FLT3-ITD mutation expands dendritic cells and alters CD4+ T cells in acute myeloid leukemia
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE238156 | GEO | 2023/08/23
REPOSITORIES: GEO
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Project description:One of the most common genetic alterations in acute myeloid leukemia is the internal tandem duplication (ITD) in the FLT3 receptor for cytokine FLT3 ligand (FLT3L). The constitutively active FLT3-ITD promotes the expansion of transformed progenitors, but also has pleiotropic effects on normal hematopoiesis. We analyzed the effect of FLT3-ITD on dendritic cells (DCs), which express FLT3 and can be expanded by FLT3L administration. We report that young pre-leukemic mice with the Flt3ITD knock-in allele manifest an expansion of all DCs including classical (cDCs) and plasmacytoid (pDCs). The expansion originated in DC progenitors, occurred in a cell-intrinsic manner and was further enhanced in Flt3ITD/ITD mice. The mutation caused the downregulation of Flt3 on the surface of DCs and reduced their responsiveness to Flt3L. Flt3ITD mice showed enhanced capacity to support T cell proliferation, including a cell-extrinsic expansion of regulatory T cells (Tregs). Accordingly, these mice restricted alloreactive T cell responses during graft-versus-host reaction, but failed to control autoimmunity in the absence of Tregs. Thus, the FLT3-ITD mutation directly affects DC development, thereby indirectly modulating T cell homeostasis and supporting Treg expansion. This effect of FLT3-ITD may subvert immunosurveillance and promote leukemogenesis in a cell-extrinsic manner.
2016-01-28 | GSE76132 | GEO
Project description:Internal tandem duplications in the tyrosine kinase receptor FLT3 (FLT3-ITD) are among the most common lesions in acute myeloid leukemia (AML) and there exists a need for new forms of treatment. Using ex vivo drug sensitivity screening, we found that FLT3-ITD+ patient cells are particularly sensitive to HSP90 inhibitors. While it is well known that HSP90 is important for FLT3-ITD stability, we found that HSP90 family members play a much more complex role in FLT3-ITD signaling than previously appreciated. First, we found that FLT3-ITD activates the unfolded protein response (UPR), leading to increased expression of GRP94/HSP90B1. GRP94 rewires FLT3-ITD signaling by binding and retaining FLT3-ITD in the ER, where it aberrantly activates downstream signaling pathways. Second, HSP90 family proteins protect FLT3-ITD+ AML cells against apoptosis by alleviating proteotoxic stress, and treatment with HSP90 inhibitors results in proteotoxic overload that triggers UPR-induced apoptosis. Importantly, leukemic stem cells are strongly dependent upon HSP90 for their survival, and the HSP90 inhibitor ganetespib causes leukemic stem cell exhaustion in mouse PDX models. Taken together, our study reveals a molecular basis for HSP90 addiction of FLT3-ITD+ AML cells and provides a rationale for including HSP90 inhibitors in the treatment regime for FLT3-ITD+ AML.
2020-09-02 | PXD009423 | Pride
Project description:FLT3 activating mutations cause myeloproliferative neoplasms by deregulating hematopoietic progenitor cell growth, and acute myeloid leukemia is on the rise. Investigational drugs targeting mutant FLT3, including Quizartinib and Crenolanib, develop inherent and acquired resistance to FLT3 targeted therapy. FLT3 inhibitor resistance in AML is dependent on co-occurring mutations, parallel survival pathways, and/or subsequent FLT3-ITD mutations. Despite the high prevalence of FLT3 mutations and their clinical significance in AML, there are few targeted therapeutic options. We identified two novel naphthyridine-based FLT3 inhibitors (HSN608 and HSN748) that specifically target FLT3-ITD at sub-nanomolar concentrations and are effective against drug-resistant secondary mutations. In the current study, we evaluated these compounds antileukemic activity against FLT3-ITD and gatekeeper mutations in drug-resistant AML, relapsed/refractory AMLs with FLT3 mutations, and in vivo mouse models with combinations of epigenetic mutations TET2 with FLT3-ITD, and AML patients PDX. In these model systems, we demonstrate that HSN748 outperforms the FDA-approved FLT3 inhibitor Gilteritinib in terms of inhibitory activity against FLT3-ITD.
