Targeting AXL Kinase Sensitizes Leukemic Stem and Progenitor Cells to Venetoclax Treatment in Acute Myeloid Leukemia

The abundance of genetic abnormalities and phenotypic heterogeneities in AML pose significant challenges to developing improved treatments. Here we demonstrated that a key GAS6/AXL axis is highly activated in AML patient cells, particularly in stem/progenitor cells. We developed a potent, selective AXL inhibitor that has favorable pharmaceutical properties and efficacy against preclinical patient-derived xenotransplantation (PDX) models of AML. Importantly, inhibition of AXL sensitized AML stem/progenitor cells to venetoclax treatment, with strong synergistic effects in vitro and in PDX models. Mechanistically, single-cell RNA-sequencing and functional validation studies uncovered that AXL inhibition or in combination with venetoclax potentially targets intrinsic metabolic vulnerabilities of AML stem/progenitor cells, which shows a distinct transcriptomic profile and inhibits mitochondrial oxidative phosphorylation. Inhibition of AXL or BCL-2 also differentially targets key signaling proteins to synergize in leukemic cell killing. These findings have direct translational impact on the treatment of AML and other cancers with high AXL activity.

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The deubiquitinase USP15 modulates cellular redox and is a therapeutic target in acute myeloid leukemia

Leukemia ◽

10.1038/s41375-021-01394-z ◽

2021 ◽

Author(s):

Madeline Niederkorn ◽

Chiharu Ishikawa ◽

Kathleen M. Hueneman ◽

James Bartram ◽

Emily Stepanchick ◽

...

Keyword(s):

Acute Myeloid Leukemia ◽

Progenitor Cells ◽

Small Molecule ◽

Myeloid Leukemia ◽

Cell Function ◽

Leukemic Cell ◽

Human And Mouse ◽

Acute Myeloid

AbstractUbiquitin-specific peptidase 15 (USP15) is a deubiquitinating enzyme implicated in critical cellular and oncogenic processes. We report that USP15 mRNA and protein are overexpressed in human acute myeloid leukemia (AML) as compared to normal hematopoietic progenitor cells. This high expression of USP15 in AML correlates with KEAP1 protein and suppression of NRF2. Knockdown or deletion of USP15 in human and mouse AML models significantly impairs leukemic progenitor function and viability and de-represses an antioxidant response through the KEAP1-NRF2 axis. Inhibition of USP15 and subsequent activation of NRF2 leads to redox perturbations in AML cells, coincident with impaired leukemic cell function. In contrast, USP15 is dispensable for human and mouse normal hematopoietic cells in vitro and in vivo. A preclinical small-molecule inhibitor of USP15 induced the KEAP1-NRF2 axis and impaired AML cell function, suggesting that targeting USP15 catalytic function can suppress AML. Based on these findings, we report that USP15 drives AML cell function, in part, by suppressing a critical oxidative stress sensor mechanism and permitting an aberrant redox state. Furthermore, we postulate that inhibition of USP15 activity with small molecule inhibitors will selectively impair leukemic progenitor cells by re-engaging homeostatic redox responses while sparing normal hematopoiesis.

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Persisting Chronic Myeloid Leukemia Stem and Progenitor Cells From Patients in Major Molecular Remission Under Imatinib Are Characterized by Low BCR/ABL Expression.

Blood ◽

10.1182/blood.v114.22.2207.2207 ◽

2009 ◽

Vol 114 (22) ◽

pp. 2207-2207

Author(s):

Ashu Kumari ◽

Cornelia Brendel ◽

Thorsten Volkmann ◽

Sonja Tajstra ◽

Andreas Neubauer ◽

...

