scholarly journals BCR-ABL expression in different subpopulations of functionally characterized Ph+ CD34+ cells from patients with chronic myeloid leukemia

Blood ◽  
1996 ◽  
Vol 88 (5) ◽  
pp. 1796-1804 ◽  
Author(s):  
V Maguer-Satta ◽  
AL Petzer ◽  
AC Eaves ◽  
CJ Eaves
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
K562 Cells ◽  
Very High Frequency ◽  
Hematopoietic Stem ◽  
Cell Counts ◽  
Cd34 Cells ◽  
Actin Mrna ◽  
White Blood Cell Counts

In patients with chronic myeloid leukemia (CML), the leukemic (BCR- ABL+/Ph+) clone typically includes cells belonging to all of the myeloid lineages and frequently some B cells. From such observations it has been inferred that the initial BCR-ABL gene rearrangement event occurs in a pluripotent hematopoietic stem cell and that the clone subsequently generated is maintained by a subpopulation of neoplastic, BCR-ABL-expressing cells that retain at least some of the defining properties of normal hematopoietic stem cells. To test this hypothesis directly, we isolated various subpopulations of CD34+ cells from fresh or cryopreserved samples of peripheral blood from 5 CML patients with high white blood cell counts, 4 of which were selected because of their exclusive content of Ph+ progenitors (both colony-forming cells and long-term culture-initiating cells [LTC-IC]). Cells in each of the CD34+ subpopulations isolated were examined for the presence of BCR-ABL mRNA using a reverse transcriptase-polymerase chain reaction technique that reproducibly gave a positive signal from single K562 cells. BCR- ABL mRNA was detected in 117 of 147 samples (80%) in which actin mRNA was demonstrable. This included 60% to 90% of a large number of individually analyzed CD34+ cells including 46 single CD34+CD71-CD38- cells and 27 single CD34+CD71+CD38+ cells from 3 patients. In 2 of these cases, the same populations also contained a very high frequency of Ph+ LTC-IC. Our findings demonstrate BCR-ABL gene expression in neoplastic cells with functional as well as surface marker characteristics of very primitive normal hematopoietic cells. This implicates the BCR-ABL gene product directly in the acquisition by these cells of properties that alter their interactions with the microenvironment and deregulate their proliferation control.

scholarly journals BCR-ABL expression in different subpopulations of functionally characterized Ph+ CD34+ cells from patients with chronic myeloid leukemia

Blood ◽  
1996 ◽  
Vol 88 (5) ◽  
pp. 1796-1804 ◽  
Author(s):  
V Maguer-Satta ◽  
AL Petzer ◽  
AC Eaves ◽  
CJ Eaves
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
K562 Cells ◽  
Very High Frequency ◽  
Hematopoietic Stem ◽  
Cell Counts ◽  
Cd34 Cells ◽  
Actin Mrna ◽  
White Blood Cell Counts

Abstract In patients with chronic myeloid leukemia (CML), the leukemic (BCR- ABL+/Ph+) clone typically includes cells belonging to all of the myeloid lineages and frequently some B cells. From such observations it has been inferred that the initial BCR-ABL gene rearrangement event occurs in a pluripotent hematopoietic stem cell and that the clone subsequently generated is maintained by a subpopulation of neoplastic, BCR-ABL-expressing cells that retain at least some of the defining properties of normal hematopoietic stem cells. To test this hypothesis directly, we isolated various subpopulations of CD34+ cells from fresh or cryopreserved samples of peripheral blood from 5 CML patients with high white blood cell counts, 4 of which were selected because of their exclusive content of Ph+ progenitors (both colony-forming cells and long-term culture-initiating cells [LTC-IC]). Cells in each of the CD34+ subpopulations isolated were examined for the presence of BCR-ABL mRNA using a reverse transcriptase-polymerase chain reaction technique that reproducibly gave a positive signal from single K562 cells. BCR- ABL mRNA was detected in 117 of 147 samples (80%) in which actin mRNA was demonstrable. This included 60% to 90% of a large number of individually analyzed CD34+ cells including 46 single CD34+CD71-CD38- cells and 27 single CD34+CD71+CD38+ cells from 3 patients. In 2 of these cases, the same populations also contained a very high frequency of Ph+ LTC-IC. Our findings demonstrate BCR-ABL gene expression in neoplastic cells with functional as well as surface marker characteristics of very primitive normal hematopoietic cells. This implicates the BCR-ABL gene product directly in the acquisition by these cells of properties that alter their interactions with the microenvironment and deregulate their proliferation control.

