Gene Summary

Gene:FLT3; fms related tyrosine kinase 3
Aliases: FLK2, STK1, CD135, FLK-2
Summary:This gene encodes a class III receptor tyrosine kinase that regulates hematopoiesis. This receptor is activated by binding of the fms-related tyrosine kinase 3 ligand to the extracellular domain, which induces homodimer formation in the plasma membrane leading to autophosphorylation of the receptor. The activated receptor kinase subsequently phosphorylates and activates multiple cytoplasmic effector molecules in pathways involved in apoptosis, proliferation, and differentiation of hematopoietic cells in bone marrow. Mutations that result in the constitutive activation of this receptor result in acute myeloid leukemia and acute lymphoblastic leukemia. [provided by RefSeq, Jan 2015]
Databases:OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:receptor-type tyrosine-protein kinase FLT3
Source:NCBIAccessed: 31 August, 2019


What does this gene/protein do?
Show (36)
Pathways:What pathways are this gene/protein implicaed in?
Show (3)

Cancer Overview

Research Indicators

Publications Per Year (1994-2019)
Graph generated 31 August 2019 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • Cell Survival
  • Niacinamide
  • Homologous Transplantat
  • FLT3
  • Phenylurea Compounds
  • Signal Transduction
  • Karyotype
  • Gene Duplication
  • Staurosporine
  • Residual Disease
  • Chromosome 13
  • DNA Mutational Analysis
  • DNA (Cytosine-5-)-Methyltransferases
  • Apoptosis
  • Drug Resistance
  • Leukaemia
  • Remission Induction
  • Cancer Gene Expression Regulation
  • High-Throughput Nucleotide Sequencing
  • Childhood Cancer
  • Bone Marrow
  • Recurrence
  • Molecular Targeted Therapy
  • DNA-Binding Proteins
  • drug, Sorafenib (Nexavar)
  • Mutation
  • Protein Kinase Inhibitors
  • Adolescents
  • Epigenetics
  • Infant
  • Antineoplastic Agents
  • Neoplasm Proteins
  • Survival Rate
  • Hematopoietic Stem Cell Transplantation
  • Biomarkers, Tumor
  • Leukemic Gene Expression Regulation
  • Genetic Predisposition
  • Disease-Free Survival
  • Cell Proliferation
  • Clinical Trials
  • Acute Myeloid Leukaemia
  • Cytarabine
Tag cloud generated 31 August, 2019 using data from PubMed, MeSH and CancerIndex

Specific Cancers (3)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: FLT3 (cancer-related)

Li Y, Lv X, Ge X, et al.
Mutational spectrum and associations with clinical features in patients with acute myeloid leukaemia based on next‑generation sequencing.
Mol Med Rep. 2019; 19(5):4147-4158 [PubMed] Free Access to Full Article Related Publications
The aim of the present study was to examine the associations between 112 acute myeloid leukaemia (AML)‑associated genes and the prognosis and clinical features of AML using bioinformatics analysis in 62 patients with AML. A total of 61 gene mutations were identified, and ≥1 mutations were detected in 96.77% of the patients. A total of 11 frequent mutations were identified, including nucleophosmin 1 (NPM1), Fms related tyrosine kinase 3 (FLT3), DNA methyltransferase 3α (DNMT3A) and Notch 2 (NOTCH2), with a mutation rate of ≥10%. The FLT3 mutation was significantly associated with the white blood cell count at the time of diagnosis, and DNMT3A was significantly associated with the French‑American‑British subtype and cytogenetics of patients with AML. The FLT3, NPM1 and DNMT3A mutations were significantly associated with a poor overall survival (OS) in patients with AML. In addition, the co‑mutation of DNMT3A‑CCAAT enhancer binding protein α (CEBPA) was observed to be significantly associated with a poor OS in patients with AML. Furthermore, the functional enrichment analysis revealed that the co‑mutations of FLT3‑NOTCH2, SETBP1‑CREBBP and DNMT3A‑CEBPA were significantly enriched in processes of 'negative regulation of cell differentiation' and 'immune system development', indicating that these mutations may serve crucial roles in the diagnosis and treatment of AML.

Bao H, Gao J, Chen YH, et al.
Rare myeloid sarcoma with KMT2A (MLL)-ELL fusion presenting as a vaginal wall mass.
Diagn Pathol. 2019; 14(1):26 [PubMed] Free Access to Full Article Related Publications
BACKGROUD: Myeloid sarcoma (MS) is a rare neoplasm of immature myeloid precursors that form tumor mass outside the bone marrow. The diagnosis of de novo MS can be challenging, particularly in patients with no prior history of hematologic malignancies or when MS involves unusual anatomic sites.
CASE PRESENTATION: The patient was a 53-year-old woman with a history of uterine fibroids and vaginal bleeding for many years who presented with a vaginal wall mass. The tumor had histologic and phenotypic features of histiocytic sarcoma, however, overlapping with a possible extramedullary MS. Using a comprehensive genomic profiling, we were able to identify recurrent chromosomal aberrations associated with MS including a rare KMT2A-ELL fusion, losses of chromosomes 1p, 9, 10, 15, 18, and gain of chromosome 1q and mutations in FLT3 and PTPN11, and achived the final diagnosis of a de novo MS. The patient received standard treatment for acute myeloid leukemia regimen with stem cell transplantation and achieved complete remission.
CONCLUSION: Our case illustrates the clinical utility of comprehensive genomic profiling in assisting the diagnosis or differential diagnosis of challenging MS or histiocytic sarcoma cases, and in providing important information in tumor biology for appropriate clinical management.

