Вопросы гематологии/онкологии и иммунопатологии в педиатрии. 2025; 24: 188-198
Внутренние тандемные дупликации в гене FLT3 при остром миелоидном лейкозе: механизм образования и клиническое значение
https://doi.org/10.24287/1726-1708-2025-24-1-188-198Аннотация
В настоящем обзоре показаны строение гена FLT3 и принцип работы кодируемого геном белка FLT3, детализированы молекулярные механизмы образования внутренних тандемных дупликаций в гене FLT3 (FLT3-ITD), а также представлены подробная структура и локализация тандемных повторов в гене FLT3. Кроме того, описаны современные методы диагностики FLT3-ITD: фрагментный анализ, который дает возможность оценить аллельную нагрузку, и высокопроизводительное секвенирование, позволяющее изучить характер дуплицированных фрагментов и локализацию тандемных повторов. В статье представлены данные последних работ, посвященных клиническому значению FLT3-ITD при остром миелоидном лейкозе с нормальным кариотипом и при сочетании FLT3-ITD с рекуррентными цитогенетическими аберрациями, а также изложены результаты исследований, показывающие влияние характера дуплицированных фрагментов и места вставки FLT3-ITD на показатели выживаемости. Описаны основные типы FLT3-ингибиторов, механизм их действия и клиническая эффективность. Представлены современные возможности мониторинга FLT3-ITD и его практическая значимость для прогнозирования исхода острого миелоидного лейкоза.
Список литературы
1. DiNardo C.D., Cortes J.E. Mutations in AML: prognostic and therapeutic implications. Hematology Am Soc Hematol Educ Program 2016; 2016 (1): 348–55. DOI: 10.1182/asheducation-2016.1.348
2. Papaemmanuil E., Gerstung M., Bullinger L., Gaidzik V., Paschka P., Roberts N.D., et al. Genomic Classification and Prognosis in Acute Myeloid Leukemia. N Engl J Med 2016; 374 (23): 2209–21. DOI: 10.1056/ NEJMoa1516192
3. Czogała M., Czogała W., Pawińska-Wąsikowska K., Książek T., Bukowska-Strakova K., Sikorska-Fic B., et al. Characteristics and Outcome of FLT3-ITD-Positive Pediatric Acute Myeloid Leukemia-Experience of Polish Pediatric Leukemia and Lymphoma Study Group from 2005 to 2022. Cancers (Basel) 2023; 15 (18): 4557. DOI: 10.3390/cancers15184557
4. Meshinchi S., Appelbaum F.R. Structural and functional alterations of FLT3 in acute myeloid leukemia. Clin Cancer Res 2009; 15 (13): 4263–9. DOI: 10.1158/1078-0432.CCR-081123
5. Maroc N., Rottapel R., Rosnet O., Marchetto S., Lavezzi C., Mannoni P., et al. Biochemical characterization and analysis of the transforming potential of the FLT3/FLK2 receptor tyrosine kinase. Oncogene 1993; 8 (4): 909–18.
6. Lyman S.D., James L., Zappone J., Sleath P.R., Beckmann M.P., Bird T. Characterization of the protein encoded by the flt3 (flk2) receptor-like tyrosine kinase gene. Oncogene 1993; 8 (4): 815–22.
7. Ke Y.Y., Singh V., Coumar M., Hsu Y.C., Wang W.C., Song J.-S., et al. Homology modeling of DFG-in FMS-like tyrosine kinase 3 (FLT3) and structure-based virtual screening for inhibitor identification. Sci Rep 2015; 5: 11702. DOI: 10.1038/srep11702
8. Griffith J., Black J., Faerman C., Swenson L., Wynn M., Lu F., et al. The Structural Basis for Autoinhibition of FLT3 by the Juxtamembrane Domain. Mol Cell 2004; 13 (Issue 2): 169–78. DOI: 10.1016/S1097-2765(03)00505-7
9. Lagunas-Rangel F.A., Chávez-Valencia V. FLT3-ITD and its current role in acute myeloid leukaemia. Med Oncol 2017; 34: 114. DOI: 10.1007/s12032-017-0970-x
10. Chan P.M., Ilangumaran S., La Rose J., Chakrabartty A., Rottapel R. Autoinhibition of the kit receptor tyrosine kinase by the cytosolic juxtamembrane region. Mol Cell Biol 2003; 23 (9): 3067–78.
11. Gilliland D.G., Griffin J.D. The roles of FLT3 in hematopoiesis and leukemia. Blood 2002; 100 (5): 1532–42. DOI: 10.1182/blood-2002-02-0492
12. Chia W., Savakis C., Karp R., Pelham H., Ashburner M. Mutation of the Adh gene of Drosophila melanogaster containing an internal tandem duplication. J Mol Biol 1985; 186 (4): 679–88. DOI: 10.1016/0022-2836(85)90388-2
13. Kiyoi H., Towatari M., Yokota S., Hamaguchi M., Ohno R., Saito H., Naoe T. Internal tandem duplication of the FLT3 gene is a novel modality of elongation mutation which causes constitutive activation of the product. Leukemia 1998; 12: 1333–7. DOI: 10.1038/sj.leu.2401130
14. Nakao M., Yokota S., Iwai T., Kaneko H., Horiike S., Kashima K., et al. Internal tandem duplication of the flt3 gene found in acute myeloid leukemia. Leukemia 1996; 10 (12): 1911–8.