Persistence of BCR-ABL-Expressing LEUKEMIC STEM CELLS IN Chronic MYELOID LEUKEMIA (CML) PATIENTS IN COMPLETE REMISSION with Undetectable MOLECULAR Disease

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 883-883 ◽  
Author(s):  
Jean-Claude Chomel ◽  
Marie Laure Bonnet ◽  
Nathalie Sorel ◽  
Angelina Bertrand ◽  
Marie Claude Meunier ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Leukemic Stem Cells ◽  
Hematopoietic Stem ◽  
Cd34 Cells ◽  
Previously Treated ◽  
Clonogenic Cells

Abstract Abstract 883 Currently Imatinib Mesylate (IM) represent the first line therapy for chronic myeloid leukemia (CML). Recent data suggest that despite unprecedented rates of complete cytogenetic responses (CCR) and major molecular responses (MMR) obtained, leukemic stem cells (LSC) persist in the majority of patients (pts). LSC have been shown to be resistant to in vitro treatments with tyrosine kinase inhibitors (TKI). Consequently, discontinuation of IM in pts with undetectable molecular residual leukemia (UMRL) attested by RQ-PCR, leads to molecular relapses in the majority of the cases. Although the persistence of CD34+ CD38- leukemic stem cells has been demonstrated in pts with complete cytogenetic remission (CCR), the persistence of BCR-ABL+ leukemic stem cells in UMRL pts with has not been studied so far. For this purpose, we have performed an extensive analysis of bone-marrow-derived clonogenic and primitive hematopoietic stem cells in 6 pts with RQ-PCR constantly negative in their blood samples. Concerning the treatments; 5 out of 6 pts were off therapy, 3 pts (UPN1, 2, 3) had been treated with interferon-a only (IFN) for 6–13 years and their therapy was discontinued for 11, 16 and 8 years, respectively and 2 pts (UPN4 and 5) had been treated successively with IFN and IM and their IM therapy was discontinued for 2 years. One patient (UPN6) had been treated with IM followed by dasatinib and was on dasatinib at the time of the study. UPN7 was previously treated with first IFN then IM (which induced a stable UMRL) and then she switched to dasatinib because of side effect with IM. Bone marrow cells were collected and CD34+ cells purified using immunomagnetic columns. After performing a clonogenic assay, CD34+ cells were used in long-term culture initiating cell (LTC-IC) assays with weekly half medium changes. At week+5, clonogenic assays were performed and LTC-IC-derived clonogenic cells activity was calculated. For each patient 20 individual and 20 pools of 10 clonogenic cells and 20 individual and 20 pools of 10 LTC-IC derived CFU-C were plucked in order to obtain information in at least 220 CFU-C. After RNA extraction, BCR-ABL was quantified by RQ-PCR and in each positive CFU-C a nested PCR was performed to confirm the results. In one patient (UPN7) a NOD/SCID mouse assay was performed. All 3 pts treated with IFN alone, had BCR-ABL+ clonogenic cells varying from 0.5% (UPN1, 2) to 45 % (UPN3). All 3 had LTC-IC derived CFU-C positive for BCR-ABL (UPN1: 20%; UPN2 5%; UPN3 3%). In two pts previously treated with IFN and IM, clonogenic CFU-C BCR-ABL positivity was 10% and 5% whereas LTC-IC-derived CFU-C was 5% in UPN4) and undetected on UPN5. In UPN6 treated with IM then dasatinib, 5% of CFU-C was BCR-ABL+ whereas 100% of LTC-IC derived CFU-C was positive. The analysis of SCID-NOD assays performed in CD34+ cells from patient UPN7 is ongoing. Overall, these data show, for the first time to our knowledge, that in pts in IFN and IFN/IM-induced long-term remissions, there is persistent clonogenic BCR-ABL+ output maintained by BCR-ABL-expressing stem cells in the absence of relapse. In the only patient with successively treated with IM and dasatinib, 100 % of primitive hematopoietic stem cells are BCR-ABL+, despite PCR-negativity in peripheral blood, suggesting their possible quiescence in vivo and highlighting a theoretical risk of relapse. It remains to be determined if in pts with TKI-induced remissions, the analysis of stem cell compartments could be of use for clinical decisions to discontinue therapy. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Characterization of primitive subpopulations of normal and leukemic cells present in the blood of patients with newly diagnosed as well as established chronic myeloid leukemia

