Phenotypic and Functional Alterations of Bone Marrow Mesenchymal Stem and Progenitor Cells in Chronic Myeloid Leukemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2398-2398
Author(s):  
Monika Dolinska ◽  
Johannis Klang ◽  
Pingnan Xiao ◽  
Andranik Durgaryan ◽  
Lakshmi Sandhow ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Chronic Myeloid Leukemia ◽  
Stromal Cells ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Stromal Cell ◽  
Molecular Mechanisms ◽  
Fusion Gene ◽  
Differentiation Potential

Abstract Chronic myeloid leukemia (CML) is a myeloproliferative stem cell neoplasm characterized by the presence of the BCR-ABL1 fusion gene. Although current treatment with tyrosine kinase inhibitors (TKI) has dramatically improved the prognosis of CML, these inhibitors do not eradicate leukemic stem cells (LSC) in most patients with the risk of recurrence of leukemia if TKI are stopped. In vitro studies have suggested that this might be attributable to protection of bone marrow (BM) stromal cells, such as osteoblasts, adipocytes, endothelial and mesenchymal stem cells (MSCs). However, how different BM stromal cells contribute to the persistence of LSC remains largely unknown. To investigate this issue we have compared freshly isolated BM stromal cell subsets including MSCs from newly diagnosed CML patients (n=10) with that from age-matched healthy donors (n=12). Distinct from the previous studies on culture-selected BM stromal cells, the naive stromal cells isolated by multi-color fluorescence activated cell sorting (FACS) were phenotypically, molecularly and functionally characterized in the present study. We observed: 1) Similar to the immunophenotype of normal MSCs (CD45-CD235a-CD31-CD44-, most of which were CD271+CD146+CD106+) (Qian et al., JBC, 2012), the CML MSCs, estimated by colony forming unit-fibroblast (CFU-F), were also enriched in the CD45-CD235a-CD31-CD44- cell fraction. 2) The frequency of CFU-Fs was significantly increased in CML BM compared to that in the age-matched healthy controls (p=0.005). 3) A decreased osteogenic, but enhanced adipogenic differentiation potential of CML MSC was revealed in multilineage differentiation assay. This suggests a skewed differentiation potential of the CML MSCs towards adipocytes, possibly related to an altered stromal cell composition in the patients; 4) An increased proportion of CD31+ endothelial cells was seen in CML BM stroma compared to controls (p=0.023) by FACS. 5) An upregulation of the adhesion receptor integrin α4/CD49D was seen in the CD44- MSCs from CML patients (p=0.0087). Conversely, a downregulation of transcripts of Angiopoietin 1, CXCL12, KIT ligand and LAMA4 in the patient MSCs was detected by Quantitative-PCR, indicating an altered hematopoiesis-supportive function of CML MSCs. 6) Importantly, no BCR-ABL fusion were found in the freshly sorted MSCs and mature stromal cells using Fluorescence In Situ Hybridization analysis, suggesting that these MSCs were not part of the leukemic clone. Taken together, our data provide evidence for phenotypic and functional alterations of BM mesenchymal cells in CML patients. The functional relationship between the stromal cell alterations and the growth of LSC as well as the underlying molecular mechanisms are currently under investigation. Disclosures Mustjoki: Finnish Cancer Institute: Research Funding; Sigrid Juselius Foundation: Research Funding; Academy of Finland: Research Funding; the Finnish Cancer Societies: Research Funding; Pfizer: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Signe and Ane Gyllenberg Foundation: Research Funding.

Functional and Molecular Alterations of Bone Marrow Mesenchymal Stem and Progenitor Cells in Patients with Myelodysplastic Syndrome with Ring Sideroblast

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1489-1489
Author(s):  
Monika Dolinska ◽  
Pingnan Xiao ◽  
Anne-Sofie Johansson ◽  
Lakshmi Sandhow ◽  
Makoto Kondo ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Endothelial Cells ◽  
Myelodysplastic Syndrome ◽  
Stromal Cell ◽  
Molecular Mechanisms ◽  
Bone Marrow Niche ◽  
Differentiation Potential ◽  
Hematopoietic Stem ◽  
Molecular Alterations

