Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023467 (acute myeloid leukemia)
 35,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hematopoiesis is highly regulated through cytokine-induced stimulation of multiple signal transduction pathways in order to mediate appropriate differentiation and proliferation of specific progenitor populations. Ligand-induced stimulation of the FMS-like tyrosine kinase 3 (FLT3) leads to activation of multiple downstream effector pathways resulting in differentiation and proliferation of specific progenitor cell populations. Genomic alterations of the FLT3 gene, including FLT3 internal tandem duplication (FLT3/ITD) and FLT3 activation loop mutation (FLT3/ALM) lead to autonomous receptor activation, dysregulation of FLT3 signal transduction pathways, contribute to myeloid pathogenesis, and have been linked to response to therapy and clinical outcome. Exploring the mechanisms by which these FLT3 alterations lead to dysregulated proliferation should provide a better understanding of the molecular pathogenesis of acute myeloid leukemia (AML) and may provide insights into potential therapeutic interventions. FLT3 inhibitors are under evaluation for their efficacy in AML patients with FLT3 mutations.
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PMID:Structural and functional alterations of FLT3 in acute myeloid leukemia. 1954 78

Mutations in the fms-like tyrosine kinase 3 (FLT3) gene (internal tandem duplication (ITD) and point mutation in the tyrosine kinase domain, FLT3/D835) as well as the nucleophosmin (NPM1) gene are the most common abnormalities in adult acute myeloid leukemia (AML). Their significance in pediatric AML is still unclear. In this study we evaluated the frequency of FLT3 and NPM1 mutations in childhood AML. We also examined clinical features and outcome of these patients. FLT3 and NPM1 mutations were analysed in 42 and 37 childhood AML patients, respectively, using polymerase chain reaction (PCR) and direct sequencing. FLT3 mutations were detected in 4/42 patients (9.5%). The frequencies of FLT3/ITD and FLT3/D835 were the same, 2/42 (4.7%). NMP1 mutations were found in 1/37 patients (2.7%). FLT3 gene mutations were correlated with induction failure. Here we report the results of the study of FLT3 and NPM1 gene mutations in childhood AML patients in Serbia. Low frequencies of these molecular markers point out that these abnormalities are rare in this cohort of patients. Comparative study of data on NPM1 mutations in childhood AML revealed that various NPM1 gene mutation types are associated with childhood AML. Our findings as well as previously reported data, contributes to a hypothesis of different biology and etiology of adult and childhood AML. More extensive studies of NPM1 and FLT3 mutations in childhood AML are needed to determine their biological and clinical importance.
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PMID:Incidence of FLT3 and nucleophosmin gene mutations in childhood acute myeloid leukemia: Serbian experience and the review of the literature. 1955 52

Mutational analysis of C-KIT, fms-like tyrosine kinase 3 (FLT3), and JAK2 genes was performed in 60 patients with core binding factor acute myeloid leukemia (CBF-AML). Patients reaching molecular remission had lower incidence of relapse and better overall survival (OS) than those not achieving molecular remission (p = 0.008 and 0.044, respectively). The overall incidence of C-KIT mutations was 33.3%, FLT3/internal tandem duplication (ITD) 6.6%, FLT3(D835) 10.0% and JAK2(V617F) mutations 3.3%. C-KIT mutations did not predict for clinical/molecular relapse (p = 0.33). OS of patients with C-KIT mutations was identical to patients without them when all patients with CBF-AML were analyzed together (p = 0.58). When AML1/ETO-positive patients were evaluated separately, OS in C-KIT-mutated patients was slightly inferior to unmutated ones (p = 0.14). Patients with CBF-AML with a mutated C-KIT gene were also more prone to extramedullary disease (p = 0.08). Of six patients harboring various FLT3(D835) mutations, four (66.7%) relapsed, whereas among 43 cases without these mutations, 16 relapses (37%) were observed (p = 0.08). Our results on minimal residual disease, C-KIT, and FLT3/ITDs are in line with previous studies. Surprisingly, a possible role for FLT3(D835) mutations was noted in addition. These results need validation in even larger patient cohorts than ours. For routine clinical practice, it may be meaningful to screen for C-KIT mutations in AML1/ETO-positive patients, as well as for FLT3(D835) mutations in CBF-AML.
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PMID:Monitoring of minimal residual disease in patients with core binding factor acute myeloid leukemia and the impact of C-KIT, FLT3, and JAK2 mutations on clinical outcome. 1967 79