Blood ◽  
1996 ◽  
Vol 88 (6) ◽  
pp. 2162-2171 ◽  
Author(s):  
AL Petzer ◽  
CJ Eaves ◽  
PM Lansdorp ◽  
L Ponchio ◽  
MJ Barnett ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Intensive Therapy ◽  
Philadelphia Chromosome ◽  
Chronic Phase ◽  
Leukemic Cells ◽  
Cell Counts ◽  
Normal Individuals ◽  
White Blood Cell Counts

Elevated numbers of primitive Philadelphia chromosome-positive (Ph+) progenitors, including long-term culture-initiating cells (LTC-IC) as well as colony-forming cells (CFC), have been previously described in the blood of patients with chronic myeloid leukemia (CML) in chronic phase with high white blood cell counts. In the present study, which focused primarily on an analysis of circulating progenitors present in such patients at diagnosis, we discovered the frequent and occasionally exclusive presence of circulating normal (Ph-) LTC-IC, often at levels above those seen for LTC-IC in the blood of normal individuals. The presence of detectable numbers of circulating Ph- LTC-IC was independent of the fact that the same peripheral blood samples also contained elevated numbers of predominantly or exclusively Ph+ CFC. Interestingly, both the Ph+ and Ph- LTC-IC in these samples were CD34+CD71- and variably CD38- and Thy-1+, as previously documented for LTC-IC in normal marrow. Thus, neither CD38 nor Thy-1 expression was useful for discriminating between Ph+ and Ph- LTC-IC in mixed populations. Nevertheless, an association of these phenotypes with LTC- IC function did allow highly enriched (> 5% pure) suspensions of either Ph+ or Ph- LTC-IC to be obtained from selected samples of CML blood in which the initial LTC-IC population was either predominantly Ph+ or Ph- , respectively. These findings suggest that the mechanisms causing mobilization of leukemic stem cells in untreated CML patients may affect their normal counterparts. They also indicate a possible new source of autologous cells for the support of intensive therapy of CML patients. Finally, they provide a method for obtaining the most highly purified populations of Ph+ LTC-IC described to date. This method should be useful for further analyses of the molecular activities of these very primitive neoplastic cells.

Long-term follow-up of allogeneic hematopoietic stem-cell transplantation with reduced-intensity conditioning for patients with chronic myeloid leukemia

Blood ◽  
2007 ◽  
Vol 110 (9) ◽  
pp. 3456-3462 ◽  
Author(s):  
Partow Kebriaei ◽  
Michelle A. Detry ◽  
Sergio Giralt ◽  
Antonio Carrasco-Yalan ◽  
Athanasios Anagnostopoulos ◽  
...  
Keyword(s):  
Stem Cell ◽  
Chronic Myeloid Leukemia ◽  
Hematopoietic Stem Cell Transplantation ◽  
Myeloid Leukemia ◽  
Chronic Phase ◽  
Reduced Intensity Conditioning ◽  
Hematopoietic Stem ◽  
Reduced Intensity

Abstract Allogeneic hematopoietic stem-cell transplantation (HSCT) remains an effective strategy for inducing durable remission in chronic myeloid leukemia (CML). Reduced-intensity conditioning (RIC) regimens extend HSCT to older patients and those with comorbidities who would otherwise not be suitable candidates for HSCT. The long-term efficacy of this approach is not established. We evaluated outcomes of 64 CML patients with advanced-phase disease (80% beyond first chronic phase), not eligible for myeloablative preparative regimens due to older age or comorbid conditions, who were treated with fludarabine-based RIC regimens. Donor type was matched related (n =30), 1 antigen-mismatched related (n =4), or matched unrelated (n =30). With median follow-up of 7 years, overall survival (OS) and progression-free survival (PFS) were 33% and 20%, respectively, at 5 years. Incidence of treatment-related mortality (TRM) was 33%, 39%, and 48% at 100 days, and 2 and 5 years after HSCT, respectively. In multivariate analysis, only disease stage at time of HSCT was significantly predictive for both OS and PFS. RIC HSCT provides adequate disease control in chronic-phase CML patients, but alternative treatment strategies need to be explored in patients with advanced disease. TRM rates are acceptable in this high-risk population but increase over time.

