scholarly journals Class III Receptor Tyrosine Kinases in Acute Leukemia – Biological Functions and Modern Laboratory Analysis

2015 ◽  
Vol 10s3 ◽  
pp. BMI.S22433 ◽  
Author(s):  
Rimma Berenstein
Keyword(s):  
Tyrosine Kinases ◽  
Complex Disease ◽  
Receptor Tyrosine Kinases ◽  
Physiological Role ◽  
Leukemic Cells ◽  
World Health ◽  
Laboratory Diagnostics ◽  
Screening Methods ◽  
Class Iii ◽  
Short Period

Acute myeloid leukemia (AML) is a complex disease caused by deregulation of multiple signaling pathways. Mutations in class III receptor tyrosine kinases (RTKs) have been implicated in alteration of cell signals concerning the growth and differentiation of leukemic cells. Point mutations, insertions, or deletions of RTKs as well as chromosomal translocations induce constitutive activation of the receptor, leading to uncontrolled proliferation of undifferentiated myeloid blasts. Aberrations can occur in all domains of RTKs causing either the ligand-independent activation or mimicking the activated conformation. The World Health Organization recommended including RTK mutations in the AML classification since their detection in routine laboratory diagnostics is a major factor for prognostic stratification of patients. Polymerase chain reaction (PCR)–based methods are well-validated for the detection of fms-related tyrosine kinase 3 ( FLT3) mutations and can easily be applied for other RTKs. However, when methodological limitations are reached, accessory techniques can be applied. For a higher resolution and more quantitative approach compared to agarose gel electrophoresis, PCR fragments can be separated by capillary electrophoresis. Furthermore, high-resolution melting and denaturing high-pressure liquid chromatography are reliable presequencing screening methods that reduce the sample amount for Sanger sequencing. Because traditional DNA sequencing is time-consuming, next-generation sequencing (NGS) is an innovative modern possibility to analyze a high amount of samples simultaneously in a short period of time. At present, standardized procedures for NGS are not established, but when this barrier is resolved, it will provide a new platform for rapid and reliable laboratory diagnostic of RTK mutations in patients with AML. In this article, the biological and physiological role of RTK mutations in AML as well as possible laboratory methods for their detection will be reviewed.

Casitas B-lineage lymphoma mutants activate AKT to induce transformation in cooperation with class III receptor tyrosine kinases

2013 ◽  
Vol 41 (3) ◽  
pp. 271-280.e4 ◽  
Author(s):  
Harald Polzer ◽  
Hanna Janke ◽  
Diana Schmid ◽  
Wolfgang Hiddemann ◽  
Karsten Spiekermann
Keyword(s):  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Class Iii ◽  
B Lineage

Adaptor Protein Lnk Binds to JAK3 and Negatively Regulates a Mutant Activating Allele Associated with Megakaryocytic Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 5044-5044
Author(s):  
Maya Koren-Michowitz ◽  
Sigal Gery ◽  
Daniel Nowak ◽  
Phillip H Koeffler
Keyword(s):  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Conflicts Of Interest ◽  
Severe Combined Immunodeficiency ◽  
Leukemia Cell ◽  
Adaptor Protein ◽  
Sh2 Domain ◽  
Leukemic Cells ◽  
Leukemia Cell Line ◽  
Ph Domains

