Project description:We report here an efficient, reproducible model of T-cell leukemia in which lentiviral transduction of normal human cord blood yields aggressive leukemia that appears indistinguishable from natural disease. We utilize this synthetic model to uncover a role for oncogene-induced HOXB activation which is operative in leukemia cells-of-origin and persists in established tumors where it defines a novel subset of patients distinct from other known genetic subtypes and with poor clinical outcome. We show further that anterior HOXB genes are specifically activated in human T-ALL by an epigenetic mechanism and confer growth advantage in both pre-leukemia cells and established clones.
Project description:Embryonic genome activation (EGA) marks the onset of embryonic program and enables the transition toward the first lineage specification. However, the molecular features of EGA and the transcription factors (TFs) orchestrating this process remain unclear. Here, by performing single-cell RNA-seq on bovine embryos, we reveal that major EGA is asynchronously initiated among blastomeres at the 8-cell stage. Integrative analyses reveal distinctive protein accumulation compared to transcription and translation activation during bovine EGA. Furthermore, we investigate the role of SP1, a TF activated at the minor EGA stage, with motifs enriched in accessible chromatin during major EGA stage in bovine and human embryos. SP1 deficiency leads to morula arrest in bovine and impairs EGA in human embryos. Multi-omics analysis demonstrates that SP1 promotes early lineage gene expression by modulating nearby chromatin states in bovine and directly targets key EGA genes in human embryos. Together, our study delineates the dynamics of bovine EGA and uncovers the conserved and species-specific roles of SP1 in regulating EGA and early development in mammals.
Project description:Global hypermethylations of histone H3 lysine 9 (H3K9) tri- and di-methylation (H3K9me3/2) have been identified in bovine cloned embryos at the embryonic genome activation (EGA) stage (eight-cell stage), but the intrinsic reason for these anomalies remains elusive. To ascertain key factors responsible for aberrant H3K9 methylation, we performed RNA sequencing of transcripts in eight-cell bovine in vitro fertilized (IVF) and SCNT embryo. From the differentially expressed genes (DEGs) between IVF and SCNT embryos, we identified that the unsuccessful reactivation of two histone demethylases, KDM4D and KDM4E, is responsible for the incomplete H3K9me3/2 demethylation in SCNT embryos at the EGA stage. By mRNA injection, ectopic expression of either KDM4D or KDM4E could erase H3K9me3/2 barriers, improve blastocyst formation, and elevate cloning efficiency of bovine SCNT. To examine the detailed genes responsive to KDM4E overexpression, we also performed RNA sequencing of bovine eight-cell SCNT embryos with KDM4E compensation and found an obvious restoration of global transcriptional patterns in SCNT embryos. Our study first provides the transcriptome data set of bovine IVF and SCNT embryos during EGA with or without KDM4E overexpression, which advance the understanding of incomplete nuclear reprogramming, and contribute to the practical implications for genetically modified livestock breeding using SCNT.
Project description:CTCF ChIP-seq of 39 primary samples derived from human acute leukemias, namely AML, T-ALL and mixed myeloid/lymphoid leukemias with CpG Island Methylator Phenotype (CIMP). Due to patient confidentiality considerations, the raw data files for this dataset have been deposited to the EGA controlled-access archive under the accession numbers EGAS00001007094 (study); EGAD00001011059 (dataset).