Similar Datasets
Project description:Dysregulated innate immune signaling is linked to preleukemic conditions and myeloid malignancies like MDS and AML. However, it is unknown whether sustained innate immune signaling contributes to malignant transformation. Here we show that cell-intrinsic innate immune signaling driven by miR-146a deletion (miR-146aKO), a commonly deleted gene in MDS and AML, cooperates with mutant RUNX1 (RUNX1mut) to initially induce marrow failure and features of MDS. However, miR-146aKO HSPCs expressing RUNX1mut eventually progress to a fatal AML. miR-146aKO HSPCs exhaust during serial transplantation, while expression of RUNX1mut restored their hematopoietic cell function. Thus, HSPCs exhibiting dysregulated innate immune signaling require a second hit to develop AML. Inhibiting the dysregulated innate immune pathways with a TRAF6-UBE2N inhibitor suppressed leukemic miR-146aKO/RUNX1mut HSPCs, highlighting the necessity of TRAF6-dependent cell-intrinsic innate immune signaling in initiating and maintaining AML. These findings underscore the critical role of dysregulated cell-intrinsic innate immune signaling in driving preleukemic cells toward AML progression.
2024-05-29 | GSE264052 | GEO
Project description:Dysregulated innate immune signaling is linked to preleukemic conditions and myeloid malignancies like MDS and AML. However, it is unknown whether sustained innate immune signaling contributes to malignant transformation. Here we show that cell-intrinsic innate immune signaling driven by miR-146a deletion (miR-146aKO), a commonly deleted gene in MDS and AML, cooperates with mutant RUNX1 (RUNX1mut) to initially induce marrow failure and features of MDS. However, miR-146aKO HSPCs expressing RUNX1mut eventually progress to a fatal AML. miR-146aKO HSPCs exhaust during serial transplantation, while expression of RUNX1mut restored their hematopoietic cell function. Thus, HSPCs exhibiting dysregulated innate immune signaling require a second hit to develop AML. Inhibiting the dysregulated innate immune pathways with a TRAF6-UBE2N inhibitor suppressed leukemic miR-146aKO/RUNX1mut HSPCs, highlighting the necessity of TRAF6-dependent cell-intrinsic innate immune signaling in initiating and maintaining AML. These findings underscore the critical role of dysregulated cell-intrinsic innate immune signaling in driving preleukemic cells toward AML progression.
2024-05-29 | GSE264051 | GEO
Project description:Dysregulated innate immune signaling cooperates with RUNX1 mutations to transform an MDS-like disease to AML
| PRJNA1100608 | ENA
Project description:Dysregulated innate immune signaling cooperates with RUNX1 mutations to transform an MDS-like disease to AML (WES)
| PRJNA1100617 | ENA
Project description:Dysregulated innate immune signaling cooperates with RUNX1 mutations to transform an MDS-like disease to AML (RNA-Seq)
| PRJNA1100613 | ENA
Project description:The mixed-lineage leukemia (MLL) H3K4 methyltransferase protein, and the heterodimeric RUNX1/CBF? transcription factor complex, are critical for definitive and adult hematopoiesis, and both are frequently targeted in human acute leukemia. We identified a physical and functional interaction between RUNX1 (AML1) and MLL and show that both are required to maintain the histone lysine 4 trimethyl mark (H3K4me3) at 2 critical regulatory regions of the AML1 target gene PU.1. Similar to CBF?, we show that MLL binds to AML1 abrogating its proteasome-dependent degradation. Furthermore, a subset of previously uncharacterized frame-shift and missense mutations at the N terminus of AML1, found in MDS and AML patients, impairs its interaction with MLL, resulting in loss of the H3K4me3 mark within PU.1 regulatory regions, and decreased PU.1 expression. The interaction between MLL and AML1 provides a mechanism for the sequence-specific binding of MLL to DNA, and identifies RUNX1 target genes as potential effectors of MLL function.
