Faculty Opinions recommendation of Deletion of the protein tyrosine phosphatase gene PTPN2 in T-cell acute lymphoblastic leukemia.

2010 ◽  
Author(s):  
Michel L Tremblay
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Protein Tyrosine Phosphatase ◽  
Lymphoblastic Leukemia ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine ◽  
Cell Acute Lymphoblastic Leukemia

scholarly journals The Role of Protein Tyrosine Phosphatase PTP4A3 in T-Cell Acute Lymphoblastic Leukemia Progression

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2539-2539
Author(s):  
Min Wei ◽  
Jessica Blackburn
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
T Cell Activation ◽  
Protein Tyrosine Phosphatase ◽  
Conflicts Of Interest ◽  
Lymphoblastic Leukemia ◽  
Tyrosine Phosphatase ◽  
Causative Role ◽  
Protein Tyrosine ◽  
Cell Acute Lymphoblastic Leukemia

The tyrosine protein tyrosine phosphatase PTP4A3 has been extensively reported to play a causative role in numerous cancers, including several types of acute leukemia. We found PTP4A3 to be highly expressed in T-cell Acute Lymphoblastic Leukemia samples, and show that PTP4A3 accelerates T-ALL onset and increases the invasive ability of T-ALL cells in a zebrafish model, and is required for T-ALL engraftment and progression in mouse xenograft. Our in vitro studies showed that PTP43A3 enhances T-ALL migration, in part via modulation of SRC signaling. However, whether SRC is a direct substrate of PTP4A3, and whether the phosphatase activity of PTP4A3 actually plays a role in T-ALL or other types of leukemia progression is unknown and remains a major question in the field. We used a BioID-based proximity labeling approach combined with PTP4A3 substrate trapping mutant pull down assay to capture the PTP4A3 substrates candidates. BioID, a biotin ligase, was fused to PTP4A3 to generate a Biotin-PTP4A3 (BP) fusion protein. The overexpression of BP in T-ALL cell lines led to biotin modification of 288 PTP4A3 proximal proteins, including the potential direct PTP4A3 substrates. PANTHER pathway analysis showed that PTP4A3 interacting proteins are largely clustered in the T-cell activation, PDGF signaling, and angiogenesis. We are in process of validating potential substrates using immunoprecipitation and phosphoenrichement assays. Finally, we are using a novel zebrafish Myc+PTP4A3 induced T-ALL model to assess the function of PTP4A3 in leukemia progression. We have created several PTP4A3 protein mutants, including a phosphatase-dead mutant, a mutant unable to bind magnesium transporter, and a prenylation deficient mutant, and are in process of assessing the effects of these mutants in T-ALL onset and progression in our in vivo model. In total, these studies will allow us to better understand function of PTP4A3 in T-ALL progression, and may provide a strong rationale for the development of PTP4A3 inhibitors for use in leukemia. Disclosures No relevant conflicts of interest to declare.

scholarly journals Deletion of the protein tyrosine phosphatase gene PTPN2 in T-cell acute lymphoblastic leukemia

2010 ◽  
Vol 42 (6) ◽  
pp. 530-535 ◽  
Author(s):  
Maria Kleppe ◽  
Idoya Lahortiga ◽  
Tiama El Chaar ◽  
Kim De Keersmaecker ◽  
Nicole Mentens ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Protein Tyrosine Phosphatase ◽  
Lymphoblastic Leukemia ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine ◽  
Cell Acute Lymphoblastic Leukemia

scholarly journals Protein Tyrosine Phosphatase 4A3 (PTP4A3) modulates Src signaling in T-cell Acute Lymphoblastic Leukemia to promote leukemia migration and progression

2019 ◽  
Author(s):  
M Wei ◽  
MG Haney ◽  
JS Blackburn
Keyword(s):  
Cell Migration ◽  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Small Molecule ◽  
Protein Tyrosine Phosphatase ◽  
Lymphoblastic Leukemia ◽  
Tyrosine Phosphatase ◽  
Knock Down ◽  
Src Signaling ◽  
Cell Acute Lymphoblastic Leukemia