Ko YC, Hu CY, Liu ZH, et al.
Int J Mol Sci. 2019; 20(5) [PubMed] Free Access to Full Article Related Publications
Internal tandem duplication of FLT3 juxtamembrane domain (FLT3-ITD)-positive acute myeloid leukemia (AML) leads to poor clinical outcomes after chemotherapy. We aimed to establish a cytarabine-resistant line from

Cioccio J, Claxton D
Therapy of acute myeloid leukemia: therapeutic targeting of tyrosine kinases.
Expert Opin Investig Drugs. 2019; 28(4):337-349 [PubMed] Related Publications
INTRODUCTION: Tyrosine kinases (TKs) drive cell survival and proliferation in many normal and malignant cell types. TKs are frequently mutated in acute myeloid leukemia (AML) and hence are increasingly targeted. The management of AML has dramatically improved because of TKI-targeted treatment.
AREAS COVERED: This review provides a biological background for TK inhibitors (TKIs) in AML and reviews their use in the clinic. TK expression and mutation in AML are explored with a focus on TKs associated with specific AML subsets and treatment outcomes. TKIs that specifically target FLT3, c-Kit, and Jak2 are discussed. TKI targeting of specific genes mutated in individual cases and general 'untargeted' use of these agents are highlighted. Lastly, the mechanisms TKI drug resistance in AML are explored
EXPERT OPINION: The use of TKIs in the clinic is improving outcomes for many patients. An improved understanding of tyrosine kinase biology and the expanding use of TKIs are likely to dramatically improve outcomes in the coming decade. TKIs and other targeted agents could gradually supplant the use of cytotoxic chemotherapy for AML.

Benard B, Gentles AJ, Köhnke T, et al.
Data mining for mutation-specific targets in acute myeloid leukemia.
Leukemia. 2019; 33(4):826-843 [PubMed] Related Publications
Three mutation-specific targeted therapies have recently been approved by the FDA for the treatment of acute myeloid leukemia (AML): midostaurin for FLT3 mutations, enasidenib for relapsed or refractory cases with IDH2 mutations, and ivosidenib for cases with an IDH1 mutation. Together, these agents offer a mutation-directed treatment approach for up to 45% of de novo adult AML cases, a welcome deluge after a prolonged drought. At the same time, a number of computational tools have recently been developed that promise to further accelerate progress in mutation-specific therapy for AML and other cancers. Technical advances together with comprehensively annotated AML tissue banks have resulted in the availability of large and complex data sets for exploration by the end-user, including (i) microarray gene expression, (ii) exome sequencing, (iii) deep sequencing data of sub-clone heterogeneity, (iv) RNA sequencing of gene expression (bulk and single cell), (v) DNA methylation and chromatin, (vi) and germline quantitative trait loci. Yet few clinicians or experimental hematologists have the time or the training to access or analyze these repositories. This review summarizes the data sets and bioinformatic tools currently available to further the discovery of mutation-specific targets with an emphasis on web-based applications that are open, accessible, user-friendly, and do not require coding experience to navigate. We show examples of how available data can be mined to identify potential targets using synthetic lethality, drug repurposing, epigenetic sub-grouping, and proteomic networks while also highlighting strengths and limitations and the need for superior models for validation.

Daver N, Schlenk RF, Russell NH, Levis MJ
Targeting FLT3 mutations in AML: review of current knowledge and evidence.
Leukemia. 2019; 33(2):299-312 [PubMed] Free Access to Full Article Related Publications
Genomic investigations of acute myeloid leukemia (AML) have demonstrated that several genes are recurrently mutated, leading to new genomic classifications, predictive biomarkers, and new therapeutic targets. Mutations of the FMS-like tyrosine kinase 3 (FLT3) gene occur in approximately 30% of all AML cases, with the internal tandem duplication (ITD) representing the most common type of FLT3 mutation (FLT3-ITD; approximately 25% of all AML cases). FLT3-ITD is a common driver mutation that presents with a high leukemic burden and confers a poor prognosis in patients with AML. The prognostic value of a FLT3 mutation in the tyrosine kinase domain (FLT3-TKD), which has a lower incidence in AML (approximately 7-10% of all cases), is uncertain. Accumulating evidence demonstrates that FLT3 mutational status evolves throughout the disease continuum. This so-called clonal evolution, together with the identification of FLT3-ITD as a negative prognostic marker, serves to highlight the importance of FLT3-ITD testing at diagnosis and again at relapse. Earlier identification of FLT3 mutations will help provide a better understanding of the patient's disease and enable targeted treatment that may help patients achieve longer and more durable remissions. First-generation FLT3 inhibitors developed for clinical use are broad-spectrum, multikinase inhibitors; however, next-generation FLT3 inhibitors are more specific, more potent, and have fewer toxicities associated with off-target effects. Primary and secondary acquired resistance to FLT3 inhibitors remains a challenge and provides a rationale for combining FLT3 inhibitors with other therapies, both conventional and investigational. This review focuses on the pathological and prognostic role of FLT3 mutations in AML, clinical classification of the disease, recent progress with next-generation FLT3 inhibitors, and mechanisms of resistance to FLT3 inhibitors.

He X, Li W, Liang X, et al.
IGF2BP2 Overexpression Indicates Poor Survival in Patients with Acute Myelocytic Leukemia.
Cell Physiol Biochem. 2018; 51(4):1945-1956 [PubMed] Related Publications
BACKGROUND/AIMS: IGF2BP2 has been reported to serve as an oncogene in various solid cancers. However, the role of IGF2BP2 in acute myelocytic leukemia (AML) is still unknown.
METHODS: Public databases Gene Omnibus was used to evaluate the expression of IGF2BP2 in AML patients and healthy controls. In addition, primary cells from these two populations were prepared by Ficoll density centrifugation. Rt-qPCR and western blot were used to detect IGF2BP2 expression in the primary cells from these two populations. Meta-analysis was performed to evaluate the association of IGF2BP2 and prognosis. Lentivirus-based shRNAs were used to knock down IGF2BP2 in AML cell lines KG-1a and Kasumi.
RESULTS: We searched the public database Gene Omnibus and analyzed IGF2BP2 expression in both AML and healthy populations. The results showed that IGF2BP2 was overexpressed in AML patients. To verify this phenomenon in fresh human samples, we compared the expression of IGF2BP2 in primary cells from 10 AML patients and 10 healthy controls and found that the expression of IGF2BP2 was upregulated in AML primary cells. More importantly, we observed that IGF2BP2 expression was negatively correlated with the CEBPA mutation status, which is an indicator of good prognosis (RR=0.648, p=0.0001). In addition, IGF2BP2 expression was positively associated with poor prognostic factors, such as the FLT3-ITD mutation (RR=1.198, p=0.0009) and IDH1 mutation (RR=1.354, p=0.0003), as well as intermediate and poor cytogenetic risk (RR=1.214, p=0.0026). To evaluate the prognostic value of IGF2BP2 in AML, we further performed a meta-analysis of 8 studies consisting of 1731 patients and found that IGF2BP2 overexpression was correlated with worse overall survival in AML patients [HR=1.31(1.16-1.49); p = 0.00]. Furthermore, we performed Gene Omnibus and Gene Set Enrichment analyses and found that the genes regulated by IGF2BP2 were mainly enriched in cell proliferation. IGF2BP2 knockdown by 4 different shRNA vectors significantly inhibited the growth of two AML cell lines, KG-1a and Kasumi.
CONCLUSION: Thus, IGF2BP2 may serve as a biomarker to predict the prognosis of AML and as a potential target in AML.

