GATA-2 L359V Mutation Is Solely Associated with Cml progression but Not Other Hematological Malignancies.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1507-1507 ◽  
Author(s):  
Su-Jiang Zhang ◽  
Jing-Yi Shi
Keyword(s):  
Transcription Factor ◽  
Myeloid Leukemia ◽  
Hematological Malignancies ◽  
Lymphoblastic Leukemia ◽  
Blast Crisis ◽  
Chronic Phase ◽  
Positive Control ◽  
Lymphocytic Leukemia ◽  
Hematopoietic Stem ◽  
Biology Process

Abstract Chronic Myeloid Leukemia (CML) is a hematopoietic stem cell disease with distinct biology and clinical features. According to clinical and biology process, CML can be divided as two different phase: the initial chronic phase (CP) and progression phase including accelerated phase (AP) followed by blast crisis (BC). In a previous study, we have identified the transcription factor GATA-2 L359V mutation in CML BC patients but not CP and its pivotal role in CML progression (PNAS 2008 105:2076–2081). Here, we continued to explore the occurrence of GATA-2 L359V mutation in other hematological malignancies using Mass-ARRAY assay and sequence analysis. A total of 652 patient samples were included in our study. These patients were referred to 270 Acute Myeloid Leukemia (AML) including M1–M7, 30 Myelodysplastic Syndrome (MDS), 50 Acute Lymphoblastic Leukemia (ALL), 12 Chronic Lymphocytic Leukemia (CLL), 40 CML CP and 250 BCR/ABL negative Myeloproliferative Disorder (MPD) patients. 5 ml bone marrow sample before therapy was collected with informed consent and genomic DNA was isolated. The diagnosis of AML, ALL, CML, CLL, MDS and MPD was established according to the 2001 WHO diagnostic criteria. In addition, 8 samples of CML BC harboring GATA-2 L359V were supplied into our study as positive control and 100 peripheral blood samples of healthy adult as normal control. As a result, no L359V mutation was detected in AML, ALL, MDS, CLL, BCR/ABL negative MPD and CML CP. Our data strongly suggested that GATA-2 L359V is solely associated with CML progression but not other hematological malignancies. Therefore, we favored this idea, i.e., BCR/ABL underlies the pathogenic basis of CML CP; However, subsequent genomic instabilities contribute to mutation of key transcription factor such as GATA-2 which ultimately trigger the blastic transformation of CML.

Use of Ubiquitin-Proteasome System Profiling for Differentiating Between Various Leukemic Processes.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4712-4712
Author(s):  
Ke Zhang ◽  
Hagop M. Kantarjian ◽  
Wanlong Ma ◽  
XI Zhang ◽  
Xiuqiang Wang ◽  
...  
Keyword(s):  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Lymphoblastic Leukemia ◽  
Blast Crisis ◽  
Chronic Phase ◽  
Direct Analysis ◽  
Cell Types ◽  
Ubiquitin Proteasome System ◽  
Lymphocytic Leukemia ◽  
Ubiquitin Proteasome

Abstract Abstract 4712 The ubiquitin-proteasome system (UPS) plays a major role in cell homeostasis in normal and neoplastic states. Expression and function of the UPS system vary with the specific characteristics of individual cell types, suggesting that determination of UPS “signatures” could be useful in identifying various cell populations. Since direct analysis of cancer cells is often problematic, even in hematologic diseases, we explored the potential of using UPS signatures in plasma to differentiate between various leukemias. We first analyzed plasma UPS profiles of patients with acute myeloid leukemia (AML; n=111), acute lymphoblastic leukemia (ALL; n=29), advanced myelodysplastic syndrome (MDS; n=20), chronic lymphocytic leukemia (CLL; n=118), or chronic myeloid leukemia (CML; n=128; 46 in accelerated/blast crisis [ACC/BL], 82 in chronic phase), and 85 healthy control subjects. Plasma levels of proteasome, ubiquitin (poly-ubiquitin), and the 3 proteasome enzymatic activities (chymotrypsin-like [Ch-L], caspase-like [Cas-L], trypsin-like [Tr-L]) were measured. Specific activities were calculated by normalizing each of the 3 enzyme activities to the levels of proteasome protein in plasma (Ch-L/p, Cas-L/p, and Tr-L/p). These 8 variables were used in multivariate logistic regression models to differentiate between leukemic processes. UPS signatures provided clear differentiation between patients with a leukemic process and normal controls (AUC=0.991), using 6 different variables (Tr-L/P, Ch-L, Ch-L/p, Cas-L, Cas-L/P, ubiquitin). Distinguishing between acute (AML, ALL, MDS) and chronic (CML, CLL) processes was less efficient (AUC=0.853 using Tr-L, Tr-L/P, Cas-L/P, Ch-L/P, proteasome, Ch-L), likely due to the high proportion (36%) of CML patients in ACC/BL phase. However, UPS signatures generally yielded powerful differentiation between individual leukemias (Table). MDS was not well differentiated from AML (AUC=0.791), reflecting the significant biological overlap of these diseases. These data support the potential usefulness of the UPS profile to aid in the differential diagnosis of various leukemias. Disclosures: No relevant conflicts of interest to declare.