Abstract Myelodysplastic Syndrome with Ring Sideroblast (MDS-RS), a clonal hematopoietic cell neoplasm, is low risk MDS, characterized by anemia, hyperplastic ineffective erythropoiesis and marrow ring sideroblasts. Mouse studies have shown that bone marrow niche, including endothelial cells, osteoblasts, adipocytes and mesenchymal stem cells (MSCs), contribute to progression of various hematological disorders. However, in vivo contribution of the different bone marrow stromal cells to the progression of MDS-RS in patients remains largely unknown. To investigate this, we have phenotypically, molecularly and functionally characterized the BM native stromal cell subsets including MSCs freshly isolated by multi-color fluorescence activated cell sorting (FACS) from bone marrow of MDS-RS patients and age-matched healthy donors. We found: 1) the MDS-RS MSCs, estimated by colony forming unit-fibroblast (CFU-F), shared similar immunophenotype with normal MSCs (CD45-CD235a-CD31-CD44-, most of which were CD271+CD146+CD106+); 2) the frequency of CFU-Fs was significantly increased in the phenotypically defined MSCs of MDS-RS bone marrow compared to that of age-matched healthy controls (p=0.005); 3) multi-lineage differentiation assay revealed impaired osteogenic differentiation potential, but enhanced adipogenic differentiation potential of MDS-RS MSCs; 4) FACS analysis showed increased frequency of the adhesion receptor integrin α4 (ITGA4) in the CD44- MSCs from MDS-RS bone marrow (p=0.013); 5) Correspondingly, RNA-sequencing of the freshly isolated bone marrow MSCs and endothelial cells revealed altered gene expression profile of these cells in MDS-RS patients. Among those, ITGA4, ITGA11, ITGAE and ITGB1 are upregulated in the MDS-RS MSCs, indicating potential abnormal adhesive interaction of the MSCs with hematopoietic stem cells in the patients. In addition, the cell cycling gene KI67 is upregulated whereas cell cycle negative regulators, like CDKN1A and CDKN1C are downregulated in the MDS-RS MSCs, which is consistent with their increased CFU-F activity. Interestingly, we detected abnormal expression of hematopoietic growth factors such as downregulation of ANGPTL4 in the MDS-RS MSCs and upregulation of ANGPT1 in the MDS-RS endothelial cells. The functional relationship between the stromal cell alterations and the abnormal hematopoiesis as well as the underlying molecular mechanisms are currently under investigation. Taken together, our data provide new evidence for phenotypic, functional and molecular alterations of bone marrow mesenchymal cells in MDS-RS patients. The molecular pathways mediating bone marrow niche alteration could be potential therapeutic targets for new treatment of MDS-RS. Disclosures No relevant conflicts of interest to declare.

scholarly journals Druggable Biochemical Pathways and Potential Therapeutic Alternatives to Target Leukemic Stem Cells and Eliminate the Residual Disease in Chronic Myeloid Leukemia

2019 ◽  
Vol 20 (22) ◽  
pp. 5616 ◽  
Author(s):  
Fabien Muselli ◽  
Jean-François Peyron ◽  
Didier Mary
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Chronic Myeloid Leukemia ◽  
Tyrosine Kinase ◽  
Myeloid Leukemia ◽  
Molecular Mechanisms ◽  
Kinase Inhibitors ◽  
Residual Disease ◽  
Leukemic Cells ◽  
Hematopoietic Stem

Chronic Myeloid Leukemia (CML) is a disease arising in stem cells expressing the BCR-ABL oncogenic tyrosine kinase that transforms one Hematopoietic stem/progenitor Cell into a Leukemic Stem Cell (LSC) at the origin of differentiated and proliferating leukemic cells in the bone marrow (BM). CML-LSCs are recognized as being responsible for resistances and relapses that occur despite the advent of BCR-ABL-targeting therapies with Tyrosine Kinase Inhibitors (TKIs). LSCs share a lot of functional properties with Hematopoietic Stem Cells (HSCs) although some phenotypical and functional differences have been described during the last two decades. Subverted mechanisms affecting epigenetic processes, apoptosis, autophagy and more recently metabolism and immunology in the bone marrow microenvironment (BMM) have been reported. The aim of this review is to bring together the modifications and molecular mechanisms that are known to account for TKI resistance in primary CML-LSCs and to focus on the potential solutions that can circumvent these resistances, in particular those that have been, or will be tested in clinical trials.