Li X, Li C, Jin J, et al.
High PARP-1 expression predicts poor survival in acute myeloid leukemia and PARP-1 inhibitor and SAHA-bendamustine hybrid inhibitor combination treatment synergistically enhances anti-tumor effects.
EBioMedicine. 2018; 38:47-56 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: PARP-1 plays a critical role in DNA damage repair and contributes to progression of cancer. To explore the role of PARP-1 in acute myeloid leukemia (AML), we analyzed the expression of PARP-1 in AML and its relation to the clinical prognosis. Then, we investigated the efficacy and mechanism of PARP inhibitor BMN673 (Talazoparib) combined with NL101, a novel SAHA-bendamustine hybrid in vitro and in vivo.
METHODS: The expression of PARP-1 in 339 cytogenetically normal AML (CN-AML) cases was evaluated using RT-PCR. According to the expression of PARP-1, the clinical characteristics and prognosis of the patients were grouped and compared. The combination effects of BMN673 and NL101 were studied in AML cells and B-NSG mice xenograft model of MV4-11.
FINDINGS: We found patients in high PARP-1 expression group had higher levels of blast cells in bone marrow (P = .003) and white blood cells (WBC) in peripheral blood (P = .008), and were associated with a more frequent FLT3-ITD mutation (28.2% vs 17.3%, P = .031). The overall survival (OS) and event free survival (EFS) of the high expression group were significantly shorter than those in the low expression group (OS, P = .005 and EFS, P = .004). BMN673 combined with NL101 had a strong synergistic effect in treating AML. The combination significantly induced cell apoptosis and arrested cell cycle in G2/M phase. Mechanistically, BMN673 and NL101 combinatorial treatment promoted DNA damage. In vivo, the combination effectively delayed the development of AML and prolonged survival.
INTERPRETATION: High PARP-1 expression predicts poor survival in CN-AML patients. The synergistic effects of PARP inhibitor BMN673 in combination with SAHA-bendamustine hybrid, NL101, provide a new therapeutic strategy against AML. FUND: National Natural Science Foundation of China and Zhejiang Provincial Key Innovation Team.

Bejar R
What biologic factors predict for transformation to AML?
Best Pract Res Clin Haematol. 2018; 31(4):341-345 [PubMed] Related Publications
Transformation of myelodysplastic syndromes (MDS) into secondary acute myeloid leukemia (sAML) is defined by an arbitrary boundary of ≥20% bone marrow blasts but does not necessarily reflect a defined biological transition. The more obvious distinction lies between MDS patients that have an isolated bone marrow failure phenotype and those with excess blasts. Subtyping of MDS might be more accurately stratified into clonal cytopenias and oligoblastic leukemias, using the degree of dysplasia and blast percentage as risk features, respectively, rather than as diagnostic criteria. Transformation from MDS to sAML often involves clonal evolution or expansion of existing subclones that can be assessed by changes in variant allele frequencies of the somatic mutations that define them. There are a number of predictors for transformation that have been identified: these include mutations of genes in growth signaling pathways (NRAS, KRAS, PTPN11, FLT3), mutations in genes more commonly observed in AML (NPM1, WT1, IDH2), certain cytogenetic abnormalities (monosomy 7, complex karyotype, loss of 17p). Gene expression profiles that divide MDS into two major categories identify a progenitor gene signature subtype associated with a high risk of AML transformation. Assessing for these genetic abnormalities may better identify MDS patients at greatest risk of transformation.

Ando N, Furuichi Y, Kasai S, et al.
Chemosensitivity is differentially regulated by the SDF-1/CXCR4 and SDF-1/CXCR7 axes in acute lymphoblastic leukemia with MLL gene rearrangements.
Leuk Res. 2018; 75:36-44 [PubMed] Related Publications
Although recent advances in chemotherapy have markedly improved outcome of acute lymphoblastic leukemia (ALL), infantile ALL with MLL gene rearrangements (MLL+ALL) is refractory to chemotherapy. We have shown that specific cytokines FLT3 ligand and TGFβ1 both of which are produced from bone marrow stromal cells synergistically induced MLL+ALL cells into chemo-resistant quiescence, and that treatment of MLL+ALL cells with inhibitors against FLT3 and/or TGFβ1 receptor partially but significantly converts them toward chemo-sensitive. In the present study, we showed that MLL+ALL cells expressed CXCR4 and CXCR7, both receptors for the same chemokine stromal cell derived factor-1 (SDF-1), but their biological events were differentially regulated by the SDF-1/CXCR4 and SDF-1/CXCR7 axes and particularly exerted an opposite effect for determining chemo-sensitivity of MLL+ALL cells; enhancement via the SDF-1/CXCR4 axis vs. suppression via the SDF-1/CXCR7 axis. Because cytosine-arabinoside-induced apoptosis of MLL+ALL cells was inhibited by pretreatment with the CXCR4 inhibitor but rather accelerated by pretreatment with the CXCR7 inhibitor, an application of the CXCR7 inhibitor may become a good treatment option in future for MLL+ALL patients. MLL+ALL has a unique gene profile distinguishable from other types of ALL and AML, and should be investigated separately in responses to biological active agents including chemokine inhibitors.