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Chronic Myeloid Leukemia ◽

Progenitor Cells ◽

Myeloid Leukemia ◽

Soft Agar ◽

Molecular Remission ◽

Stem And Progenitor Cells ◽

First Diagnosis

Abstract Abstract 2207 Poster Board II-184 Introduction: Treatment with the Abl-kinase specific inhibitor imatinib (IM) is very effective in chronic myeloid leukemia (CML). However, IM presumably fails to eradicate CML stem cells (HSC) leading to disease persistence and relapse after IM-discontinuation. Although causes of CML persistence under imatinib remain ill defined, quiescence and BCR/ABL-overexpression of CML stem and progenitor cells have been suggested as underlying mechanisms. We here set out to identify means to directly study persistence mechanisms in residual BCR/ABL-positive progenitor and stem cell clones from chronic phase CML patients in major molecular remission (mmR) under imatinib. Methods: Bone marrow specimens of twenty-one CML patients in at least major molecular remission (mmR) according to the international scale, first diagnosis (FD) patients (n=5) and healthy donors (n=4) were sorted into HSC, common myeloid progenitors (CMP), granulocyte/macrophage progenitors (GMP) and megakaryocate-erythrocyte progenitors (MEP) and BCR-ABL mRNA expression was directly assessed by quantitative real time (qPCR) and/or nested PCR (mRNA of 4.000 sorted cells). Alternatively, HSC, CMP, GMP and MEP were seeded into soft agar and mRNA was extracted from individual colony forming units (CFU) to assess BCR/ABL-mRNA expression by qPCR. Moreover, CFU of sub-fractions of first diagnosis CML patients were treated in vitro with IM at 3mM and BCR/ABL-expression of surviving CFU was compared with the BCR/ABL expression levels of mock-treated CML-CFU. In total, 595 soft agar colonies were analyzed. Results: By nested PCR, BCR/ABL-mRNA was readily detectable in the HSC compartments of 7 of 10 (7/10) CML patients in mmR. BCR/ABL was also detected in the CMP-, GMP-, and MEP-compartments in 6, 10 and 8 of the 10 patients, respectively. Real time qRT-PCR suggested only a trend toward stronger BCR/ABL positivity of the HSC compartment when compared to the other progenitor compartments (table 1). A detailed analysis of the BCR/ABL-expression of individual CFU from HSC-, CMP-, GMP-, and MEP-compartments of mmR patients revealed that persisting CML-CFU expressed significantly less BCR/ABL than first diagnosis CML-CFU obtained before imatinib therapy (table 1). This finding could be recapitulated in vitro: primary CML-CD34+ cells of first diagnosis CML patients (n=4) were seeded into soft agar in the presence or absence of 3 uM imatinib. After 14 days BCR/ABL expression only of BCR/ABL-positive CFU was compared. BCR/ABL-positive CML-CFU (n=30) that had survived imatinib exposure expressed significantly less BCR/ABL than mock-treated CML-CFU (n=175) (p<0.001). Work is in progress providing in vitro evidence that selection/induction of low BCR/ABL expression in immature progenitor and stem cells is a new mechanism of imatinib persistence in mmR patients via reducing oncogenic addiction from BCR/ABL. Conclusions: We showed that BCR/ABL-persistence is not confined to the quiescent CML-stem cell compartment, but seems to affect also the highly proliferative progenitor compartments. More intriguingly, persisting CML-HSC and -precursor cells express remarkably low levels of BCR/ABL when compared to first diagnosis HSC and progenitors, implying that low BCR/ABL expression reduces imatinib sensitivity in vivo. The simple model of selection / induction of low BCR/ABL expression as mechanism of imatinib persistence in CML would explain the low propensity of disease progression after achieving mmR, and the low genetic instability of CML clones from mmR patients. Disclosures: No relevant conflicts of interest to declare.

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Global gene expression profiles of hematopoietic stem and progenitor cells from patients with chronic myeloid leukemia: the effect of in vitro culture with or without imatinib

Cancer Medicine ◽

10.1002/cam4.1187 ◽

2017 ◽

Vol 6 (12) ◽

pp. 2942-2956 ◽

Cited By ~ 10

Author(s):

Sócrates Avilés-Vázquez ◽

Antonieta Chávez-González ◽

Alfredo Hidalgo-Miranda ◽

Dafne Moreno-Lorenzana ◽

Lourdes Arriaga-Pizano ◽

...

Keyword(s):

Gene Expression ◽

Chronic Myeloid Leukemia ◽

Progenitor Cells ◽

Myeloid Leukemia ◽

Expression Profiles ◽

Gene Expression Profiles ◽

Global Gene Expression ◽

Hematopoietic Stem ◽

Stem And Progenitor Cells

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Leukotriene signaling via ALOX5 and cysteinyl leukotriene receptor 1 is dispensable for in vitro growth of CD34 + CD38 − stem and progenitor cells in chronic myeloid leukemia

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2017.06.051 ◽

2017 ◽

Vol 490 (2) ◽

pp. 378-384 ◽

Cited By ~ 4

Author(s):

Monika Dolinska ◽

Alexandre Piccini ◽

Wan Man Wong ◽

Eleni Gelali ◽

Anne-Sofie Johansson ◽

...

Keyword(s):

Chronic Myeloid Leukemia ◽

Progenitor Cells ◽

Myeloid Leukemia ◽

In Vitro Growth ◽

Cysteinyl Leukotriene ◽

Stem And Progenitor Cells ◽

Leukotriene Receptor ◽

Cysteinyl Leukotriene Receptor

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Mechanism of Action of Diallyl Sulphide in Ameliorating the Hematopoietic Radiation Injury

Journal of Health and Allied Sciences NU ◽

10.1055/s-0041-1730094 ◽

2021 ◽

Author(s):

Omika Katoch ◽

Mrinalini Tiwari ◽

Namita Kalra ◽

Paban K. Agrawala

Keyword(s):