15. Levis M., Small D. FLT3: ITDoes matter in leukemia. Leukemia 2003; 17 (9): 1738–52. DOI:10.1038/sj.leu.2403099
16. Thiede C., Steudel C., Mohr B., Schaich M., Schäkel U., Platzbecker U., et al. Analysis of FLT3-activating mutations in 979 patients with acute myelogenous leukemia: association with FAB subtypes and identification of subgroups with poor prognosis. Blood 2002; 99 (12): 4326–35. DOI: 10.1182/blood.v99.12.4326
17. Castaño-Bonilla T., Alonso-Dominguez J.M., Barragán E., Rodríguez-Veiga R., Sargas C., Gil C., et al. Prognostic significance of FLT3-ITD length in AML patients treated with intensive regimens. Sci Rep 2021; 11: 20745. DOI: 10.1038/s41598-021-00050-x
18. Kiyoi H., Ohno R., Ueda R., Saito H, Naoe T. Mechanism of constitutive activation of FLT3 with internal tandem duplication in the juxtamembrane domain. Oncogene 2002; 21: 2555–63. DOI: 10.1038/sj.onc.1205332
19. Breitenbuecher F., Schnittger S., Grundler R., Markova B., Carius B., Brecht A., et al. Identification of a novel type of ITD mutations located in nonjuxtamembrane domains of the FLT3 tyrosine kinase receptor. Blood 2009; 113 (17): 4074–7. DOI: 10.1182/blood-2007-11-125476
20. Vempati S., Reindl C., Kaza S.K., Kern R., Malamoussi T., Dugas M., et al. Arginine 595 is duplicated in patients with acute leukemias carrying internal tandem duplications of FLT3 and modulates its transforming potential. Blood 2007; 110 (2): 686–94. DOI: 10.1182/blood-2006-10-053181
21. Kayser S., Schlenk R.F., Londono M.C., Breitenbuecher F. Wittke K., Du J., et al. Insertion of FLT3 internal tandem duplication in the tyrosine kinase domain-1 is associated with resistance to chemotherapy and inferior outcome. Blood 2009; 114 (12): 2386–92. DOI: 10.1182/blood-2009-03-209999
22. Meshinchi S., Stirewalt D.L., Alonzo T.A., Boggon T.J., Gerbing R.B., Rocnik J.L., et al. Structural and numerical variation of FLT3/ITD in pediatric AML. Blood 2008; 111 (10): 4930–3. DOI: 10.1182/blood-2008-01-117770
23. Sakaguchi M., Nakajima N., Yamaguchi H., Najima Y., Shono Ka., Marumo A., et al. The sensitivity of the FLT3-ITD detection method is an important consideration when diagnosing acute myeloid leukemia. Leukemia Res Rep 2020; 13: 100198. DOI: 10.1016/j.lrr.2020.100198
24. Wang T.-Y., Yang R. ScanITD: detecting internal tandem duplication with robust variant allele frequency estimation. Gigascience 2020; 9: giaa089.
25. Döhner H., Estey E., Grimwade D., Amadori S., Appelbaum F.R., Büchner T., et al. Diagnosis and management of AML in adults: 2017 ELN recommendations from an international expert panel. Blood 2017; 129 (4): 424–47. DOI: 10.1182/blood-2016-08-733196
26. Kim Y., Lee G.D., Park J., Yoon J.H., Kim H.J., Min W.S., et al. Quantitative fragment analysis of FLT3-ITD efficiently identifying poor prognostic group with high mutant allele burden or long ITD length. Blood Cancer J 2015; 5 (8): e336. DOI: 10.1038/bcj.2015.61
27. Murphy K.M., Levis M., Hafez M.J., Geiger T., Cooper L.C., Smith B.D., et al. Detection of FLT3 internal tandem duplication and D835 mutations by a multiplex polymerase chain reaction and capillary electrophoresis assay. J Mol Diagn 2003; 5 (2): 96–102. DOI: 10.1016/s1525-1578(10)60458-8
28. Ye K., Schulz M.H., Long Q., A pweiler R., Ning Z. Pindel: a pattern growth approach to detect break points of large deletions and medium sized insertions from paired-end short reads. Bioinformatics 2009; 25 (Issue 21): 2865–71. DOI: 10.1093/bioinformatics/btp394
29. Au C.H., Wa A., Ho D.N., Chan T.L., Ma E.S.K. Clinical evaluation of panel testing by next-generation sequencing (NGS) for gene mutations in myeloid neoplasms. Diagn Pathol 2016; 11: 11.
30. Blätte T.J., Schmalbrock L.K., Skambraks S., Lux S., Cocciardi S., Dolnik A., et al. getITD for FLT3-ITDbased MRD monitoring in AML. Leukemia 2019; 33: 2535–9.
31. Tsai H.K., Brackett D.G., Szeto D., Frazier R., MacLeay A., Davineni P., et al. Targeted informatics for optimal detection, characterization, and quantification of FLT3 internal tandem duplications across multiple next-generation sequencing platforms. J Mol Diagn 2020; 22: 1162–78.
