RESUMO
Epigenome regulation is a critical mechanism that governs cell identity, lineage specification and developmental cell fates. With the advent of low-input and single-cell technologies as well as sophisticated cell labeling techniques, our understanding of transcriptional and epigenetic regulation of hematopoiesis is currently undergoing dramatic changes. Increasingly, evidence suggests that the epigenome conformation acts as a critical decision-making mechanism that instructs self-renewal, differentiation and developmental fates of hematopoietic progenitor cells. When dysregulated, this leads to the evolution of disease states such as leukemia. Indeed, aberrations in DNA methylation, histone modifications and genome architecture are characteristic features of many hematopoietic neoplasms in which epigenetic enzymes are frequently mutated. Sequencing studies and characterization of the epigenetic landscape in lymphomas, leukemias and in aged healthy individuals with clonal hematopoiesis have been indispensible to identify epigenetic regulators that play a role in transformation or pre-disposition to hematopoietic malignancies. In this review, we outline the current view of the hematopoietic system and the epigenetic mechanisms regulating hematopoiesis under homeostatic conditions, with a particular focus on the role of DNA methylation in this process. We will also summarize the current knowledge on the mechanisms underlying dysregulated DNA methylation in hematologic malignancies and how this contributes to our understanding of the physiological functions of epigenetic regulators in hematopoiesis.
Assuntos
Diferenciação Celular , Metilação de DNA , Epigênese Genética , Regulação Leucêmica da Expressão Gênica , Neoplasias Hematológicas/genética , Hematopoese , Animais , Neoplasias Hematológicas/patologia , HumanosRESUMO
Targeted analysis of DNA methylation patterns based on bisulfite-treated genomic DNA (BT-DNA) is considered as a gold-standard for epigenetic biomarker development. Existing software tools facilitate primer design, primer quality control or visualization of primer localization. However, high-throughput design of primers for BT-DNA amplification is hampered by limits in throughput and functionality of existing tools, requiring users to repeatedly perform specific tasks manually. Consequently, the design of PCR primers for BT-DNA remains a tedious and time-consuming process. To bridge this gap, we developed AmpliconDesign, a webserver providing a scalable and user-friendly platform for the design and analysis of targeted DNA methylation studies based on BT-DNA, e.g. deep amplicon bisulfite sequencing (ampBS-seq) or EpiTYPER MassArray. Core functionality of the web server includes high-throughput primer design and binding site validation based on in silico bisulfite-converted DNA sequences, prediction of fragmentation patterns for EpiTYPER MassArray, an interactive quality control as well as a streamlined analysis workflow for ampBS-seq.
Assuntos
Metilação de DNA , Sulfitos , Epigenômica , Sequenciamento de Nucleotídeos em Larga Escala , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , SoftwareRESUMO
Androgen receptor (AR) signaling is a key driver of prostate cancer, and androgen-deprivation therapy (ADT) is a standard treatment for patients with advanced and metastatic disease. However, patients receiving ADT eventually develop incurable castration-resistant prostate cancer (CRPC). Here, we report that the chromatin modifier LSD1, an important regulator of AR transcriptional activity, undergoes epigenetic reprogramming in CRPC. LSD1 reprogramming in this setting activated a subset of cell-cycle genes, including CENPE, a centromere binding protein and mitotic kinesin. CENPE was regulated by the co-binding of LSD1 and AR to its promoter, which was associated with loss of RB1 in CRPC. Notably, genetic deletion or pharmacological inhibition of CENPE significantly decreases tumor growth. Our findings show how LSD1-mediated epigenetic reprogramming drives CRPC, and they offer a mechanistic rationale for its therapeutic targeting in this disease. Cancer Res; 77(20); 5479-90. ©2017 AACR.
Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Histona Desmetilases/genética , Neoplasias de Próstata Resistentes à Castração/enzimologia , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias da Próstata/embriologia , Neoplasias da Próstata/genética , Androgênios/metabolismo , Animais , Linhagem Celular Tumoral , Reprogramação Celular/genética , Proteínas Cromossômicas não Histona/biossíntese , Proteínas Cromossômicas não Histona/genética , Progressão da Doença , Epigênese Genética , Xenoenxertos , Histona Desmetilases/metabolismo , Humanos , Masculino , Camundongos , Neoplasias da Próstata/metabolismo , Neoplasias de Próstata Resistentes à Castração/metabolismo , Transdução de Sinais , TransfecçãoRESUMO
Juvenile myelomonocytic leukemia (JMML) is an aggressive myeloproliferative disorder of early childhood characterized by mutations activating RAS signaling. Established clinical and genetic markers fail to fully recapitulate the clinical and biological heterogeneity of this disease. Here we report DNA methylome analysis and mutation profiling of 167 JMML samples. We identify three JMML subgroups with unique molecular and clinical characteristics. The high methylation group (HM) is characterized by somatic PTPN11 mutations and poor clinical outcome. The low methylation group is enriched for somatic NRAS and CBL mutations, as well as for Noonan patients, and has a good prognosis. The intermediate methylation group (IM) shows enrichment for monosomy 7 and somatic KRAS mutations. Hypermethylation is associated with repressed chromatin, genes regulated by RAS signaling, frequent co-occurrence of RAS pathway mutations and upregulation of DNMT1 and DNMT3B, suggesting a link between activation of the DNA methylation machinery and mutational patterns in JMML.
Assuntos
Metilação de DNA , Leucemia Mielomonocítica Juvenil/genética , Síndrome de Noonan/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Transdução de Sinais/genética , Antineoplásicos/uso terapêutico , Biópsia , Criança , Pré-Escolar , Cromatina/genética , Cromatina/metabolismo , DNA (Citosina-5-)-Metiltransferase 1/metabolismo , DNA (Citosina-5-)-Metiltransferases/metabolismo , Análise Mutacional de DNA , Epigenômica , Feminino , Regulação Leucêmica da Expressão Gênica , Transplante de Células-Tronco Hematopoéticas , Humanos , Lactente , Leucemia Mielomonocítica Juvenil/mortalidade , Leucemia Mielomonocítica Juvenil/patologia , Leucemia Mielomonocítica Juvenil/terapia , Masculino , Mutação , Síndrome de Noonan/patologia , Prognóstico , Estudos Prospectivos , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Proteínas Proto-Oncogênicas c-cbl , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Regulação para Cima , DNA Metiltransferase 3BRESUMO
Long noncoding RNAs (lncRNAs) represent an attractive class of candidates to mediate cancer risk. Through integrative analysis of the lncRNA transcriptome with genomic data and SNP data from prostate cancer genome-wide association studies (GWAS), we identified 45 candidate lncRNAs associated with risk to prostate cancer. We further evaluated the mechanism underlying the top hit, PCAT1, and found that a risk-associated variant at rs7463708 increases binding of ONECUT2, a novel androgen receptor (AR)-interacting transcription factor, at a distal enhancer that loops to the PCAT1 promoter, resulting in upregulation of PCAT1 upon prolonged androgen treatment. In addition, PCAT1 interacts with AR and LSD1 and is required for their recruitment to the enhancers of GNMT and DHCR24, two androgen late-response genes implicated in prostate cancer development and progression. PCAT1 promotes prostate cancer cell proliferation and tumor growth in vitro and in vivo. These findings suggest that modulating lncRNA expression is an important mechanism for risk-associated SNPs in promoting prostate transformation.