Long-Term Follow-up Results Over 7 Years for Survival, and Safety with Imatinib Mesylate Accompany with Allogeneic Transplantation for Chronic Myeloid Leukemia

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4529-4529
Author(s):  
Jun Wang ◽  
Aining Sun ◽  
Wu Depei ◽  
Huiying Qiu ◽  
XiaoWen Tang
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Imatinib Mesylate ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Allogeneic Transplantation ◽  
Cytogenetic Response ◽  
Hematopoietic Stem ◽  
Long Term Follow Up

Abstract Abstract 4529 Objective: To observe the efficacy and safety of imatinib mesylate (IM) accompany with allogeneic transplantation for chronic myeloid leukemia (CML). Methods: During the period from January 2003 to August 2011,we retrospectively observed 95 patients with CML receiving IM for a minimum of 4 months before allogeneic hematopoietic stem cell transplantation (HSCT). Patients with advanced CML received IM from 3 month after transplantation for 12 months. Results: Among 95 enrolled patients (CML-CP 76, CML-AP 10, CML-BP 9), types of transplantation: sib-matched HSCT 64, unrelated-HSCT 19, haplo-HSCT 12. For the whole patients, 7 year overall survival (OS) is 80.5%, and disease free survival (DFS) is 74.5%. Complete hematologic response (CHR) is 93.6%, complete cytogenetic response (CCR) is 84.5%, major cytogenetic response (MCR) is 60.3% at 7 year. For CML-CP1, OS is 83.2% and CML-AP/BC is 33.3% (P<0.05). Compared patients of advanced CML achieving CP2 after IM and with no CP2,the former has better results of CCR or MCR, OS and PFS (P<0.05). The total treatment related mortality (TRM) is 16.8%. Cox multivariate regression analysis of prognostic factors indicates that status of CML and severe acute graft-versus-host disease (aGVHD III-‡W) retain independent predictive value. No increase in rates of serious adverse events was observed with continuous use of IM for up to 7 years. Conclusions: For chronic myeloid leukemia, combining with imatinib mesylate and allogeneic transplantation is a good strategy, with favorable long-term follow-up results and acceptable TRM, especially for the patients with advanced CML. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Achieving Complete Cytogenetic Response and BCR-ABL PCRIS <1% within 12 Moths Are Important Goals for Imatinib Therapy in Newly Diagnosed, TKI-Naive Chronic Myeloid Leukemia Accelated Phase Patients

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3158-3158
Author(s):  
Hawk Kim ◽  
Eun-Jung Jang ◽  
Sung-Eun Lee ◽  
Won Sik Lee ◽  
Sukjoong Oh ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Platelet Count ◽  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Cytogenetic Response ◽  
Molecular Response ◽  
Hematopoietic Stem ◽  
Long Term Outcome