32. Abo R.P., Ducar M., Garcia E.P., Thorner A.R., Rojas-Rudilla V., Lin L., et al. BreaKmer: detection of structural variation in targeted massively parallel sequencing data using kmers. Nucleic Acids Res 2014; 43: e19.
33. Chiba K., Shiraishi Y., Nagata Y., Yoshida K., Imoto S., Ogawa S., Miyano S. Genomon ITDetector: a tool for somatic internal tandem duplication detection from cancer genome sequencing data. Bioinformatics 2014; 31: 116–8.
34. Rustagi N., Hampton O.A., Li J., Xi L., Gibbs R.A., Plon S.E., et al. ITD assembler: an algorithm for internal tandem duplication discovery from short-read sequencing data. BMC Bioinformatics 2016; 17: 188.
35. Kottaridis P.D., Gale R.E., Frew M.E., Harrison G., Langabeer S.E., Belton A.A., et al. The presence of a FLT3 internal tandem duplication in patients with acute myeloid leukemia (AML) adds important prognostic information to cytogenetic risk group and response to the first cycle of chemotherapy: analysis of 854 patients from the United Kingdom Medical Research Council AML 10 and 12 trials. Blood 2001; 98 (6): 1752–9. DOI: 10.1182/blood.v98.6.1752
36. Meshinchi S., Woods W.G., Stirewalt D.L., Sweetser D.A., Buckley J.D., Tjoa T.K., et al. Prevalence and prognostic significance of Flt3 internal tandem duplication in pediatric acute myeloid leukemia. Blood 2001; 97 (1): 89–94. DOI: https://doi.org/10.1182/blood.V97.1.89
37. Liang D.C., Shih L.Y., Hung I.J., Yang C.P., Chen S.H., Jaing T.H., et al. Clinical relevance of internal tandem duplication of the FLT3 gene in childhood acute myeloid leukemia. Cancer 2002; 94: 3292–8. DOI: 10.1002/cncr.10598
38. Kiyoi H., Naoe T., Nakano Y., Yokota S., Minami S., Miyawaki S., et al. Prognostic implication of FLT3 and N-RAS gene mutations in acute myeloid leukemia. Blood 1999; 93: 3074–80.
39. Gabbianelli M., Pelosi E., Montesoro E., Valtieri M., Luchetti L., Samoggia P., et al. Multi-level effects of flt3 ligand on human hematopoiesis: expansion of putative stem cells and proliferation of granulomonocytic progenitors/monocytic precursors. Blood 1995; 86 (5): 1661–70.
40. Herlin M.K., Yones S.A., Kjeldsen E., Holmfeldt L., Hasle H. What Is Abnormal in Normal Karyotype Acute Myeloid Leukemia in Children? Analysis of the Mutational Landscape and Prognosis of the TARGET-AML Cohort. Genes (Basel) 2021; 12 (6): 792. DOI: 10.3390/genes12060792
41. Meshinchi S., Alonzo T.A., Stirewalt D.L., Zwaan M., Zimmerman M., Reinhardt D., et al. Clinical implications of FLT3 mutations in pediatric AML. Blood 2006; 108 (12): 3654–61. DOI: 10.1182/blood-2006-03-009233
42. Wang J.W., Yu-Li, Yang X.G., Xu L.H. NUP98::NSD1 and FLT3/ITD co-expression is an independent predictor of poor prognosis in pediatric AML patients. BMC Pediatr 2024; 24 (1): 547. DOI: 10.1186/s12887-024-05007-3
43. Potluri S., Kellaway S.G., Coleman D.J.L., Keane P., Imperato M.R., Assi S.A., et al. Gene regulation in t(6;9) DEK::NUP214 Acute Myeloid Leukemia resembles that of FLT3-ITD/NPM1 Acute Myeloid Leukemia but with an altered HOX/MEIS axis. Leukemia 2024; 38 (2): 403–7. DOI: 10.1038/s41375-023-02118-1
44. Virtaneva K., Wright F.A., Tanner S.M., Yuan B., Lemon W.J., Caligiuri M.A., et al. Expression profiling reveals fundamental biological differences in acute myeloid leukemia with isolated trisomy 8 and normal cytogenetics. Proc Natl Acad Sci U S A. 2001; 98 (3): 1124–9. DOI: 10.1073/pnas.98.3.1124
45. Falini B., Brunetti L., Sportoletti P., Martelli M.P. NPM1-mutated acute myeloid leukemia: From bench to bedside. Blood 2020; 136: 1707–21. DOI: 10.1182/blood.2019004226
46. Toska E., Roberts S.G. Mechanisms of transcriptional regulation by WT1 (Wilms' tumour 1). Biochem J 2014; 461 (1): 15–32. DOI: 10.1042/BJ20131587
47. Zwaan C.M., Meshinchi S., Radich J.P., Veerman A.J., Huismans D.R., Munske L., et al. FLT3 internal tandem duplication in 234 children with acute myeloid leukemia: prognostic significance and relation to cellular drug resistance. Blood 2003; 102 (7): 2387–94. DOI: 10.1182/blood-2002-12-3627