scholarly journals CD93 Is a Novel Biomarker of Leukemia Stem Cells in Chronic Myeloid Leukemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 49-49 ◽  
Author(s):  
Ross Kinstrie ◽  
Gillian A. Horne ◽  
Heather Morrison ◽  
Hothri A. Moka ◽  
Jennifer Cassels ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Chronic Myeloid Leukemia ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Fold Increase ◽  
Leukemia Stem Cells ◽  
Advisory Committees

Abstract The introduction of BCR-ABL tyrosine kinase inhibitors (TKIs) has revolutionized the treatment of chronic myeloid leukemia (CML). However, although the majority of patients with chronic phase (CP)-CML obtain durable complete cytogenetic and major molecular responses, there is low level disease persistence postulated to be due to a population of TKI-insensitive leukemia stem cells (LSC). The aims of this study were (1) to fully characterize differences in gene expression between normal hematopoietic stem cells (HSC) and CP-CML LSC and (2) identify potential novel therapeutic targets specific to CML LSC. Lin-CD34+CD38- CD45RA-CD90+ normal HSC (n=3) and CP-CML LSC (n=6 patients at diagnosis), populations were isolated using a FACSAria and applied to Affymetrix HuGene 1.0ST arrays. The raw data (.CEL files) was imported into Partek Genomics Suite and Ingenuity Pathway Analysis software and principal component analysis and gene ontology ANOVA performed. A total of 1217 genes were significantly deregulated between normal HSC and CP-CML LSC. The most significantly deregulated genes and pathways were involved with the molecular and cellular functions of cell cycle, cell assembly and organisation, cellular movement, cell death and DNA replication, recombination and repair. These results suggested that CML LSC were less quiescent than normal HSC. Importantly, complimentary functional studies indicated that CML LSC have significantly increased proliferation (14 fold expansion; P<0.001) compared to normal HSC (no expansion) after 5 days in vitro culture. In addition, equivalent numbers of CML LSC produce ~4-fold more colonies in colony forming cell (CFC) assays than normal HSC (329±56 versus 86±17 per 2,000 cells, respectively; P<0.05). Fluorescence in situ hybridisation (FISH) demonstrated that >90% of lin- CD34+ CD38- CD45RA- CD90+ CML LSC from all patient samples were BCR-ABL positive (+). In addition to these deregulated intracellular pathways, we sought to assess if there were differences in expression of cell surface molecules that may be amenable to therapeutic manipulation. Of particular interest, our microarray studies demonstrated that CD93 was highly upregulated in CP-CML LSC (6 fold, p = 2.5x10-6). Increased CD93 expression was validated by Fluidigm digital PCR (6 fold increase, p = 0.02; n=6). Furthermore, using flow cytometry, we demonstrated significant upregulation of CD93 protein expression on lin-CD34+ CD38- CD45RA- CD90+ CML LSC from peripheral blood and bone marrow of CP-CML patients (n= 17; mean = 63.8% CD93+) compared to normal HSC from healthy peripheral blood stem cell donors (n=7; mean = 0.8% CD93+) and bone marrow donors (n=4; mean = 0.2% CD93+; p < 0.0001). FISH confirmed that 100% of lin-CD34+ CD38- CD90+ CD93+ CML cells were BCR-ABL+ in all samples assessed. CD93 (also known as C1qRp) is a C-type lectin-like domain (CTLD)-containing glycoprotein which regulates phagocytosis, with roles in cell adhesion and leukocyte migration. It is normally expressed on endothelial cells, hematopoietic precursors and mature cells including neutrophils, monocytes and platelets. Previous studies have shown CD93 to be upregulated in a proportion of AML patients (Saito et al, Sci Transl Med, 2010. 2(17): p. 17ra9). Short term (24h) in vitro exposure of lin-CD34+CD38- CD45RA- CD90+ CML LSC to TKIs (Imatinib or Dasatinib; n=3) reduced, but did not fully eliminate CD93 expression (Imatinib, 48.5% to 22.9%; Dasatinib, 47.7% to 9.2%). Importantly, following long-term TKI treatment of patients, lin-CD34+CD38-CD45RA-CD90+ cells from CP-CML patient bone marrow samples (n=2) taken in major molecular response demonstrated a small, but persistent population of CD93+ LSC which were BCR-ABL+ by FISH. Furthermore, in xenograft transplantation experiments (n = 5), after 16 weeks, CD34+CD93+ CML LSC engrafted lethally irradiated NOD/SCID/IL-2Rg-/- (NSG) mice with BCR-ABL+ cells, whereas CD34+CD93- cells from the same patient samples failed to engraft to significant levels (3.5-30 fold increase in engraftment with CD34+CD93- cells; p < 0.03). FISH confirmed that engrafted human cells were BCR-ABL+. Taken together, our results identify CD93 as a potential novel biomarker of CML LSC, which may also be helpful in assessing minimal residual disease at the LSC level. Further studies are ongoing to assess the therapeutic potential of inhibiting CD93 in CML LSC. Disclosures Copland: Ariad: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