GATA-2 L359V Mutation Is Exclusively Associated with CML Progression but Not Other Hematological Malignancies and GATA-2 P250A Is a Novel Single Nucleotide Polymorphism.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2187-2187
Author(s):  
Su-Jiang Zhang ◽  
Jing-Yi Shi ◽  
Jianyong Li
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Myeloid Leukemia ◽  
Hematological Malignancies ◽  
Conflicts Of Interest ◽  
Lymphoblastic Leukemia ◽  
Chronic Phase ◽  
Lymphocytic Leukemia ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Molecular Abnormalities

Abstract Abstract 2187 Poster Board II-164 Chronic myeloid leukemia (CML) progression is characterized by occurrence of new cytogenetic and molecular abnormalities. In the previous study, we have shown the important role of GATA-2 L359V mutation in CML progression. To further ascertain the truth of transcription factor GATA-2 in hematological malignancies, we expanded our study to GATA-2 full length by directly sequencing and applied MassARRAY assay into GATA-2 L359V mutation analysis. Finally, no GATA-2 L359V mutation was found in 270 acute myeloid leukemia, 30 myelodysplastic syndrome, 50 acute lymphoblastic leukemia, 12 chronic lymphocytic leukemia, 40 CML chronic phase and 286 BCR/ABL negative myeloproliferative disorders except CML blast crisis. A new variation of GATA-2 resulted in P250A change was identified, which was not found to have statistical difference between patients with hematological malignancies and healthy control. Hence, we concluded GATA-2 L359V is exclusively associated with CML progression but not other hematological malignancies and P250A is a new single nucleotide polymorphism. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Homozygous deletions of the p16 tumor-suppressor gene are associated with lymphoid transformation of chronic myeloid leukemia

Blood ◽  
1995 ◽  
Vol 85 (8) ◽  
pp. 2013-2016 ◽  
Author(s):  
H Sill ◽  
JM Goldman ◽  
NC Cross
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Tumor Suppressor ◽  
Myeloid Leukemia ◽  
Lymphoblastic Leukemia ◽  
Blast Crisis ◽  
Chronic Phase ◽  
P16 Gene ◽  
Number Of Patients ◽  
Wide Range ◽  
Homozygous Deletions

The p16 gene, also referred to as MTS1, INK4, CDK4I, or CDKN2, at chromosome 9p21 has recently been described as a tumor suppressor that may be involved in a wide range of tumors. We have used a semiquantitative multiplex polymerase chain reaction assay to search for deletions of the p16 gene in 34 patients with chronic myeloid leukemia in blast crisis (CML BC), 19 patients with acute lymphoblastic leukemia (ALL), and 25 patients with acute myeloid leukemia (AML). Homozygous deletions of p16 exons were found in 5 of 10 (50%) patients with CML in lymphoid BC and in 5 (26%) ALL patients, but in only 1 (2%) case with AML. No deletions were found in CML BC of nonlymphoid phenotype. Comparison of chronic phase DNA or remission DNA with acute leukemia DNA in 5 individuals showed that the p16 deletions were acquired and not inherited, directly implicating these lesions in the pathogenesis of the disease. We conclude that functional elimination of the p16 gene, or a closely mapping gene, is involved in a significant number of patients with CML in lymphoid transformation.

