Project description:To identify cooperating lesions in de novo and therapy-related acute myeloid leukemia (t-AML) with translocation t(9;11)(p22;q23) we performed high-resolution SNP-array profiling on 40 leukemia samples [de novo: n=22; t-AML: n=16; unknown: n=2]. A mean of 1.73 copy number alterations (CNAs)/case were identified with no differences between de novo and t-AML cases. We identified a novel minimally deleted region (MDR) at 7q36.1-q36.2 partly overlapping with a MDR previously identified in core-binding factor AML; MLL3 was the only gene affected in both regions. In addition, a recurrent gain was found at 13q21.33-q22.1 harboring the potential oncogene KLF5. Sequence/expression analysis of selected candidate genes revealed deregulated EVI1 at high frequency (50%). Copy-neutral loss-of-heterozygosity (CN-LOH) was absent in the paired cohort Further analysis of the candidate genes might provide novel insights into the pathogenesis of t(9;11) AML SNP genotyping was performed on 40 de novo and therapy-related MLL-MLLT3-rearranged acute myeloid leukemia samples; Germline control DNA from remission bone marrow or peripheral blood was available for paired analysis in 15 patients. Data were processed using reference alignment, dChipSNP and circular binary segmentation.
Project description:To identify cooperating lesions in de novo and therapy-related acute myeloid leukemia (t-AML) with translocation t(9;11)(p22;q23) we performed high-resolution SNP-array profiling on 40 leukemia samples [de novo: n=22; t-AML: n=16; unknown: n=2]. A mean of 1.73 copy number alterations (CNAs)/case were identified with no differences between de novo and t-AML cases. We identified a novel minimally deleted region (MDR) at 7q36.1-q36.2 partly overlapping with a MDR previously identified in core-binding factor AML; MLL3 was the only gene affected in both regions. In addition, a recurrent gain was found at 13q21.33-q22.1 harboring the potential oncogene KLF5. Sequence/expression analysis of selected candidate genes revealed deregulated EVI1 at high frequency (50%). Copy-neutral loss-of-heterozygosity (CN-LOH) was absent in the paired cohort Further analysis of the candidate genes might provide novel insights into the pathogenesis of t(9;11) AML
Project description:DNA methylation is an epigenetic modification associated with transcriptional repression of promoters and is essential for mammalian development. Establishment of DNA methylation is mediated by the de novo DNA methyltransferases DNMT3A and DNMT3B, whereas DNMT1 ensures maintenance of methylation through replication. Absence of these enzymes is lethal, and somatic mutations in these genes have been associated with several human diseases. How genomic DNA methylation patterns are regulated remains poorly understood, as the mechanisms that guide recruitment and activity of DNMTs in vivo are largely unknown. To gain insights into this matter we determined chromosomal binding and site-specific activity of the mammalian de novo DNA methyltransferases DNMT3A and DNMT3B. We show that both enzymes localize to methylated, CpG dense regions in mouse stem cells, yet are excluded from active promoters and enhancers. By specifically measuring sites of de novo methylation, we observe that enzymatic activity reflects chromosomal binding. De novo methylation increases with CpG density, yet is excluded from nucleosomes. Notably, we observed selective binding of DNMT3B to the bodies of transcribed genes, which leads to their preferential methylation. This targeting to transcribed sequences requires SETD2-mediated methylation of lysine 36 on histone H3 and a functional PWWP domain of DNMT3B. Together these findings reveal how sequence and chromatin cues guide de novo methyltransferase activity to ensure methylome integrity. Genome-wide binding analysis for biotin-tagged DNMT3A2 and DNMT3B and variants in wild type ES, wild type neuroprogenitor cells, ES cells triple-KO for Dnmt1,3a,3b and ES cell mutant for Setd2
Project description:This SuperSeries is composed of the SubSeries listed below. DNA methylation is an epigenetic modification associated with transcriptional repression of promoters and is essential for mammalian development. Establishment of DNA methylation is mediated by the de novo DNA methyltransferases DNMT3A and DNMT3B, whereas DNMT1 ensures maintenance of methylation through replication. Absence of these enzymes is lethal, and somatic mutations in these genes have been associated with several human diseases. How genomic DNA methylation patterns are regulated remains poorly understood, as the mechanisms that guide recruitment and activity of DNMTs in vivo are largely unknown. To gain insights into this matter we determined chromosomal binding and site-specific activity of the mammalian de novo DNA methyltransferases DNMT3A and DNMT3B. We show that both enzymes localize to methylated, CpG dense regions in mouse stem cells, yet are excluded from active promoters and enhancers. By specifically measuring sites of de novo methylation, we observe that enzymatic activity reflects chromosomal binding. De novo methylation increases with CpG density, yet is excluded from nucleosomes. Notably, we observed selective binding of DNMT3B to the bodies of transcribed genes, which leads to their preferential methylation. This targeting to transcribed sequences requires SETD2-mediated methylation of lysine 36 on histone H3 and a functional PWWP domain of DNMT3B. Together these findings reveal how sequence and chromatin cues guide de novo methyltransferase activity to ensure methylome integrity. Refer to individual Series
Project description:DNA methylation is an epigenetic modification associated with transcriptional repression of promoters and is essential for mammalian development. Establishment of DNA methylation is mediated by the de novo DNA methyltransferases DNMT3A and DNMT3B, whereas DNMT1 ensures maintenance of methylation through replication. Absence of these enzymes is lethal, and somatic mutations in these genes have been associated with several human diseases. How genomic DNA methylation patterns are regulated remains poorly understood, as the mechanisms that guide recruitment and activity of DNMTs in vivo are largely unknown. To gain insights into this matter we determined chromosomal binding and site-specific activity of the mammalian de novo DNA methyltransferases DNMT3A and DNMT3B. We show that both enzymes localize to methylated, CpG dense regions in mouse stem cells, yet are excluded from active promoters and enhancers. By specifically measuring sites of de novo methylation, we observe that enzymatic activity reflects chromosomal binding. De novo methylation increases with CpG density, yet is excluded from nucleosomes. Notably, we observed selective binding of DNMT3B to the bodies of transcribed genes, which leads to their preferential methylation. This targeting to transcribed sequences requires SETD2-mediated methylation of lysine 36 on histone H3 and a functional PWWP domain of DNMT3B. Together these findings reveal how sequence and chromatin cues guide de novo methyltransferase activity to ensure methylome integrity. Whole-genome bisulfite sequencing for Dnmt1,3a,3b-triple-KO ES cells expressing DNMT3A2 or DNMT3B1 and for Dnmt1,3a,3b,Setd2-KO ES cells expressing DNMT3B1
Project description:We combined multi-omics approaches including de novo transcriptome assembly, ribosome profiling and MS-based peptidomics to study the global role of mRNA translation and small ORFs (sORFs) in rice herbicide resistant mutant.