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Robust patient-derived xenografts of MDS/MPN overlap syndromes capture the unique characteristics of CMML and JMML

Akihide Yoshimi, Maria E. Balasis, Alexis Vedder, Kira Feldman, Yan Ma, Hailing Zhang, Stanley Chun-Wei Lee, Christopher Letson, Sandrine Niyongere, Sydney X. Lu, Markus Ball, Justin Taylor, Qing Zhang, Yulong Zhao, Salma Youssef, Young Rock Chung, Xiao Jing Zhang, Benjamin H. Durham, Wendy Yang, Alan F. List, Mignon L. Loh, Virginia Klimek, Michael F. Berger, Elliot Stieglitz, Eric Padron and Omar Abdel-Wahab
This article has an Erratum 130(13):1602

Key Points

  • Genetically accurate xenografts of CMML are achievable with near 100% frequency in NSGS mice.

  • Robust human engraftment and overt phenotypes of CMML and JMML xenografts here facilitate preclinical therapeutic evaluation in vivo.

Publisher's Note: There is an Inside Blood Commentary on this article in this issue.

Abstract

Chronic myelomonocytic leukemia (CMML) and juvenile myelomonocytic leukemia (JMML) are myelodysplastic syndrome (MDS)/myeloproliferative neoplasm (MPN) overlap disorders characterized by monocytosis, myelodysplasia, and a characteristic hypersensitivity to granulocyte-macrophage colony-stimulating factor (GM-CSF). Currently, there are no available disease-modifying therapies for CMML, nor are there preclinical models that fully recapitulate the unique features of CMML. Through use of immunocompromised mice with transgenic expression of human GM-CSF, interleukin-3, and stem cell factor in a NOD/SCID-IL2Rγnull background (NSGS mice), we demonstrate remarkable engraftment of CMML and JMML providing the first examples of serially transplantable and genetically accurate models of CMML. Xenotransplantation of CD34+ cells (n = 8 patients) or unfractionated bone marrow (BM) or peripheral blood mononuclear cells (n = 10) resulted in robust engraftment of CMML in BM, spleen, liver, and lung of recipients (n = 82 total mice). Engrafted cells were myeloid-restricted and matched the immunophenotype, morphology, and genetic mutations of the corresponding patient. Similar levels of engraftment were seen upon serial transplantation of human CD34+ cells in secondary NSGS recipients (2/5 patients, 6/11 mice), demonstrating the durability of CMML grafts and functionally validating CD34+ cells as harboring the disease-initiating compartment in vivo. Successful engraftments of JMML primary samples were also achieved in all NSGS recipients (n = 4 patients, n = 12 mice). Engraftment of CMML and JMML resulted in overt phenotypic abnormalities and lethality in recipients, which facilitated evaluation of the JAK2/FLT3 inhibitor pacritinib in vivo. These data reveal that NSGS mice support the development of CMML and JMML disease-initiating and mature leukemic cells in vivo, allowing creation of genetically accurate preclinical models of these disorders.

  • Submitted January 17, 2017.
  • Accepted June 1, 2017.
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