This study was aimed to investigate the status of c-KIT, Fms-like tyrosine kinase 3 (FLT3) and Janus kinase 2 (JAK2) mutations in acute myeloid leukemia (AML) patients with t (8; 21) and to analyze their relation to clinical feature and prognosis. PCR, AS-PCR, restriction and sequencing methods were used respectively to detect the FLT3, JAK 2 and c-KIT mutations in 8 cases of de novo AML with t (8; 21) and 6 cases of relapsed AML with t (8; 21). The results showed that the c-KIT mutation was found in 2 cases out of 14 AML patients with t (8; 21) (14.3%), among them 1 case had c-KIT D816V mutation, the other had c-KIT D816Y mutation. The FLT3-ITD mutation was detect in 1 out of 14 patients (7.1%), but JAK2 mutation could not be detected in all 14 cases. In conclusion, tyrosine kinase mutation relates to AML with t (8; 21), patients with tyrosine kinase mutation may have higher relapse, extramedullary infiltration and poor prognosis. The screening c-KIT, FLT3 mutations may play an important role in evaluating prognosis and guiding treatment of t (8; 21) AML.
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PMID:[Tyrosine kinase mutation and acute myeloid leukemia with T (8; 21)]. 1969 18

This study was aimed to investigate the frequency of FMS-like tyrosine kinase 3 (FLT3) mutations including internal tandem duplication (ITD) mutation of juxtamembrane region and point mutation of the second tyrosine kinase domain (TKD) in acute myeloid leukemia (AML) patients and its clinical significance. The ITD mutation in FLT3 exon 14, 15 of bone marrow mononuclear cells was detected by genomic DNA-PCR, the TKD point mutation in FLT3 exon 20 was detected by genomic DNA-PCR combined with restriction endonuclease digest. The results indicated that among 131 newly diagnosed AML patients, 21 patients (16.0%) showed FLT3-ITD positive, 3 patients (2.3%) showed FLT3-TKD positive. None was found harboring both mutations. The WBC and bone marrow blast counts in FLT3-ITD positive patients seemed both higher than those in patients with wild-type FLT3 (FLT3-wt), but there was significant difference only in WBC count (p<0.05). The complete remission (CR) rate in FLT3-ITD positive patients was 47.6%, which was significantly lower than that in FLT3-wt patients (88.1%, p<0.05). There was no statistical difference in CR rate between FLT3-ITD positive and negative patients in 20 cases of M3; the CR rate in FLT3-ITD positive patients with non M(3) was 37.5 (6/16) which was obviously lower than that in FLT3-wt patients with non M3 (90.6%, 48/53) (p<0.05). 3 FLT3-ITD positive patients with CR relapsed after CR for 14 (2-20) months with relapse rate 50% (3/6) which was higher than that in FLT3-wt patients (29.2%, 14/48). It is concluded that FLT3 mutation is common in AML patients, while FLT3-ITD mutation is more frequent than FLT3-TKD mutation. The AML patients with FLT3-ITD mutation have a poor prognosis, while FLT3-TKD point mutation does not significantly influences prognosis of the patients. Therefore early detection of FLT3 mutation may be important for targeting therapy and evaluating clinical prognosis of AML patients.
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PMID:[FMS-like tyrosine kinase 3 gene mutations in acute myeloid leukemia]. 1984 Apr 37

Mutation of the FMS-like tyrosine kinase 3 (FLT3) gene in Indian population remains unclear till date. Here, we found FLT3-ITD mutations in 19.1%, FLT3-Asp835 mutations in 4.7%, and dual mutations in 4.2%, accounting for overall mutation in 28% of acute myeloid leukemia (AML) patients. FLT3 mutation was more prevalent in APL than non-APL patients (32.2% vs 26.3%), adults tend to show higher incidence than children (30.6% vs 18.2%, p = .1), and were significantly associated with normal karyotype, high WBCs, with no specific distribution in FAB subtypes. Notably, FLT3 mutation was present in 50% of patients with NPM1-Mt, when compared to only 22.6% of patients with NPM1-wt (p < .001). Sequence analyses of internal tandem duplications (ITDs) revealed that duplications were mostly restricted to JM domain (3 to 165 nucleotides). Interestingly, 92.3% cases showed duplication of at least one amino acid (AA) within the stretch Y589 to K602 that includes the two SH2-binding motifs. Analysis of frequency of single AA in the duplicated region revealed that E598 was the most frequently duplicated single AA in 72%, followed by R595 (69.2%), and Y599 (66.7%). Finally, three types of point mutations were identified, including D835Y, D835H, and D835A.
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PMID:Analysis of FLT3-ITD and FLT3-Asp835 mutations in de novo acute myeloid leukemia: evaluation of incidence, distribution pattern, correlation with cytogenetics and characterization of internal tandem duplication from Indian population. 1999 25

