preceding genetic mutation, offering unique opportunities for intervention therapies. Therefore, targeting the cancer epigenome or cancer epigenetic dysregulation with some selected agents (called epi-drugs) represents an evolving and promising strategy for cancer chemoprevention and therapy. Phytochemicals, as a class of pleiotropic molecules, have manifested great potential in modulating different cancer processes through epigenetic machinery, of which green tea polyphenol epigallocatechin-3-gallate (EGCG) is one of the most extensively studied. In this review, we first summarize epigenetic events involved in the pathogenesis of cancer, including DNA/RNA methylations, histone modifications and ncRNAs' dysregulations. We then focus on the recently discovered roles of phytochemicals, with a special emphasis on EGCG, in modulating different cancer processes through regulating epigenetic machinery. We finally discuss limitations of EGCG as an epigenetic modulator for cancer chemoprevention and treatment and offer potential strategies to overcome the shortcomings.


Asunto(s)
Neoplasias , , Catequina/análogos & derivados , Epigénesis Genética , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Polifenoles/farmacología , Polifenoles/uso terapéutico , Té/química
6.
Semin Cancer Biol ; 83: 503-522, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-33309850

RESUMEN

Epigenetic modifications are heritable yet reversible, essential for normal physiological functions and biological development. Aberrant epigenetic modifications, including DNA methylation, histone modification, and non-coding RNA (ncRNA)-mediated gene regulation play a crucial role in cancer progression. In cellular reprogramming, irregular epigenomic modulations alter cell signaling pathways and the expression of tumor suppressor genes and oncogenes, resulting in cancer growth and metastasis. Therefore, alteration of epigenetic-status in cancer cells can be used as a potential target for cancer therapy. Several synthetic epigenetic inhibitors (epi-drugs) and natural epigenetic modulatory bioactives (epi-diets) have been shown to have the potential to alter the aberrant epigenetic status and inhibit cancer progression. Further, the use of combinatorial approaches with epigenetic drugs and diets has brought promising outcomes in cancer prevention and therapy. In this article, we have summarized the epigenetic modulatory activities of epi-drugs, epi-diets, and their combination against various cancers. We have also compiled the preclinical and clinical status of these epigenetic modulators in different cancers.


Asunto(s)
Epigenómica , Neoplasias , Metilación de ADN , Dieta , Epigénesis Genética , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Neoplasias/prevención & control
7.
Semin Cancer Biol ; 83: 4-14, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-33798724

RESUMEN

Cancer was thought to be caused solely by genetic mutations in oncogenes and tumor suppressor genes. In the last 35 years, however, epigenetic changes have been increasingly recognized as another primary driver of carcinogenesis and cancer progression. Epigenetic deregulation in cancer often includes mutations and/or aberrant expression of chromatin-modifying enzymes, their associated proteins, and even non-coding RNAs, which can alter chromatin structure and dynamics. This leads to changes in gene expression that ultimately contribute to the emergence and evolution of cancer cells. Studies of the deregulation of chromatin modifiers in cancer cells have reshaped the way we approach cancer and guided the development of novel anticancer therapeutics that target epigenetic factors. There remain, however, a number of unanswered questions in this field that are the focus of present research. Areas of particular interest include the actions of emerging classes of epigenetic regulators of carcinogenesis and the tumor microenvironment, as well as epigenetic tumor heterogeneity. In this review, we discuss past findings on epigenetic mechanisms of cancer, current trends in the field of cancer epigenetics, and the directions of future research that may lead to the identification of new prognostic markers for cancer and the development of more effective anticancer therapeutics.


Asunto(s)
Metilación de ADN , Neoplasias , Carcinogénesis/genética , Cromatina/genética , Epigénesis Genética , Humanos , Neoplasias/genética , Microambiente Tumoral/genética
8.
Mol Cell Proteomics ; 20: 100067, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33775892

