RESUMO
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.
Assuntos
Leucemia Mieloide Aguda , Ubiquitina-Proteína Ligases , Humanos , Animais , Camundongos , Ubiquitina-Proteína Ligases/metabolismo , Monoéster Fosfórico Hidrolases/genética , Transdução de Sinais/genética , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Proteínas Proto-Oncogênicas c-cbl/genética , Proteínas Proto-Oncogênicas c-cbl/metabolismo , Tirosina Quinase 3 Semelhante a fms/genética , Tirosina Quinase 3 Semelhante a fms/metabolismo , MutaçãoRESUMO
Acute myeloid leukaemia (AML) is an aggressive form of blood cancer that carries a dismal prognosis. Several studies suggest that the poor outcome is due to a small fraction of leukaemic cells that elude treatment and survive in specialised, oxygen (O2 )-deprived niches of the bone marrow. Although several AML drug targets such as FLT3, IDH1/2 and CD33 have been established in recent years, survival rates remain unsatisfactory, which indicates that other, yet unrecognized, mechanisms influence the ability of AML cells to escape cell death and to proliferate in hypoxic environments. Our data illustrates that Carbonic Anhydrases IX and XII (CA IX/XII) are critical for leukaemic cell survival in the O2 -deprived milieu. CA IX and XII function as transmembrane proteins that mediate intracellular pH under low O2 conditions. Because maintaining a neutral pH represents a key survival mechanism for tumour cells in O2 -deprived settings, we sought to elucidate the role of dual CA IX/XII inhibition as a novel strategy to eliminate AML cells under hypoxic conditions. Our findings demonstrate that the dual CA IX/XII inhibitor FC531 may prove to be of value as an adjunct to chemotherapy for the treatment of AML.
Assuntos
Antineoplásicos/farmacologia , Anidrase Carbônica IX/antagonistas & inibidores , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Hipóxia Tumoral/efeitos dos fármacos , Adulto , Idoso , Animais , Antígenos de Neoplasias/genética , Anidrase Carbônica IX/genética , Anidrases Carbônicas/genética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Modelos Animais de Doenças , Sinergismo Farmacológico , Feminino , Duplicação Gênica , Expressão Gênica , Humanos , Concentração de Íons de Hidrogênio , Imuno-Histoquímica , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/etiologia , Leucemia Mieloide Aguda/metabolismo , Masculino , Pessoa de Meia-Idade , Hipóxia Tumoral/genética , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/genética , Ensaios Antitumorais Modelo de Xenoenxerto , Adulto Jovem , Tirosina Quinase 3 Semelhante a fms/genéticaRESUMO
There is an ongoing shift in demographics such that older persons will outnumber young persons in the coming years, and with it age-associated tissue attrition and increased diseases and disorders. There has been increased information on the association of the aging process with dysregulation of hematopoietic stem (HSC) and progenitor (HPC) cells, and hematopoiesis. This review provides an extensive up-to date summary on the literature of aged hematopoiesis and HSCs placed in context of potential artifacts of the collection and processing procedure, that may not be totally representative of the status of HSCs in their in vivo bone marrow microenvironment, and what the implications of this are for understanding aged hematopoiesis. This review covers a number of interactive areas, many of which have not been adequately explored. There are still many unknowns and mechanistic insights to be elucidated to better understand effects of aging on the hematopoietic system, efforts that will take multidisciplinary approaches, and that could lead to means to ameliorate at least some of the dysregulation of HSCs and HPCs associated with the aging process. Graphical Abstract.