Identification of Novel Cancer-Testis Antigen Expressed in Leukemic Stem Cells of Chronic Myelogenous Leukemia

2014 ◽  
Vol 42 (8) ◽  
pp. S68
Author(s):  
Maiko Matsushita ◽  
Miki Nakamura ◽  
Daiju Ichikawa ◽  
Nobuo Tsukamoto ◽  
Yutaka Kawakami ◽  
...  
Keyword(s):  
Stem Cells ◽  
Chronic Myelogenous Leukemia ◽  
Myelogenous Leukemia ◽  
Cancer Testis Antigen ◽  
Leukemic Stem Cells ◽  
Cancer Testis

Deletion of Rac2 inhibits Proliferation of Chronic Myelogenous Leukemia (CML) Stems Cells and Progenitors (HSC/P) In Vivo and Promotes Survival of Scl/p210-BCR-ABL Mice.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3253-3253
Author(s):  
Amitava Sengupta ◽  
Jorden Arnett ◽  
Susan Dunn ◽  
Jose Cancelas
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Chronic Myelogenous Leukemia ◽  
Research Funding ◽  
Myelogenous Leukemia ◽  
Leukemic Stem Cells ◽  
Hematopoietic Stem ◽  
Rac Gtpases ◽  
And Migration

Abstract Abstract 3253 Poster Board III-1 Chronic myelogenous leukemia (CML) is a hematopoietic stem cell (HSC) malignancy induced by p210-BCR-ABL and is characterized by myeloproliferation in the bone marrow (BM) and egress of leukemic stem cells and progenitors (LSC/P) to extramedullary sites. Persistence of BCR-ABL+ HSCs in patients under imatinib suggests that inhibition of ABL-kinase alone is not sufficient to completely eliminate the LSC/P population. Rac GTPases represent integrative molecular switches for p210-BCR-ABL-induced HSC transformation and combined pharmacological and genetic attenuation of Rac GTPases significantly prolong survival in vivo, as reported in a retroviral transduction/transplantation model (Thomas EK & Cancelas JA et al, Cancer Cell 2008). Here, we analyzed the role of Rac2 GTPase in the leukemic maintenance and in the interaction of LSC/P with the leukemic microenvironment in vivo. We used a stem cell leukemia (Scl) promoter-driven, tet-off, Scl-tTA x TRE-BCR-ABL (Scl/p210-BCR-ABL) binary transgenic mouse model (Koschmieder S et al., Blood 2005), where expression of BCR-ABL is restricted to the HSC/P compartment, allowing the study of the intrinsic molecular changes in LSC/P during leukemogenesis. In these mice, Scl-driven expression of BCR-ABL is active in HSC (Lin-/Sca1+/c-kit+; LSK) and progenitors (Lin-/c-kit+/Sca-1-; LK), and CML development is associated with the activation of downstream signaling effectors CrkL, p38-MAPK and JNK. Additionally, Scl/p210-BCR-ABL mice had increased cycling of LSK cells and expansion of circulating and splenic, but not BM, LSC/P, suggesting egress of LSC/Ps from the marrow. These mice share all the characteristics of HSC/P transformation in CML, including increased HSC/P proliferation and survival, severely reduced adhesion to fibronectin, increased migration towards CXCL12, increased cell surface expression of CD44 and decreased expression of L-selectin. Myeloproliferative disease (MPD) in these mice is transplantable into recipient mice, and CML splenocytes have a 10-fold increase in homing to the spleen than towards BM (P<0.05). Leukemic splenocytes are also enriched in endosteal lodging progenitors, compared to the BM-derived progenitors (1.9-fold, P≤0.05). In order to determine the contribution of Rac2 GTPase in the transformation phenotype of leukemic stem cells and progenitors, Scl/p210 mice were intercrossed with Rac2-/- mice. Interestingly loss of Rac2 GTPase alone significantly prolongs survival of the leukemic mice (P≤0.001). Prolonged survival, as observed in Scl/p210 x Rac2-/-, is associated with significantly reduced proliferation of leukemic LK (3-fold, P<0.05) and LSK (6-fold P<0.005) cells, both in BM as well as in spleen, in vivo. Scl/p210 x Rac2-/- mice are also characterized by increased apoptosis (1.7-fold) and lower frequency of LSK cells (2-fold) compared to the Scl/p210 mice in vivo. However, deletion of Rac2 does not significantly reverse the adhesion and migration transformation phenotype of LSC/P. In summary, Rac2 deficiency induces a significant survival of CML mice in a HSC-initiated model of disease through decrease proliferation and survival but does not reverse the transformation phenotype affecting adhesion and migration. This murine model may represent an adequate in vivo system to dissect out the specific signaling pathways involved in p210-BCR-ABL-induced stem cell transformation. Disclosures: Cancelas: CERUS CO: Research Funding; CARIDIAN BCT: Research Funding; HEMERUS INC: Research Funding.