AbstractT-cell Acute Lymphoblastic Leukemia (T-ALL) is an aggressive blood cancer, and currently, there are no immunotherapies or molecularly targeted therapeutics available for treatment of this malignancy. The identification and characterization of genes and pathways that drive T-ALL progression is critical for development of new therapies for T-ALL. Here, we determined that Protein Tyrosine Phosphatase 4A3 (PTP4A3) plays a critical role in disease initiation and progression by promoting cell migration in T-ALL. PTP4A3 expression was upregulated in patient T-ALL samples at both the mRNA and protein levels compared to normal lymphocytes. Inhibition of PTP4A3 function with a small molecule inhibitor and knock-down of PTP4A3 expression using short-hairpin RNA (shRNA) in human T-ALL cells significantly impeded T-ALL cell migration capacityin vitroand reduced their ability to engraft and proliferatein vivoin xenograft mouse models. Additionally, PTP4A3 overexpression in aMyc-induced zebrafish T-ALL model significantly accelerated disease onset and shortened the time needed for cells to enter blood circulation. Reverse phase protein array (RPPA) revealed that manipulation of PTP4A3 expression levels in T-ALL cells directly affected the SRC signaling pathway, which plays a well-characterized role in migratory behavior of several cell types. Taken together, our study revealed that PTP4A3 is a key regulator of T-ALL migration via SRC signaling, and suggests that PTP4A3 plays an important role as an oncogenic driver in T-ALL.HighlightsA subset of T-cell Acute Lymphoblastic Leukemia (T-ALL) highly express the phosphatase PTP4A3PTP4A3 expression promotes leukemia development in zebrafish T-ALL modelsLoss of PTP4A3 prevents T-ALL engraftment in mouse xenograft modelsKnock-down or small molecule inhibition of PTP4A3 prevents T-ALL migration in part via modulation of SRC signaling.

Deletion of the Protein Tyrosine Phosphatase Gene PTPN2 in T-Cell Acute Lymphoblastic Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 141-141
Author(s):  
Maria Kleppe ◽  
Idoya Lahortiga ◽  
Tiama El Chaar ◽  
Kim De Keersmaecker ◽  
Nicole Mentens ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Lines ◽  
Protein Tyrosine Phosphatase ◽  
Lymphoblastic Leukemia ◽  
Tyrosine Phosphatase ◽  
Janus Kinase ◽  
Negative Regulator ◽  
Aberrant Expression ◽  
Protein Tyrosine ◽  
Knock Down

Abstract Abstract 141 Introduction: T-cell lymphoblastic leukemia (T-ALL) arises from clonal expansion of a lymphoid progenitor that has undergone stepwise alteration at distinct stages of differentiation. It is suggested that a set of cooperative mutations that affect different pathways are required before thymocytes become fully malignant. Despite major improvements in our understanding of the molecular genetics of T-ALL, the underlying mechanisms that lead to the abnormal proliferation and enhanced survival of the leukemic cells remain largely unknown. Results: Array CGH analysis revealed an acquired homozygous microdeletion at chromosome 18p11 in 6 % of T-ALL cases. The deleted region was only 125 kb in size and restricted to the PTPN2 (protein tyrosine phosphatase, non-receptor type 2) locus. PTPN2 encodes an intracellular non-transmembrane tyrosine-specific phosphatase that functions as a negative regulator of a variety of signaling proteins including several members of the janus kinase (JAK) and of signal transducer and activator of transcription (STAT) families, growth factor receptors and SRC family kinases. Homozygous deletion of PTPN2 was specifically found in cases with aberrant expression of the TLX1 transcription factor, with two cases also harboring the NUP214-ABL1 fusion. Analysis of additional TLX1 positive cases by quantitative PCR identified loss of one copy of PTPN2 in 5 out of 20 cases. No mutations were detected in the coding region of PTPN2. To determine the effect of loss of PTPN2 in T-cells, we downregulated the expression of PTPN2 using RNAi technology. siRNA mediated knock-down of PTPN2 affected activation of JAK1 associated cytokine receptors implicated in T-cell development. Ligand stimulation of IL7 and interferon gamma receptor resulted in an augmented and prolonged phosphorylation of JAK1 as well as downstream targets STAT1 and STAT5 in T-ALL cell lines with knock-down of PTPN2. In addition, knock- down of Ptpn2 sensitized the pro B-cell line Ba/F3 to transformation by wild type JAK1 confirming a clear relationship between loss of PTPN2 and JAK1 activation. Knock-down of PTPN2 expression also provided a proliferative advantage and reduced sensitivity to kinase inhibitors in lymphoblastic leukemia cell lines HSB-2 and ALL-SIL. Conclusion: In conclusion, our data provide genetic and functional evidence for a tumor suppressor role of PTPN2 in T-ALL and warrant testing of JAK inhibitors for the treatment of this specific subset of T-ALLs as well as further analysis of a potential negative impact of loss of PTPN2 on responsiveness to anti-cancer treatments. Disclosures: Ferrando: Merck, Pfizer: Research Funding.