Mutations of the Fms-like tyrosine kinase 3 (FLT3) can be detected in a significant number of acute myeloid leukemias (AML). Seventy-five cases of acute myeloid leukemia were evaluated for FLT3-internal tandem duplications (ITD) by polymerase chain reaction. Paraffin-embedded formalin-fixed trephine biopsies of these cases were evaluated for expression of phosphorylated signal transducer and activator of transcription 1 (pSTAT1), pSTAT3, and pSTAT5. Specific expression of pSTAT5 was proven in leukemic blasts in situ by double staining with a blast-specific marker. Expression of pSTAT5 in > or =1% of blasts was highly predictive of FLT3-ITD. Neither expression of pSTAT1 nor pSTAT3 were associated with FLT3 mutations. Altogether we conclude that pSTAT5 expression can precisely be assessed by immunohistochemistry in routinely processed bone marrow trephines, STAT5 is highly likely the preferred second messenger of FLT3-mediated signaling in AML, and expression of pSTAT5 is predictive of FLT3-ITD.
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PMID:Expression of pSTAT5 predicts FLT3 internal tandem duplications in acute myeloid leukemia. 2006 33

NEDD8 activating enzyme (NAE) has been identified as an essential regulator of the NEDD8 conjugation pathway, which controls the degradation of many proteins with important roles in cell-cycle progression, DNA damage, and stress responses. Here we report that MLN4924, a novel inhibitor of NAE, has potent activity in acute myeloid leukemia (AML) models. MLN4924 induced cell death in AML cell lines and primary patient specimens independent of Fms-like tyrosine kinase 3 expression and stromal-mediated survival signaling and led to the stabilization of key NAE targets, inhibition of nuclear factor-kappaB activity, DNA damage, and reactive oxygen species generation. Disruption of cellular redox status was shown to be a key event in MLN4924-induced apoptosis. Administration of MLN4924 to mice bearing AML xenografts led to stable disease regression and inhibition of NEDDylated cullins. Our findings indicate that MLN4924 is a highly promising novel agent that has advanced into clinical trials for the treatment of AML.
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PMID:Inhibition of NEDD8-activating enzyme: a novel approach for the treatment of acute myeloid leukemia. 2020 61

Mice deficient in c-fms-like tyrosine kinase 3 (FLT3) signaling have reductions in early multipotent and lymphoid progenitors, whereas no evident myeloid phenotype has been reported. However, activating mutations of Flt3 are among the most common genetic events in acute myeloid leukemia and mice harboring internal tandem duplications within Flt3 (Flt3-ITD) develop myeloproliferative disease, with characteristic expansion of granulocyte-monocyte (GM) progenitors (GMP), possibly compatible with FLT3-ITD promoting a myeloid fate of multipotent progenitors. Alternatively, FLT3 might be expressed at the earliest stages of GM development. Herein, we investigated the expression, function, and role of FLT3 in recently identified early GMPs. Flt3-cre fate-mapping established that most progenitors and mature progeny of the GM lineage are derived from Flt3-expressing progenitors. A higher expression of FLT3 was found in preGMP compared with GMP, and preGMPs were more responsive to stimulation with FLT3 ligand (FL). Whereas preGMPs and GMPs were reduced in Fl(-/-) mice, megakaryocyte-erythroid progenitors were unaffected and lacked FLT3 expression. Notably, mice deficient in both thrombopoietin (THPO) and FL had a more pronounced GMP phenotype than Thpo(-/-) mice, establishing a role of FL in THPO-dependent and -independent regulation of GMPs, of likely significance for myeloid malignancies with Flt3-ITD mutations.
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PMID:Expression and role of FLT3 in regulation of the earliest stage of normal granulocyte-monocyte progenitor development. 2039 30

The class III receptor tyrosine kinase FMS-like tyrosine kinase 3 (FLT3) regulates normal hematopoiesis and immunological functions. Nonetheless, constitutively active mutant FLT3 (FLT3-ITD) causally contributes to transformation and is associated with poor prognosis of acute myeloid leukemia (AML) patients. Histone deacetylase inhibitors (HDACi) can counteract deregulated gene expression profiles and decrease oncoprotein stability, which renders them candidate drugs for AML treatment. However, these drugs have pleiotropic effects and it is often unclear how they correct oncogenic transcriptomes and proteomes. We report here that treatment of AML cells with the HDACi LBH589 induces the ubiquitin-conjugating enzyme UBCH8 and degradation of FLT3-ITD. Gain- and loss-of-function approaches show that UBCH8 and the ubiquitin-ligase SIAH1 physically interact with and target FLT3-ITD for proteasomal degradation. These ubiquitinylating enzymes though have a significantly lesser effect on wild-type FLT3. Furthermore, physiological and pharmacological stimulation of FLT3 phosphorylation, inhibition of FLT3-ITD autophosphorylation and analysis of kinase-inactive FLT3-ITD revealed that tyrosine phosphorylation determines degradation of FLT3 and FLT3-ITD by the proteasome. These results provide novel insights into antileukemic activities of HDACi and position UBCH8, which have been implicated primarily in processes in the nucleus, as a previously unrecognized important modulator of FLT3-ITD stability and leukemic cell survival.
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PMID:Ubiquitin conjugase UBCH8 targets active FMS-like tyrosine kinase 3 for proteasomal degradation. 2050 17


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