scholarly journals Expression of axl, a transforming receptor tyrosine kinase, in normal and malignant hematopoiesis

Blood ◽  
1994 ◽  
Vol 84 (6) ◽  
pp. 1931-1941 ◽  
Author(s):  
A Neubauer ◽  
A Fiebeler ◽  
DK Graham ◽  
JP O'Bryan ◽  
CA Schmidt ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Receptor Tyrosine Kinase ◽  
Intracellular Signaling ◽  
Myeloid Leukemia ◽  
Blast Crisis ◽  
Chronic Phase ◽  
Lymphocytic Leukemia ◽  
Myelogenous Leukemia ◽  
Hematopoietic Tissue ◽  
Blood Leukocytes

Abstract We previously reported the cloning, and characterization of a receptor tyrosine kinase, axl, from two patients with chronic myelogenous leukemia. Herein, we describe the expression pattern of axl in normal and malignant hematopoietic tissue axl message is detected in normal human bone marrow but not significantly in normal blood leukocytes. Cell separation experiments showed that axl is expressed in hematopoietic CD34+ progenitor and marrow stromal cells, at low levels in peripheral monocytes, but not in lymphocytes or granulocytes. Consistent with the normal pattern of axl expression, axl RNA was found predominantly in diseases of the myeloid lineage: 39 of 66 (59%) patients with myeloproliferative disorders (acute myeloid leukemia, chronic myeloid leukemia (CML) in chronic phase, CML in myeloid blast crisis, and myelodysplasia) showed significant axl transcription, as compared with 1 of 45 (2%) lymphoid leukemias (chronic lymphocytic leukemia, acute lymphocytic leukemia, and CML in lymphoid blast crisis). Treatment of K562 cells with the phorbol ester, 12-O- tetradecanoylphorbol-13-acetate (TPA), administration of interferon alpha (IFN alpha) to normal monocytes, and treatment of U937 cells with TPA and IFN tau significantly induced axl expression, supporting a role for this kinase in the intracellular signaling of myeloid cells through a variety of biochemical pathways. These results suggest that the axl kinase may be operative in normal and malignant myeloid biology.

scholarly journals Adenosine deaminase and ecto-5'-nucleotidase activities in various leukemias with special reference to blast crisis: significance of ecto- 5'-nucleotidase in lymphoid blast crisis of chronic myeloid leukemia

Blood ◽  
1981 ◽  
Vol 58 (6) ◽  
pp. 1107-1111 ◽  
Author(s):  
M Koya ◽  
T Kanoh ◽  
H Sawada ◽  
H Uchino ◽  
K Ueda
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Adenosine Deaminase ◽  
Myeloid Leukemia ◽  
Blast Crisis ◽  
Chronic Phase ◽  
Lymphocytic Leukemia ◽  
Lymphoid Cells ◽  
Leukemia Cells ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Acute Myeloid Leukemia Cells

Abstract Adenosine deaminase (ADA) and ecto-5′-nucleotidase (5′-N) activities were examined in peripheral leukocytes from patients with leukemias, including nine patients with chronic myeloid leukemia (CML) in blast crisis. Four of none cases of CML in blast crisis were myeloid and the remaining lymphoid morphologically. The diagnosis of CML in lymphoid blast crisis was further contributed by the measurement of terminal deoxynucleotidyl transferase (TdT) activity. In all four cases of lymphoid blast crisis and one of myeloid blast crisis, leukemia cells had high 5′-N activity, while there was a little or no detectable activity in those from four cases of myeloid blast crisis and all of CML in chronic phase. ADA activity was high in seven of nine patients with blast crisis. Taken together, leukemia cells from two cases of lymphoid blast crisis had high ADA and 5′-N activities comparable to those in acute lymphocytic leukemia (ALL) cells. In contrast, the enzyme activities of leukemia cells from all but one patient in myeloid blast crisis were in a range similar to acute myeloid leukemia cells. The implications of these findings are as follows: (1) 5′-N may be used as a new biochemical marker of CML in lymphoid blast crisis. (2) Some lymphoid cells of CML in blast crisis have high ADA, 5′-N, and TdT activities and thus are very similar to ALL cells.