Huang KB, Liu RY, Peng QH, et al.
EGFR mono-antibody salvage therapy for locally advanced and distant metastatic penile cancer: Clinical outcomes and genetic analysis.
Urol Oncol. 2019; 37(1):71-77 [PubMed] Related Publications
PURPOSE: There are limited therapeutic options for patients with advanced penile squamous cell carcinoma (PSCC) after chemotherapy failure. Thus, we evaluated the feasibility of salvage treatment using the epidermal growth factor receptor (EGFR) mono-antibody nimotuzumab in chemotherapy-failed PSCC patients and explored potential response or resistance biomarkers.
MATERIALS AND METHODS: Six chemotherapy-failed PSCC patients with locally advanced disease or distant metastasis were enrolled consecutively to nimotuzumab treatment. Clinical responses and side effects were evaluated, and genetic characteristics of cancer specimens were analyzed through the next-generation sequencing of hotspot regions in cancer-related genes.
RESULTS: Two of 6 patients showed partial responses, one was identified as having stable disease, while the other 3 had disease progression after nimotuzumab therapy. Side effects were all welltolerated. Genetic analysis revealed that TP53, CDKN2A, RB1, SMAD4, FLT3, and PIK3CA were the most frequently mutated genes in PSCC specimens, while altered KRAS, HRAS, EGFR, ERBB2, and FLT3 may be correlated with nimotuzumab resistance. Furthermore, 3 patients that were human papillomavirus-positive each showed clinical response or stable disease.
CONCLUSIONS: EGFR mono-antibody may be a potential modality for locally advanced PSCC patients after chemotherapy failure. Further large-scale clinical studies are needed to elucidate the role of human papillomavirus status and critical gene mutations in the clinical response to EGFR-targeted therapy.

Guo Y, Li Y, Wang FF, et al.
The combination of Nutlin-3 and Tanshinone IIA promotes synergistic cytotoxicity in acute leukemic cells expressing wild-type p53 by co-regulating MDM2-P53 and the AKT/mTOR pathway.
Int J Biochem Cell Biol. 2019; 106:8-20 [PubMed] Related Publications
P53 dysfunction has been associated with various malignant tumors, including acute leukemia. The overexpression of mouse double minute 2 (MDM2) causes the inactivation of p53 in acute leukemia. MDM2 inhibitors that activate p53 and induce apoptosis are currently being developed for potential treatment of acute leukemia. However, MDM2 inhibitors alone have limited efficacy in acute leukemia therapeutics. Combining other drugs to enhance the efficacy of MDM2 inhibitors is the thus considered as a potential treatment scheme. Here, we report that the combination of Nutlin-3 and Tanshinone IIA synergistically induces cytotoxicity, cell cycle arrest, apoptosis, and autophagic cell death, thereby imparting anti-leukemia effect in an acute leukemia cell line with wild-type p53 by effectively activating p53, inhibiting the AKT/mTOR pathway, and activating the RAF/MEK pathway. Using primary samples from acute leukemia patients, we show that the combination of Nutlin-3 plus Tanshinone IIA synergistically induces cytotoxicity by activating p53 and inhibiting the AKT/mTOR pathway. This specific combination of Nutlin-3 and Tanshinone IIA is also effective in preventing the recurrence of refractory leukemia, such as Ph+ ALL with the ABL kinase T315I mutation and AML with the FLT3-ITD mutation. Taken together, the results of this study demonstrate that the Nutlin-3 plus Tanshinone IIA combination exerts synergistic anti-leukemia effects by regulating the p53 and AKT/mTOR pathways, although further investigation is warranted. Small-molecule MDM2 antagonists plus Tanshinone IIA may thus be a promising strategy for the treatment of acute leukemia.

Staudt D, Murray HC, McLachlan T, et al.
Targeting Oncogenic Signaling in Mutant FLT3 Acute Myeloid Leukemia: The Path to Least Resistance.
Int J Mol Sci. 2018; 19(10) [PubMed] Free Access to Full Article Related Publications
The identification of recurrent driver mutations in genes encoding tyrosine kinases has resulted in the development of molecularly-targeted treatment strategies designed to improve outcomes for patients diagnosed with acute myeloid leukemia (AML). The receptor tyrosine kinase FLT3 is the most commonly mutated gene in AML, with internal tandem duplications within the juxtamembrane domain (FLT3-ITD) or missense mutations in the tyrosine kinase domain (FLT3-TKD) present in 30⁻35% of AML patients at diagnosis. An established driver mutation and marker of poor prognosis, the FLT3 tyrosine kinase has emerged as an attractive therapeutic target, and thus, encouraged the development of FLT3 tyrosine kinase inhibitors (TKIs). However, the therapeutic benefit of FLT3 inhibition, particularly as a monotherapy, frequently results in the development of treatment resistance and disease relapse. Commonly, FLT3 inhibitor resistance occurs by the emergence of secondary lesions in the

Liu SB, Qiu QC, Bao XB, et al.
Pattern and prognostic value of FLT3-ITD mutations in Chinese de novo adult acute myeloid leukemia.
Cancer Sci. 2018; 109(12):3981-3992 [PubMed] Free Access to Full Article Related Publications
FMS-like tyrosine kinase 3 (FLT3) is one of the most frequently mutated genes in hematological malignancies. FLT3 internal tandem duplication (FLT3-ITD) mutations located in juxtamembrane domain (JMD) and tyrosine kinase domain 1 (TKD1) regions account for two-thirds of all FLT3 mutations. The outcome of patients remains unsatisfactory, with low survival rates. It is not yet known whether the different mutations within the FLT3 gene are all associated with patient outcome. In addition, the cause of FLT3-ITD in-frame duplication events remains unknown. Although there are some published studies investigating the FLT3-ITD mutation and its clinical implications in Chinese acute myeloid leukemia (AML) patients, sample sizes tend to be small and detailed molecular profiles of FLT3 mutations are lacking in these studies. In our study, 227 FLT3-ITD sequences were analyzed from 227 Chinese de novo AML patients. ITD were next classified into 3 types based on molecular profiles of insertion DNA sequences: DNA complete duplication (type I), DNA partial duplication (type II) and complete random sequence (type III). From the 154 patients, we confirmed that high ITD allelic ratio (≥.5) and allogeneic stem cell transplant treatment under CR1 are independent prognostic factors. We also presented evidence that ITD integration sites in the hinge region or beta1-sheet region are an unfavorable prognostic factor in adult AML patients with FLT3-ITD mutations. These findings may help to decipher the mechanisms of FLT3-ITD in-frame duplication events and stratify patients when considering different therapeutic combinations.