scholarly journals Targeting Chronic Myeloid Leukemia Stem/Progenitor Cells Using Immunolipsome Loaded Venetoclax

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 39-39
Author(s):  
Mohammad Houshmand ◽  
Paola Circosta ◽  
Francesca Garello ◽  
Valentina Gaidano ◽  
Alessandro Cignetti ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Side Effects ◽  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Residual Disease ◽  
Molecular Response ◽  
Newly Diagnosed ◽  
Number Of Patients

The introduction of different generations of tyrosine kinase inhibitors (TKIs) significantly improved outcome and survival rate in chronic myeloid leukemia (CML) patients. However, long-term use of TKIs is concomitant with many side effects that affect the quality of life in patients. Approximately half of CML patients achieve deep molecular response (DMR), this makes them suitable candidates to discontinue the TKI therapy in a controlled condition, and about half of them will remain in treatment free remission (TFR) after discontinuation. It has been shown that a small population of leukemia stem cells (LSCs) as the residual disease burden is present at diagnosis, during the treatment, and in patients who are in TFR. While CML LSCs have many features in common with HSCs, they express specific markers such as CD25, CD26, IL1-RAP, etc., which can be used for the diagnosis and targeting. Protection by the bone marrow microenvironment and activity of signaling pathways such as WNT/β catenin, Hedgehog, PI3K, JAK/STAT in CML LSCs in a BCR-ABL dependent and independent manner guarantee their survival and elimination of these cells solely using TKIs seems ineffective. Herein we designed a pegylated liposomal nanocarrier conjugated with a specific antibody against CD26 (Begelomab, ADIENNE, Lugano, Switzerland). Then we loaded this immunoliposome with venetoclax, a BCL2 inhibitor, to eliminate CML LSCs selectively and to spare normal HSCs. First, we measured the expression of CD26 in the bone marrow and peripheral blood samples of newly diagnosed patients. We had a high expression of CD26 in CD34+/CD38- of both PB and BM, and a low expression on CD34+/CD38+ (progenitors) cells. Also, the expression of this marker in resistant patients to TKIs was visible while it was absent in normal stem cells. After the synthesis of the liposome, we conjugated Begelomab to the liposome. Then, we tested the selectivity of the designed system in different positive and negative cells. Our designed immunoliposome showed a strong selectivity toward CD26 positive cells. We also tested the selectivity on CML primary cells; in particular, we sorted newly diagnosed CML samples based on CD34+/CD38-/CD26- for HSCs and CD34+/CD38-/CD26+ for LSCs. Based on the confocal and flow cytometry analysis, our designed immunoliposome selectively targets LSCs and spares HSCs. Then we loaded this immunoliposome with venetoclax, and we treated CD26 positive and negative cells with this system. Based on our preliminary results, this immunoliposome loaded venetoclax specifically induced apoptosis in CD26+ cells, with higher activity compared to free venetoclax at the same dose. However, more analysis will be performed to confirm the selectivity of this system. Based on the obtained results, CD26 in newly diagnosed CML patients is expressed by CML LSCs and is a suitable option for diagnosis and targeting. Our preliminary data strongly suggest that we can selectively target CML LSCs. The main advantage of this system is its precision to hit the target. So we expect that after the drug release, the LSCs will be eliminated without any side effects on normal cells. Liposomes are suitable carriers because of their biocompatibility, self-assembly, large drug payload, and minimal toxicity. This strategy may help us to increase the number of patients attaining and maintaining TFR without relapsing. Disclosures Saglio: Ariad: Research Funding; Pfizer: Research Funding; Incyte: Research Funding; Roche: Research Funding; Bristol-Myers Squibb: Research Funding; Novartis: Research Funding.