The Transcription Factor ELF4 Promotes Survival of Myeloid Leukemic Stem Cells.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1209-1209
Author(s):  
Chun Shik Park ◽  
Koramit Suppipat ◽  
H. Daniel Lacorazza
Keyword(s):  
Stem Cells ◽  
Transcription Factor ◽  
Kinase Inhibitor ◽  
Conflicts Of Interest ◽  
Blast Crisis ◽  
Philadelphia Chromosome ◽  
Lymphocytic Leukemia ◽  
Leukemic Cells ◽  
Leukemic Stem Cells ◽  
Hematopoietic Stem

Abstract Abstract 1209 Chronic myeloid leukemia (CML) is a myeloproliferative disease that originate in hematopoietic stem cells (HSCs) as a result of the t(9;22) translocation, giving rise to the Ph (Philadelphia chromosome) and BCR-ABL oncoprotein. Although treatment of CML patients with tyrosine kinase inhibitor can efficiently eliminate most leukemic cells, chemoresistant leukemic stem cells (LSCs) can survive and drive recurrence of CML in these patients. A number of genes have been described to promote or inhibit proliferation of LSCs. Some of them have similar roles in normal HSCs. The transcription factor ELF4 promotes cell cycle entry of quiescent HSCs during homeostasis (Lacorazza et al., 2006). Thus, to investigate the function of ELF4 in CML initiation and maintenance, we developed a BCR-ABL-induced CML-like disease using retroviral transfer of BCR-ABL in Elf4-null bone marrow (BM) cells. We first investigated whether ELF4 is required for the induction of CML. Recipient mice of BCR-ABL-transduced WT BM cells developed CML and died with a latency 16–23 days, whereas recipient mice of BCR-ABL-transduced Elf4-/- BM cells showed longer latency of 45–47 days (n=20; p<0.0005). Progression of leukemia was monitored in peripheral blood, BM and spleen by flow cytometry. In mice transplanted with BCR-ABL-transduced Elf4-null BM cells, Gr-1+ leukemic cells expanded the first two weeks after BM transplantation followed by a decline at expense of a secondary expansion of B220+ cells. In contrast, Gr-1+ leukemic cells continuously expanded in mice receiving BCR-ABL-transduced WT BM cells. These results suggest that loss of ELF4 causes a profound abrogation in BCR-ABL-induced CML, while allowing progression of B-cell acute lymphocytic leukemia. Since loss of Elf4 led to impaired maintenance of myeloid leukemic cells, we postulated that ELF4 may affect survival of LSCs. Thus, we analyzed the frequency of Lin-c-Kit+Sca-1+ (LSK) cells that are BCR-ABL positive in BM and spleen. We found that BCR-ABL+ LSK cells were significantly reduced in recipients of BCR-ABL-transduced Elf4-/- BM cells. These studies indicate that ELF4 is essential to maintain the LSC pool in CML acting as a molecular switch between myeloid and lymphoid blast crisis. Disclosures: No relevant conflicts of interest to declare.

A Bio-Integrative Approach Identifies an Inflammatory Signature in Chronic Myeloid Leukemia (CML) Stem Cells That Is Highly Perturbed in CML Blast Crisis and Involves REL transcription Factor

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4017-4017
Author(s):  
Christophe Desterke ◽  
Ludovic Marie-Sainte ◽  
Amine Sbitti ◽  
Ali Naama ◽  
Annelise Bennaceur-Griscelli ◽  
...  
Keyword(s):  
Stem Cells ◽  
Transcription Factor ◽  
Stem Cell ◽  
Chronic Myeloid Leukemia ◽  
Disease Progression ◽  
Myeloid Leukemia ◽  
Blast Crisis ◽  
Integrative Approach ◽  
Hematopoietic Stem ◽  
Gene Set