RESUMEN

Histones are highly posttranslationally modified proteins that regulate gene expression by modulating chromatin structure and function. Acetylation and methylation are the most abundant histone modifications, with methylation occurring on lysine (mono-, di-, and trimethylation) and arginine (mono- and dimethylation) predominately on histones H3 and H4. In addition, arginine dimethylation can occur either symmetrically (SDMA) or asymmetrically (ADMA) conferring different biological functions. Despite the importance of histone methylation on gene regulation, characterization and quantitation of this modification have proven to be quite challenging. Great advances have been made in the analysis of histone modification using both bottom-up and top-down mass spectrometry (MS). However, MS-based analysis of histone posttranslational modifications (PTMs) is still problematic, due both to the basic nature of the histone N-terminal tails and to the combinatorial complexity of the histone PTMs. In this report, we describe a simplified MS-based platform for histone methylation analysis. The strategy uses chemical acetylation with d0-acetic anhydride to collapse all the differently acetylated histone forms into one form, greatly reducing the complexity of the peptide mixture and improving sensitivity for the detection of methylation via summation of all the differently acetylated forms. We have used this strategy for the robust identification and relative quantitation of H4R3 methylation, for which stoichiometry and symmetry status were determined, providing an antibody-independent evidence that H4R3 is a substrate for both Type I and Type II PRMTs. Additionally, this approach permitted the robust detection of H4K5 monomethylation, a very low stoichiometry methylation event (0.02% methylation). In an independent example, we developed an in vitro assay to profile H3K27 methylation and applied it to an EZH2 mutant xenograft model following small-molecule inhibition of the EZH2 methyltransferase. These specific examples highlight the utility of this simplified MS-based approach to quantify histone methylation profiles.


Asunto(s)
Histonas/metabolismo , Acetilación , Línea Celular Tumoral , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Humanos , Espectrometría de Masas , Metilación
9.
Int J Mol Sci ; 24(22)2023 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-38003666

RESUMEN

Cadherins (calcium-dependent adhesion proteins) are important in cellular adhesion and may play a role in the development and progression of renal cell carcinoma (RCC). This study investigated changes in cadherin 3 (CDH3; P-cadherin) mRNA expression, DNA methylation, and protein expression in RCC and compared the results with the histopathological and clinical characteristics of patients. The possible contribution of CDH3 to tumor cell invasiveness was tested in a functional assay using siRNA-based suppression of CDH3 expression and subsequent real-time impedance analysis using a Matrigel invasion model. Our analyses revealed a tumor-specific loss of CDH3 mRNA expression, CDH3 DNA hypermethylation, and loss of distal tubular and collecting duct CDH3 protein expression in RCC. A relatively higher methylation level in tumors was associated with a loss of cell differentiation and higher clinical stage. siRNA-induced suppression of CDH3 expression modulated the invasion characteristics of tumor cells in the impedance-based real-time cellular analysis. Our results indicate that loss of CDH3 expression is common in RCC and may contribute to the pathogenesis of a subset of RCC. Further studies to reveal the mechanisms of loss of expression and its effects on the invasive behavior of renal tumor cells are required.


Asunto(s)
Cadherinas , Carcinoma de Células Renales , Neoplasias Renales , Humanos , Cadherinas/metabolismo , Carcinoma de Células Renales/genética , Metilación de ADN , Neoplasias Renales/genética , ARN Mensajero/genética , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo
10.
Esophagus ; 20(4): 704-712, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37173453

RESUMEN

BACKGROUND: We previously demonstrated the relationship of human microbiome Fusobacterium nucleatum with unfavorable clinical outcomes and inferior chemotherapeutic responses in esophageal cancer. Global DNA methylation is associated with the occurrence and development of various cancers. In our previous study, LINE-1 hypomethylation (i.e., global DNA hypomethylation) was associated with a poor prognosis in esophageal cancer. As the gut microbiota may play crucial roles in the DNA methylation of host cells, we hypothesized that F. nucleatum might influence LINE-1 methylation levels in esophageal cancer. METHODS: We qualified the F. nucleatum DNA using a quantitative PCR assay and LINE-1 methylation via a pyrosequencing assay using formalin-fixed paraffin-embedded specimens from 306 esophageal cancer patients. RESULTS: Intratumoral F. nucleatum DNA was detected in 65 cases (21.2%). The LINE-1 methylation scores ranged from 26.9 to 91.8 (median = 64.8) in tumors. F. nucleatum DNA was related to the LINE-1 hypomethylation of tumor lesions in esophageal cancer (P < 0.0001). The receiver operating characteristic curve analysis showed that the area under the curve was 0.71 for F. nucleatum positivity. Finally, we found that the impact of F. nucleatum on clinical outcomes was not modified by LINE-1 hypomethylation (P for interaction = 0.34). CONCLUSIONS: F. nucleatum alters genome-wide methylation levels in cancer cells, which may be one of the mechanisms by which F. nucleatum affects the malignant behavior of esophageal cancer.


