Browsing by Author "Band, Hamid"

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    PRL2 phosphatase enhances oncogenic FLT3 signaling via dephosphorylation of the E3 ubiquitin ligase CBL at tyrosine 371
    (American Society of Hematology, 2023) Chen, Hongxia; Bai, Yunpeng; Kobayashi, Michihiro; Xiao, Shiyu; Cai, Wenjie; Barajas, Sergio; Chen, Sisi; Miao, Jinmin; Nguele Meke, Frederick; Vemula, Sasidhar; Ropa, James P.; Croop, James M.; Boswell, H. Scott; Wan, Jun; Jia, Yuzhi; Liu, Huiping; Li, Loretta S.; Altman, Jessica K.; Eklund, Elizabeth A.; Ji, Peng; Tong, Wei; Band, Hamid; Huang, Danny T.; Platanias, Leonidas C.; Zhang, Zhong-Yin; Liu, Yan; Pediatrics, School of Medicine
    Acute myeloid leukemia (AML) is an aggressive blood cancer with poor prognosis. FMS-like tyrosine kinase receptor-3 (FLT3) is one of the major oncogenic receptor tyrosine kinases aberrantly activated in AML. Although protein tyrosine phosphatase PRL2 is highly expressed in some subtypes of AML compared with normal human hematopoietic stem and progenitor cells, the mechanisms by which PRL2 promotes leukemogenesis are largely unknown. We discovered that genetic and pharmacological inhibition of PRL2 significantly reduce the burden of FLT3-internal tandem duplications-driven leukemia and extend the survival of leukemic mice. Furthermore, we found that PRL2 enhances oncogenic FLT3 signaling in leukemia cells, promoting their proliferation and survival. Mechanistically, PRL2 dephosphorylates the E3 ubiquitin ligase CBL at tyrosine 371 and attenuates CBL-mediated ubiquitination and degradation of FLT3, leading to enhanced FLT3 signaling in leukemia cells. Thus, our study reveals that PRL2 enhances oncogenic FLT3 signaling in leukemia cells through dephosphorylation of CBL and will likely establish PRL2 as a novel druggable target for AML.
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    PRL2 Phosphatase Promotes Oncogenic KIT Signaling in Leukemia Cells through Modulating CBL Phosphorylation
    (American Association for Cancer Research, 2024) Chen, Hongxia; Bai, Yunpeng; Kobayashi, Michihiro; Xiao, Shiyu; Barajas, Sergio; Cai, Wenjie; Chen, Sisi; Miao, Jinmin; Meke, Frederick Nguele; Yao, Chonghua; Yang, Yuxia; Strube, Katherine; Satchivi, Odelia; Sun, Jianmin; Rönnstrand, Lars; Croop, James M.; Boswell, H. Scott; Jia, Yuzhi; Liu, Huiping; Li, Loretta S.; Altman, Jessica K.; Eklund, Elizabeth A.; Sukhanova, Madina; Ji, Peng; Tong, Wei; Band, Hamid; Huang, Danny T.; Platanias, Leonidas C.; Zhang, Zhong-Yin; Liu, Yan; Pediatrics, School of Medicine
    Receptor tyrosine kinase KIT is frequently activated in acute myeloid leukemia (AML). While high PRL2 (PTP4A2) expression is correlated with activation of SCF/KIT signaling in AML, the underlying mechanisms are not fully understood. We discovered that inhibition of PRL2 significantly reduces the burden of oncogenic KIT-driven leukemia and extends leukemic mice survival. PRL2 enhances oncogenic KIT signaling in leukemia cells, promoting their proliferation and survival. We found that PRL2 dephosphorylates CBL at tyrosine 371 and inhibits its activity toward KIT, leading to decreased KIT ubiquitination and enhanced AKT and ERK signaling in leukemia cells. Implications: Our studies uncover a novel mechanism that fine-tunes oncogenic KIT signaling in leukemia cells and will likely identify PRL2 as a novel therapeutic target in AML with KIT mutations.