Ibáñez M, Carbonell-Caballero J, Such E, et al.
The modular network structure of the mutational landscape of Acute Myeloid Leukemia.
PLoS One. 2018; 13(10):e0202926 [PubMed] Free Access to Full Article Related Publications
Acute myeloid leukemia (AML) is associated with the sequential accumulation of acquired genetic alterations. Although at diagnosis cytogenetic alterations are frequent in AML, roughly 50% of patients present an apparently normal karyotype (NK), leading to a highly heterogeneous prognosis. Due to this significant heterogeneity, it has been suggested that different molecular mechanisms may trigger the disease with diverse prognostic implications. We performed whole-exome sequencing (WES) of tumor-normal matched samples of de novo AML-NK patients lacking mutations in NPM1, CEBPA or FLT3-ITD to identify new gene mutations with potential prognostic and therapeutic relevance to patients with AML. Novel candidate-genes, together with others previously described, were targeted resequenced in an independent cohort of 100 de novo AML patients classified in the cytogenetic intermediate-risk (IR) category. A mean of 4.89 mutations per sample were detected in 73 genes, 35 of which were mutated in more than one patient. After a network enrichment analysis, we defined a single in silico model and established a set of seed-genes that may trigger leukemogenesis in patients with normal karyotype. The high heterogeneity of gene mutations observed in AML patients suggested that a specific alteration could not be as essential as the interaction of deregulated pathways.

Siekmann IK, Dierck K, Prall S, et al.
Combined inhibition of receptor tyrosine and p21-activated kinases as a therapeutic strategy in childhood ALL.
Blood Adv. 2018; 2(19):2554-2567 [PubMed] Free Access to Full Article Related Publications
Receptor tyrosine kinase (RTK)-dependent signaling has been implicated in the pathogenesis of acute lymphoblastic leukemia (ALL) of childhood. However, the RTK-dependent signaling state and its interpretation with regard to biological behavior are often elusive. To decipher signaling circuits that link RTK activity with biological output in vivo, we established patient-derived xenograft ALL (PDX-ALL) models with dependencies on fms-like tyrosine kinase 3 (FLT3) and platelet-derived growth factor receptor β (PDGFRB), which were interrogated by phosphoproteomics using iTRAQ mass spectrometry. Signaling circuits were determined by receptor type and cellular context with few generic features, among which we identified group I p21-activated kinases (PAKs) as potential therapeutic targets. Growth factor stimulation markedly increased catalytic activities of PAK1 and PAK2. RNA interference (RNAi)-mediated or pharmacological inhibition of PAKs using allosteric or adenosine triphosphate (ATP)-competitive compounds attenuated cell growth and increased apoptosis in vitro. Notably, PAK1- or PAK2-directed RNAi enhanced the antiproliferative effects of the type III RTK and protein kinase C inhibitor midostaurin. Treatment of FLT3- or PDGFRB-dependent ALLs with ATP-competitive PAK inhibitors markedly decreased catalytic activities of both PAK isoforms. In FLT3-driven ALL, this effect was augmented by coadministration of midostaurin resulting in synergistic effects on growth inhibition and apoptosis. Finally, combined treatment of

Döhner H, Dolnik A, Tang L, et al.
Cytogenetics and gene mutations influence survival in older patients with acute myeloid leukemia treated with azacitidine or conventional care.
Leukemia. 2018; 32(12):2546-2557 [PubMed] Free Access to Full Article Related Publications
Older patients with newly diagnosed acute myeloid leukemia (AML) in the phase 3 AZA-AML-001 study were evaluated at entry for cytogenetic abnormalities, and a subgroup of patients was assessed for gene mutations. Patients received azacitidine 75 mg/m

Ger M, Kaupinis A, Petrulionis M, et al.
Proteomic Identification of FLT3 and PCBP3 as Potential Prognostic Biomarkers for Pancreatic Cancer.
Anticancer Res. 2018; 38(10):5759-5765 [PubMed] Related Publications
BACKGROUND/AIM: Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest types of cancer, particularly due to its aggressive course and challenging diagnostics in early-stage disease. The aim of this study was to discover new potential prognostic and diagnostic pancreatic cancer biomarkers.
MATERIALS AND METHODS: The proteomes of 37 samples from pancreatic cancer, inflammatory or healthy pancreatic tissue derived through in-depth differential proteomic analysis were compared.
RESULTS: A set of candidate proteins as pancreatic cancer-specific diagnostic or prognostic biomarkers were identified. Survival data of patients after two-year follow-up indicated FLT3 and PCBP3 proteins as potential biomarkers for favourable pancreatic cancer prognosis. The levels of PCBP3 correlated with tumour stage and FLT3 levels, were evaluated as independent prognostic marker.
CONCLUSION: FLT3 and PCBP3 represent potential biomarkers for improved individualized pancreatic cancer prognosis. Moreover, FLT3 may play a role in future treatment selection.

Tran HV, Kiemer AK, Helms V
Copy Number Alterations in Tumor Genomes Deleting Antineoplastic Drug Targets Partially Compensated by Complementary Amplifications.
Cancer Genomics Proteomics. 2018 Sep-Oct; 15(5):365-378 [PubMed] Free Access to Full Article Related Publications
BACKGROUND/AIM: Genomic DNA copy number alterations (CNAs) are frequent in tumors and have been catalogued by The Cancer Genome Atlas project. Emergence of chemoresistance frequently renders drug therapies ineffective.
MATERIALS AND METHODS: We analyzed how CNAs recurrently found in the genomes of TCGA patients of thirty-one tumor types affect protein targets of antineoplastic (AN) agents.
RESULTS: CNA deletions more frequently affected the targets of AN agents than CNA amplifications. Interestingly, in seven tumors we observed signs of compensatory CNAs. For example, in glioblastoma multiforme, two target genes (FLT1, FLT3) of the experimental drug sorafenib were recurrently deleted, whereas another target (KDR) of sorafenib was recurrently amplified. In renal clear cell carcinoma, the target FLT1 of pazopanib, sunitinib, sorafenib, and axitinib was recurrently deleted, whereas FLT4 bound by the same drugs, was recurrently amplified.
CONCLUSION: Deletions of AN target proteins can be compensated by amplification of alternative targets.