Asunto(s)
Neoplasias Colorrectales , Neoplasias Esofágicas , Microbioma Gastrointestinal , Humanos , Fusobacterium nucleatum/genética , Metilación , Microbioma Gastrointestinal/genética , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/microbiología , Neoplasias Colorrectales/patología , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patología
11.
Int J Cancer ; 151(9): 1431-1446, 2022 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-35603902

RESUMEN

Glial-lineage malignancies (gliomas) recurrently mutate and/or delete the master regulators of apoptosis p53 and/or p16/CDKN2A, undermining apoptosis-intending (cytotoxic) treatments. By contrast to disrupted p53/p16, glioma cells are live-wired with the master transcription factor circuits that specify and drive glial lineage fates: these transcription factors activate early-glial and replication programs as expected, but fail in their other usual function of forcing onward glial lineage-maturation-late-glial genes have constitutively "closed" chromatin requiring chromatin-remodeling for activation-glioma-genesis disrupts several epigenetic components needed to perform this work, and simultaneously amplifies repressing epigenetic machinery instead. Pharmacologic inhibition of repressing epigenetic enzymes thus allows activation of late-glial genes and terminates glioma self-replication (self-replication = replication without lineage-maturation), independent of p53/p16/apoptosis. Lineage-specifying master transcription factors therefore contrast with p53/p16 in being enriched in self-replicating glioma cells, reveal a cause-effect relationship between aberrant epigenetic repression of late-lineage programs and malignant self-replication, and point to specific epigenetic targets for noncytotoxic glioma-therapy.


Asunto(s)
Neoplasias Encefálicas , Glioma , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Cromatina , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Glioma/tratamiento farmacológico , Glioma/genética , Glioma/patología , Humanos , Factores de Transcripción/genética , Proteína p53 Supresora de Tumor/genética
12.
Methods ; 187: 77-91, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-32315755

RESUMEN

Cancer therapeutics is an ever-evolving field due to incessant demands for effective and precise treatment options. Over the last few decades, cancer treatment strategies have shifted somewhat from surgery to targeted precision medicine. CRISPR-dCas9 is an emerging version of precision cancer therapy that has been adapted from the prokaryotic CRISPR-Cas system. Once ligated to epigenetic effectors (EE), CRISPR-dCas9 can function as an epigenetic editing tool and CRISPR-dCas9-EE complexes could be exploited to alter cancerous epigenetic features associated with different cancer hallmarks. In this article, we discuss the rationale of epigenetic editing as a therapeutic strategy against cancer. We also outline how sgRNA-dCas9 was derived from the CRISPR-Cas system. In addition, the current status of sgRNA-dCas9 use (in vivo and in vitro) in cancer is updated with a molecular illustration of CRISPR-dCas9-mediated epigenetic and transcriptional modulation. As sgRNA-dCas9 is still at the developmental phase, challenges are inherent to its use. We evaluate major challenges in targeting cancer with sgRNA-dCas9 such as off-target effects, lack of sgRNA designing rubrics, target site selection dilemmas and deficient sgRNA-dCas9 delivery systems. Finally, we appraise the sgRNA-dCas9 as a prospective cancer therapeutic by summarizing ongoing improvements of sgRNA-dCas9 methodology.


Asunto(s)
Sistemas CRISPR-Cas/genética , Epigénesis Genética , Edición Génica/métodos , Terapia Genética/métodos , Neoplasias/terapia , Animales , Carcinogénesis/genética , Línea Celular Tumoral , Ensayos Clínicos Fase I como Asunto , Modelos Animales de Enfermedad , Regulación Neoplásica de la Expresión Génica , Humanos , Ratones , Ratones Transgénicos , Neoplasias/genética , Regiones Promotoras Genéticas , ARN Guía de Kinetoplastida/genética , Resultado del Tratamiento , Ensayos Antitumor por Modelo de Xenoinjerto
13.
Adv Exp Med Biol ; 1389: 317-348, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36350516

