Project description:Background: Although genetic or epigenetic alterations have shown to affect the three-dimensional organization of genomes, the utility of chromatin conformation in the classification of human disease has never been addressed. Results: Here, we explore whether chromatin conformation can be used to classify human leukemia. We map the conformation of the HOXA gene cluster in a panel of cell lines with 5C chromosome conformation capture technology, and use the data to train and test a support vector machine classifier named 3D-SP. We show that 3D-SP is able to accurately distinguish leukemias expressing MLL-fusion proteins from those expressing only wild-type MLL, and that it can also classify leukemia subtypes according to MLL fusion partner, based solely on 5C data. Conclusions: Our study provides the first proof-of-principle demonstration that chromatin conformation contains the information value necessary for classification of leukemia subtypes. Examination of CTCF and RAD21 binding sites in THP-1 cell.
Project description:Simultaneous measurement of lineage relationship and information on cell fate is desireable for human tissues. Here we describe a new strategy to track cell lineage using endogenous mitochondrial DNA variants in ATAC-seq data, which simultaneously measures the chromatin profiling. We first provide a proof of principle that somatic mutations in the mitochondrial genome can be used as a genetic marker to depict cellular lineage relationships and further quantified the power of lineage definition with these genetic markers. Using this method, we demonstrated the genetic and epigenetic heterogeneity of hematopoietic stem cells from patient with acute myeloid leukemia.
Project description:Simultaneous measurement of lineage relationship and information on cell fate is desireable for human tissues. Here we describe a new strategy to track cell lineage using endogenous mitochondrial DNA variants in ATAC-seq data, which simultaneously measures the chromatin profiling. We first provide a proof of principle that somatic mutations in the mitochondrial genome can be used as a genetic marker to depict cellular lineage relationships and further quantified the power of lineage definition with these genetic markers. Using this method, we demonstrated the genetic and epigenetic heterogeneity of hematopoietic stem cells from patient with acute myeloid leukemia.
Project description:Except for the well-known association with Down syndrome, there is little information on the genetic factors predisposing to acute myeloid leukemia. Germinal gene copy-number variations may represent risk factors for the disease. To identify copy number variants present in both normal and leukemic cells, we compared the Comparative Genomic Hybridization profiles of the blasts and healthy cells (CD3+ cells or peripheral lymphocytes during remission) of 13 patients (SET-A) and the blasts of a further 12 normal-karyotype acute myeloid leukemia patients (SET-B) for which only blasts DNA were available.
Project description:Background: Although genetic or epigenetic alterations have shown to affect the three-dimensional organization of genomes, the utility of chromatin conformation in the classification of human disease has never been addressed. Results: Here, we explore whether chromatin conformation can be used to classify human leukemia. We map the conformation of the HOXA gene cluster in a panel of cell lines with 5C chromosome conformation capture technology, and use the data to train and test a support vector machine classifier named 3D-SP. We show that 3D-SP is able to accurately distinguish leukemias expressing MLL-fusion proteins from those expressing only wild-type MLL, and that it can also classify leukemia subtypes according to MLL fusion partner, based solely on 5C data. Conclusions: Our study provides the first proof-of-principle demonstration that chromatin conformation contains the information value necessary for classification of leukemia subtypes.
Project description:Genetic and epigenetic intra-tumoral heterogeneity cooperate to shape the evolutionary course of cancer. In addition to genetic mutations, chronic lymphocytic leukemia (CLL) undergoes diversification through stochastic DNA methylation changes – epimutations. To measure the epimutation rate at single-cell resolution, we applied multiplexed reduced representation bisulfite sequencing (MscRRBS) to healthy donors B cells and CLL patient samples. We observed that the common clonal CLL origin results in consistently elevated epimutation rate (i.e., low cell-to-cell epimutation rate variability). In contrast, variable epimutation rates across normal B cells reflect diverse evolutionary ages across the B cell differentiation trajectory, consistent with epimutations serving as a molecular clock. Heritable epimutation information allowed high-resolution lineage reconstruction with single-cell data, applicable directly to patient sample. CLL lineage tree shape revealed earlier branching and longer branch lengths than normal B cells, reflecting rapid drift after the initial malignant transformation and a greater proliferative history. To validate the inferred tree topology, we integrated MscRRBS with single-cell transcriptomes and genotyping, which confirmed that genetic subclones map to distinct clades inferred solely based on epimutation information. Lastly, to examine potential lineage biases during therapy, we profiled serial CLL samples prior to and during ibrutinib-associated lymphocytosis. Lineage trees revealed divergent clades of cells preferentially expelled from the lymph node with ibrutinib therapy, marked by distinct transcriptional profiles. These data offer direct single-cell integration of genetic, epigenetic and transcriptional information in the study of leukemia evolution, providing deeper insight into its lineage topology and enabling the charting of its evolution with therapy.
2019-05-02 | GSE109085 | GEO
Project description:Spatially regulated editing of genetic information within a squid neuron
Project description:Cancer evolution is fueled by genetic and epigenetic diversity, and intra-tumoral heterogeneity in DNA methylation has been shown to co-operate with genetic heterogeneity to empower evolutionary capacity of cancers such as chronic lymphocytic leukemia. Here, we show that epigenetic diversification leads to decreased coordination across layers of epigenetic information, likely reflecting an admixture of cells with diverging epigenetic identities. This manifests in incomplete gene silencing by the Polycomb complex, unexpected co-occurrence of typically mutually exclusive activating and repressing histone modifications, and greater cell-to-cell transcriptional heterogeneity.
Project description:Acute myeloid leukemia study. Supplementary Table 1: Clinical, morphological, cytogenetic and molecular genetic information on 116 AML patient samples. Supplementary Table 2: Summary of the distribution of clinical and molecular genetic characteristics within the AML sample set. Supplementary Table 3: Fluorescence ratios of the 6,283 well-measured and variably-expressed genes. Supplementary Table 4: Clinical and laboratory characteristics of normal karyotype predominant subtypes I and II. Supplementary Table 5: Supervised analysis of group-specific gene expression signatures. Supplementary Table 6: Gene-expression outcome class predictor. Supplementary Table 7: Multivariate proportional hazards analysis. Keywords: other