48. Sakaguchi M., Yamaguchi H., Najima Y., Usuki K., Ueki T., Oh I., et al. Prognostic impact of low allelic ratio FLT3-ITD and NPM1 mutation in acute myeloid leukemia. Blood Adv 2018; 2 (20): 2744–54. DOI: 10.1182/bloodadvances.2018020305
49. Oran B., Cortes J., Beitinjaneh A., Chen H.C., de Lima M., Patel K., et al. Allogeneic Transplantation in First Remission Improves Outcomes Irrespective of FLT3-ITD Allelic Ratio in FLT3-ITD-Positive Acute Myelogenous Leukemia. Biol Blood Marrow Transplant 2016; 22 (7): 1218–26. DOI: 10.1016/j.bbmt.2016.03.027
50. Tarlock K., Gerbing R.B., Ries R.E., Smith J.L., Leonti A., Huang B.J., et al. Prognostic impact of cooccurring mutations in FLT3-ITD pediatric acute myeloid leukemia. Blood Adv 2024; 8 (9): 2094–103. DOI: 10.1182/bloodadvances.2023011980
51. Kayser S., Kramer M., Martínez-Cuadrón D., Grenet J., Metzeler K.H., Sustkova Z., et al. Characteristics and outcome of patients with core-binding factor acute myeloid leukemia and FLT3-ITD: results from an international collaborative study. Haematologica 2022; 107 (4): 836–43. DOI: 10.3324/haematol.2021.278645
52. Liu J., Han W., Cai X., Wang Z., Cao L., Hua H., et al. Molecular genetic and clinical characterization of acute myeloid leukemia with trisomy 8 as the sole chromosome abnormality. Hematology 2022; 27 (1): 565–74. DOI: 10.1080/16078454.2022.2071799
53. Bhatnagar B., Kohlschmidt J., Orwick S.J., Buelow D.R., Fobare S., Oakes C.C., et al. Framework of clonal mutations concurrent with WT1 mutations in adults with acute myeloid leukemia: Alliance for Clinical Trials in Oncology study. Blood Adv 2023; 7 (16): 4671–5. DOI: 10.1182/bloodad-vances.2023010482
54. Gale R.E., Green C., Allen C., Mead A.J., Burnett A.K., Hills R.K., et al. The impact of FLT3 internal tandem duplication mutant level, number, size, and interaction with NPM1 mutations in a large cohort of young adult patients with acute myeloid leukemia. Blood 2008; 111 (5): 2776–84. DOI: 10.1182/blood-2007-08-109090
55. Corley E.M., Mustafa Ali M.K., Alharthy H., Kline K.A.F., Sewell D., Law J.Y., et al. Impact of FLT3-ITD Insertion Length on Outcomes in Acute Myeloid Leukemia: A Propensity Score-Adjusted Cohort Study. Biology (Basel) 2022; 11 (6): 916. DOI: 10.3390/biology11060916
56. Fischer M., Schnetzke U., Spies-Weisshart B., Walther M., Fleischmann M., Hilgendorf I., et al. Impact of FLT3-ITD diversity on response to induction chemotherapy in patients with acute myeloid leukemia. Haematologica 2017; 102 (4): e129–31. DOI: 10.3324/haematol.2016.157180
57. Stone R.M., Mandrekar S.J., Sanford B.L., Laumann K., Geyer S., Bloomfield C.D., et al. Midostaurin plus chemotherapy for acute myeloid leukemia with a FLT3 mutation. N Engl J Med 2017; 377: 454–64. DOI: 10.1056/NEJMoa1614359
58. Weisberg E., Roesel J., Furet P., Bold G., Imbach P., Florsheimer A., et al. Antileukemic effects of novel firstand second-generation FLT3 inhibitors: structure-affinity comparison. Genes Cancer 2010; 1: 1021–32.
59. Schlenk R.F., Weber D., Fiedler W., Salih H.R., Wulf G., Salwender H., et al. Midostaurin added to chemotherapy and continued single-agent maintenance therapy in acute myeloid leukemia with FLT3-ITD. Blood 2019; 133: 840–51.
60. Altman J.K., Foran J.M., Pratz K.W., Trone D., Cortes J.E., Tallman M.S. Phase 1 study of quizartinib in combination with induction and consolidation chemotherapy in patients with newly diagnosed acute myeloid leukemia. Am J Hematol 2018; 93: 213–21.
61. Kottaridis P.D., Gale R.E., Langabeer S.E., Frew M.E., Bowen D.T., Linch D.C. Studies of FLT3 mutations in paired presentation and relapse samples from patients with acute myeloid leukemia: Implications for the role of FLT3 mutations in leukemogenesis, minimal residual disease detection, and possible therapy with FLT3 inhibitors. Blood 2002; 100: 2393–8.