Imatinib-resistant lymphoid clone of chronic myelogenous leukemia in blast phase arising from B cell-committed progenitor leukemic stem cells

2010 ◽  
Vol 90 (3) ◽  
pp. 367-368
Author(s):  
Shinichi Kobayashi ◽  
Ken Sato ◽  
Ayako Kobayashi ◽  
Yukiko Osawa ◽  
Yukitsugu Nakamura ◽  
...  
Keyword(s):  
Stem Cells ◽  
B Cell ◽  
Chronic Myelogenous Leukemia ◽  
Myelogenous Leukemia ◽  
Leukemic Stem Cells ◽  
Blast Phase ◽  
Imatinib Resistant

Leukemic Stem Cells and Progenitors Demonstrate Impaired Interaction with the Hematopoietic Microenvironment in Vivo in An Inducible Murine Model of Chronic Myelogenous Leukemia

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 191-191
Author(s):  
Amitava Sengupta ◽  
Jose Cancelas
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Chronic Myelogenous Leukemia ◽  
Murine Model ◽  
Chronic Phase ◽  
Myelogenous Leukemia ◽  
Cell Surface Expression ◽  
Leukemic Stem Cells ◽  
Hematopoietic Microenvironment

Abstract Chronic myelogenous leukemia (CML) is a stem cell malignancy induced by p210 BCR-ABL and characterized by myeloproliferation in BM and egression of leukemic stem cells and progenitors (LSC/P) to extramedullary sites. Persistence of BCR-ABL+ HSC in patients under Imatinib suggests inhibition of ABL-kinase alone is not sufficient to eliminate the LSC/P. One of the major hallmarks of CML induced by signaling downstream BCR-ABL is the loss of control of the hematopoietic microenvironment on LSC/P. Expression of p210 BCR-ABL has been associated with loss of adhesion to the bone marrow, impaired migration in response to CXCL12 and decreased retention in the BM. In order to study the putative LSC/P niches in steady-state chronic-phase leukemia, we have analyzed the ability of LSC/P to proliferate and get retained in the bone marrow (BM) in an inducible model of CML. Binary transgenic SCL-tTA/TRE-BCR-ABL mice (Koschmieder S et al., Blood 2005) express p210 BCR-ABL in LSC/P upon doxycycline withdrawal (CML mice). Induced myeloproliferation was associated with activation of the downstream signaling effectors CrkL and p38-MAPK and expansion of circulating (Table 1) and splenic LSC/P but not in BM, suggesting massive LSC/P egression from the marrow (Table 2). Proliferation analysis showed that myeloid expansion in the spleen was secondary to increased cycling of Lin−Sca1+c-Kit+ (LSK) cells (3.1-fold increase in S-phase cells, P&lt;0.05), but not in Lin−/c-Kit+ (LK) population, compared with the control spleens. In agreement with the LSC/P BM content data, the frequency of BM-derived LSK and LK cells incorporating BrdU in CML and in control mice remained similar, suggesting a specific egression of LSC/P from the BM to extramedullary sites. To test whether this model truly represented a model of BM LSC/P egression, we compared the splenic and BM LSC/P compared with their controls regarding their adhesion molecule expression, interaction with the hematopoietic microenvironment (HM) and homing to the overall marrow cavity and endosteal space. Splenic, but not BM-derived, LSK and LSK CD34+ ST-HSCs had increased cell surface expression of CD44 compared to controls (1.35 fold, P=0.006 and 1.23 fold, P&lt;0.05 respectively) and decreased expression of L-selectin (8.7 fold, P&lt;0.05) while expression of CXCR4, α4β1 and α5β1 integrins remain similar in bone marrow and splenocytes from CML and control mice. CML BM progenitors also showed 18-fold reduced adhesion to fibronectin and 1.4-fold increased migration towards CXCL12 compared to control BM progenitors. Myeloproliferative disease was transplantable into non-transgenic littermates and homing of CML BM progenitors was increased (4.3 fold, P&lt;0.005) in myeloablated littermate recipient BM. However, lineage-negative leukemic BM-derived cells which had increased homing in BM of recipient mice had an impaired ability to migrate to the BM endosteal space compared with their littermate controls (control: 31 ± 18% vs CML mice: 17.6 ± 17%), suggesting an specific impairment to lodge in specialized anatomically-defined hematopoietic “niches”. Altogether, this murine model may represent an adequate in vivo system to analyze the ability of p210 BCR-ABL-expressing LSC/P to interact with BM niches and study the control of the hematopoietic microenvironment on LSC/P survival, proliferation and retention. Table 1 Increase in circulating LSC/P in the CML mice after withdrawal of doxycyclin Peripheral Blood LSK (×103)Cells/mL Blood P&lt;0.05 LT-HSC(×103)Cells/mL Blood P&lt;0.05 CFU-GM+BFU-E/mL Blood P&lt;0.05 Control 1.56 ± 0.25 0.459 ± 0.29 60.86 ± 51.09 CML mice 3.56 ± 1.52 2.159 ± 2.03 869.6 ± 628.4 Table 2. Immunophenotypic analysis of BM and splenocytes in control and CML mice Population BM (Cells ×104) (Control) BM (Cells x104) (CML) SP (Cells ×104) (Control) SP (Cells x104) (CML) C-Kit + Sca1 + 24.3 ± 9.9 21.3 ± 11 6.8 ± 4.5 30.1 ± 12.3 (P&lt;0.05) Mac1 + Gr1 + 1779 ± 307 1583 ± 265 78.4 ± 32 608 ± 377 (P&lt;0.05) CFU-C/10 5 Cells 342 ± 66 334 ± 99 63.3 ± 7.09 79 ± 6.54 (P&lt;0.05)