Abstract Chronic myeloid leukemia is a clonal myeloproliferative neoplasm defined by the presence of BCR-ABL fusion gene. This oncogenic event occurs in a hematopoietic stem cell (HSC) involved in CML initiation, maintenance, relapse and progression. Several evidences suggest that inflammatory pathways may participate to the pathophysiology of CML as well as disease progression to blast crisis. It has been shown that NFKB/REL pathway is constitutively activated both in BCR-ABL positive leukemic cell lines as well as in primary blast cells from CML-BC patients. More recent works identified IL6 as key cytokine acting on CML multipotent progenitors and their normal bystander counterpart to favor their differentiation toward the myeloid lineage. In addition, high levels of autocrine TNFα secretion by quiescent CML stem/progenitor cells activate NFKB pathway and promote their survival. Although all of these observations are linked to inflammatory processes, a focused analysis of inflammatory pathways in primary CML stem cells has not been performed so far. In the present study we undertook a text-mining strategy using pubmed e-querying to generate an exhaustive set of genes linked to inflammation. Then we integrated transcriptome analysis of highly purified CML stem cells to evaluate the contribution of these genes in CML development and progression. Methods : We queried 6 key words (Inflammation, macrophages, inflammatory response, chemokines, leukocytes and interleukins) that returned a total of 332000 hits in Pubmed. A raw gene set of 918 genes was found significantly associated (p<0.05) with these hits. Using R-package, we applied a false discovery rate correction that decreased the set to 588 relevant genes. The expression level of this gene set was then analyzed in previously reported microarray data (GEO accession: GSE47927) of highly purified normal cord blood CD34+CD38-CD90+ HSCs (CB; n=3), chronic phase (CP; n= 6), accelerated phase (AP; n =4) and Blast crisis (BC; n=2) CML cells. Results: Among the 588 genes related to inflammation we found 70 genes differentially expressed between the four groups (normal, CP, AP and BC, p<0.01; ANOVA test). Enrichment analysis confirmed 29 up regulated genes (NES = 2.12; p<0.0001) among which IL-6, PARP1, IL1R2, IRF5, IRF8, IL20. 39 genes such as STAT3, STAT4, CD47, CXCR4 IL-11, IL15, TLR-1, were down-regulated in CML CD34+CD38-CD90+ (all phases) as compared with normal HSCs (NES = -2,58; p<0.0001). Using principal component analysis on the 70 inflammatory deregulated genes we identified 10 genes such as IRAK1, IL1R2, VEGF and ESAM that discriminate "all phase" CML samples from normal HSCs (Dim 2 = 22.7%). Another inflammatory gene subset (n=26 genes) comprising IL6, REL, CXCR4, CXCL2, IL11, TLR1, IL1R2, PPARA highly separated CML stem cells according to the disease phase. The later gene set highly separates CP and AP-CML stem cells from BC-CML stem cell (Dim 1 = 50.3%). We next performed a random forest analysis with machine learning (1000 trees) and found that the inflammatory transcript level that best predicted CML phase was REL transcription factor. The expression of 413 genes were found positively correlated with REL expression in CP, AP and BC-CML CD34+CD38-CD90+ cells (r>0.75 and p-value <0.001). A search using JASPAR and TRANSFAC database identified a significant enrichment of NFKB1 and RELA binding motif in the promoter regions of these 413 genes (p<0.00001) among which several regulatory factors of hematopoietic stem cell biology. Conclusion : Using a bio-integrative approach we identified a specific inflammatory signature in CD34+CD38-CD90+ CML stem cells. This inflammatory network is highly altered in blast crisis suggesting its contribution to disease evolution. We identified REL overexpression as a good predictor for disease progression to blast crisis and found NFKB1and RELA (p=3.2x10-13) as the best REL target candidates. RELA/NFKB1 was previously shown to be constitutively activated in CML and Ph+ ALL and this analysis suggests that this may also take place in the most primitive subset of CML cells although REL may be the main partner of NFKB in CML stem cells. These results which are currently validated using functional assays, could lead to identification of novel therapeutic strategies. Disclosures Turhan: Bristol Myers Squibb: Consultancy; Novartis: Research Funding.

scholarly journals Propagation of human blastic myeloid leukemias in the SCID mouse

Blood ◽  
1992 ◽  
Vol 79 (8) ◽  
pp. 2089-2098 ◽  
Author(s):  
CL Sawyers ◽  
ML Gishizky ◽  
S Quan ◽  
DW Golde ◽  
ON Witte
Keyword(s):  
Bone Marrow ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Scid Mouse ◽  
Lymphoblastic Leukemia ◽  
Blast Crisis ◽  
Late Phase ◽  
Severe Combined Immunodeficiency ◽  
Chronic Phase ◽  
Myeloid Leukemias

