Genome-wide DNA methylation in CEBPA mutant and CEBPA silenced AML

Acute Myeloid Leukemia (AML) is a heterogeneous disease from the molecular and biological standpoints, and even patients with a specific gene expression profile may present clinical and molecular heterogeneity. We studied the epigenetic profiles of a cohort of patients that shared a common gene expression profile but differed in that only half of them harbored mutations of the CEBPA locus, while the rest presented with silencing of this gene and co-expression of certain T cell markers. DNA methylation studies revealed that these two groups of patients could be readily segregated in an unsupervised fashion based on their DNA methylation profiles alone. Furthermore, CEBPA silencing was associated with the presence of an aberrant DNA hypermethylation signature, which was not present in the CEBPA mutant group. This aberrant hypermethylation occurred more frequently at sites within CpG islands. CEBPA silenced leukemias also displayed marked hypermethylation when compared with normal CD34+ hematopoietic cells, while CEBPA mutant cases showed only mild changes in DNA methylation when compared to these normal progenitors. Biologically, CEBPA silenced leukemias presented with a decreased response to myeloid growth factors in vitro. Keywords: DNA methylation profiling Direct comparison of DNA methylation in leukemic blasts from 8 patients with Acute Myeloid Leukemia (AML) carrying a CEBPA mutation and 8 patients with AML without CEBPA mutation but with silencing of CEBPA expression. Two control groups are included: 8 CD34+ bone marrow samples from healthy donors and 9 samples of T Acute Lymphoblastic Leukemia (T-ALL) patients

Transcription profiling by array of human lymphoblasts from patients with acute myeloid lymphoma or T acute lymphoblastic leukemia, mutant for CEBPA

Acute Myeloid Leukemia (AML) is a heterogeneous disease from the molecular and biological standpoints, and even patients with a specific gene expression profile may present clinical and molecular heterogeneity. We studied the epigenetic profiles of a cohort of patients that shared a common gene expression profile but differed in that only half of them harbored mutations of the CEBPA locus, while the rest presented with silencing of this gene and co-expression of certain T cell markers. DNA methylation studies revealed that these two groups of patients could be readily segregated in an unsupervised fashion based on their DNA methylation profiles alone. Furthermore, CEBPA silencing was associated with the presence of an aberrant DNA hypermethylation signature, which was not present in the CEBPA mutant group. This aberrant hypermethylation occurred more frequently at sites within CpG islands. CEBPA silenced leukemias also displayed marked hypermethylation when compared with normal CD34+ hematopoietic cells, while CEBPA mutant cases showed only mild changes in DNA methylation when compared to these normal progenitors. Biologically, CEBPA silenced leukemias presented with a decreased response to myeloid growth factors in vitro. Experiment Overall Design: Direct comparison of gene expression in leukemic blasts from 8 patients with Acute Myeloid Leukemia (AML) carrying a CEBPA mutation and 8 patients with AML without CEBPA mutation but with silencing of CEBPA expression, and with 9 samples of T Acute Lymphoblastic Leukemia (T-ALL) patients

Transcription profiling by array of human lymphoblasts from patients with acute myeloid lymphoma or T acute lymphoblastic leukemia, mutant for CEBPA

Acute Myeloid Leukemia (AML) is a heterogeneous disease from the molecular and biological standpoints, and even patients with a specific gene expression profile may present clinical and molecular heterogeneity. We studied the epigenetic profiles of a cohort of patients that shared a common gene expression profile but differed in that only half of them harbored mutations of the CEBPA locus, while the rest presented with silencing of this gene and co-expression of certain T cell markers. DNA methylation studies revealed that these two groups of patients could be readily segregated in an unsupervised fashion based on their DNA methylation profiles alone. Furthermore, CEBPA silencing was associated with the presence of an aberrant DNA hypermethylation signature, which was not present in the CEBPA mutant group. This aberrant hypermethylation occurred more frequently at sites within CpG islands. CEBPA silenced leukemias also displayed marked hypermethylation when compared with normal CD34+ hematopoietic cells, while CEBPA mutant cases showed only mild changes in DNA methylation when compared to these normal progenitors. Biologically, CEBPA silenced leukemias presented with a decreased response to myeloid growth factors in vitro. Experiment Overall Design: Direct comparison of gene expression in leukemic blasts from 8 patients with Acute Myeloid Leukemia (AML) carrying a CEBPA mutation and 8 patients with AML without CEBPA mutation but with silencing of CEBPA expression, and with 9 samples of T Acute Lymphoblastic Leukemia (T-ALL) patients

