Deciphering KRAS and NRAS mutated clones dynamics in MLL-AF4 pediatric leukemia by ultra deep sequencing analysis
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE77416 | GEO | 2016/10/04
SECONDARY ACCESSION(S): PRJNA310245
REPOSITORIES: GEO
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Project description:Purpose: Emerging evidence in the field of RAS biology is beginning to illustrate that RAS mutations are functionally distinct. To elucidate functional differences between NRAS mutants we performed RNA-sequencing on mouse embryonic fibroblasts (MEFs) expressing different NRAS codon 61 variants from the endogenous gene locus Methods: MEFs were isolated from Tyr::CRE-ERT2 LSL-Nras mouse models containing different Nras variants in the endogeous gene locus. NRAS expression was induced in MEFs using an Adenoviral Cre delivery system. RNA was isolated from MEFs six days post-NRAS induction and submitted for RNA-sequencing Results: Differential expression and gene set enrichment analysis (GSEA) between NRAS variants revealed enrichment of transcripts associated with cellular proliferation between all mutant Nras alleles versus wild-type Nras. Further, MEFs expressing NRAS mutants capable of driving melanoma formation were enriched for transcripts associated with RAS-MYC signaling axis. Conclusion: While all NRAS mutants are capable of enhancing cellular proliferation versus wild-type NRAS, the melanomagenic potential of these mutants correlates with the ability to enhance activation of the RAS-MYC signaling axis
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Project description:DNA Methyltransferase 3A (DNMT3A) is frequently mutated in various hematopoietic malignancies; however, the underlying oncogenic mechanisms remain elusive. Here, we report that DNMT3A mutational âhotspotâ at Arg882 (DNMT3A-R882H) cooperates with constitutively activated RAS in transforming murine hematopoietic stem/progenitor cells (HSPCs) ex vivo and inducing acute leukemias in vivo. DNMT3A-R882H potentiates aberrant transactivation of âstemnessâ gene expression programs, notably transcription factors Meis1, Hox-A, Mn1 and Mycn. Mechanistically, R882-mutated DNMT3A directly binds to cis-regulatory elements of these genes and induces focal CpG hypomethylation reminiscent of what was seen in human leukemias bearing DNMT3A R882 mutation. Furthermore, DNMT3A-R882H induced DNA hypomethylation facilitates gene enhancer/promoter activation and recruitment of Dot1l-associated transcription elongation machineries. Inactivation of Dot1l represses DNMT3AR882H-mediated stem cell gene dysregulation and acute leukemogenicity. In this dataset, we provided H3K4me1, H3K27ac and H3K79me2 ChIP-seq profiling data showing effect of DNMT3A R882H mutation or WT expression on epigenetic landscapes of hematopoietic stem/progenitor cells with NRAS G12D co-transduction. ChIP-seq analysis of Lin- enriched hematopoietic stem/progenitor cells with retroviral infection of NRAS G12D alone (EV-RAS), DNMT3A R882H with NRAS G12D (RH-RAS) or DNMT3A WT with NRAS G12D (WT-RAS) 3 weeks post-transduction. Antibodies of H3K4me1, H3K27ac and H3K79me2 were used.
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Project description:DNA Methyltransferase 3A (DNMT3A) is frequently mutated in various hematopoietic malignancies; however, the underlying oncogenic mechanisms remain elusive. Here, we report that DNMT3A mutational âhotspotâ at Arg882 (DNMT3A-R882H) cooperates with constitutively activated RAS in transforming murine hematopoietic stem/progenitor cells (HSPCs) ex vivo and inducing acute leukemias in vivo. DNMT3A-R882H potentiates aberrant transactivation of âstemnessâ gene expression programs, notably transcription factors Meis1, Hox-A, Mn1 and Mycn. Mechanistically, R882-mutated DNMT3A directly binds to cis-regulatory elements of these genes and induces focal CpG hypomethylation reminiscent of what was seen in human leukemias bearing DNMT3A R882 mutation. Furthermore, DNMT3A-R882H induced DNA hypomethylation facilitates gene enhancer/promoter activation and recruitment of Dot1l-associated transcription elongation machineries. Inactivation of Dot1l represses DNMT3AR882H-mediated stem cell gene dysregulation and acute leukemogenicity. In this dataset, we provided enhanced Reduced Representation Bisulfite Sequencing (eRRBS) DNA methylome profiling data showing effect of DNMT3A R882H mutation or WT expression on hematopoietic stem/progenitor cells with NRAS G12D co-transduction. eRRBBs DNA methylome analysis of Lin- enriched hematopoietic stem/progenitor cells with retroviral infection of NRAS G12D alone (EV-RAS), DNMT3A R882H with NRAS G12D (RH-RAS) or DNMT3A WT with NRAS G12D (WT-RAS) at day 16 post-transduction.
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