RESUMEN

The malignant transformation of normal cells is driven by both genetic and epigenetic changes. With the advent of next-generation sequencing and large-scale international consortia, it is now possible to profile the genomes and epigenomes of thousands of primary tumors from nearly every cancer type. These studies clearly demonstrate that the dynamic regulation of DNA methylation is a critical epigenetic mechanism of cancer initiation, maintenance, and progression. Proper control of DNA methylation is not only crucial for regulating gene transcription and tissue-specific cellular functions, but its broader consequences include maintaining the integrity of the genome and modulating the immune response. Here, we describe the aberrant DNA methylation changes in human cancers and how they contribute to the disease phenotypes. Aside from CpG island promoter DNA hypermethylation-based gene silencing, human cancers also display gene body DNA hypomethylation that is also associated with downregulated gene expression. In addition, the implementation of whole genome bisulfite sequencing (WGBS) has unveiled DNA hypomethylation of large blocks of the genome, known as partially methylated domains (PMDs), as well as cancer-specific DNA methylation aberrancies at enhancers and super-enhancers. Integrating WGBS and DNA methylation array data with mutation, copy number, and gene expression data has allowed for the identification of novel tumor suppressor genes and candidate driver genes of the disease state. Finally, we highlight potential clinical implications of these changes in the context of prognostic and diagnostic biomarkers, as well as therapeutic targets. Mounting evidence shows that DNA methylation data are effective and highly-sensitive disease classifiers, not only from analyses of the primary tumor but also from tumor-derived, cell free DNA (cfDNA) in blood of cancer patients. These findings highlight the power of DNA methylation aberrancies in providing efficacious biomarkers for clinical utility in improving patient diagnostics and their reversal using DNA methylation inhibitors in cancer treatment may be key in surveillance, treatment, and quality of life for cancer patients.


Asunto(s)
Metilación de ADN , Neoplasias , Humanos , Metilación de ADN/genética , Calidad de Vida , Islas de CpG/genética , Epigénesis Genética/genética , Metilasas de Modificación del ADN/genética , Neoplasias/diagnóstico , Neoplasias/genética , Neoplasias/patología , Regulación Neoplásica de la Expresión Génica
14.
Int J Mol Sci ; 23(3)2022 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-35163027

RESUMEN

Cancer cells accumulate epigenomic aberrations that contribute to cancer initiation and progression by altering both the genomic stability and the expression of genes. The awareness of such alterations could improve our understanding of cancer dynamics and the identification of new therapeutic strategies and biomarkers to refine tumor classification and treatment. Formalin fixation and paraffin embedding (FFPE) is the gold standard to preserve both tissue integrity and organization, and, in the last decades, a huge number of biological samples have been archived all over the world following this procedure. Recently, new chromatin immunoprecipitation (ChIP) techniques have been developed to allow the analysis of histone post-translational modifications (PTMs) and transcription factor (TF) distribution in FFPE tissues. The application of ChIP to genome-wide chromatin studies using real archival samples represents an unprecedented opportunity to conduct retrospective clinical studies thanks to the possibility of accessing large cohorts of samples and their associated diagnostic records. However, although recent attempts to standardize have been made, fixation and storage conditions of clinical specimens are still extremely variable and can affect the success of chromatin studies. The procedures introduced in the last few years dealt with this problem proponing successful strategies to obtain high-resolution ChIP profiles from FFPE archival samples. In this review, we compare the different FFPE-ChIP techniques, highlighting their strengths, limitations, common features, and peculiarities, as well as pitfalls and caveats related to ChIP studies in FFPE samples, in order to facilitate their application.


Asunto(s)
Inmunoprecipitación de Cromatina/métodos , Epigenómica/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Adhesión en Parafina/métodos , Fijación del Tejido/métodos , Animales , Humanos
15.
Int J Mol Sci ; 23(21)2022 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-36361550

RESUMEN

Alterations in DNA methylation are critical for the carcinogenesis of ovarian tumors, especially ovarian carcinoma (OC). DNMT3B, a de novo DNA methyltransferase (DNMT), encodes for fifteen spliced protein products or isoforms. DNMT3B isoforms lack exons for the catalytic domain, with functional consequences on catalytic activity. Abnormal expression of DNMT3B isoforms is frequently observed in several types of cancer, such as breast, lung, kidney, gastric, liver, skin, leukemia, and sarcoma. However, the expression patterns and consequences of DNMT3B isoforms in OC are unknown. In this study, we analyzed each DNMT and DNMT3B isoforms expression by qPCR in 63 OC samples and their association with disease-free survival (DFS), overall survival (OS), and tumor progression. We included OC patients with the main histological subtypes of EOC and patients in all the disease stages and found that DNMTs were overexpressed in advanced stages (p-value < 0.05) and high-grade OC (p-value < 0.05). Remarkably, we found DNMT3B1 overexpression in advanced stages (p-value = 0.0251) and high-grade serous ovarian carcinoma (HGSOC) (p-value = 0.0313), and DNMT3B3 was overexpressed in advanced stages (p-value = 0.0098) and high-grade (p-value = 0.0004) serous ovarian carcinoma (SOC). Finally, we observed that overexpression of DNMT3B isoforms was associated with poor prognosis in OC and SOC. DNMT3B3 was also associated with FDS (p-value = 0.017) and OS (p-value = 0.038) in SOC patients. In addition, the ovarian carcinoma cell lines OVCAR3 and SKOV3 also overexpress DNMT3B3. Interestingly, exogenous overexpression of DNMT3B3 in OVCAR3 causes demethylation of satellite 2 sequences in the pericentromeric region. In summary, our results suggest that DNMT3B3 expression is altered in OC.