Abstract Background; Accelerated phase of chronic myeloid leukemia (AP-CML) is not clearly defined yet. There are different definitions to classify AP. In European Leukemia Net (ELN) 2013 recommendation, considerable therapeutic approach of de novo AP would be hematopoietic stem cell transplantation (HSCT) followed by frontline tyrosine kinase inhibitor (TKI). To explore long-term efficacy of frontline imatinib (IM) treatment and early predictors of long-term outcome, we analyzed a total of 73 patients who received frontline IM.. Method; AP defined as a definition of ELN recommendation.. A progression to blastic phase and loss of response were considered as progression. Patients who had received HCT were censored at the time of HCT when calculating overall survival (OS) and progression-free survival (PFS). Results; Of 83 patients who diagnosed as AP, 73 patients received IM and other 10 patients had HSCT (n=7) or no treatment (n=3). Of 73 IM-treated patients, 36 patients maintained IM therapy and 37 patients discontinued IM with switch to 2G TKI (n=23) or HSCT (n=14). Analysis of baseline characteristics revealed prior cytogenetic response (CyR), and molecular response at 6 and 12 months for prediction of survivals. Clinical factors for better survival including Sokal score (p=0.203), Hasford sore (p=0.832), peripheral blood (PB) basophil count (p=0.374), spleen size (p=0.656), bone marrow (BM) promelocyte (p=0.839), BM basophil (p=0.478 were not significant. PB blast<10% (p=0.0670), PB eosinophil count>5% (p=0.031), platelet count >20x109/L (p=0.008), PB promyelocyte<2% (p=0.171), PB blast+promelocyte<20% (p=0.095), BM blast+promelocyte<20% (p=0.006), BM blast<10% (p=0.020) at diagnosis, achieving CCyR (p<0.001), achieving BCR-ABL PCRIS <10% (MR1.0) at 3M (p=0.020), BCR-ABL PCRIS <1% (MR2.0) at 6M (p=0.005) and MR2.0 at 12M (p=0.001) were included in multivariate analysis. Platelet count >20x109/L at diagnosis (p=0.002), achieving CCyR (p=0.007) and MR2.0 at 12M (p=0.048) were significant prognostic factors in multivariate analysis. Probability of 10Y OS for patients who acheived CCyR vs. no CCyR were 85.2% vs. 0% (p<0.001); median survival for patients without CCyR was 31.737 (95% CI, 16.269-47.147) months (Figure 2). Probabilities of 10Y OS for MR1.0 at 6M and MR2.0 at 12M were 81.3% vs. 59.7% (p=0.016) and 96.5% vs. 57.4% (p=0.003), respectively. However, time to CCyR<6M was not significant 10Y OS rate 75% vs. 67.6%, p=0.173). The 10Y PFS probability in patients who had acheived CCyR was 66.0% vs. 0% (p<0.001); median PFS for patients without CCyR was 9.462 (95% CI, 1.978-16.946) months. Probabilities of 10Y PFS in MR1.0 at 6M and MR2.0 at 12M were 63.2% vs. 44.9% (p=0.076) and 77.1% vs. 39.8% (p=0.005), respectively. Median PFS for patients not achieving MR1.0 at 6M and MR2.0 at 12M were 30.555 (95% CI, 0.0-61.252) and 22.867 (95% CI, 0.0-50.208), respectively. Time to CCyR<6M was not significant for PFS (10Y PFS rate 50.8% vs. 58.5%, p=0.828). Conclusion: Achievement of CCyR or achievement of MR1.0 at 12M was important goals not only in progression but also in survival. Therefore if a patient doesnÕt achieve the goals, the treatments need to be changed. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

scholarly journals Leukemia Stem Cells as a Potential Target to Achieve Therapy-Free Remission in Chronic Myeloid Leukemia

Cancers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 5822
Author(s):  
Kyoko Ito ◽  
Keisuke Ito
Keyword(s):  
Stem Cells ◽  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Drug Binding ◽  
Leukemia Stem Cells ◽  
Phase Point ◽  
Hematopoietic Stem ◽  
Wide Range ◽  
Tki Resistance

Leukemia stem cells (LSCs, also known as leukemia-initiating cells) not only drive leukemia initiation and progression, but also contribute to drug resistance and/or disease relapse. Therefore, eradication of every last LSC is critical for a patient’s long-term cure. Chronic myeloid leukemia (CML) is a myeloproliferative disorder that arises from multipotent hematopoietic stem and progenitor cells. Tyrosine kinase inhibitors (TKIs) have dramatically improved long-term outcomes and quality of life for patients with CML in the chronic phase. Point mutations of the kinase domain of BCR-ABL1 lead to TKI resistance through a reduction in drug binding, and as a result, several new generations of TKIs have been introduced to the clinic. Some patients develop TKI resistance without known mutations, however, and the presence of LSCs is believed to be at least partially associated with resistance development and CML relapse. We previously proposed targeting quiescent LSCs as a therapeutic approach to CML, and a number of potential strategies for targeting insensitive LSCs have been presented over the last decade. The identification of specific markers distinguishing CML-LSCs from healthy HSCs, and the potential contributions of the bone marrow microenvironment to CML pathogenesis, have also been explored. Nonetheless, 25% of CML patients are still expected to switch TKIs at least once, and various TKI discontinuation studies have shown a wide range in the incidence of molecular relapse (from 30% to 60%). In this review, we revisit the current knowledge regarding the role(s) of LSCs in CML leukemogenesis and response to pharmacological treatment and explore how durable treatment-free remission may be achieved and maintained after discontinuing TKI treatment.

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