Abstract Abstract 5044 The adaptor protein Lnk is known to associate with hematopoietic cytokine receptors such as cKIT, MPL and PDGFR, as well as, non-receptor tyrosine kinases such as JAK2, and is considered to have an inhibitory effect on these signaling pathways. JAK3 is expressed mainly in the hematopoietic system and its absence is associated with autosomal recessive severe combined immunodeficiency (SCID). Recently, activating mutations of JAK3 were described in transient myeloproliferative disorder (TMD) and acute megakaryocytic leukemia (AMKL) in Down syndrome (DS) patients as well as adult non-DS AMKL. JAK3 mutations were also rarely described in solid tumors and B-ALL. The 50% homology between JAK3 and JAK2 has led us to study the association between Lnk and JAK3.293T cells were co-transfected with cDNAs encoding either wild-type (WT) JAK3 or JAK3 harboring an activating A572V mutation (JAK3 A572V), as well as the WT V5-tagged Lnk. Whole cell lysates were used for immunoprecipitation with either V5-tag or JAK3 antibodies. Binding of Lnk and JAK3 was detected by Western blot probed with JAK3 or V5-tag antibodies. To determine which domain of Lnk is responsible for the binding, we constructed a series of V5-tagged Lnk mutants including a mutation in the SH2 domain (R392E), deletion of the SH2 domain (del SH2) and deletion of the PH and SH2 (del SH2/PH) domains. Our results show that WT Lnk binds to WT JAK3, as well as JAK3 A572V. The R392E and del SH2 Lnk mutants retained JAK3 binding capacity while deletion of both SH2 and PH domains of Lnk abolished JAK3 binding. In order to study the biological effect of Lnk binding to JAK3, we infected CMK cells, a megakaryocytic leukemia cell line harboring JAK3 A572V, with a bicistronic retroviral MSCV-IRES-GFP (MIG) WT Lnk vector. Effect on growth was assessed in GFP positive sorted cells by cell count and colony formation in methylcellulose. CMK cells infected with MIG WT Lnk grew slower in liquid culture and had decreased clonogenic growth in soft agar culture compared to cells infected with MIG vector alone. In summary, we show for the first time that Lnk can bind to WT and mutant JAK3 and slow the growth of leukemic cells harboring an activating JAK3 mutation. Developing a small molecule mimetic of Lnk may have a therapeutic role in the treatment of hematopoietic malignancies associated with a variety of activated tyrosine kinase receptors and non-receptor tyrosine kinases including JAK3, as well as secondary signaling proteins. Disclosures No relevant conflicts of interest to declare.

The insulin receptor: structure, function, and signaling

1994 ◽  
Vol 266 (2) ◽  
pp. C319-C334 ◽  
Author(s):  
J. Lee ◽  
P. F. Pilch
Keyword(s):  
Insulin Receptor ◽  
Tyrosine Kinases ◽  
Intracellular Signaling ◽  
Metabolic Regulation ◽  
Receptor Tyrosine Kinases ◽  
Physiological Role ◽  
Biochemical Properties ◽  
Therapeutic Interventions ◽  
Intracellular Signaling Pathway ◽  
Effector Molecules

The insulin receptor is a member of the ligand-activated receptor and tyrosine kinase family of transmembrane signaling proteins that collectively are fundamentally important regulators of cell differentiation, growth, and metabolism. The insulin receptor has a number of unique physiological and biochemical properties that distinguish it from other members of this large well-studied receptor family. The main physiological role of the insulin receptor appears to be metabolic regulation, whereas all other receptor tyrosine kinases are engaged in regulating cell growth and/or differentiation. Receptor tyrosine kinases are allosterically regulated by their cognate ligands and function as dimers. In all cases but the insulin receptor (and 2 closely related receptors), these dimers are noncovalent, but insulin receptors are covalently maintained as functional dimers by disulfide bonds. The initial response to the ligand is receptor autophosphorylation for all receptor tyrosine kinases. In most cases, this results in receptor association of effector molecules that have unique recognition domains for phosphotyrosine residues and whose binding to these results in a biological response. For the insulin receptor, this does not occur; rather, it phosphorylates a large substrate protein that, in turn, engages effector molecules. Possible reasons for these differences are discussed in this review. The chemistry of insulin is very well characterized because of possible therapeutic interventions in diabetes using insulin derivatives. This has allowed the synthesis of many insulin derivatives, and we review our recent exploitation of one such derivative to understand the biochemistry of the interaction of this ligand with the receptor and to dissect the complicated steps of ligand-induced insulin receptor autophosphorylation. We note possible future directions in the study of the insulin receptor and its intracellular signaling pathway(s).

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