FLT3 Is Up-Regulated in Blast Crisis of Chronic Myeloid Leukemia and Combination of Small Interference RNA of FLT3 and Gleevec (STI571) Synergistically Induces the Apoptosis in K562 Cells.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4532-4532
Author(s):  
Young Y. Lee ◽  
Kwang-Sung Ahn ◽  
Sung-Soo Yoon ◽  
Jung H. Choi ◽  
Byoung B. Park ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Blast Crisis ◽  
Chronic Phase ◽  
K562 Cells ◽  
Pcr Analysis ◽  
Wild Type ◽  
Small Interference Rna ◽  
Expression Levels ◽  
Significant Difference

Abstract To identify a gene signature for prognostic markers at transition from chronic phase to blast crisis of chronic myeloid leukemia (CML), we have applied Affymetrix Genechips of 22,000 transcripts to analyze total RNA of CML cells from 12 patients with chronic phase and 12 patients with blast crisis. Data analysis using GeneSpring 6.0 generated a list of 143 differentially expressed genes. A total of 89 genes were up-regulated and 54 genes were down-regulated in blast crisis of CML, and vice versa in chronic phase of CML. Array data for 32 genes was validated using quantitative realtime PCR analysis. The expression levels of HSA6591, FLT3, NTE5, RSG1, LAF4, CPA3, ATF, FCGR3A, MYD88, IFIT1, TP73L, DTNA, MDA, and IL18R1 showed statistically significant difference (p < 0.05) between chronic phase and blast crisis. Since CML cells of blast crisis were generally unresponsive to STI571, we further analyzed roles of FLT3 which is known to be a poor prognositic marker in acute myeloid leukemia. For this experiment, K562 cells (CML blast cells) were transfected with small hairpin RNAs (shRNAs), also referred to as small interfering RNAs, to target human FLT3, resulting in the significant inhibition of FLT3 expression at mRNA and protein levels. MTT assay demonstrated that FLT3 knockdown K562 cells by shRNAs were more sensitive to STI571 compared to wild type of K562, although there was no difference at high concentration of STI571 (320 nM) between FLT3 knockdown K562 cells and wild type of K562 cells. The higher expression levels of apoptosis related genes (PARP, caspase-3, Bax) were observed in FLT3 knockdown K562 cells compared to wild type of K562 cells. Thus, RNA interference-directed targeting of FLT3 might be a novel treatment modality in STI571 refractory CML patients.

FLT3, CD32, PU.1, ERG, uPAR, and TAP2 Are Strongly Associated with the Progression of Chronic Myeloid Leukemia and Combination of Small Interference RNA of FLT3 and STI571 Synergistically Induced Apoptosis of K562 Cells

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4237-4237
Author(s):  
Kyung Im Kim ◽  
Kwang-Sung Ahn ◽  
Juwon Park ◽  
Chansu Lee ◽  
Byoung Kook Kim ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Real Time ◽  
Mtt Assay ◽  
Real Time Pcr ◽  
Myeloid Leukemia ◽  
Caspase 3 ◽  
Blast Crisis ◽  
Chronic Phase ◽  
K562 Cells ◽  
Potential Candidate

Abstract To characterize molecular mechanisms by which transition from chronic phase to blast crisis in chronic myeloid leukemia (CML) for developing novel therapeutic targets, we analyzed gene-expression profiles of leukemic cells from 12 patients in chronic phase and 9 patients in blast crisis using a 8.7K cDNA chip. We identified 89 genes that were up-regulated as well as 54 genes that were down-regulated in blast crisis of CML. The expression profile included oncogenes, tumor suppression genes, and human genes encoding proteins involved in transcription, signal transduction, metabolism, cell growth, differentiation, apoptosis and immune functions. 18 genes were selected among the up-regulated group for analysis using real-time PCR. Real-time PCR data indicated that the expression of FLT3 (p &lt; 0.001), CD32 (p &lt; 0.001), ERG (p &lt; 0.001), uPAR (p &lt; 0.001), MAD (p &lt; 0.001) and TAP2 (p &lt; 0.001) showed statistically significant difference between chronic phase and blast crisis. For further analysis, we utilized small hairpin RNAs (shRNAs), also referred to as small interfering RNAs, to target human FLT3. These small interfering RNA constructs significantly inhibited FLT3 expression at mRNA and protein levels in K562 cells. After treating both the FLT3 knockdown cells and control cells (FLT3 wild type) with STI571, MTT assay and the expression patterns of apoptosis related genes (PARP, caspase-3, Bax) were examined. MTT assay and caspase-3 activity assay showed that silencing of the gene for FLT3 significantly reduced cell viability and ultimately facilitated the induction of apoptotic cell death by STI571. These findings uncovered evidence of a complex signaling network operating down-stream of FLT3 that actively contributes to tumor progression. Thus, RNA interference-directed targeting of FLT3 can be a potential candidate anticancer agent in association with STI571 against chronic myeloid leukemia.

