Assessment of Drug Sensitivity in Hematopoietic Stem and Progenitor Cells from Acute Myelogenous Leukemia and Myelodysplastic Syndrome Ex Vivo

Abstract

Current understanding suggests that malignant stem and progenitor cells must be reduced or eliminated for prolonged remissions in myeloid neoplasms such as acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS). Multicolor flow cytometry has been widely used to distinguish stem and myeloid progenitor cells from other populations in normal and malignant bone marrow. In this study, we present a method for assessing drug sensitivity in MDS and AML patient hematopoietic stem and myeloid progenitor cell populations ex vivo using the investigational Nedd8‐activating enzyme inhibitor MLN4924 and standard‐of‐care agent cytarabine as examples. Utilizing a multicolor flow cytometry antibody panel for identification of hematopoietic stem cells, multipotent progenitors, common myeloid progenitors, granulocyte‐monocyte progenitors, and megakaryocyte‐erythroid progenitors present in mononuclear cell fractions isolated from bone marrow aspirates, we compare stem and progenitor cell counts after treatment for 24 hours with drug versus diluent. We demonstrate that MLN4924 exerts a cytotoxic effect on MDS and AML stem and progenitor cell populations, whereas cytarabine has more limited effects. Further application of this method for evaluating drug effects on these populations ex vivo and in vivo may inform rational design and selection of therapies in the clinical setting. Stem Cells Translational Medicine 2017;6:840–850

Antitumor Effects of Blocking Protein Neddylation in T315I-BCR-ABL Leukemia Cells and Leukemia Stem Cells

“…MLN4924 also effectively reduced the survival, frequency, and self-renewal capacity of LSK cells in BCR-ABL-driven CML mice. Our results are in agreement with previous report that MLN4924 is toxic to AML and MDS stem/progenitor cells without toxicity to normal stem/progenitor cells (31). Therefore, MLN4924 might be a promising strategy and the relevant clinical trial in CML is warranted.…”

The Cks1/Cks2 axis fine-tunes Mll1 expression and is crucial for MLL-rearranged leukaemia cell viability

“…ML-2 (DSMZ, Braunschweig, Germany; ACC15), THP-1 (DSMZ; ACC16), KOPN-8 (DSMZ; ACC552), ML-1, and RS4; 11 cell lines and peripheral blood mononuclear cells (PBMCs) [38] , [39] were cultured in RPMI 1640 (ThermoScientific) with 10% FBS and 5% penicillin/streptomycin.…”

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“…In the hope of identifying novel and efficient treatment options for myeloid malignancies such as AML, researchers from the laboratory of Scott Kaufmann (Mayo Clinic, Minnesota) recently developed an assay that efficiently identifies therapeutic agents that specifically target malignant HSPC populations. In their STEM CELLS Translational Medicine article, 8 Knorr et al reported on a comparison of cytarabine, a nucleoside analog that represents the standard‐of‐care agent for AML treatment, 21 and MLN4924, a first‐in‐class investigational Nedd8‐activating enzyme inhibitor with promising clinical activity in myeloid malignancies, 22 using an ex vivo drug sensitivity assay that assessed multiple malignant HSPC populations. The authors began by employing a multicolor flow cytometry antibody panel to identify the HSPC populations present in mononuclear cell fractions isolated from bone marrow aspirates of healthy patients and those suffering from myeloid malignancies.…”

“…7 In a Related Article published recently in STEM CELLS Translational Medicine, Knorr et al reported on the discovery of a chemotherapeutic agent with improved activity against AML-associated HSPCs employing a novel ex vivo method for assessing drug sensitivity. 8 Studies in the 1970s highlighted the ability of urine-derived cells to survive and expand in culture, 9 and the isolation of mesenchymal stem cell (MSC)-like cells with a male karyotype in the urine of a female patient who received a male donor kidney revealed their renal origin. Subsequent research then highlighted the transcriptomic similarity of so-called urine-derived stem cells (USCs) to renal parietal cells and renal progenitor cells to confirm their original residence in the kidney.…”

“…In our first Featured Article published this month in STEM CELLS , Shingai et al describe autonomous transforming growth factor‐beta (TGF‐β) signaling as a crucial molecular mechanism that mediates the heterogeneity of AML LSCs and a potential therapeutic target 7 . In a Related Article published recently in STEM CELLS Translational Medicine , Knorr et al reported on the discovery of a chemotherapeutic agent with improved activity against AML‐associated HSPCs employing a novel ex vivo method for assessing drug sensitivity 8 …”