76f63e02-006f-438f-8f09-06c84f0d49a1 - samples
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ABSTRACT:
PROVIDER: EGAD00001011258 | EGA |
REPOSITORIES: EGA
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Project description:We identified a T-cell receptor (TCR) reactive to the recurrent FLT3 D835Y mutation in the tyrosine-kinase domain frequently expressed in acute myeloid leukemia (AML). To validate the TCRs' elimination efficacy of leukemic cells, we transplanted human AML cells with FLT3 D835Y mutation into NSG-SGM3 mice and treated either with TCR FLT3 D835Y redirected T cells, or control TCR (TCR 1G4). After treatment, we performed flow sorting of human AML cells from the mice (mCD45-hCD45+hCD3-hCD19-) and compared to primary AML blasts (hCD3-hCD19-) and primary T cells (hCD3+hCD8+orhCD4+hCD19-hCD33-) by whole-exome sequencing.
| EGAS00001007467 | EGA
Project description:This paper presents a T-cell receptor (TCR) reactive to the recurrent D835Y driver mutation in the FLT3 tyrosine-kinase domain. TCRFLT3D/Y-redirected T cells selectively eliminated primary human AML cells harboring the D835Y mutation in vitro and in vivo. The TCRFLT3D/Y cells rejected both CD34+ and CD34- AML in mice engrafted with primary leukemia from patients, reaching minimal residual disease negative levels, and eliminated primary CD34+ AML leukemia-propagating cells in vivo. Thus, T cells targeting a single shared mutation can provide efficient immunotherapy towards selective elimination of clonally involved primary AML cells in vivo.
2023-08-28 | PXD043908 | Pride
Project description:Internal tandem duplication (ITD) mutations within the FMS-like receptor tyrosine kinase-3 (FLT3) can be found in up to 25~30% of acute myeloid leukemia (AML) patients and confer a poor prognosis. Although FLT3 tyrosine kinase inhibitors (TKIs) have shown clinical responses, the overall outcome of FLT3-ITD+ AML patients remains poor, and most of them would relapse very shortly. TKIs can not eliminate primitive FLT3-ITD+ AML cells, which are potential sources of relapse. Therefore, elucidating the mechanisms underlying FLT3-ITD+ AML maintenance and drug resistance is essential to develop novel, effective treatment strategies. Here, we demonstrate that FLT3 inhibition induces histone deacetylase 8 (HDAC8) upregulation through FOXO1 and FOXO3-mediated transactivation in FLT3-ITD+ AML cells. Upregulated HDAC8 deacetylates and inactivates p53, leading to leukemia maintenance and drug resistance upon TKIs treatment. Genetic or pharmacological inhibition of HDAC8 re-activates p53, abrogates leukemia maintenance and significantly enhances TKI-mediated elimination of FLT3-ITD+ AML cells. Importantly, in FLT3-ITD+ AML patient-derived xenograft models, the combination of FLT3 TKI (AC220) with a HDAC8 inhibitor (22d) significantly inhibits leukemia progression and effectively reduces primitive FLT3-ITD+ AML cells. Moreover, we extend these findings to an AML subtype harboring another tyrosine kinase activating mutation. In conclusion, our study demonstrates that HDAC8 upregulation as an important mechanism to resist TKIs and promote leukemia maintenance, and suggests that combining HDAC8 inhibition with TKI treatment could be a promising strategy to treat FLT3-ITD+ AML and other tyrosine kinase mutation-harboring leukemias.
2020-02-13 | GSE138057 | GEO
Project description:The presence of FLT3-ITD mutations in patients with acute myeloid leukemia (AML) is associated with poor clinical outcome. FLT3 tyrosine kinase inhibitors (TKIs), although effective in kinase ablation, do not eliminate FLT3-ITD+ leukemia stem cells (LSCs) which are potential sources of disease relapse, prompting us to ask whether FLT3-ITD protein regulates the AML LSCs survival through a kinase-independent mechanism. Here, we show that expression of PRMT1, the primary type I arginine methyltransferase, significantly increases in LSC-enriched CD34+CD38- populations relative to normal counterparts. Genetic PRMT1 depletion blocked AML CD34+ cell survival, and had more potent effects in AML cells from patients harboring FLT3-ITD. Our genome wide analysis of gene expression and PRMT1 conditional KO mouse study confirmed that PRMT1 preferentially cooperates with FLT3-ITD contributing to AML cell maintenance. Mechanistically, PRMT1 catalyzed FLT3-ITD protein methylation at arginines 972/973, and PRMT1 promoted leukemia cell growth in a FLT3 methylation-dependent manner. Moreover, effects of FLT3-ITD methylation in AML cells were in part due to crosstalk with FLT3-ITD phosphorylation at tyrosine 969 (Y969). Importantly, FLT3 methylation persisted in FLT3-ITD+ AML cells following TKI (AC220) treatment, indicating that methylation occurs independently of kinase activity. Finally, in both patient-derived xenograft (PDX) and murine AML models, combined administration of AC220 with a type I PRMT inhibitor (MS023) enhanced elimination of FLT3-ITD+ AML relative to AC220 treatment alone. Our study demonstrates that PRMT1-mediated FLT3 methylation promotes LSC activity and suggests that combining PRMT1 inhibition with FLT3 TKI treatment could be a promising approach to selectively target FLT3-ITD+ LSCs.