Stem Cells ◽

Bone Marrow ◽

Progenitor Cells ◽

Hematopoietic Stem ◽

Proliferation And Differentiation ◽

Stem And Progenitor Cells ◽

Radiation Induced ◽

Medicinal Properties ◽

Marrow Cellularity

AbstractDiallyl sulphide (DAS), the pungent component of garlic, is known to have several medicinal properties and has recently been shown to have radiomitigative properties. The present study was performed to better understand its mode of action in rendering radiomitigation. Evaluation of the colonogenic ability of hematopoietic progenitor cells (HPCs) on methocult media, proliferation and differentiation of hematopoietic stem cells (HSCs), and transplantation of stem cells were performed. The supporting tissue of HSCs was also evaluated by examining the histology of bone marrow and in vitro colony-forming unit–fibroblast (CFU-F) count. Alterations in the levels of IL-5, IL-6 and COX-2 were studied as a function of radiation or DAS treatment. It was observed that an increase in proliferation and differentiation of hematopoietic stem and progenitor cells occurred by postirradiation DAS administration. It also resulted in increased circulating and bone marrow homing of transplanted stem cells. Enhancement in bone marrow cellularity, CFU-F count, and cytokine IL-5 level were also evident. All those actions of DAS that could possibly add to its radiomitigative potential and can be attributed to its HDAC inhibitory properties, as was observed by the reversal radiation induced increase in histone acetylation.

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FGF7 supports hematopoietic stem and progenitor cells and niche-dependent myeloblastoma cells via autocrine action on bone marrow stromal cells in vitro

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2013.09.044 ◽

2013 ◽

Vol 440 (1) ◽

pp. 125-131 ◽

Cited By ~ 9

Author(s):

Ruri Ishino ◽

Kaori Minami ◽

Satowa Tanaka ◽

Mami Nagai ◽

Keiji Matsui ◽

...

Keyword(s):

Bone Marrow ◽

Progenitor Cells ◽

Stromal Cells ◽

Bone Marrow Stromal Cells ◽

Marrow Stromal Cells ◽

Hematopoietic Stem ◽

Stem And Progenitor Cells

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Effects of novel retinoid X receptor-selective ligands on myeloid leukemia differentiation and proliferation in vitro

Blood ◽

10.1182/blood.v87.5.1977.bloodjournal8751977 ◽

1996 ◽

Vol 87 (5) ◽

pp. 1977-1984 ◽

Cited By ~ 1

Author(s):

M Kizaki ◽

MI Dawson ◽

R Heyman ◽

E Elster ◽

R Morosetti ◽

...

Keyword(s):

Retinoic Acid ◽

Clonal Growth ◽

Myeloid Leukemia ◽

Target Genes ◽

Synergistic Effects ◽

Leukemic Cells ◽

Acute Myeloid Leukemia Cells ◽

Differentiation And Proliferation ◽

Acute Myeloid

The biologic effects of retinoids such as all-trans-retinoic acid (ATRA) and 9-cis-retinoic acid on proliferation and differentiation of hematopoietic cells are mediated by binding and activating two distinct families of transcription factors: the retinoic acid receptors (RARs) and the retinoid X receptors (RXRs). The RARs require heterodimerization with RXRs; in addition, RXRs can form homodimers, which can bind to DNA response elements that are either distinct or the same as those bound by the RAR/RXR heterodimers. Therefore, the two retinoid pathways provide sequences that are specific for effective DNA binding and activation of target genes. We have developed several series of novel synthetic retinoids that selectively interact with RXR/RXR homodimers and RAR/RXR heterodimers. We show here that SR11236 and SR11246, which are RXR-selective analogs, had little ability to inhibit clonal growth and induce differentiation of leukemic cells (HL- 60 cells and fresh acute myeloid leukemia cells). However, SR11249, SR11256, and LGD1069, which activated both RXR/RXR homodimers and RAR/RXR heterodimers, could inhibit clonal growth and induce differentiation of HL-60 cells as well as leukemic cells from patients, including those with acute promyelocytic leukemia (APL). This is similar to results observed with RAR/RXR-specific ligands. Interestingly, the combination of ATRA and either SR11249, SR11256, or LGD1069 showed synergistic effects in inducing differentiation of HL-60 cells. A retinoid (SR11238) with strong anti-AP-1 activity that did not activate the RARs and RXRs for gene transcription from the response element TREpal was inactive in our assay systems, suggesting that the antiproliferative effects of retinoids on leukemic cells is not mediated by inhibiting the AP-1 pathway. We conclude that the RAR/RXR pathway is more important than RXR/RXR pathway for differentiation and proliferation of acute myeloid leukemic cells, and certain retinoids or combination of retinoids with both RAR and RXR specificities may synergistically enhance the differentiation activity of ATRA, which may be relevant in several clinical situations.