Tien FM, Hou HA, Tsai CH, et al.
GATA2 zinc finger 1 mutations are associated with distinct clinico-biological features and outcomes different from GATA2 zinc finger 2 mutations in adult acute myeloid leukemia.
Blood Cancer J. 2018; 8(9):87 [PubMed] Free Access to Full Article Related Publications
Mutations of the GATA binding protein 2 (GATA2) gene in myeloid malignancies usually cluster in the zinc finger 1 (ZF1) and the ZF2 domains. Mutations in different locations of GATA2 may have distinct impact on clinico-biological features and outcomes in AML patients, but little is known in this aspect. In this study, we explored GATA2 mutations in 693 de novo non-M3 AML patients and identified 44 GATA2 mutations in 43 (6.2%) patients, including 31 in ZF1, 10 in ZF2, and three outside the two domains. Different from GATA2 ZF2 mutations, ZF1 mutations were closely associated with French-American-British (FAB) M1 subtype, CEBPA double mutations (CEBPA

Thol F, Gabdoulline R, Liebich A, et al.
Measurable residual disease monitoring by NGS before allogeneic hematopoietic cell transplantation in AML.
Blood. 2018; 132(16):1703-1713 [PubMed] Related Publications
Molecular measurable residual disease (MRD) assessment is not established in approximately 60% of acute myeloid leukemia (AML) patients because of the lack of suitable markers for quantitative real-time polymerase chain reaction. To overcome this limitation, we established an error-corrected next-generation sequencing (NGS) MRD approach that can be applied to any somatic gene mutation. The clinical significance of this approach was evaluated in 116 AML patients undergoing allogeneic hematopoietic cell transplantation (alloHCT) in complete morphologic remission (CR). Targeted resequencing at the time of diagnosis identified a suitable mutation in 93% of the patients, covering 24 different genes. MRD was measured in CR samples from peripheral blood or bone marrow before alloHCT and identified 12 patients with persistence of an ancestral clone (variant allele frequency [VAF] >5%). The remaining 96 patients formed the final cohort of which 45% were MRD

Manley PW, Caravatti G, Furet P, et al.
Comparison of the Kinase Profile of Midostaurin (Rydapt) with That of Its Predominant Metabolites and the Potential Relevance of Some Newly Identified Targets to Leukemia Therapy.
Biochemistry. 2018; 57(38):5576-5590 [PubMed] Related Publications
The multitargeted protein kinase inhibitor midostaurin is approved for the treatment of both newly diagnosed FLT3-mutated acute myeloid leukemia (AML) and KIT-driven advanced systemic mastocytosis. AML is a heterogeneous malignancy, and investigational drugs targeting FLT3 have shown disparate effects in patients with FLT3-mutated AML, probably as a result of their inhibiting different targets and pathways at the administered doses. However, the efficacy and side effects of drugs do not just reflect the biochemical and pharmacodynamic properties of the parent compound but are often comprised of complex cooperative effects between the properties of the parent and active metabolites. Following chronic dosing, two midostaurin metabolites attain steady-state plasma trough levels greater than that of the parent drug. In this study, we characterized these metabolites and determined their profiles as kinase inhibitors using radiometric transphosphorylation assays. Like midostaurin, the metabolites potently inhibit mutant forms of FLT3 and KIT and several additional kinases that either are directly involved in the deregulated signaling pathways or have been implicated as playing a role in AML via stromal support, such as IGF1R, LYN, PDPK1, RET, SYK, TRKA, and VEGFR2. Consequently, a complex interplay between the kinase activities of midostaurin and its metabolites is likely to contribute to the efficacy of midostaurin in AML and helps to engender the distinctive effects of the drug compared to those of other FLT3 inhibitors in this malignancy.

Minzel W, Venkatachalam A, Fink A, et al.
Small Molecules Co-targeting CKIα and the Transcriptional Kinases CDK7/9 Control AML in Preclinical Models.
Cell. 2018; 175(1):171-185.e25 [PubMed] Free Access to Full Article Related Publications
CKIα ablation induces p53 activation, and CKIα degradation underlies the therapeutic effect of lenalidomide in a pre-leukemia syndrome. Here we describe the development of CKIα inhibitors, which co-target the transcriptional kinases CDK7 and CDK9, thereby augmenting CKIα-induced p53 activation and its anti-leukemic activity. Oncogene-driving super-enhancers (SEs) are highly sensitive to CDK7/9 inhibition. We identified multiple newly gained SEs in primary mouse acute myeloid leukemia (AML) cells and demonstrate that the inhibitors abolish many SEs and preferentially suppress the transcription elongation of SE-driven oncogenes. We show that blocking CKIα together with CDK7 and/or CDK9 synergistically stabilize p53, deprive leukemia cells of survival and proliferation-maintaining SE-driven oncogenes, and induce apoptosis. Leukemia progenitors are selectively eliminated by the inhibitors, explaining their therapeutic efficacy with preserved hematopoiesis and leukemia cure potential; they eradicate leukemia in MLL-AF9 and Tet2

Valdez BC, Tang X, Li Y, et al.
Epigenetic modification enhances the cytotoxicity of busulfan and4-hydroperoxycyclophosphamide in AML cells.
Exp Hematol. 2018; 67:49-59.e1 [PubMed] Article available free on PMC after 01/11/2019 Related Publications
The combination of the DNA-alkylating agents busulfan (Bu) and cyclophosphamide is the most commonly used myeloablative pretransplantation conditioning therapy for myeloid leukemias. However, it is associated with significant nonrelapse mortality, which prohibits dose escalation to control relapse. We hypothesized that combining these two drugs with an epigenetic modifier would increase antileukemic efficacy without jeopardizing patient safety. A preclinical study was performed to determine the synergistic cytotoxicity of Bu, 4-hydroperoxycyclophosphamide (4HC), and the hypomethylating agent decitabine (DAC) in human acute myeloid leukemia (AML) cell lines. Exposure of KBM3/Bu250