62. Grob T., Sanders M.A., Vonk C.M., Kavelaars F.G., Rijken M., Hanekamp D.W., et al. Prognostic Value of FLT3-Internal Tandem Duplication Residual Disease in Acute Myeloid Leukemia. J Clin Oncol 2023; 41 (4): 756–65. DOI: 10.1200/JCO.22.00715
63. Rücker F.G., Bullinger L., Cocciardi S., Skambraks S., Luck T.J., Weber D., et. al. Measurable residual disease monitoring in AML with FLT3ITD treated with intensive chemotherapy plus midostaurin. Blood Adv 2024; 8 (23): 6067–80. DOI: 10.1182/bloodadvances.2024013758
Pediatric Hematology/Oncology and Immunopathology. 2025; 24: 188-198
FLT3 internal tandem duplications in acute myeloid leukemia: mechanism of formation and clinical significance
https://doi.org/10.24287/1726-1708-2025-24-1-188-198Abstract
This review presents the FLT3 gene structure and the working principle of the FLT3 protein coded by the gene, details the molecular mechanisms of FLT3 internal tandem duplication formation, the detailed structure and localization of tandem duplications in the FLT3 gene. Modern methods of FLT3-ITD diagnosis are described: fragment analysis, which provides an opportunity to estimate the allelic ratio, and next-generation sequencing, which allows for the study of the character of duplicated fragments and the localization of tandem duplications. This work presents the results of recent studies on the clinical significance of FLT3-ITD in acute myeloid leukemia with a normal karyotype and in the combination of FLT3-ITD with recurrent cytogenetic aberrations, as well as the results of studies showing the influence of the character of duplicated fragments and the location of FLT3-ITD insertion on survival rates. The main types of FLT3-inhibitors, their mechanism of action and clinical efficacy are described. Modern possibilities of FLT3-ITD monitoring and its practical significance for predicting the outcome of acute myeloid leukemia are presented.
References
1. DiNardo C.D., Cortes J.E. Mutations in AML: prognostic and therapeutic implications. Hematology Am Soc Hematol Educ Program 2016; 2016 (1): 348–55. DOI: 10.1182/asheducation-2016.1.348
2. Papaemmanuil E., Gerstung M., Bullinger L., Gaidzik V., Paschka P., Roberts N.D., et al. Genomic Classification and Prognosis in Acute Myeloid Leukemia. N Engl J Med 2016; 374 (23): 2209–21. DOI: 10.1056/ NEJMoa1516192
3. Czogała M., Czogała W., Pawińska-Wąsikowska K., Książek T., Bukowska-Strakova K., Sikorska-Fic B., et al. Characteristics and Outcome of FLT3-ITD-Positive Pediatric Acute Myeloid Leukemia-Experience of Polish Pediatric Leukemia and Lymphoma Study Group from 2005 to 2022. Cancers (Basel) 2023; 15 (18): 4557. DOI: 10.3390/cancers15184557
4. Meshinchi S., Appelbaum F.R. Structural and functional alterations of FLT3 in acute myeloid leukemia. Clin Cancer Res 2009; 15 (13): 4263–9. DOI: 10.1158/1078-0432.CCR-081123
5. Maroc N., Rottapel R., Rosnet O., Marchetto S., Lavezzi C., Mannoni P., et al. Biochemical characterization and analysis of the transforming potential of the FLT3/FLK2 receptor tyrosine kinase. Oncogene 1993; 8 (4): 909–18.
6. Lyman S.D., James L., Zappone J., Sleath P.R., Beckmann M.P., Bird T. Characterization of the protein encoded by the flt3 (flk2) receptor-like tyrosine kinase gene. Oncogene 1993; 8 (4): 815–22.
7. Ke Y.Y., Singh V., Coumar M., Hsu Y.C., Wang W.C., Song J.-S., et al. Homology modeling of DFG-in FMS-like tyrosine kinase 3 (FLT3) and structure-based virtual screening for inhibitor identification. Sci Rep 2015; 5: 11702. DOI: 10.1038/srep11702
8. Griffith J., Black J., Faerman C., Swenson L., Wynn M., Lu F., et al. The Structural Basis for Autoinhibition of FLT3 by the Juxtamembrane Domain. Mol Cell 2004; 13 (Issue 2): 169–78. DOI: 10.1016/S1097-2765(03)00505-7
9. Lagunas-Rangel F.A., Chávez-Valencia V. FLT3-ITD and its current role in acute myeloid leukaemia. Med Oncol 2017; 34: 114. DOI: 10.1007/s12032-017-0970-x
10. Chan P.M., Ilangumaran S., La Rose J., Chakrabartty A., Rottapel R. Autoinhibition of the kit receptor tyrosine kinase by the cytosolic juxtamembrane region. Mol Cell Biol 2003; 23 (9): 3067–78.
11. Gilliland D.G., Griffin J.D. The roles of FLT3 in hematopoiesis and leukemia. Blood 2002; 100 (5): 1532–42. DOI: 10.1182/blood-2002-02-0492
12. Chia W., Savakis C., Karp R., Pelham H., Ashburner M. Mutation of the Adh gene of Drosophila melanogaster containing an internal tandem duplication. J Mol Biol 1985; 186 (4): 679–88. DOI: 10.1016/0022-2836(85)90388-2
13. Kiyoi H., Towatari M., Yokota S., Hamaguchi M., Ohno R., Saito H., Naoe T. Internal tandem duplication of the FLT3 gene is a novel modality of elongation mutation which causes constitutive activation of the product. Leukemia 1998; 12: 1333–7. DOI: 10.1038/sj.leu.2401130
14. Nakao M., Yokota S., Iwai T., Kaneko H., Horiike S., Kashima K., et al. Internal tandem duplication of the flt3 gene found in acute myeloid leukemia. Leukemia 1996; 10 (12): 1911–8.