Parathyroid Hormone-Induced Modulation of the Bone Marrow Microenvironment Reduces Leukemic Stem Cells in Murine Chronic Myelogenous-Leukemia-Like Disease Via a TGFbeta-Dependent Pathway

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1670-1670
Author(s):  
Daniela S. Krause ◽  
Keertik Fulzele ◽  
Andre Catic ◽  
Michael Hurley ◽  
Sanon Lezeau ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Parathyroid Hormone ◽  
Cell Line ◽  
Chronic Myelogenous Leukemia ◽  
Bone Marrow Microenvironment ◽  
Myelogenous Leukemia ◽  
Osteoblastic Cells ◽  
Leukemic Stem Cells ◽  
Antibody Treatment

Abstract Abstract 1670 It is known that osteoblastic cells regulate the normal hematopoietic stem cell (HSC) niche and control its size. Parathyroid hormone (PTH) is an important regulator of osteoblasts and osteoclasts maintaining calcium homeostasis and, additionally, increasing HSC number in transplant recipients and protecting HSCs from repeated exposure to cytotoxic chemotherapy. We, therefore, hypothesized, that PTH-treatment may allow normal HSCs to outcompete leukemic stem cells (LSCs) in a murine model of chronic myelogenous leukemia. Mice with osteoblastic cell-specific constitutive activation of the receptor for PTH and PTH-related protein (Col1-caPPR mice) are characterized by activation of osteoblastic cells and increases in osteoclast and osteoblast number, trabecular bone, bone turnover and cortical porosity. Col1-caPPR mice have significantly prolonged survival and reduced leukemic mortality compared to wildtype (wt) littermates in a murine retroviral transduction/transplantation model of BCR-ABL1-induced CML-like disease (p=0.002) and B-cell acute lymphoblastic leukemia (B-ALL) (p=0.0004). However, a leukemogenic fusion transcription factor, MLL-AF9, known to cause acute myeloid leukemia in this model, led to more rapid death in the Col1-caPPR recipients compared with their wt counterparts (p<0.0001), indicating that the increased survival of Col1-caPPR recipients is specific for BCR-ABL1-induced leukemia. Continuous infusion of human PTH(1–34) into wt mice with BCR-ABL1-induced CML led to a statistically significant decrease in spleen weights and decreased bone marrow infiltration by BCR-ABL+ cells. Limiting dilution secondary transplantation of BM cells from saline- or PTH-treated primary animals with fully established CML into wt recipients revealed a 15-fold reduction of LSCs in a PTH-treated environment. Secondary mice who received BM from saline-treated donors had an overall survival that was 1/4 that of recipients of marrow from a PTH-treated BM microenvironment. Transforming growth factor beta-1 (TGFβ-1), whose largest and most concentrated tissue source is bone, was increased in the bones of Col1-caPPR mice. TGFβ-1 significantly decreased the in-vitro growth of the BCR-ABL+ cell line K562, but not the MLL-AF9+ cell line THP-1 suggesting that TGFβ-1, increased in the bone marrow microenvironment of Col1-caPPR mice, may be actively suppressing the growth of the BCR-ABL+ diseases, but not of MLL-AF9+ AML. Conversely, blockade of TGFβ-1, -2, and -3 by anti- TGFβ antibody treatment increased the incidence of CML in Col1-caPPR mice from 50% to 75%. Knockdown of TGF Receptor I in transplanted BCR-ABL+ BM in the CML model increased the percentage of BCR-ABL+ myeloid cells in peripheral blood in wt and, more strikingly, in Col1-caPPR recipient mice and increased the overall incidence of CML in Col1-caPPR mice. These results argue that reduction in TGFβ-1 signaling may rescue the CML phenotype in Col1-caPPR mice. In conclusion, these studies suggest that modulation of the bone marrow microenvironment by PTH reduces the frequency of LSCs in CML, possibly by suppression of LSCs via TGFβ-1. Consequently, a clinical trial on the combined use of imatinib and PTH in patients with CML has been initiated at our institution. Disclosures: No relevant conflicts of interest to declare.

An Extended Mathematical Model of Pathophysiology and Response to Treatment in Chronic Myelogenous Leukemia

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4220-4220
Author(s):  
Yasuhito Nannya ◽  
Yoichi Imai ◽  
Akira Hangaishi ◽  