2022-12-07 | MSV000090855 | MassIVE
Project description:Fms-like tyrosine kinase 3 (Flt3) tyrosine kinase inhibitors (Flt3-TKI) have improved outcomes for patients with Flt3-mutated acute myeloid leukemia (AML) but are limited by resistance and relapse, suggesting persistence of leukemia stem cells (LSC). Here we utilized a Flt3-internal tandem duplication (Flt3-ITD) and Tet2-deleted AML genetic mouse model to characterize Flt3-ITD AML LSC and their resistance to Flt3-TKI. We show that LSC were enriched within the primitive ST-HSC population. CXCl12-expressing osteoprogenitors were increased in the Flt3-ITD AML marrow and FLT3-ITD LSC showed increased expression of the CXCL12 receptor CXCR4. CXCL12 deletion from the microenvironment enhanced AML targeting by combined Flt3-TKI and chemotherapy treatment with enhanced LSC targeting. We found that both treatment and CXCL12 deletion partially reduced p38 mitogen-activated protein kinase (p38) signaling with increased, but not complete, reduction seen with combined treatment and CXCL12 deletion. Our studies suggest that p38 contributes to CXCL12-mediated maintenance of AML LSC following Flt3-TKI and chemotherapy treatment, but that p38 inhibition enhances AML LSC response to treatment to a greater extent than CXCL12 deletion alone. This study supports a role for p38 signaling in CXCL12-mediated protection of AML LSC from treatment and provide a rationale for targeting p38 signaling to enhance Flt3-ITD AML targeting.
2024-01-03 | GSE212428 | GEO
Project description:Constitutively activating internal tandem duplication (ITD) alterations of the receptor tyrosine kinase FLT3 (Fms-like tyrosine kinase 3) are common in acute myeloid leukemia (AML) and classifies FLT3 as an attractive therapeutic target. So far, application of FLT3 small molecule inhibitors such as Sorafenib has resulted only in partial and transient clinical responses in FLT3-ITD+ patients. Only recently, a prolonged event-free survival has been observed in AML patients who were treated with Sorafenib in addition to standard therapy. Here, we studied the Sorafenib effect on proliferation in a panel of 13 FLT3-ITD- and FLT3-ITD+ AML cell lines. Sorafenib IC50 values ranged from 0.001 to 5.6 µM, whereas FLT3-ITD+ cells (MOLM-13, MV4;11) were found more sensitive to Sorafenib than FLT3-ITD- cells. However, we identified two FLT3-ITD- cell lines (MONO-MAC-1 and OCI-AML-2) which were also Sorafenib sensitive. Phosphoproteome analyses revealed that the affected pathways differed in Sorafenib sensitive FLT3-ITD- and FLT3-ITD+ cells. In MV4;11 cells Sorafenib suppressed mTOR signalling by inhibiting direct inhibition of FLT3. In MONO-MAC-1 cells Sorafenib inhibited the MEK/ERK pathway by inhibition of the RET tyrosine kinase. These data suggest that the FLT3 status in AML patients might not be the only predictive factor for a response to Sorafenib.
2017-05-02 | PXD004442 | Pride
Project description:The FLT3-ITD mutation occurs in about 30% of acute myeloid leukemia (AML) and is associated with poor prognosis. However, FLT3 inhibitors are only partially effective and prone to acquired resistance. Here, we identified Yes-associated protein 1 (YAP1) as a tumor suppressor in FLT3-ITD+ AML. YAP1 inactivation conferred FLT3-ITD+ AML cells resistance to chemo- and targeted therapy. Mass spectrometric assay revealed DNA damage repair gene poly (ADP-ribose) polymerase 1 (PARP1) might be the downstream of YAP1, and the pro-proliferative effect by YAP1 knockdown were partly reversed via PARP1 inhibitor. Importantly, histone deacetylase 10 (HDAC10) contributed to decreased YAP1 acetylation levels through histone H3 lysine 27 (H3K27) acetylation, leading to the reduced nuclear accumulation of YAP1. Selective HDAC10 inhibitor chidamide or HDAC10 knockdown activated YAP1, enhanced DNA damage and significantly attenuated FLT3-ITD+ AML cells resistance. Additionally, combination chidamide with FLT3 inhibitors or chemotherapy agents synergistically inhibited growth and increased apoptosis of FLT3-ITD+AML cell lines and acquired resistant cells from the relapse FLT3-ITD+ AML patients. These findings demonstrate that the HDAC10-YAP1-PARP1 axis maintains FLT3-ITD+ AML cells and targeting this axis might improve clinical outcomes in FLT3-ITD+ AML patients._x001F__x001F__x001F__x001F_
2022-02-09 | GSE196258 | 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: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: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:FLT3-ITD mutations are found in 30% of acute myeloid leukemia (AML) and portend a poor prognosis. Patient AML samples with FLT3-ITD express high levels of RUNX1, a transcription factor with known tumor-suppressor function. Using an inducible system, we demonstrate that RUNX1 cooperates with FLT3-ITD to trigger AML and that RUNX1 expression as well as its Tyr-phosphorylation is necessary for both initiation and maintenance of leukemogenesis. Inactivating RUNX1 in tumors released the differentiation block and downregulated genes controlling ribosome biogenesis. We identified Hhex as a direct target of RUNX1 and FLT3-ITD stimulation and confirmed high HHEX expression levels in FLT3-ITD AMLs. Importantly, HHEX could replace RUNX1 in AML induction with FLT3-ITD. These results establish and elucidate the unanticipated oncogenic function of RUNX1 in AML.
2017-01-30 | GSE81421 | GEO