15. Levis M., Small D. FLT3: ITDoes matter in leukemia. Leukemia 2003; 17 (9): 1738–52. DOI:10.1038/sj.leu.2403099
16. Thiede C., Steudel C., Mohr B., Schaich M., Schäkel U., Platzbecker U., et al. Analysis of FLT3-activating mutations in 979 patients with acute myelogenous leukemia: association with FAB subtypes and identification of subgroups with poor prognosis. Blood 2002; 99 (12): 4326–35. DOI: 10.1182/blood.v99.12.4326
17. Castaño-Bonilla T., Alonso-Dominguez J.M., Barragán E., Rodríguez-Veiga R., Sargas C., Gil C., et al. Prognostic significance of FLT3-ITD length in AML patients treated with intensive regimens. Sci Rep 2021; 11: 20745. DOI: 10.1038/s41598-021-00050-x
18. Kiyoi H., Ohno R., Ueda R., Saito H, Naoe T. Mechanism of constitutive activation of FLT3 with internal tandem duplication in the juxtamembrane domain. Oncogene 2002; 21: 2555–63. DOI: 10.1038/sj.onc.1205332
19. Breitenbuecher F., Schnittger S., Grundler R., Markova B., Carius B., Brecht A., et al. Identification of a novel type of ITD mutations located in nonjuxtamembrane domains of the FLT3 tyrosine kinase receptor. Blood 2009; 113 (17): 4074–7. DOI: 10.1182/blood-2007-11-125476
20. Vempati S., Reindl C., Kaza S.K., Kern R., Malamoussi T., Dugas M., et al. Arginine 595 is duplicated in patients with acute leukemias carrying internal tandem duplications of FLT3 and modulates its transforming potential. Blood 2007; 110 (2): 686–94. DOI: 10.1182/blood-2006-10-053181
21. Kayser S., Schlenk R.F., Londono M.C., Breitenbuecher F. Wittke K., Du J., et al. Insertion of FLT3 internal tandem duplication in the tyrosine kinase domain-1 is associated with resistance to chemotherapy and inferior outcome. Blood 2009; 114 (12): 2386–92. DOI: 10.1182/blood-2009-03-209999
22. Meshinchi S., Stirewalt D.L., Alonzo T.A., Boggon T.J., Gerbing R.B., Rocnik J.L., et al. Structural and numerical variation of FLT3/ITD in pediatric AML. Blood 2008; 111 (10): 4930–3. DOI: 10.1182/blood-2008-01-117770
23. Sakaguchi M., Nakajima N., Yamaguchi H., Najima Y., Shono Ka., Marumo A., et al. The sensitivity of the FLT3-ITD detection method is an important consideration when diagnosing acute myeloid leukemia. Leukemia Res Rep 2020; 13: 100198. DOI: 10.1016/j.lrr.2020.100198
24. Wang T.-Y., Yang R. ScanITD: detecting internal tandem duplication with robust variant allele frequency estimation. Gigascience 2020; 9: giaa089.
25. Döhner H., Estey E., Grimwade D., Amadori S., Appelbaum F.R., Büchner T., et al. Diagnosis and management of AML in adults: 2017 ELN recommendations from an international expert panel. Blood 2017; 129 (4): 424–47. DOI: 10.1182/blood-2016-08-733196
26. Kim Y., Lee G.D., Park J., Yoon J.H., Kim H.J., Min W.S., et al. Quantitative fragment analysis of FLT3-ITD efficiently identifying poor prognostic group with high mutant allele burden or long ITD length. Blood Cancer J 2015; 5 (8): e336. DOI: 10.1038/bcj.2015.61
27. Murphy K.M., Levis M., Hafez M.J., Geiger T., Cooper L.C., Smith B.D., et al. Detection of FLT3 internal tandem duplication and D835 mutations by a multiplex polymerase chain reaction and capillary electrophoresis assay. J Mol Diagn 2003; 5 (2): 96–102. DOI: 10.1016/s1525-1578(10)60458-8
28. Ye K., Schulz M.H., Long Q., A pweiler R., Ning Z. Pindel: a pattern growth approach to detect break points of large deletions and medium sized insertions from paired-end short reads. Bioinformatics 2009; 25 (Issue 21): 2865–71. DOI: 10.1093/bioinformatics/btp394
29. Au C.H., Wa A., Ho D.N., Chan T.L., Ma E.S.K. Clinical evaluation of panel testing by next-generation sequencing (NGS) for gene mutations in myeloid neoplasms. Diagn Pathol 2016; 11: 11.
30. Blätte T.J., Schmalbrock L.K., Skambraks S., Lux S., Cocciardi S., Dolnik A., et al. getITD for FLT3-ITDbased MRD monitoring in AML. Leukemia 2019; 33: 2535–9.
31. Tsai H.K., Brackett D.G., Szeto D., Frazier R., MacLeay A., Davineni P., et al. Targeted informatics for optimal detection, characterization, and quantification of FLT3 internal tandem duplications across multiple next-generation sequencing platforms. J Mol Diagn 2020; 22: 1162–78.