2021-11-10 | GSE122435 | GEO
Project description:Effectively targeting leukemia-initiating cells (LIC) in FLT3-internal-tandem-duplication (ITD)-mutated acute myeloid leukemia (AML) remains a crucial goal for achievement of cure. FLT3 tyrosine kinase inhibitors (TKI) have limited impact as single agents and have thus far been unable to eradicate LIC enriched in the CD34+CD38- bone marrow compartment and protected by contact with niche cells.Using primary AML samples in vitro as well as in an in vivo xenograft model, we investigated whether combining the novel FLT3-selective TKI crenolanib with the hypomethylating agent azacitidine (AZA) can eliminate LIC in FLT3-ITD+ AML and determined whether efficacy of this combination is dependent on coexisting genetic mutations in DNMT3A, NPM1 and TET2. Our data show that crenolanib as a single agent was unable to target FLT3-ITD+ LIC in contact with niche cells while the addition of AZA overcame stromal protection and resulted in dramatically reduced clonogenic capacity of FLT3-ITD+ LIC in vitro as well as severely impaired engraftment capacity of FLT3-ITD+ LIC in NSG mice. Strikingly, FLT3-mutated AML samples harboring concurrent TET2 mutations were completely resistant to crenolanib as a single agent. Mutations in DNMT3A or NPM1 had no influence on response to crenolanib while DNMT3A mutations conferred increased sensitivity of FLT3-ITD+ LIC to AZA. Our data suggest that response to crenolanib or AZA as single agents in FLT3-ITD+ AML is highly dependent on coexisting mutations in epigenetic regulators. However, the combination of AZA + crenolanib effectively eliminated FLT3-ITD+ LIC irrespective of additional mutations in NPM1, DNMT3A or TET2.
2017-04-03 | GSE86021 | GEO
Project description:Leukemic stem cells (LSCs) fuel relapse in acute myeloid leukemia (AML), but therapies tailored at eradicating LSCs without harming healthy hematopoietic stem cells (HSCs) are lacking. FLT3 is frequently mutated in AML and associated with relapse; but FLT3 targeting has met with limited clinical success. This raises questions of whether more potent inhibitors would increase effectiveness but whether toxicity to HSC would become limiting. Here, we tested the consequence of complete FLT3 ablation using CRISPR/Cas9 FLT3 knock-out (FLT3-KO) in human HSCs and LSCs followed by functional xenograft assays to test their ability to regenerate human hematopoiesis and leukemia, respectively. FLT3-KO in HSCs from human fetal liver, cord blood and adult bone marrow showed no impairment in multilineage hematopoiesis in primary and secondary xenografts. By contrast, FLT3-KO LSCs from 6 of 7 FLT3-ITD mutated AMLs were able to generate short-term engraftment but were completely exhausted by 12 weeks. Thus, FLT3 is essential for LSC long-term propagation. This dependency was unique to FLT3-ITD AML samples as non-FLT3-ITD AML samples generated leukemic grafts upon FLT3-KO. Transcriptomic analysis revealed that FLT3-KO induced downregulation of DNA repair and cell cycle checkpoints, uniquely in FLT3-ITD AML, but not in healthy HSCs or other AMLs. Our research highlights a critical distinction between healthy HSCs and LSCs: whereas healthy hematopoiesis proceeds unperturbed upon FLT3-KO, FLT3-ITD leukemogenesis is impaired through elimination of LSCs. This evidence underscores the necessity for more potent FLT3-targeting and places FLT3 as an ideal therapeutic target to selectively eradicate LSCs, while sparing HSC.