scholarly journals Interferon-alpha overrides the deficient adhesion of chronic myeloid leukemia primitive progenitor cells to bone marrow stromal cells

Blood ◽  
1991 ◽  
Vol 78 (2) ◽  
pp. 499-505 ◽  
Author(s):  
C Dowding ◽  
AP Guo ◽  
J Osterholz ◽  
M Siczkowski ◽  
J Goldman ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Chronic Myeloid Leukemia ◽  
Progenitor Cells ◽  
Interferon Alpha ◽  
Stromal Cells ◽  
Myeloid Leukemia ◽  
Neuraminidase Treatment ◽  
Recombinant Interferon ◽  
Ifn Alpha

Abstract Primitive blast colony-forming cells (BI-CFC) from chronic myeloid leukemia (CML) patients are defective in their attachment to bone marrow-derived stromal cells compared with normal BI-CFC. We investigated the effect of recombinant interferon-alpha 2a (IFN-alpha) on this interaction between hematopoietic progenitor cells and bone marrow-derived stromal cells by culturing normal stromal cells with IFN- alpha (50 to 5,000 U/mL). At 50 U/mL we found that: (1) the capacity of stromal cells to bind two types of CML primitive progenitor cells (BI- CFC and long-term culture-initiating cells) was increased; and (2) the amount of sulfated glycosaminoglycans (GAGs) in the stromal layer was increased. However, sulfated GAGs were not directly involved in binding CML BI-CFC, unlike binding by normal BI-CFC, which is sulfated GAG- dependent. Neuraminidase-treated control stromal cells bound an increased number of CML BI-CFC, reproducing the effect of IFN-alpha, whereas the binding to IFN-alpha-treated stromal cells was unaffected by neuraminidase treatment. Thus, the enhanced attachment by primitive CML progenitor cells to INF-alpha-treated stromal cells might be due to changes in the neuraminic acid composition in the stromal cell layer. Our in vitro evidence may provide insights into the mechanism of action of IFN-alpha in vivo. Prolonged administration may alter the marrow microenvironment in some patients such that it can restrain the aberrant proliferation of Philadelphia chromosome (Ph)-positive stem cells while permitting Ph-negative stem cells to function normally.

scholarly journals Interferon-alpha overrides the deficient adhesion of chronic myeloid leukemia primitive progenitor cells to bone marrow stromal cells

Blood ◽  
1991 ◽  
Vol 78 (2) ◽  
pp. 499-505
Author(s):  
C Dowding ◽  
AP Guo ◽  
J Osterholz ◽  
M Siczkowski ◽  
J Goldman ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Chronic Myeloid Leukemia ◽  
Progenitor Cells ◽  
Interferon Alpha ◽  
Stromal Cells ◽  
Myeloid Leukemia ◽  
Neuraminidase Treatment ◽  
Recombinant Interferon ◽  
Ifn Alpha

Primitive blast colony-forming cells (BI-CFC) from chronic myeloid leukemia (CML) patients are defective in their attachment to bone marrow-derived stromal cells compared with normal BI-CFC. We investigated the effect of recombinant interferon-alpha 2a (IFN-alpha) on this interaction between hematopoietic progenitor cells and bone marrow-derived stromal cells by culturing normal stromal cells with IFN- alpha (50 to 5,000 U/mL). At 50 U/mL we found that: (1) the capacity of stromal cells to bind two types of CML primitive progenitor cells (BI- CFC and long-term culture-initiating cells) was increased; and (2) the amount of sulfated glycosaminoglycans (GAGs) in the stromal layer was increased. However, sulfated GAGs were not directly involved in binding CML BI-CFC, unlike binding by normal BI-CFC, which is sulfated GAG- dependent. Neuraminidase-treated control stromal cells bound an increased number of CML BI-CFC, reproducing the effect of IFN-alpha, whereas the binding to IFN-alpha-treated stromal cells was unaffected by neuraminidase treatment. Thus, the enhanced attachment by primitive CML progenitor cells to INF-alpha-treated stromal cells might be due to changes in the neuraminic acid composition in the stromal cell layer. Our in vitro evidence may provide insights into the mechanism of action of IFN-alpha in vivo. Prolonged administration may alter the marrow microenvironment in some patients such that it can restrain the aberrant proliferation of Philadelphia chromosome (Ph)-positive stem cells while permitting Ph-negative stem cells to function normally.