Papadopoulos KP, Ben-Ami E, Patnaik A, et al.
Safety and tolerability of quizartinib, a FLT3 inhibitor, in advanced solid tumors: a phase 1 dose-escalation trial.
BMC Cancer. 2018; 18(1):790 [PubMed] Article available free on PMC after 01/11/2019 Related Publications
BACKGROUND: Quizartinib, an inhibitor of class III receptor tyrosine kinases (RTKs), is currently in phase 3 development for the treatment of acute myeloid leukemia (AML) bearing internal tandem duplications in the FLT3 gene. Aberrant RTK signaling is implicated in the pathogenesis of a variety of solid tumors, suggesting that inhibiting quizartinib-sensitive RTKs may be beneficial in precision cancer therapy.
METHODS: This was a phase 1, open-label, modified Fibonacci dose-escalation study of orally administered quizartinib in patients with advanced solid tumors whose disease progressed despite standard therapy or for which there was no available standard treatment. Patients received quizartinib dihydrochloride (henceforth referred to as quizartinib) once daily throughout a 28-day treatment cycle. The primary endpoint was evaluation of the maximum tolerated dose (MTD) of quizartinib. Secondary endpoints included preliminary evidence of antitumor activity and determination of the pharmacokinetic and pharmacodynamic parameters of quizartinib.
RESULTS: Thirteen patients were enrolled. Five patients received a starting dose of quizartinib 135 mg/day; dose-limiting toxicities (DLTs) of grade 3 pancytopenia, asymptomatic grade 3 QTc prolongation, and febrile neutropenia were observed in 1 patient each at this dose. A lower dose of quizartinib (90 mg/day [n = 8]) was administered without DLTs. The most common treatment-related treatment-emergent adverse events (AEs) were fatigue (n = 7, 54%), dysgeusia (n = 5, 38%), neutropenia (n = 3, 23%), and QTc prolongation (n = 3, 23%). Overall, all patients experienced at least 1 AE, and 4 experienced serious AEs (2 patients each in the 135-mg and 90-mg dose groups) including hematologic AEs, infections, and gastrointestinal disorders. Six patients (including 3 patients with gastrointestinal stromal tumors [GIST]) had a best response of stable disease.
CONCLUSION: The MTD of quizartinib in patients with advanced solid tumors was 90 mg/day. Overall, the safety and tolerability of quizartinib were manageable, with no unexpected AEs. Quizartinib monotherapy had limited evidence of activity in this small group of patients with advanced solid tumors.
TRIAL REGISTRATION: Clinical Trials Registration Number: NCT01049893 ; First Posted: January 15, 2010.

Zięba S, Kowalik A, Zalewski K, et al.
Somatic mutation profiling of vulvar cancer: Exploring therapeutic targets.
Gynecol Oncol. 2018; 150(3):552-561 [PubMed] Related Publications
BACKGROUND: Vulvar squamous cell carcinoma (VSCC) constitutes over 90% of vulvar cancer. Its pathogenesis can follow two different pathways; high risk human papillomavirus (hrHPV)-dependent and HPV-independent. Due to the rarity of VSCC, molecular mechanisms underlying VSCC development remain largely unknown. The study aimed to identify pathogenic mutations implicated in the two pathways of VSCC development.
METHODS: Using next generation sequencing, 81 VSCC tumors, 52 hrHPV(+) and 29 hrHPV(-), were screened for hotspot mutations in 50 genes covered by the Ion AmpliSeq Cancer Hotspot Panel v2 Kit (Thermo Fisher Scientific).
RESULTS: Mutations of TP53 (46% and 41%, of hrHPV(+) and hrHPV(-) cases respectively) and CDKN2A (p16) (25% and 21%, of hrHPV(+) and hrHPV(-) cases respectively) were the most common genetic alterations identified in VSCC tumors. Further mutations were identified in PIK3CA, FBXW7, HRAS, FGFR3, STK11, AKT1, SMAD4, FLT3, JAK3, GNAQ, and PTEN, albeit at low frequencies. Some of the identified mutations may activate the PI3K/AKT/mTOR pathway. The activation of mTOR was confirmed in the vast majority of VSCC samples by immunohistochemical staining.
CONCLUSIONS: Detecting pathogenic mutations in 13/50 genes examined at comparable frequencies in hrHPV(+) and hrHPV(-) tumors suggest that genetic mechanisms of the two routes of VSCC pathogenesis may be similar, despite being initiated from different premalignant lesions. Importantly, our data provide a rationale for new anti-VSCC therapies targeting the PI3K/AKT/mTOR pathway.

Shah K, Moharram SA, Kazi JU
Acute leukemia cells resistant to PI3K/mTOR inhibition display upregulation of P2RY14 expression.
Clin Epigenetics. 2018; 10:83 [PubMed] Article available free on PMC after 01/11/2019 Related Publications
The PI3K/mTOR pathway is the second most frequently deregulated pathway in a majority of cancers such as breast cancer, lung cancer, and melanomas as well as leukemia. Mutations in the genes coding for receptor tyrosine kinases (RTKs) and G-protein-coupled receptors (GPCRs) are quite common in all forms of acute leukemia. This can be a major cause of deregulation of the PI3K-mTOR pathway. To understand how cells display resistance to the dual PI3K/mTOR inhibitor, we used a panel of 25 acute leukemia cell lines. We observed that while a number of cell lines displayed sensitivity to the dual PI3K/mTOR pathway inhibitor PKI-587, many cells displayed substantial resistance. Cells sensitive to PKI-587 also showed aberrant activation of PI3K/mTOR pathway components such as AKT and S6K and also displayed sensitivity to a panel of various other PI3K/mTOR inhibitors. Using RNA sequencing data, we observed that expression of a G protein-coupled receptor, P2RY14, was upregulated nine-fold in cells showing resistance to the PI3K/mTOR inhibitor. P2RY14 has not been much studied in hematologic malignancies. However, this receptor seems to have a role in the localization of hematopoietic stem cells (HSCs) and in promoting regenerative capabilities following injury. We observed that acute lymphoblastic leukemia (ALL) and FLT3-ITD-positive acute myeloid leukemia (AML) patients with higher expression of P2RY14 mRNA displayed relatively poor survival compared to patients carrying lower expression of P2RY14 suggesting a role of P2RY14 in patient survival. To understand the role of this receptor in cell signaling, we used phospho-protein arrays and observed activation of distinct signaling cascades. Furthermore, array data were verified using murine pro-B cell line Ba/F3 stably transfected with P2RY14. We observed that activation of P2RY14 by its ligand, UDP-glucose, resulted in selective induction of ERK1/2 phosphorylation. Taken together, our data suggest that acute leukemia cells resistant to PI3K/mTOR inhibition display upregulation of a GPCR, P2RY14, which has a role in patient survival and also couples to the activation of ERK signaling.