32. Abo R.P., Ducar M., Garcia E.P., Thorner A.R., Rojas-Rudilla V., Lin L., et al. BreaKmer: detection of structural variation in targeted massively parallel sequencing data using kmers. Nucleic Acids Res 2014; 43: e19.
33. Chiba K., Shiraishi Y., Nagata Y., Yoshida K., Imoto S., Ogawa S., Miyano S. Genomon ITDetector: a tool for somatic internal tandem duplication detection from cancer genome sequencing data. Bioinformatics 2014; 31: 116–8.
34. Rustagi N., Hampton O.A., Li J., Xi L., Gibbs R.A., Plon S.E., et al. ITD assembler: an algorithm for internal tandem duplication discovery from short-read sequencing data. BMC Bioinformatics 2016; 17: 188.
35. Kottaridis P.D., Gale R.E., Frew M.E., Harrison G., Langabeer S.E., Belton A.A., et al. The presence of a FLT3 internal tandem duplication in patients with acute myeloid leukemia (AML) adds important prognostic information to cytogenetic risk group and response to the first cycle of chemotherapy: analysis of 854 patients from the United Kingdom Medical Research Council AML 10 and 12 trials. Blood 2001; 98 (6): 1752–9. DOI: 10.1182/blood.v98.6.1752
36. Meshinchi S., Woods W.G., Stirewalt D.L., Sweetser D.A., Buckley J.D., Tjoa T.K., et al. Prevalence and prognostic significance of Flt3 internal tandem duplication in pediatric acute myeloid leukemia. Blood 2001; 97 (1): 89–94. DOI: https://doi.org/10.1182/blood.V97.1.89
37. Liang D.C., Shih L.Y., Hung I.J., Yang C.P., Chen S.H., Jaing T.H., et al. Clinical relevance of internal tandem duplication of the FLT3 gene in childhood acute myeloid leukemia. Cancer 2002; 94: 3292–8. DOI: 10.1002/cncr.10598
38. Kiyoi H., Naoe T., Nakano Y., Yokota S., Minami S., Miyawaki S., et al. Prognostic implication of FLT3 and N-RAS gene mutations in acute myeloid leukemia. Blood 1999; 93: 3074–80.
39. Gabbianelli M., Pelosi E., Montesoro E., Valtieri M., Luchetti L., Samoggia P., et al. Multi-level effects of flt3 ligand on human hematopoiesis: expansion of putative stem cells and proliferation of granulomonocytic progenitors/monocytic precursors. Blood 1995; 86 (5): 1661–70.
40. Herlin M.K., Yones S.A., Kjeldsen E., Holmfeldt L., Hasle H. What Is Abnormal in Normal Karyotype Acute Myeloid Leukemia in Children? Analysis of the Mutational Landscape and Prognosis of the TARGET-AML Cohort. Genes (Basel) 2021; 12 (6): 792. DOI: 10.3390/genes12060792
41. Meshinchi S., Alonzo T.A., Stirewalt D.L., Zwaan M., Zimmerman M., Reinhardt D., et al. Clinical implications of FLT3 mutations in pediatric AML. Blood 2006; 108 (12): 3654–61. DOI: 10.1182/blood-2006-03-009233
42. Wang J.W., Yu-Li, Yang X.G., Xu L.H. NUP98::NSD1 and FLT3/ITD co-expression is an independent predictor of poor prognosis in pediatric AML patients. BMC Pediatr 2024; 24 (1): 547. DOI: 10.1186/s12887-024-05007-3
43. Potluri S., Kellaway S.G., Coleman D.J.L., Keane P., Imperato M.R., Assi S.A., et al. Gene regulation in t(6;9) DEK::NUP214 Acute Myeloid Leukemia resembles that of FLT3-ITD/NPM1 Acute Myeloid Leukemia but with an altered HOX/MEIS axis. Leukemia 2024; 38 (2): 403–7. DOI: 10.1038/s41375-023-02118-1
44. Virtaneva K., Wright F.A., Tanner S.M., Yuan B., Lemon W.J., Caligiuri M.A., et al. Expression profiling reveals fundamental biological differences in acute myeloid leukemia with isolated trisomy 8 and normal cytogenetics. Proc Natl Acad Sci U S A. 2001; 98 (3): 1124–9. DOI: 10.1073/pnas.98.3.1124
45. Falini B., Brunetti L., Sportoletti P., Martelli M.P. NPM1-mutated acute myeloid leukemia: From bench to bedside. Blood 2020; 136: 1707–21. DOI: 10.1182/blood.2019004226
46. Toska E., Roberts S.G. Mechanisms of transcriptional regulation by WT1 (Wilms' tumour 1). Biochem J 2014; 461 (1): 15–32. DOI: 10.1042/BJ20131587
47. Zwaan C.M., Meshinchi S., Radich J.P., Veerman A.J., Huismans D.R., Munske L., et al. FLT3 internal tandem duplication in 234 children with acute myeloid leukemia: prognostic significance and relation to cellular drug resistance. Blood 2003; 102 (7): 2387–94. DOI: 10.1182/blood-2002-12-3627
48. Sakaguchi M., Yamaguchi H., Najima Y., Usuki K., Ueki T., Oh I., et al. Prognostic impact of low allelic ratio FLT3-ITD and NPM1 mutation in acute myeloid leukemia. Blood Adv 2018; 2 (20): 2744–54. DOI: 10.1182/bloodadvances.2018020305