Genome-wide DNA methylation in CEBPA mutant and CEBPA silenced AML

Acute Myeloid Leukemia (AML) is a heterogeneous disease from the molecular and biological standpoints, and even patients with a specific gene expression profile may present clinical and molecular heterogeneity. We studied the epigenetic profiles of a cohort of patients that shared a common gene expression profile but differed in that only half of them harbored mutations of the CEBPA locus, while the rest presented with silencing of this gene and co-expression of certain T cell markers. DNA methylation studies revealed that these two groups of patients could be readily segregated in an unsupervised fashion based on their DNA methylation profiles alone. Furthermore, CEBPA silencing was associated with the presence of an aberrant DNA hypermethylation signature, which was not present in the CEBPA mutant group. This aberrant hypermethylation occurred more frequently at sites within CpG islands. CEBPA silenced leukemias also displayed marked hypermethylation when compared with normal CD34+ hematopoietic cells, while CEBPA mutant cases showed only mild changes in DNA methylation when compared to these normal progenitors. Biologically, CEBPA silenced leukemias presented with a decreased response to myeloid growth factors in vitro. Keywords: DNA methylation profiling Direct comparison of DNA methylation in leukemic blasts from 8 patients with Acute Myeloid Leukemia (AML) carrying a CEBPA mutation and 8 patients with AML without CEBPA mutation but with silencing of CEBPA expression. Two control groups are included: 8 CD34+ bone marrow samples from healthy donors and 9 samples of T Acute Lymphoblastic Leukemia (T-ALL) patients

Transcription profiling by high throughput sequencing of c-KIT+ splenocytes from murine acute myeloid leukemia and myeloproliferative neoplasm

Cytogenetically normal acute myeloid leukemia (CN-AML) represents nearly 50% of human acute myeloid leukemia (AML) cases with a 5-year overall survival of approximately 30%. In CN-AML with poorer prognosis, mutations in the de novo DNA methyltransferase (DNMT3A) and the FMS-like tyrosine kinase 3 (Flt3) commonly co-occur (1-3). We demonstrate that mice with Flt3-internal-tandem duplication (Flt3ITD) and inducible deletion of Dnmt3a spontaneously develop a rapidly-lethal, completely-penetrant, and transplantable AML of normal karyotype. These murine AML retain a single Dnmt3a floxed allele, revealing the oncogenic potential of Dnmt3a haploinsufficiency. FLT3-ITD/DNMT3A-mutant primary human and murine AML demonstrate a similar pattern of global DNA methylation. In the murine model, rescuing DNMT3A expression was accompanied by DNA re-methylation and loss of clonogenic potential, suggesting that Dnmt3a-mutant oncogenic effects are reversible. Differentially methylated genomic regions were associated with changes in the expression of nearby genes. Moreover, dissection of the cellular architecture of the AML model using single-cell RNA-Seq, flow cytometry and colony assays identified clonogenic subpopulations that differentially express genes that are sensitive to the methylation of nearby genomic loci and varied in response to Dnmt3a levels. Thus, Dnmt3a haploinsufficiency transforms Flt3ITD myeloproliferative disease by modulating methylation-sensitive gene expression within a clonogenic AML subpopulation. To identify the gene expression changes associated with Dnmt3a loss of function in human and murine Flt3-ITD and Dnmt3a-mutant AML (Bulk RNA-Seq)

Transcription profiling by high throughput sequencing of c-KIT+ splenocytes from murine acute myeloid leukemia and myeloproliferative neoplasm

Cytogenetically normal acute myeloid leukemia (CN-AML) represents nearly 50% of human acute myeloid leukemia (AML) cases with a 5-year overall survival of approximately 30%. In CN-AML with poorer prognosis, mutations in the de novo DNA methyltransferase (DNMT3A) and the FMS-like tyrosine kinase 3 (Flt3) commonly co-occur (1-3). We demonstrate that mice with Flt3-internal-tandem duplication (Flt3ITD) and inducible deletion of Dnmt3a spontaneously develop a rapidly-lethal, completely-penetrant, and transplantable AML of normal karyotype. These murine AML retain a single Dnmt3a floxed allele, revealing the oncogenic potential of Dnmt3a haploinsufficiency. FLT3-ITD/DNMT3A-mutant primary human and murine AML demonstrate a similar pattern of global DNA methylation. In the murine model, rescuing DNMT3A expression was accompanied by DNA re-methylation and loss of clonogenic potential, suggesting that Dnmt3a-mutant oncogenic effects are reversible. Differentially methylated genomic regions were associated with changes in the expression of nearby genes. Moreover, dissection of the cellular architecture of the AML model using single-cell RNA-Seq, flow cytometry and colony assays identified clonogenic subpopulations that differentially express genes that are sensitive to the methylation of nearby genomic loci and varied in response to Dnmt3a levels. Thus, Dnmt3a haploinsufficiency transforms Flt3ITD myeloproliferative disease by modulating methylation-sensitive gene expression within a clonogenic AML subpopulation. To identify the gene expression changes associated with Dnmt3a loss of function in human and murine Flt3-ITD and Dnmt3a-mutant AML (Bulk RNA-Seq)