Xiang Y, Zhou X
Octamer-binding transcription factor 4 correlates with complex karyotype, FLT3-ITD mutation and poorer risk stratification, and predicts unfavourable prognosis in patients with acute myeloid leukaemia.
Hematology. 2018; 23(10):721-728 [PubMed] Related Publications
Objective To investigate the correlation of octamer-binding transcription factor 4 (OCT4) expression with clinicopathological features and its predictive value for treatment response as well as survival profiles in de novo acute myeloid leukaemia (AML) patients. Method One hundred fifty-two de novo AML patients and 52 non-hematologic malignancy patients were recruited in this prospective cohort study. OCT4 expression was determined in bone marrow sample collected before treatment. Complete response (CR), event free survival (EFS) and overall survival (OS) were evaluated. Results Compared with the controls, OCT4 mRNA expression was higher in AML patients (P < .001), and higher OCT4 expression was correlated with presence of complex karyotype (CK) (P = .037), FLT3-ITD mutation (P = .012) and poorer risk stratification (P < .001) in AML patients. As to predictive value, OCT4 mRNA expression was decreased in patients achieved CR compared to non-CR patients (P = .022). Kaplan-Meier (K-M) curves showed that shorter EFS (9.0 (95% CI (7.7-10.3)) months vs. 25.0 (95% CI (17.5-32.5)) months, P < .001) and shorter OS (20.0 (95% CI (17.8-22.2) months vs. 33.0 months, P < .001) were observed in OCT4 mRNA high expression patients compared to OCT4 mRNA low expression patients. Multivariate Cox's proportional hazards regression analyses revealed that OCT4 mRNA high expression was an independent predictive factor for shorter EFS and OS in AML patients. Conclusion OCT4 correlates with presence of CK, FLT3-ITD mutation and poorer risk stratification, and it could be served as a convincing biomarker for predicting unfavourable prognosis in AML patients.

Akin DF, Oner DA, Kurekci E, Akar N
Determination of CEBPA mutations by next generation sequencing in pediatric acute leukemia.
Bratisl Lek Listy. 2018; 119(6):366-372 [PubMed] Related Publications
OBJECTIVES: The CCAAT/enhancer-binding protein-alpha (CEBPA) is lineage-specific transcription factor in the hematopoietic system. In this study, we aimed on the clinical features and the prognostic significance associated with CEBPA mutations in 30 pediatric patients with acute leukemia.
METHODS: In addition, the association between found variants and mutations of Ten-Eleven-Translocation 2 (TET2), Kirsten rat sarcoma viral oncogene homolog (KRAS), and Casitas B-cell lymphoma (CBL), FLT3 (Fms-Related Tyrosine Kinase), JAK2 (Januse Kinase-2) and Nucleophosmin 1 (NPM1) were analyzed, which are important prognostic risk factors for pediatric acute leukemia patients. The entire CEBPA coding region was screened using the NGS method.
RESULTS: CEBPA mutations were detected in 16 (53.3 %) of 30 patients. In total, ten distinct of nucleotide changes were identified in 30 patients, including 6 novel and 4 known mutations by sequencing the entire CEBPA gene. We found 6 frame shift mutations, 1 missense mutation, 3 synonymous variants. The most common mutation was the c.487del G resulting p.Glu163Ser in 5 cases. Three patients carried CEBPA double mutations.
CONCLUSION: The detected variants in this article seemed to be the first screening results of genes studied by NGS in pediatric acute leukemia patients. Our results also showed some degree of association between FLT3-ITD, TET2, KRAS, CBL and CEBPA mutations (Tab. 4, Fig. 1, Ref. 24).

Barry KC, Hsu J, Broz ML, et al.
A natural killer-dendritic cell axis defines checkpoint therapy-responsive tumor microenvironments.
Nat Med. 2018; 24(8):1178-1191 [PubMed] Article available free on PMC after 01/11/2019 Related Publications
Intratumoral stimulatory dendritic cells (SDCs) play an important role in stimulating cytotoxic T cells and driving immune responses against cancer. Understanding the mechanisms that regulate their abundance in the tumor microenvironment (TME) could unveil new therapeutic opportunities. We find that in human melanoma, SDC abundance is associated with intratumoral expression of the gene encoding the cytokine FLT3LG. FLT3LG is predominantly produced by lymphocytes, notably natural killer (NK) cells in mouse and human tumors. NK cells stably form conjugates with SDCs in the mouse TME, and genetic and cellular ablation of NK cells in mice demonstrates their importance in positively regulating SDC abundance in tumor through production of FLT3L. Although anti-PD-1 'checkpoint' immunotherapy for cancer largely targets T cells, we find that NK cell frequency correlates with protective SDCs in human cancers, with patient responsiveness to anti-PD-1 immunotherapy, and with increased overall survival. Our studies reveal that innate immune SDCs and NK cells cluster together as an excellent prognostic tool for T cell-directed immunotherapy and that these innate cells are necessary for enhanced T cell tumor responses, suggesting this axis as a target for new therapies.

Disclaimer: This site is for educational purposes only; it can not be used in diagnosis or treatment.

Cite this page: Cotterill SJ. FLT3, Cancer Genetics Web: http://www.cancer-genetics.org/FLT3.htm Accessed:

Creative Commons License
This page in Cancer Genetics Web by Simon Cotterill is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Note: content of abstracts copyright of respective publishers - seek permission where appropriate.

 [Home]    Page last revised: 31 August, 2019     Cancer Genetics Web, Established 1999