Asunto(s)
Cistadenocarcinoma Seroso , Neoplasias Ováricas , Humanos , Femenino , Metilación de ADN , Apoptosis , Neoplasias Ováricas/genética , Neoplasias Ováricas/patología , Línea Celular Tumoral , ADN (Citosina-5-)-Metiltransferasas/genética , ADN (Citosina-5-)-Metiltransferasas/metabolismo , Carcinoma Epitelial de Ovario/genética , Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/patología , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , ADN/metabolismo , ADN Metiltransferasa 3B
16.
Hum Genomics ; 14(1): 15, 2020 05 06.
Artículo en Inglés | MEDLINE | ID: mdl-32375881

RESUMEN

5-Methylcytosine (5mC) is considered as a common epigenetic modification that plays an important role in the regulation of gene expression. At the same time, 5-hydroxymethylcytosine (5hmC) has been found as an emerging modification of cytosine bases of recent years. Unlike 5mC, global 5hmC levels vary from tissues that have differential distribution both in mammalian tissues and in the genome. DNA hydroxymethylation is the process that 5mC oxidates into 5hmC with the catalysis of TET (ten-eleven translocation) enzymes. It is an essential option of DNA demethylation, which modulates gene expression by adjusting the DNA methylation level. Various factors can regulate the demethylation of DNA, such as environmental toxins and mental stress. In this review, we summarize the progress in the formation of 5hmC, and obtaining 5hmC in a cell-free DNA sample presents multiple advantages and challenges for the subject. Furthermore, the clinical potential for 5hmC modification in dealing with cancer early diagnosis, prognostic evaluation, and prediction of therapeutic effect is also mentioned.


Asunto(s)
5-Metilcitosina/análogos & derivados , Biomarcadores de Tumor/análisis , Metilación de ADN , Epigénesis Genética , Neoplasias/diagnóstico , Neoplasias/terapia , 5-Metilcitosina/química , Animales , Humanos , Neoplasias/genética
17.
Proc Natl Acad Sci U S A ; 114(4): 758-763, 2017 01 24.
Artículo en Inglés | MEDLINE | ID: mdl-28057861

RESUMEN

The spectrum of genetic mutations differs among cancers in different organs, implying a cellular context-dependent effect for genetic aberrations. However, the extent to which the cellular context affects the consequences of oncogenic mutations remains to be fully elucidated. We reprogrammed colon tumor cells in an ApcMin/+ (adenomatous polyposis coli) mouse model, in which the loss of the Apc gene plays a critical role in tumor development and subsequently, established reprogrammed tumor cells (RTCs) that exhibit pluripotent stem cell (PSC)-like signatures of gene expression. We show that the majority of the genes in RTCs that were affected by Apc mutations did not overlap with the genes affected in the intestine. RTCs lacked pluripotency but exhibited an increased expression of Cdx2 and a differentiation propensity that was biased toward the trophectoderm cell lineage. Genetic rescue of the mutated Apc allele conferred pluripotency on RTCs and enabled their differentiation into various cell types in vivo. The redisruption of Apc in RTC-derived differentiated cells resulted in neoplastic growth that was exclusive to the intestine, but the majority of the intestinal lesions remained as pretumoral microadenomas. These results highlight the significant influence of cellular context on gene regulation, cellular plasticity, and cellular behavior in response to the loss of the Apc function. Our results also imply that the transition from microadenomas to macroscopic tumors is reprogrammable, which underscores the importance of epigenetic regulation on tumor promotion.