Mineo Kurokawa
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitors ◽  
Chronic Myelogenous Leukemia ◽  
Peripheral Blood ◽  
Kinase Inhibitors ◽  
Myelogenous Leukemia ◽  
Leukemic Stem Cells

Abstract Chronic myelogenous leukemia (CML) is a malignant clonal disorder of hematopoietic stem cells that results in increase in myeloid, erythroid cells, and platelets in the peripheral blood and marked myeloid hyperplasia in the bone marrow. This disorder is characterized by the specific cytogenetic abnormality, the Philadelphia (Ph) chromosome, which results from a balanced translocation between the long arms of chromosomes 9 and 22, generating the bcr/abl chimeric gene that expresses an abnormal fusion protein with altered tyrosine kinase activity. Imatinib mesylate (IM, Gleevec, Novartis, Basel, Switzerland), is a potent and selective competitive inhibitor of the BCR-ABL protein tyrosine kinase and has shown to induce a high rate of cytogenetic and hematologic response in patients with chronic phase (CP) CML both as initial therapy and as secondary therapy after previous interferon therapy failed. Because the pathophysiology of CML and the mechanism for the clinical effects by IM is relatively uniform among patients, simplification and generalization with mathematical models have been proposed and they have excellently simulated the regression of leukemic cells by IM therapy and the regrowth of CML cells after appearance of IM-resistant clones. These models are based on the assumption that the transition rate of leukemic stem cells or precursor cells to more differentiated fractions are profoundly diminished by the administration of IM. This assumption is sufficient to explain the response as long as the observation period is short. In contrast, the issue regarding the influence of IM on the self-reproduction rate of leukemic stem cells was not focused on in these models because this issue had little effect on short-term outcomes with IM. After a decade since the appearance of IM, accumulated observations of CML patients treated with IM revealed long-term effectiveness; novel transformations to accelerate phase or blastic crisis are rarely observed in patients who continue to receive 400mg/day of IM for five or six years. Our aim is to clarify the effect of IM on leukemic stem cell fractions by extending and modifying the existing models so that they are compatible with actual long-term outcomes of IM therapy. First, we demonstrated that sustained effectiveness of IM for over six years cannot be achieved unless a stem cell fraction of CML is decremented by IM. In order to estimate the degree of stem cell attack by IM, we computed the rate of novel generation of IM-resistant clones before and after IM administration. In this model, we presumed that this rate is proportional to the accumulated number of self-duplication of leukemic stem cells. In order to simulate the actual observation that the clonal evolution decrease annually after IM administration, we illustrated that the rate of self duplication is depleted to at one fourth or less with IM compared to without IM. With this simulation, we show that the tyrosine kinase inhibitors can eradicate malignant cells thus leading to the radical cure of the disease. We also showed that the achievement of major molecular response (MMR; defined as at least three-log reduction of bcr/abl positive clones in the peripheral blood) at the 18th month of IM therapy is roughly associated with the absence of resistant clones at the moment of IM administration, and is obviously linked to successful therapy of CML after IM therapy is launched. This provides the supportive evidence of the previously reported observation that MMR at 18th month is associated with long-term effectiveness. Our model underscores the significance of prompt elimination of leukemic stem cells in order to diminish the generation of novel resistant clones and accomplish complete cure of CML. Development of the evaluation system to quantify residual leukemic stem cells would verify this hypothesis and pursuit to maximal response including early administration of second-generation tyrosine kinase inhibitors would be justified.