The Landscape of Protein Tyrosine Phosphatase (Shp2) and Cancer

2019 ◽  
Vol 24 (32) ◽  
pp. 3767-3777 ◽  
Author(s):  
Ashfaq Ur Rehman ◽  
Mueed Ur Rahman ◽  
Muhammad T. Khan ◽  
Shah Saud ◽  
Hao Liu ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Lymphoblastic Leukemia ◽  
Tyrosine Phosphatase ◽  
Allosteric Regulation ◽  
Sh2 Domain ◽  
Ptpn11 Gene ◽  
Cancer Disease ◽  
Protein Tyrosine ◽  
Extracellular Stimuli ◽  
Cell Acute Lymphoblastic Leukemia

Role of Shp2: The dysregulation of cell signaling cascades associated with the cell differentiation and growth, due to the deletion, insertion or point mutation in specific amino acids which alters the intrinsic conformation of the protein, can ultimately lead to a fatal cancer disease. The protein tyrosine phosphatase has been recognized as a key regulator of extracellular stimuli such as cytokine receptor and receptor tyrosine kinase signaling. In the last era, the PTPN11 gene (encode a Shp2 protein) and its association with acute myeloid, juvenile myelomonocytic, and B-cell acute lymphoblastic leukemia, Noonan syndrome, and myelodysplastic have been recognized as the cause of such deadly disease due to the occurrence of germline mutations in the interface of PTP and SH2 domain. Conclusion: The current study was designed to focus on the allosteric regulation (autoinhibition) of the of Shp2 protein. Subsequently, it will cover the last 10-year recap of Shp2 protein, their role in cancer, and regulation in numerous ways (allosteric regulation).

scholarly journals Mutation of the receptor tyrosine phosphatase PTPRC (CD45) in T-cell acute lymphoblastic leukemia

Blood ◽  
2012 ◽  
Vol 119 (19) ◽  
pp. 4476-4479 ◽  
Author(s):  
Michaël Porcu ◽  
Maria Kleppe ◽  
Valentina Gianfelici ◽  
Ellen Geerdens ◽  
Kim De Keersmaecker ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Lymphoblastic Leukemia ◽  
Tyrosine Phosphatase ◽  
Cell Receptor ◽  
Loss Of Function ◽  
Down Regulation ◽  
Activating Mutations ◽  
Cell Acute Lymphoblastic Leukemia ◽  
Cytokine Stimulation

Abstract The protein tyrosine phosphatase CD45, encoded by the PTPRC gene, is well known as a regulator of B- and T-cell receptor signaling. In addition, CD45 negatively regulates JAK family kinases downstream of cytokine receptors. Here, we report the presence of CD45 inactivating mutations in T-cell acute lymphoblastic leukemia. Loss-of-function mutations of CD45 were detected in combination with activating mutations in IL-7R, JAK1, or LCK, and down-regulation of CD45 expression caused increased signaling downstream of these oncoproteins. Furthermore, we demonstrate that down-regulation of CD45 expression sensitizes T cells to cytokine stimulation, as observed by increased JAK/STAT signaling, whereas overexpression of CD45 decreases cytokine-induced signaling. Taken together, our data identify a tumor suppressor role for CD45 in T-cell acute lymphoblastic leukemia.

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