Recent approaches for isolating and culturing mouse bone marrow-derived mesenchymal stromal stem cells

2020 ◽  
Vol 15 ◽  
Author(s):  
Basem M. Abdallah ◽  
Hany M. Khattab
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Molecular Mechanisms ◽  
Replicative Senescence ◽  
Cellular Heterogeneity ◽  
High Yield ◽  
Mouse Strains ◽  
Mouse Bone Marrow ◽  
Differentiation Potential ◽  
Stromal Stem Cells

: The isolation and culture of murine bone marrow-derived mesenchymal stromal stem cells (mBMSCs) have attracted great interest in terms of the pre-clinical applications of stem cells in tissue engineering and regenerative medicine. In addition, culturing mBMSCs is important for studying the molecular mechanisms of bone remodelling using relevant transgenic mice. Several factors have created challenges in the isolation and high-yield expansion of homogenous mBMSCs; these factors include low frequencies of bone marrow-derived mesenchymal stromal stem cells (BMSCs) in bone marrow, variation among inbred mouse strains, contamination with haematopoietic progenitor cells (HPCs), the replicative senescence phenotype and cellular heterogeneity. In this review, we provide an overview of nearly all protocols used for isolating and culturing mBMSCs with the aim of clarifying the most important guidelines for culturing highly purified mBMSC populations retaining in vitro and in vivo differentiation potential.

scholarly journals Acute myeloid leukemia induces protumoral p16INK4a-driven senescence in the bone marrow microenvironment

Blood ◽  
2019 ◽  
Vol 133 (5) ◽  
pp. 446-456 ◽  
Author(s):  
Amina M. Abdul-Aziz ◽  
Yu Sun ◽  
Charlotte Hellmich ◽  
Christopher R. Marlein ◽  
Jayna Mistry ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Stromal Cells ◽  
Myeloid Leukemia ◽  
Stromal Cell ◽  
Cell Senescence ◽  
Senescent Phenotype ◽  
Age Related ◽  
Acute Myeloid

Abstract Acute myeloid leukemia (AML) is an age-related disease that is highly dependent on the bone marrow (BM) microenvironment. With increasing age, tissues accumulate senescent cells, characterized by an irreversible arrest of cell proliferation and the secretion of a set of proinflammatory cytokines, chemokines, and growth factors, collectively known as the senescence-associated secretory phenotype (SASP). Here, we report that AML blasts induce a senescent phenotype in the stromal cells within the BM microenvironment and that the BM stromal cell senescence is driven by p16INK4a expression. The p16INK4a-expressing senescent stromal cells then feed back to promote AML blast survival and proliferation via the SASP. Importantly, selective elimination of p16INK4a+ senescent BM stromal cells in vivo improved the survival of mice with leukemia. Next, we find that the leukemia-driven senescent tumor microenvironment is caused by AML-induced NOX2-derived superoxide. Finally, using the p16-3MR mouse model, we show that by targeting NOX2 we reduced BM stromal cell senescence and consequently reduced AML proliferation. Together, these data identify leukemia-generated NOX2-derived superoxide as a driver of protumoral p16INK4a-dependent senescence in BM stromal cells. Our findings reveal the importance of a senescent microenvironment for the pathophysiology of leukemia. These data now open the door to investigate drugs that specifically target the “benign” senescent cells that surround and support AML.

scholarly journals Expression of Bcl-2 protein and the amplification of c-myc gene in patients with chronic myeloid leukemia