| S-EPMC3242717 | biostudies-literature
Project description:Myelodysplastic syndromes (MDSs) are a heterogeneous group of hematologic malignancies with a propensity to progress to acute myeloid leukemia. Causal mutations in multiple classes of genes have been identified in patients with MDS with some patients harboring more than 1 mutation. Interestingly, double mutations tend to occur in different classes rather than the same class of genes, as exemplified by frequent cooccurring mutations in the transcription factor RUNX1 and the splicing factor SRSF2. This prototypic double mutant provides an opportunity to understand how their divergent functions in transcription and posttranscriptional regulation may be altered to jointly promote MDS. Here, we report a mouse model in which Runx1 knockout was combined with the Srsf2 P95H mutation to cause multilineage hematopoietic defects. Besides their additive and synergistic effects, we also unexpectedly noted a degree of antagonizing activity of single mutations in specific hematopoietic progenitors. To uncover the mechanism, we further developed a cellular model using human K562 cells and performed parallel gene expression and splicing analyses in both human and murine contexts. Strikingly, although RUNX1 deficiency was responsible for altered transcription in both single and double mutants, it also induced dramatic changes in global splicing, as seen with mutant SRSF2, and only their combination induced missplicing of genes selectively enriched in the DNA damage response and cell cycle checkpoint pathways. Collectively, these data reveal the convergent impact of a prototypic MDS-associated double mutant on RNA processing and suggest that aberrant DNA damage repair and cell cycle regulation critically contribute to MDS development.
| S-EPMC9772487 | biostudies-literature
Project description:In spite of the recent discovery of genetic mutations in most MDS, pathophysiology of those disorders remain poorly known, and few animal are available. We performed global exome specific gene expression profiling and functional pathway analysis in purified Sca1+ spleen cells of two MDS transgenic mouse models developed by our group. Those models mimic high-risk MDS (HR MDS) and AML post MDS, depending on the transgene promoters used (MRP8NRASD12/tethBCL-2 and MRP8NRASD12/MRP8hBCL-2 respectively). We found common deregulated pathways in both models showing disease continuum. The most significantly deregulated pathways identified have previously been reported in MDS patients such as cell cycle, DNA replication/damage/repair, apoptosis, immune responses and canonical Wnt pathways. Interestingly, this analysis highlights other deregulated pathways such as non-canonical Wnt pathways including Rho signaling and circadian rhythm that may be critical in a human MDS setting.
2017-02-11 | GSE72934 | GEO
Project description:The heterogeneity of acute myeloid leukaemia (AML) and myelodysplastic syndromes (MDS) has led to a multiplicity of treatments, from cytotoxic agents to signal transduction modulators, cell-cycle inhibitors and epigenetic therapies. While some have shown promising initial results, the outlook for AML patients, particularly older and relapsed patients, as well as patients whose cells exhibit certain adverse chromosomal abnormalities or mutant oncoproteins, continues to be grim. Combination chemotherapy using new agents that act at a number of different levels may provide the greatest potential for successful future therapies. A select number of new agents, approaches and combinations are reviewed here.
| S-EPMC2793080 | biostudies-other
Project description:The use of low dose hypomethylating agents for patients with myelodysplastic syndrome (MDS) and secondary acute myeloid leukemia (AML) has had made a significant impact. In the past, therapies for these diseases were limited and patients who elected to receive treatment were subject to highly toxic, inpatient chemotherapeutics, which were often ineffective. In the era of hypomethylating agents (azacitidine and decitabine), a patient with high grade MDS or AML with multilineage dysplasia can be offered the alternative of outpatient, relatively low-toxicity therapy. Despite the fact that CR (CR) rates to such agents remain relatively low at 15-20%, a much larger percentage of patients will have clinically significant improvements in hemoglobin, platelet, and neutrophil counts while maintaining good outpatient quality of life. As our clinical experience with azanucleotides expands, questions regarding patient selection, optimal dosing strategy, latency to best response and optimal duration of therapy following disease progression remain, but there is no question that for some patients these agents offer, for a time, an almost miraculous clinical benefit. Ongoing clinical trials in combination and in sequence with conventional therapeutics, with other epigenetically active agents, or in conjunction with bone marrow transplantation continue to provide promise for optimization of these agents for patients with myeloid disease. Although the mechanism(s) responsible for the proven efficacy of these agents remain a matter of some controversy, activity is thought to stem from induction of DNA hypomethylation, direct DNA damage, or possibly even immune modulation; there is no question that they have become a permanent part of the armamentarium against myeloid neoplasms.
| S-EPMC4086806 | biostudies-other