Existing in vitro culture technology does not permit the routine propagation of most human myeloid leukemias. Previous work has shown the usefulness of mice with severe combined immunodeficiency (SCID) for the growth of human lymphoblastic leukemia. We show here that human myeloid cell lines and bone marrow samples from patients with acute myeloid leukemia (AML) and blast crisis of chronic myeloid leukemia (CML) also grow in SCID mice. Human AML or CML cell lines (three of three lines tested) grew in the bone marrow and peripheral blood of the mice after intravenous (IV) inoculation in a pattern closely resembling human AML. To define the best conditions for the growth of primary human myeloid leukemia cells, samples were transplanted into mice at several alternative sites. Using flow cytometry and Southern analysis, mice were analyzed at defined intervals up to 36 weeks after transplantation for the presence of human cells in various tissues. For four of four patients with AML and two of two patients with blast crisis of CML, myeloblasts grew locally at the site of implantation and were detected in the murine hematopoietic tissues. In contrast, marrow implants from patients in the chronic phase of CML (six patients) showed infrequent and limited myeloid growth in the mice. These findings demonstrate that the SCID mouse is a reproducible system for the propagation of blastic human myeloid leukemias. The differential growth of early- versus late-phase CML suggests that the SCID mouse may be a useful assay for identifying biologically aggressive leukemias early in their clinical presentation.

scholarly journals Loss of expression of both miR-15/16 loci in CML transition to blast crisis

2021 ◽  
Vol 118 (11) ◽  
pp. e2101566118
Author(s):  
Francesca Lovat ◽  
Pierluigi Gasparini ◽  
Giovanni Nigita ◽  
Karilyn Larkin ◽  
John C. Byrd ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Blast Crisis ◽  
Chronic Phase ◽  
Lymphocytic Leukemia ◽  
Oncogenic Driver

Despite advances that have improved the treatment of chronic myeloid leukemia (CML) patients in chronic phase, the mechanisms of the transition from chronic phase CML to blast crisis (BC) are not fully understood. Considering the key role of miR-15/16 loci in the pathogenesis of myeloid and lymphocytic leukemia, here we aimed to correlate the expression of miR-15a/16 and miR-15b/16 to progression of CML from chronic phase to BC. We analyzed the expression of the two miR-15/16 clusters in 17 CML patients in chronic phase and 22 patients in BC and in 11 paired chronic phase and BC CML patients. BC CMLs show a significant reduction of the expression of miR-15a/-15b/16 compared to CMLs in chronic phase. Moreover, BC CMLs showed an overexpression of miR-15/16 direct targets such as Bmi-1, ROR1, and Bcl-2 compared to CMLs in chronic phase. This study highlights the loss of both miR-15/16 clusters as a potential oncogenic driver in the transition from chronic phase to BC in CML patients.

scholarly journals A Novel Approach to Identify a Putative Leukemia Stem Cell Population in Acute Lymphocytic Leukemia (ALL) and Distinguish Philadelphia Chromosome-Positive ALL from Lymphoid Blast Crisis Chronic Myeloid Leukemia

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2912-2912
Author(s):  
Jonathan M. Gerber ◽  
Lawrence J. Druhan ◽  
David Foureau ◽  
Elizabeth Jandrisevits ◽  
Amanda Lance ◽  
...  
Keyword(s):  
B Cell ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Blast Crisis ◽  
Philadelphia Chromosome ◽  
Chronic Phase ◽  
Lymphocytic Leukemia ◽  
Aldh Activity ◽  
Advisory Committees