2006 ◽  
Vol 63 (4) ◽  
pp. 364-369 ◽  
Author(s):  
Milica Strnad ◽  
Goran Brajuskovic ◽  
Natasa Strelic ◽  
Biljana Zivanovic-Todoric ◽  
Ljiljana Tukic ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Alkaline Phosphatase ◽  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Molecular Mechanisms ◽  
Bone Marrow Cells ◽  
Chronic Phase ◽  
Blast Transformation ◽  
Hematopoietic Stem ◽  
Myc Gene

Background/Aim. Chronic myeloid leukemia (CML) represents a malignant myeloproliferative disease developed out of pluripotent hematopoietic stem cell that contains the fusion bcr-abl gene. Disorders that occur in the process of apoptosis represent one of the possible molecular mechanisms that bring about the disease progress. The aim of our study was to carry out the analysis of the presence of the amplification of the cmyc oncogene, as well as the analysis of the changes in the expression of Bcl-2 in the patients with CML. Methods. Our study included 25 patients with CML (18 in chronic phase, 7 in blast transformation). Using an immunohistochemical alkaline phosphatase-anti-alkaline phosphatase (APAAP) method, we analyzed the expression of cell death protein in the mononuclear bone marrow cells of 25 CML patients. By a differential PCR (polymerase chain reaction) method, we followed the presence of amplified c-myc gene in mononuclear peripheral blood cells. Results. The level of the expression of Bcl-2 protein was considerably higher in the bone marrow samples of the patients undergoing blast transformation of the disease. The amplification of c-myc gene was detected in 30% of the patients in blast transformation of the disease. Conclusion. The expression of Bcl-2 protein and the amplification of c-myc gene are in correlation with the disease progression.

scholarly journals Identification of BCR/ABL-negative primitive hematopoietic progenitor cells within chronic myeloid leukemia marrow

Blood ◽  
1993 ◽  
Vol 81 (3) ◽  
pp. 801-807 ◽  
Author(s):  
T Leemhuis ◽  
D Leibowitz ◽  
G Cox ◽  
R Silver ◽  
EF Srour ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Chronic Myeloid Leukemia ◽  
Progenitor Cells ◽  
Myeloid Leukemia ◽  
Chronic Phase ◽  
Polymerase Chain Reaction Analysis ◽  
Hematopoietic Progenitor Cells ◽  
Hematopoietic Progenitor ◽  
Hematopoietic Stem

Chronic myeloid leukemia (CML) is a malignant disorder of the hematopoietic stem cell. It has been shown that normal stem cells coexist with malignant stem cells in the bone marrow of patients with chronic-phase CML. To characterize the primitive hematopoietic progenitor cells within CML marrow, CD34+DR- and CD34+DR+ cells were isolated using centrifugal elutriation, monoclonal antibody labeling, and flow cytometric cell sorting. Polymerase chain reaction analysis of RNA samples from these CD34+ subpopulations was used to detect the presence of the BCR/ABL translocation characteristic of CML. The CD34+DR+ subpopulation contained BCR/ABL(+) cells in 11 of 12 marrow samples studied, whereas the CD34+DR- subpopulation contained BCR/ABL(+) cells in 6 of 9 CML marrow specimens. These cell populations were assayed for hematopoietic progenitor cells, and individual hematopoietic colonies were analyzed by PCR for their BCR/ABL status. Results from six patients showed that nearly half of the myeloid colonies cloned from CD34+DR- cells were BCR/ABL(+), although the CD34+DR- subpopulation contained significantly fewer BCR/ABL(+) progenitor cells than either low-density bone marrow (LDBM) or the CD34+DR+ fraction. These CD34+ cells were also used to establish stromal cell-free long-term bone marrow cultures to assess the BCR/ABL status of hematopoietic stem cells within these CML marrow populations. After 28 days in culture, three of five cultures initiated with CD34+DR- cells produced BCR/ABL(-) cells. By contrast, only one of eight cultures initiated with CD34+DR+ cells were BCR/ABL(-) after 28 days. These results indicate that the CD34+DR- subpopulation of CML marrow still contains leukemic progenitor cells, although to a lesser extent than either LDBM or CD34+DR+ cells.

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