49. Oran B., Cortes J., Beitinjaneh A., Chen H.C., de Lima M., Patel K., et al. Allogeneic Transplantation in First Remission Improves Outcomes Irrespective of FLT3-ITD Allelic Ratio in FLT3-ITD-Positive Acute Myelogenous Leukemia. Biol Blood Marrow Transplant 2016; 22 (7): 1218–26. DOI: 10.1016/j.bbmt.2016.03.027
50. Tarlock K., Gerbing R.B., Ries R.E., Smith J.L., Leonti A., Huang B.J., et al. Prognostic impact of cooccurring mutations in FLT3-ITD pediatric acute myeloid leukemia. Blood Adv 2024; 8 (9): 2094–103. DOI: 10.1182/bloodadvances.2023011980
51. Kayser S., Kramer M., Martínez-Cuadrón D., Grenet J., Metzeler K.H., Sustkova Z., et al. Characteristics and outcome of patients with core-binding factor acute myeloid leukemia and FLT3-ITD: results from an international collaborative study. Haematologica 2022; 107 (4): 836–43. DOI: 10.3324/haematol.2021.278645
52. Liu J., Han W., Cai X., Wang Z., Cao L., Hua H., et al. Molecular genetic and clinical characterization of acute myeloid leukemia with trisomy 8 as the sole chromosome abnormality. Hematology 2022; 27 (1): 565–74. DOI: 10.1080/16078454.2022.2071799
53. Bhatnagar B., Kohlschmidt J., Orwick S.J., Buelow D.R., Fobare S., Oakes C.C., et al. Framework of clonal mutations concurrent with WT1 mutations in adults with acute myeloid leukemia: Alliance for Clinical Trials in Oncology study. Blood Adv 2023; 7 (16): 4671–5. DOI: 10.1182/bloodad-vances.2023010482
54. Gale R.E., Green C., Allen C., Mead A.J., Burnett A.K., Hills R.K., et al. The impact of FLT3 internal tandem duplication mutant level, number, size, and interaction with NPM1 mutations in a large cohort of young adult patients with acute myeloid leukemia. Blood 2008; 111 (5): 2776–84. DOI: 10.1182/blood-2007-08-109090
55. Corley E.M., Mustafa Ali M.K., Alharthy H., Kline K.A.F., Sewell D., Law J.Y., et al. Impact of FLT3-ITD Insertion Length on Outcomes in Acute Myeloid Leukemia: A Propensity Score-Adjusted Cohort Study. Biology (Basel) 2022; 11 (6): 916. DOI: 10.3390/biology11060916
56. Fischer M., Schnetzke U., Spies-Weisshart B., Walther M., Fleischmann M., Hilgendorf I., et al. Impact of FLT3-ITD diversity on response to induction chemotherapy in patients with acute myeloid leukemia. Haematologica 2017; 102 (4): e129–31. DOI: 10.3324/haematol.2016.157180
57. Stone R.M., Mandrekar S.J., Sanford B.L., Laumann K., Geyer S., Bloomfield C.D., et al. Midostaurin plus chemotherapy for acute myeloid leukemia with a FLT3 mutation. N Engl J Med 2017; 377: 454–64. DOI: 10.1056/NEJMoa1614359
58. Weisberg E., Roesel J., Furet P., Bold G., Imbach P., Florsheimer A., et al. Antileukemic effects of novel firstand second-generation FLT3 inhibitors: structure-affinity comparison. Genes Cancer 2010; 1: 1021–32.
59. Schlenk R.F., Weber D., Fiedler W., Salih H.R., Wulf G., Salwender H., et al. Midostaurin added to chemotherapy and continued single-agent maintenance therapy in acute myeloid leukemia with FLT3-ITD. Blood 2019; 133: 840–51.
60. Altman J.K., Foran J.M., Pratz K.W., Trone D., Cortes J.E., Tallman M.S. Phase 1 study of quizartinib in combination with induction and consolidation chemotherapy in patients with newly diagnosed acute myeloid leukemia. Am J Hematol 2018; 93: 213–21.
61. Kottaridis P.D., Gale R.E., Langabeer S.E., Frew M.E., Bowen D.T., Linch D.C. Studies of FLT3 mutations in paired presentation and relapse samples from patients with acute myeloid leukemia: Implications for the role of FLT3 mutations in leukemogenesis, minimal residual disease detection, and possible therapy with FLT3 inhibitors. Blood 2002; 100: 2393–8.
62. Grob T., Sanders M.A., Vonk C.M., Kavelaars F.G., Rijken M., Hanekamp D.W., et al. Prognostic Value of FLT3-Internal Tandem Duplication Residual Disease in Acute Myeloid Leukemia. J Clin Oncol 2023; 41 (4): 756–65. DOI: 10.1200/JCO.22.00715
63. Rücker F.G., Bullinger L., Cocciardi S., Skambraks S., Luck T.J., Weber D., et. al. Measurable residual disease monitoring in AML with FLT3ITD treated with intensive chemotherapy plus midostaurin. Blood Adv 2024; 8 (23): 6067–80. DOI: 10.1182/bloodadvances.2024013758