Abstract Introduction: Recent evidence supports the clinical significance of leukemia stem cells (LSCs) in acute myeloid leukemia (AML). However, the identification of LSCs in acute lymphocytic leukemia (ALL) has proved challenging, as transplantation studies in immunocompromised mice have yielded conflicting results. The distinction between Philadelphia chromosome-positive (Ph+) ALL and lymphoid blast crisis (LBC) chronic myeloid leukemia (CML) is also controversial. We previously identified a clinically relevant CD34+CD38- population of LSCs with intermediate (int) levels of aldehyde dehydrogenase (ALDH) activity (CD34+CD38-ALDHint) in AML [Gerber, et al. Blood, 2012]. This population was not present in healthy controls and could be distinguished from normal hematopoietic stem cells (HSCs), which had higher levels of ALDH activity (CD34+CD38-ALDHhigh). We hypothesized that the same approach could be used to identify a putative LSC population in ALL. Furthermore, in contrast to most cases of AML, the chronic phase CML stem cell was found to reside in the same CD34+CD38-ALDHhigh population as normal HSCs [Gerber, et al. Am J Hematol, 2011]. We therefore also hypothesized that the presence of BCR/ABL mutations in the CD34+CD38-ALDHhigh population might help distinguish LBC CML from Ph+ ALL. Methods: Bone marrow and/or peripheral blood specimens were collected at diagnosis from patients with B cell ALL or LBC CML on an IRB-approved protocol. A total of 7 patients were evaluated: 2 Ph- ALL, 2 Ph+ ALL, and 3 LBC CML patients. CD34+ cells were isolated by magnetic bead and column selection, then analyzed by flow cytometry with respect to CD38 expression and ALDH activity. Sorted cell populations were analyzed by fluorescence in situ hybridization (FISH) for leukemia-specific abnormalities. Polymerase chain reaction was performed on clinical samples to determine the presence of a p190 vs. p210 transcript. Results: All patients harbored an aberrant CD34+CD38-ALDHint population, similar to that previously seen in AML. This population was ≥95% positive for BCR/ABL by FISH in all Ph+ ALL and LBC CML cases. It was similarly positive (≥75%) for other leukemia-specific FISH abnormalities (including trisomy 4, 8, 10, 12, and/or 21) in all four ALL cases, as well as one LBC CML case. Conversely, the CD34+CD38-ALDHhigh population (which typically contains the normal HSCs) lacked any of the other cytogenetic abnormalities in all of the cases, irrespective of Ph status or a diagnosis of ALL vs. CML. Notably, the CD34+CD38-ALDHhigh population was negative for BCR/ABL in the Ph+ ALL cases but was >95% positive for BCR/ABL by FISH in the LBC CML cases. The B cell differentiation marker, CD19, was expressed on the CD34+CD38-ALDHint but not the CD34+CD38-ALDHhigh population in all ALL cases, both Ph- and Ph+. In contrast, CD19 expression was variable in the LBC CML cases. Both Ph+ ALL cases possessed a p190 BCR/ABL transcript, whereas all of the LBC CML cases contained a p210 transcript. Also of note, the CD34+CD38-ALDHint population was persistently detectable in one of the LBC CML patients while in complete remission after induction therapy; that patient subsequently relapsed. Conclusions: An abnormal CD34+CD38-ALDHint population was identified in all cases of B cell ALL and LBC CML. This population is analogous to a previously identified, clinically relevant LSC population in AML and may represent a putative LSC population in ALL. The CD34+CD38-ALDHhigh population was normal by FISH in the ALL cases but contained the BCR/ABL mutation in the LBC CML cases, thus permitting distinction between Ph+ ALL and LBC CML (which also differed based on the presence of p190 vs. p210 transcripts, respectively). Additionally, clonal evolution from chronic phase to lymphoid blast crisis CML was apparent, based on the acquisition of additional cytogenetic abnormalities unique to the CD34+CD38-ALDHint population as compared to the CD34+CD38-ALDHhigh population. The presence of CD19 on the putative LSCs in the four cases of ALL suggest that CD19-directed therapies may target the LSCs and thus may have curative potential in those cases. This assay may serve as a means to evaluate other possible therapeutic targets. Lastly, the detection of the abnormal CD34+CD38-ALDHint population may have utility as a minimal residual disease assay for monitoring response to treatment. These findings warrant validation in a larger patient cohort. Disclosures Gerber: Janssen: Research Funding; Alexion: Membership on an entity's Board of Directors or advisory committees; Spectrum: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees. Grunwald:Alexion: Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Incyte Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Medtronic: Equity Ownership; Janssen: Research Funding; Ariad: Membership on an entity's Board of Directors or advisory committees; Forma Therapeutics: Research Funding. Avalos:Seattle Genetics: Membership on an entity's Board of Directors or advisory committees.

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