Similar Datasets
Project description:Gain-of-function mutations in the chromatin ‘reader’ ENL, identified in AML and Wilms tumor, have been shown to induce aberrant formation of transcriptional condensates in cellular systems. However, the precise role of these mutations and their condensate forming property in tumorigenesis remains unclear. By creating a conditional knock-in mouse model for the most prevalent ENL mutation, we establish ENL mutant as a bona fide oncogenic driver of acute myeloid leukemia in vivo. Heterozygous expression of ENL mutant perturbs the normal hematopoietic hierarchy and results in the aberrant expansion of myeloid progenitors with increased self-renewal property. Furthermore, the ENL mutant remodels histone modifications to alter differentiation processes and drive oncogenic gene expression during hematopoietic development. Importantly, targeted point mutagenesis to disrupt the condensate formation property completely abolishes ENL mutant’s oncogenic function in hematopoietic stem and progenitor cells (HSPCs). Lastly, short-term treatment with a small molecule inhibitor that blocks the acetyl-binding activity of ENL mutant reverts its impact on chromatin and significantly delays leukemia development in mice. Our studies reveal the crucial biological function of mutation-induced transcriptional condensates in chromatin regulation and cancer in vivo and provide proof-of-concept for targeting of pathogenic condensates as a promising therapy for certain cancers.
2024-04-14 | GSE239469 | GEO
Project description:Condensate-promoting ENL mutation induces tumorigenesis via chromatin remodeling
| PRJNA999344 | ENA
Project description:Gain-of-function mutations in the chromatin ‘reader’ ENL, identified in AML and Wilms tumor, have been shown to induce aberrant formation of transcriptional condensates in cellular systems. However, the precise role of these mutations and their condensate forming property in tumorigenesis remains unclear. By creating a conditional knock-in mouse model for the most prevalent ENL mutation, we establish ENL mutant as a bona fide oncogenic driver of acute myeloid leukemia in vivo. Heterozygous expression of ENL mutant perturbs the normal hematopoietic hierarchy and results in the aberrant expansion of myeloid progenitors with increased self-renewal property. Furthermore, the ENL mutant remodels histone modifications to alter differentiation processes and drive oncogenic gene expression during hematopoietic development. Importantly, targeted point mutagenesis to disrupt the condensate formation property completely abolishes ENL mutant’s oncogenic function in hematopoietic stem and progenitor cells (HSPCs). Lastly, short-term treatment with a small molecule inhibitor that blocks the acetyl-binding activity of ENL mutant reverts its impact on chromatin and significantly delays leukemia development in mice. Our studies reveal the crucial biological function of mutation-induced transcriptional condensates in chromatin regulation and cancer in vivo and provide proof-of-concept for targeting of pathogenic condensates as a promising therapy for certain cancers.
2024-04-14 | GSE239468 | GEO
Project description:Condensate-promoting ENL mutation induces tumorigenesis via chromatin remodeling [RNA-seq]
| PRJNA999347 | ENA
Project description:Condensate-promoting ENL mutation induces tumorigenesis via chromatin remodeling [ChIP-seq and CUT&Tag]
| PRJNA999348 | ENA
Project description:DNA methylation and histone modifications have essential roles in remodeling chromatin structure of genes necessary for multi-lineage differentiation of mammary stem/progenitor cells. The role of this well-defined epigenetic programming is to heritably maintain transcriptional plasticity of these loci over multiple cell divisions in the differentiated progeny. Epigenetic events can be deregulated in progenitor cells chronically exposed to xenoestrogen or inflammatory microenvironment. In addition, epigenetically mediated silencing of genes associated with tumor suppression can take place, resulting in clonal proliferation of undifferentiated or semidifferentiated cells. Alternatively, microRNAs that negatively regulate the expression of their protein-coding targets may become epigenetically repressed, leading to oncogenic expression of these genes. Here we further discuss interactions between DNA methylation and histone modifications that have significant contributions to the differentiation of mammary stem/progenitor cells and to tumor initiation and progression.