2025-06-01 | GSE268962 | GEO
Project description:Internal tandem duplication (ITD) of the fms-related tyrosine kinase-3 (FLT3) gene occurs in 30% acute myeloid leukemias (AML) and confers a poor prognosis. Thirteen relapsed or chemo-refractory FLT3-ITD+ AML patients were treated with sorafenib (200-400 mg twice daily). Twelve patients showed clearance or near clearance of bone marrow (BM) myeloblasts after 27 (range 21–84) days with evidence of differentiation of leukemia cells. The sorafenib response was lost in most patients after 72 (range 54–287) days but the FLT3 and downstream effectors remained suppressed. Four pairs patients (before sorafenib treatment and after sorafenib relapse), total eight samples from four patients at the two time-points were subjected to microarray analysis. Gene expression profiling showed that leukemia cells which have become sorafenib resistant expressed a number of genes including ALDH1A1, JAK3 and MMP15, whose functions were unknown in AML. NOD/SCID mice transplanted with leukemia cells from patients before and during sorafenib resistance recapitulated the clinical results. Both ITD and tyrosine kinase domain (TKD) mutations at D835 were identified in leukemia initiating cells (LIC) from samples before sorafenib treatment. LIC bearing the D835 mutant have expanded during sorafenib treatment and dominated during the subsequent clinical resistance. These results suggested that sorafenib have selected more aggressive sorafenib-resistant subclones carrying both FLT3-ITD and D835 mutations and might provide important leads to further improvement of treatment outcome with FLT3 inhibitors. RNA from CD33+CD34+ myeloblasts at pre-sorafenib-treatment and post-sorafenib-relapse were collected and subjected to microarray analysis
2012-02-18 | E-GEOD-35907 | biostudies-arrayexpress
Project description:Purpose: Compare transcriptional changes between drug treated (gilteritinib, TP-0903) and vehicle in acute myeloid leukemia xenografts. Methods: FLT3-ITD+ MOLM13-RES-Luc+ (MOLM13 cells with a D835Y mutation generating a resistant phenotype) AML cells were xenografted into NSG mice. Mice were randomized according to bioluminescence imaging, and treatment of FLT3 tyrosine kinase inhibitor (gilteritinib, 30 mg/kg, once daily for 5 days/week) was started on day 13 post-tail vein injection. At study end point, mice were humanely euthanized and bone marrow was collected. AML cells (human CD45+) were isolated, and ATAC-seq was performed on HiSeq 4000, total RNA. Sequencing reads were aligned and analyzed for differential gene expression of treatment vs vehicle cohorts. Results: The analysis revealed the chromatin accessibility changes induced by gilteritinib in MOLM13-RES AML xenograft model.
2021-07-07 | GSE179421 | GEO
Project description:Chimeric antigen receptor (CAR) therapy targeting CD19 yielded remarkable outcomes in patients with acute lymphoblastic leukemia. To identify potential CAR targets in acute myeloid leukemia (AML), we probed the AML surfaceome for over-expressed molecules with potentially tolerable systemic expression. We integrated large transcriptomics and proteomics data sets from malignant and normal tissues, and developed an algorithm to identify potential targets expressed in leukemia stem cells, but not in normal CD34+CD38– hematopoietic cells, T cells or vital tissues. As these investigations did not uncover candidate targets with a profile as favorable as CD19, we developed a generalizable combinatorial targeting strategy fulfilling stringent efficacy and safety criteria. Our findings indicate that several target pairings hold great promise for CAR therapy of AML.
2017-10-24 | PXD007552 | Pride
Project description:Purpose: Compare transcriptional changes between drug treated (gilteritinib, TP-0903) and vehicle in acute myeloid leukemia xenografts. Methods: FLT3-ITD+ MOLM13-Luc+ AML cells were xenografted into NSG mice. Mice were randomized according to bioluminescence imaging, and treatment of FLT3 tyrosine kinase inhibitors (TP-0903, 60 mg/kg, once daily for 5 days/week; gilteritinib, 30 mg/kg, once daily for 5 days/week) was started on day 7 post-tail vein injection. At study end point, mice were humanely euthanized and bone marrow was collected. AML cells (human CD45+) were isolated, and RNA-seq was performed on total RNA. Sequencing reads were aligned and analyzed for differential gene expression of treatment vs vehicle cohorts. Results: The analysis revealed the transcriptional changes induced by TP-0903 or gilteritinib in MOLM13 AML xenograft model.
2021-07-22 | GSE180181 | GEO