Project description:Dnmt3a is the most recurrently mutated gene in clonal hematopoiesis (CH), and it is a critical regulator of hematopoietic stem cells (HSCs). Conditional deletion of Dnmt3a in mouse HSC results in enhanced self-renewal but impaired differentiation. Dnmt3a encodes for a de novo DNA methyltransferase enzyme but both mouse and human cells with loss of Dnmt3a show minimal change in DNA methylation levels which do not correlate with gene expression differences. To understand if there are methylation differences between control and mutant (R878H) Dnmt3a, we are performing WGBS.
Project description:DNA methyltransferase 3A (DNMT3A) gene is mutated in various myeloid neoplasms including acute myeloid leukemia (AML), especially at the Arg882 and associated with inferior outcomes. Here we wished to perform the differential genomic-methylation profile in EOL-1 cells over-expressed with DNMT3A-Arg882Cys(R882C) and DNMT3A-Ser714Cys (S714C) mutations including DNMT3A-WT and vector. Results: Differential genomic-methylation assess identified both hypo- and hypermethylation features in different regions throughout the whole genome of DNMT3A mutants-transduced EOL-1 cells.
Project description:DNA methyltransferase 3A (DNMT3A) gene is mutated in various myeloid neoplasms including acute myeloid leukemia (AML), especially at the Arg882 and associated with inferior outcomes. Despite the current progress of functional role of DNMT3A mutations, the molecular pathogenesis of myeloid malignancies remains poorly understood. The mechanisms of AML transformation and functional role of DNMT3A mutations through its target genes in the leukemogenesis remain to be explored. Here we wished to perform the differential genomic-methylation profile in U937 cells over-expressed with DNMT3A-Arg882His/Cys (R882H/C) mutations including DNMT3A-WT and vector using Illumina MethylationEPIC BeadChip microarray. Results: Differential genomic-methylation assess identified both hypo- and hypermethylation features in different regions throughout the whole genome of DNMT3A mutants-transduced U937 cells.
Project description:DNA methyltransferase 3A (DNMT3A) gene is mutated in various myeloid neoplasms including acute myeloid leukemia (AML), especially at the Arg882 and associated with inferior outcomes. Despite the current progress of functional role of DNMT3A mutations, the molecular pathogenesis of myeloid malignancies remains poorly understood. The mechanisms of AML transformation and functional role of DNMT3A mutations through its target genes in the leukemogenesis remain to be explored. Here we wished to perform the differential gene expression profile in U937 cells over-expressed with DNMT3A-Arg882His/Cys (R882H/C) mutations including DNMT3A-WT and vector. Results: Gene expression profiling analysis revealed aberrant expression of several cell-cycle and apoptosis-related genes in U937 cells transduced with mutant DNMT3A compared to WT- or vector control.
Project description:DNA methyltransferase 3A (DNMT3A) plays a critical role in establishing and maintaining DNA methylation patterns, essential for the dynamic organization of vertebrate genomes. However, the mechanisms underlying DNMT3A1's recruitment and function within different chromatin environments remain unclear. We find that DNMT3A interacts with modified nucleosomes through multivalent interactions, involving both direct binding to chromatin features and site-specific post-translational histone modifications.
Project description:Calorie restriction has long been known to extend lifespans and inhibit carcinogenesis in multiple species by slowing age-related epigenetic changes while the underlying mechanisms remain largely unknown. Herein, we found that starvation activated autophagy to remodel DNA methylation profile by inhibiting DNMT3a expression. Autophagy is impaired in chemoresistance which was associated with differential DNA methylation and could be reversed by DNMT3a inhibition. Autophagy activation decreases the expression of DNMT3a mRNA, accompanied with the downregulation of chemoresistance-related Linc00942. Knockdown of Linc00942 reduces DNMT3a expression and genome-wide DNA methylation while Linc00942 overexpression increased DNMT3a expression and correlated hypermethylation in cancer cells and primary tumor tissues. As a result, inhibition of autophagy increases Linc00942 expression to promote chemoresistance and autophagy activation or hypomethylating agent decitabine restores chemosensitivity by reducing global DNA methylation.
Project description:Calorie restriction has long been known to extend lifespans and inhibit carcinogenesis in multiple species by slowing age-related epigenetic changes while the underlying mechanisms remain largely unknown. Herein, we found that starvation activated autophagy to remodel DNA methylation profile by inhibiting DNMT3a expression. Autophagy is impaired in chemoresistance which was associated with differential DNA methylation and could be reversed by DNMT3a inhibition. Autophagy activation decreases the expression of DNMT3a mRNA, accompanied with the downregulation of chemoresistance-related Linc00942. Knockdown of Linc00942 reduces DNMT3a expression and genome-wide DNA methylation while Linc00942 overexpression increased DNMT3a expression and correlated hypermethylation in cancer cells and primary tumor tissues. As a result, inhibition of autophagy increases Linc00942 expression to promote chemoresistance and autophagy activation or hypomethylating agent decitabine restores chemosensitivity by reducing global DNA methylation. Taken together, our study identifies a novel methylation cascade linking impaired RNautophagy to global hypermethylation in chemoresistance, and provides a rationale for repurposing decitabine to overcome chemoresistance in cancer treatment.
Project description:To examine whether Dnmt3a deficiency resulted in genomic methylation changes we performed an unbiased methylome analysis. Methylated DNA isolated from three Dnmt3a deficient and two WT tumors was immunoprecipitated and subjected to high throughput sequencing (MeDIP-Seq). We observed that genes that were less expressed in Dnmt3a deficient tumors tended to have lower methylation levels in gene bodies. Examination of methylcytosine in two tumor types