| S-EPMC2926750 | biostudies-literature
Project description:For cells to adapt to different tissues and changes in tissue mechanics, they must be able to respond to mechanical cues by changing their gene expression patterns. Biochemical signaling pathways for these responses have been elucidated, and recent evidence points to the involvement of force-induced deformation of the nucleus. However, it is still unclear how physical cues received at the plasma membrane (PM) spatiotemporally integrate to the functional chromatin organization of the cell nucleus. To investigate this issue, we applied mechanical forces through magnetic particles adhered to the PM of single cells and mapped the accompanying changes in actin polymerization, nuclear morphology, chromatin remodeling, and nuclear transport of soluble signaling intermediates using high-resolution fluorescence anisotropy imaging. Using this approach, we show the timescales associated with force-induced polymerization of actin and changes in the F/G actin ratio resulting in nuclear translocation of the G-actin-associated transcriptional cofactor, megakaryoblastic acute leukemia factor-1 (MKL). Further, this method of measuring nuclear organization at high spatiotemporal resolution with simultaneous force application revealed the physical propagation of forces to the nucleus, resulting in changes to chromatin organization, followed by nuclear deformation. We also describe a quantitative model that incorporates active stresses and chemical kinetics to evaluate the observed timescales. Our work suggests that mechanical activation of cells is accompanied by distinct timescales involved in the reorganization of actin and chromatin assembly, followed by translocation of transcription cofactors from the cytoplasm to the nucleus.
| S-EPMC3471483 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2023-05-31 | GSE181582 | GEO
Project description:Recent human exome-sequencing studies have implicated polymorphic Brg1-associated factor (BAF) complexes (mammalian SWI/SNF chromatin remodeling complexes) in several intellectual disabilities and cognitive disorders, including autism. However, it remains unclear how mutations in BAF complexes result in impaired cognitive function. Post-mitotic neurons express a neuron-specific assembly, nBAF, characterized by the neuron-specific subunit BAF53b. Subdomain 2 of BAF53b is essential for the differentiation of neuronal precursor cells into neurons. We generated transgenic mice lacking subdomain 2 of Baf53b (BAF53bΔSB2). Long-term synaptic potentiation (LTP) and long-term memory, both of which are associated with phosphorylation of the actin severing protein cofilin, were assessed in these animals. A phosphorylation mimic of cofilin was stereotaxically delivered into the hippocampus of BAF53bΔSB2 mice in an effort to rescue LTP and memory. BAF53bΔSB2 mutant mice show impairments in phosphorylation of synaptic cofilin, LTP, and memory. Both the synaptic plasticity and memory deficits are rescued by overexpression of a phosphorylation mimetic of cofilin. Baseline physiology and behavior were not affected by the mutation or the experimental treatment. This study suggests a potential link between nBAF function, actin cytoskeletal remodeling at the dendritic spine, and memory formation. This work shows that a targeted manipulation of synaptic function can rescue adult plasticity and memory deficits caused by manipulations of nBAF, and thereby provides potential novel avenues for therapeutic development for multiple intellectual disability disorders.
| S-EPMC5397687 | biostudies-literature
Project description:Rsf-1 (HBXAP) has been reported as an amplified gene in human cancer, including the highly aggressive ovarian serous carcinoma. Rsf-1 protein interacts with SNF2H to form an ISWI chromatin remodeling complex, RSF. In this study, we investigated the functional role of Rsf-1 by observing phenotypes after expressing it in nontransformed cells. Acute expression of Rsf-1 resulted in DNA damage as evidenced by DNA strand breaks, nuclear ?H2AX foci, and activation of the ATM-CHK2-p53-p21 pathway, leading to growth arrest and apoptosis. Deletion mutation and gene knockdown assays revealed that formation of a functional RSF complex with SNF2H was required for Rsf-1 to trigger DNA damage response (DDR). Gene knock-out of TP53 alleles, TP53 mutation, or treatment with an ATM inhibitor abolished up-regulation of p53 and p21 and prevented Rsf-1-induced growth arrest. Chronic induction of Rsf-1 expression resulted in chromosomal aberration and clonal selection for cells with c-myc amplification and CDKN2A/B deletion. Co-culture assays indicated Rsf-1-induced DDR as a selecting barrier that favored outgrowth of cell clones with a TP53 mutation. The above findings suggest that increased Rsf-1 expression and thus excessive RSF activity, which occurs in tumors harboring Rsf-1 amplification, can induce chromosomal instability likely through DDR.
| S-EPMC2992260 | biostudies-other