Deregulated Bcl-2 Family Expression Drives Chronic Myeloid Leukemia Cancer Stem Cell Survival.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1074-1074
Author(s):  
Daniel Jacob Goff ◽  
Annelie Abrahamsson ◽  
Ifat Geron ◽  
Catriona Jamieson
Keyword(s):  
Stem Cells ◽  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Blast Crisis ◽  
Chronic Phase ◽  
Myelogenous Leukemia ◽  
Rt Pcr ◽  
Significant Difference ◽  
Apoptotic Pathways ◽  
Serial Transplantation

Abstract Introduction: A growing body of evidence suggests that a relatively rare subset of cells within a cancer subverts properties normally ascribed to stem cells in regenerating tissues, such as enhanced self-renewal and survival capacity. Recent studies suggest that these cancer stem cells (CSC) are resistant to treatments that target rapidly dividing cells. In blast crisis chronic myeloid leukemia (BC CML) and some forms of acute myelogenous leukemia (AML), research performed by ourselves and others indicates that CSC originate from the CD34+CD38+lineage- compartment of hematopoietic cells and can serially transplant blast crisis leukemia in immunodeficient mice. Despite abundant data indicating that Bcl-2 family proteins are involved in CML progression, the importance of these proteins in CSC survival remains to be elucidated. Clinical data have shown that CML stem cells become more resistant to therapies targeting BCR-ABL with progression to blast crisis. As BCR-ABL targeted therapy initiates apoptosis, these results suggest that CML CSC may become increasingly resistant to apoptosis with progression. Based on these findings and the results from our serial transplantation experiments, we hypothesized that CML CSC deregulate apoptosis pathways by differential expression of Bcl-2 family molecules and that these changes contribute to CSC ability to survive serial transplantation. Methods: Quantitative FACS Aria analysis of Bcl-2 protein levels was compared in blast crisis (n=5) and chronic phase CML (n=3) patient samples. Mean fluorescence intensity (MFI) of Bcl-2 staining was compared between different hematopoietic populations within the patient samples. For gene expression analysis, cDNA was made from RNA isolated from sorted progenitor populations (CD34+CD38+Lin −). Isoform specific RT-PCR was used to determine expression levels of Bcl-2, Bcl-X, and Mcl-1 isoforms. Mcl-1 expression was confirmed using qPCR. In addition, preliminary experiments were performed (n=2) to determine if CSC engraftment could be reduced in vivo by targeted inhibition of Bcl-2 family molecules using Apogossypol, a clinically tested Bcl-2-family inhibitor. Briefly, immunocompromised neonatal mice were transplanted intrahepatically with luciferase GFP transduced granulocytic sarcomas from mice transplanted with BC CSC using our previously published methodology (Geron et al, Cancer Cell 2008). Transplanted mice were treated for 15 days with Apogossypol by oral gavage and engraftment was monitored by weekly bioluminescent imaging. Engraftment levels were determined by FACS analysis of human CD45+ expression in mouse livers on week 11 post-transplant. Results: Comparing the MFI of Bcl-2 staining in the entire live mononuclear cell population, we detected no statistically significant difference in levels between the blast crisis and chronic phase samples. However, when we gated on separate cell populations, differences in the Bcl-2 MFI emerged. There was a statistically significant increase (P&lt;0.03) in Bcl-2 MFI exclusively in the CD34+CD38+lineage- population of the blast crisis samples indicative of cell type and context specific deregulation of apoptosis in the CSC population. Further, we were interested in whether there were differences in Bcl-2 family expression at the transcriptional level. Notably, while we detected no difference in the levels of the isoforms of Bcl-2 and Bcl-X, splice isoform specific RT-PCR and qPCR revealed a decrease in the expression of the short isoform of Mcl-1, which encodes a pro-apoptotic protein, in serially transplanted BC CSC (CD34+CD38+). Together these results indicate that CML CSC may indeed deregulate the expression of several Bcl-2 family proteins. To test the therapeutic potential of inhibiting these deregulated apoptotic pathways in CML, we treated mice engrafted with CML CSC with Apogossypol, a broad-spectrum inhibitor of pro-survival Bcl-2 molecules. We saw a statistically significant decrease (P&lt;0.05) in the number of CD45+ cells engrafted in the mouse liver after 3 weeks of Apogossypol treatment. Overall, our results suggest that the subversion of apoptosis plays an important role in allowing CML CSC to be serially transplanted and that apoptotic pathways may be a useful target for therapeutics aimed at inhibiting these cells.