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IGFBP7 activates retinoid acid–induced responses in acute myeloid leukemia stem and progenitor cells

Blood Advances ◽

10.1182/bloodadvances.2020002812 ◽

2020 ◽

Vol 4 (24) ◽

pp. 6368-6383

Author(s):

Noortje van Gils ◽

Han J. M. P. Verhagen ◽

Arjo Rutten ◽

Renee X. Menezes ◽

Mei-Ling Tsui ◽

...

Keyword(s):

Cell Death ◽

Acute Myeloid Leukemia ◽

Progenitor Cells ◽

Myeloid Leukemia ◽

Survival Rates ◽

Induced Responses ◽

Term Survival ◽

All Trans Retinoic Acid ◽

Stem And Progenitor Cells ◽

Acute Myeloid

Abstract Treatment of acute promyelocytic leukemia (APL) with all-trans retinoic acid (ATRA) in combination with low doses of arsenic trioxide or chemotherapy leads to exceptionally high cure rates (>90%). ATRA forces APL cells into differentiation and cell death. Unfortunately, ATRA-based therapy has not been effective among any other acute myeloid leukemia (AML) subtype, and long-term survival rates remain unacceptably low; only 30% of AML patients survive 5 years after diagnosis. Here, we identified insulin-like growth factor binding protein 7 (IGFBP7) as part of ATRA-induced responses in APL cells. Most importantly, we observed that addition of recombinant human IGFBP7 (rhIGFBP7) increased ATRA-driven responses in a subset of non-APL AML samples: those with high RARA expression. In nonpromyelocytic AML, rhIGFBP7 treatment induced a transcriptional program that sensitized AML cells for ATRA-induced differentiation, cell death, and inhibition of leukemic stem/progenitor cell survival. Furthermore, the engraftment of primary AML in mice was significantly reduced following treatment with the combination of rhIGFBP7 and ATRA. Mechanistically, we showed that the synergism of ATRA and rhIGFBP7 is due, at least in part, to reduction of the transcription factor GFI1. Together, these results suggest a potential clinical utility of IGFBP7 and ATRA combination treatment to eliminate primary AML (leukemic stem/progenitor) cells and reduce relapse in AML patients.

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Delineation of target expression profiles in CD34+/CD38− and CD34+/CD38+ stem and progenitor cells in AML and CML

Blood Advances ◽

10.1182/bloodadvances.2020001742 ◽

2020 ◽

Vol 4 (20) ◽

pp. 5118-5132 ◽

Cited By ~ 1

Author(s):

Harald Herrmann ◽

Irina Sadovnik ◽

Gregor Eisenwort ◽

Thomas Rülicke ◽

Katharina Blatt ◽

...

Keyword(s):

Stem Cells ◽

Messenger Rna ◽

Myeloid Leukemia ◽

Expression Profiles ◽

Quantitative Polymerase Chain Reaction ◽

Gene Array ◽

Nsg Mice ◽

Stem And Progenitor Cells ◽

Membrane Antigens

Abstract In an attempt to identify novel markers and immunological targets in leukemic stem cells (LSCs) in acute myeloid leukemia (AML) and chronic myeloid leukemia (CML), we screened bone marrow (BM) samples from patients with AML (n = 274) or CML (n = 97) and controls (n = 288) for expression of cell membrane antigens on CD34+/CD38− and CD34+/CD38+ cells by multicolor flow cytometry. In addition, we established messenger RNA expression profiles in purified sorted CD34+/CD38− and CD34+/CD38+ cells using gene array and quantitative polymerase chain reaction. Aberrantly expressed markers were identified in all cohorts. In CML, CD34+/CD38− LSCs exhibited an almost invariable aberration profile, defined as CD25+/CD26+/CD56+/CD93+/IL-1RAP+. By contrast, in patients with AML, CD34+/CD38− cells variably expressed “aberrant” membrane antigens, including CD25 (48%), CD96 (40%), CD371 (CLL-1; 68%), and IL-1RAP (65%). With the exception of a subgroup of FLT3 internal tandem duplication–mutated patients, AML LSCs did not exhibit CD26. All other surface markers and target antigens detected on AML and/or CML LSCs, including CD33, CD44, CD47, CD52, CD105, CD114, CD117, CD133, CD135, CD184, and roundabout-4, were also found on normal BM stem cells. However, several of these surface targets, including CD25, CD33, and CD123, were expressed at higher levels on CD34+/CD38− LSCs compared with normal BM stem cells. Moreover, antibody-mediated immunological targeting through CD33 or CD52 resulted in LSC depletion in vitro and a substantially reduced LSC engraftment in NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG) mice. Together, we have established surface marker and target expression profiles of AML LSCs and CML LSCs, which should facilitate LSC enrichment, diagnostic LSC phenotyping, and development of LSC-eradicating immunotherapies.

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