Identification of human chronic myelogenous leukemia progenitor cells with hemangioblastic characteristics

Blood ◽  
2005 ◽  
Vol 105 (7) ◽  
pp. 2733-2740 ◽  
Author(s):  
Baijun Fang ◽  
Chunmei Zheng ◽  
Lianming Liao ◽  
Qin Han ◽  
Zhao Sun ◽  
...  
Keyword(s):  
Stem Cells ◽  
Endothelial Cells ◽  
Progenitor Cells ◽  
Chronic Myelogenous Leukemia ◽  
Blood Cells ◽  
Fusion Gene ◽  
Fetal Liver ◽  
Philadelphia Chromosome ◽  
Myelogenous Leukemia ◽  
Leukemic Cells

AbstractOverwhelming evidence from leukemia research has shown that the clonal population of neoplastic cells exhibits marked heterogeneity with respect to proliferation and differentiation. There are rare stem cells within the leukemic population that possess extensive proliferation and self-renewal capacity not found in the majority of the leukemic cells. These leukemic stem cells are necessary and sufficient to maintain the leukemia. Interestingly, the BCR/ABL fusion gene, which is present in chronic myelogenous leukemia (CML), was also detected in the endothelial cells of patients with CML, suggesting that CML might originate from hemangioblastic progenitor cells that can give rise to both blood cells and endothelial cells. Here we isolated fetal liver kinase-1–positive (Flk1+) cells carrying the BCR/ABL fusion gene from the bone marrow of 17 Philadelphia chromosome–positive (Ph+) patients with CML and found that these cells could differentiate into malignant blood cells and phenotypically defined endothelial cells at the single-cell level. These findings provide direct evidence for the first time that rearrangement of the BCR/ABL gene might happen at or even before the level of hemangioblastic progenitor cells, thus resulting in detection of the BCR/ABL fusion gene in both blood and endothelial cells.

scholarly journals Polyclonal hematopoiesis in interferon-induced cytogenetic remissions of chronic myelogenous leukemia

Blood ◽  
1992 ◽  
Vol 79 (4) ◽  
pp. 997-1002 ◽  
Author(s):  
D Claxton ◽  
A Deisseroth ◽  
M Talpaz ◽  
C Reading ◽  
H Kantarjian ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Gene Polymorphism ◽  
Chronic Myelogenous Leukemia ◽  
Myelogenous Leukemia ◽  
Hematopoietic Stem ◽  
Clonality Analysis ◽  
Ifn Therapy ◽  
Cytogenetic Remission ◽  
The One

Interferon (IFN) therapy of early chronic myelogenous leukemia (CML) frequently produces partial or complete cytogenetic remission of the disease. Patients with complete cytogenetic remission often continue on therapy for several years with bone marrow showing only diploid (normal) metaphases. We studied hematopoiesis in five female patients with major cytogenetic remissions from CML during IFN therapy. Clonality analysis using the BstXI PGK gene polymorphism showed that granulocytes were nonclonal in all patients during cytogenetic remission. BCR region studies showed rearrangement only in the one patient whose remission was incomplete at the time of sampling. Granulopoiesis is nonclonal in IFN-induced remissions of CML and may be derived from normal hematopoietic stem cells.

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