Asunto(s)
Poliposis Adenomatosa del Colon/genética , Regulación de la Expresión Génica/genética , Genes APC/fisiología , Mutación/genética , Alelos , Animales , Linaje de la Célula/genética , Plasticidad de la Célula/genética , Neoplasias del Colon/genética , Neoplasias del Colon/metabolismo , Epigénesis Genética/genética , Expresión Génica/genética , Regulación Neoplásica de la Expresión Génica/genética , Mucosa Intestinal/metabolismo , Ratones , Células Madre Pluripotentes/metabolismo
18.
Int J Cancer ; 145(3): 614-620, 2019 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-30628063

RESUMEN

The lysine-specific demethylase 6A/UTX (gene name KDM6A) acts as a component of the COMPASS complex to control gene activation. UTX demethylates H3K27me2/3 at genes and enhancers. Deleterious mutations in KDM6A are found in many cancer types, prominently urothelial carcinoma and certain T-cell leukemias. In certain cancers, however, UTX supports oncogenic transcription factors, e.g. steroid hormone receptors in breast and prostate cancer. In fetal development, UTX regulates lineage choice and cell differentiation. Analogously, loss of UTX function in cancer may lead to metaplasia or impede differentiation. Likely because its function is contingent on its interacting transcription factors, the effects of UTX inactivation are not uniform and require detailed investigation in each cancer type. In urothelial carcinoma, in particular, the functional consequences of the frequent mutations in KDM6A and other COMPASS component genes are poorly understood. Nevertheless, UTX inactivation appears to sensitize many cancers to inhibitors of the H3K27 methyltransferase EZH2. Conversely, inhibitors of UTX enzymatic activity may be applicable in cancers with an oncogenic UTX function. Intriguingly, the fact that KDM6A is localized on the X-chromosome, but both copies are expressed, may account for gender-specific differences in cancer susceptibility. In conclusion, despite recent progress, many open questions need to be addressed, most importantly, the detailed mechanisms by which KDM6A inactivation promotes various cancers, but also with which proteins UTX interacts in and apart from the COMPASS complex, and to which extent its catalytic function is required for its tumor-suppressive function.


Asunto(s)
Histona Demetilasas/metabolismo , Neoplasias/enzimología , Animales , Humanos , Neoplasias/patología
19.
Prostate ; 79(14): 1705-1714, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31433512

RESUMEN

BACKGROUND: We identify and validate accurate diagnostic biomarkers for prostate cancer through a systematic evaluation of DNA methylation alterations. MATERIALS AND METHODS: We assembled three early prostate cancer cohorts (total patients = 699) from which we collected and processed over 1300 prostatectomy tissue samples for DNA extraction. Using real-time methylation-specific PCR, we measured normalized methylation levels at 15 frequently methylated loci. After partitioning sample sets into independent training and validation cohorts, classifiers were developed using logistic regression, analyzed, and validated. RESULTS: In the training dataset, DNA methylation levels at 7 of 15 genomic loci (glutathione S-transferase Pi 1 [GSTP1], CCDC181, hyaluronan, and proteoglycan link protein 3 [HAPLN3], GSTM2, growth arrest-specific 6 [GAS6], RASSF1, and APC) showed large differences between cancer and benign samples. The best binary classifier was the GAS6/GSTP1/HAPLN3 logistic regression model, with an area under these curves of 0.97, which showed a sensitivity of 94%, and a specificity of 93% after external validation. CONCLUSION: We created and validated a multigene model for the classification of benign and malignant prostate tissue. With false positive and negative rates below 7%, this three-gene biomarker represents a promising basis for more accurate prostate cancer diagnosis.


Asunto(s)
Biomarcadores de Tumor , Metilación de ADN/genética , Neoplasias de la Próstata/clasificación , Neoplasias de la Próstata/patología , ADN/aislamiento & purificación , Epigénesis Genética , Proteínas de la Matriz Extracelular/análisis , Proteínas de la Matriz Extracelular/genética , Gutatión-S-Transferasa pi/análisis , Gutatión-S-Transferasa pi/genética , Humanos , Péptidos y Proteínas de Señalización Intercelular/análisis , Péptidos y Proteínas de Señalización Intercelular/genética , Masculino , Neoplasias de la Próstata/química , Proteoglicanos/análisis , Proteoglicanos/genética , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
20.
Hematol Oncol ; 35(4): 397-407, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28378425

RESUMEN

The 13th International Conference on Malignant Lymphoma held in Lugano in June 2015 was preceded by a closed workshop (organized in collaboration with the American Association for Cancer Research and the European School of Oncology) with the aim of developing an up-to-date understanding of the biology of follicular lymphoma and the clinical implications of new findings in the field. Discussed topics included the mutational spectrum at diagnosis, the clinical correlates of genetic and epigenetic alterations, the mechanisms of clonal evolution and histological transformation, the cross talk between tumor cells and microenvironment, and the development of novel treatments. This report represents a summary of the workshop.


Asunto(s)
Linfoma Folicular , Femenino , Historia del Siglo XXI , Humanos , Masculino , Suiza
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