Expression of the miR-17-92 polycistron in chronic myeloid leukemia (CML) CD34+ cells

Blood ◽  
2007 ◽  
Vol 109 (10) ◽  
pp. 4399-4405 ◽  
Author(s):  
Letizia Venturini ◽  
Karin Battmer ◽  
Mirco Castoldi ◽  
Beate Schultheis ◽  
Andreas Hochhaus ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Mirna Expression ◽  
Myeloid Leukemia ◽  
Blast Crisis ◽  
Chronic Phase ◽  
K562 Cells ◽  
Mature Mirnas ◽  
Micro Rna ◽  
Imatinib Treatment ◽  
Cd34 Cells

Abstract Aberrant micro RNA (miRNA) expression has been described in human malignancies including B-cell lymphomas. We here report BCR-ABL– and c-MYC–dependent regulation of miRNA expression in chronic myeloid leukemia (CML) using microarray analysis (miCHIP) and miRNA-specific quantitative real-time reverse transcriptase–polymerase chain reaction (miR-qRT-PCR). In 3 bcr-abl–positive cell lines, expression of miRNAs encoded within the polycistronic miR-17-92 cluster is specifically down-regulated (2- to 5-fold) by both imatinib treatment and anti–BCR-ABL RNA interference (RNAi). In addition, anti–c-MYC RNAi reduces miR-17-92 expression in K562 cells in which miRNAs can specifically repress reporter gene expression, as demonstrated by specific miRNA inhibition with antagomirs. Furthermore, lentivirus-mediated overexpression of polycistronic miRNAs in K562 cells confers increased proliferation, partial resistance against anti–c-MYC RNAi, and enhanced sensitivity to imatinib-induced cell death. Finally, we determined miR-17-92 expression in purified normal (n = 4), early chronic-phase (CP) (n = 24), and blast-crisis (BC) (n = 7) CML CD34+ cells and found up-regulation of polycistronic pri-miRNA transcripts in CML and mature miRNAs in CP but not in BC CML. These data are in accordance with a BCR-ABL–c-MYC–miR-17-92 pathway that mediates enhanced miRNA expression in CP but not BC CML CD34+ cells. Altered miRNA expression may contribute to the pathophysiology of the disease and may provide potential targets for therapeutic intervention.

scholarly journals ASXL1, TP53 and IKZF3 mutations are present in the chronic phase and blast crisis of chronic myeloid leukemia

2013 ◽  
Vol 3 (11) ◽  
pp. e157-e157 ◽  
Author(s):  
J Menezes ◽  
R N Salgado ◽  
F Acquadro ◽  
G Gómez-López ◽  
M C Carralero ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Blast Crisis ◽  
Chronic Phase

scholarly journals Concurrent Diagnosis of Chronic Myeloid Leukemia and Follicular Lymphoma: An Unreported Presentation

2018 ◽  
Vol 2018 ◽  
pp. 1-4
Author(s):  
Amy G. Starr ◽  
Sushma R. Jonna ◽  
Joeffrey J. Chahine ◽  
Bhaskar V. Kallakury ◽  
Chaitra S. Ujjani
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Follicular Lymphoma ◽  
Myeloid Leukemia ◽  
Chronic Phase ◽  
Mediastinal Lymphadenopathy ◽  
Pcr Analysis ◽  
Molecular Testing ◽  
Fish Analysis ◽  
Rt Pcr ◽  
Non Hodgkin Lymphoma

Lymphadenopathy in chronic myeloid leukemia (CML) is usually due to extramedullary involvement with accelerated or blast phases of the disease. The occurrence of non-Hodgkin lymphoma (NHL) as a synchronous malignancy with CML is rare. We report a case of a 73-year-old male who presented with dyspnea and right-sided lower extremity edema in the setting of leukocytosis. Bone marrow evaluation indicated a chronic phase chronic myeloid leukemia (CML), confirmed by molecular testing. Imaging of the chest for persistent dyspnea revealed supraclavicular and mediastinal lymphadenopathy. Biopsy of the cervical node showed expanded lymphoid follicles with atypical germinal centers that were positive for CD10, BCL-2, and BCL-6, consistent with follicular lymphoma (FL). Nodal PCR demonstrated clonal IGH and IGK gene rearrangements, and FISH analysis was positive for IGH-BCL-2 fusion. Together, these tests supported the diagnosis of FL. Additionally, the lymph node showed paracortical expansion by maturing pan-hematopoietic elements, no blastic groups, and positive RT-PCR analysis for BCR-ABL1, indicating concomitant involvement by chronic phase-CML. To our knowledge, this is the first reported case of a patient with a concurrent diagnosis of CML and FL.

scholarly journals An integrative model of pathway convergence in genetically heterogeneous blast crisis chronic myeloid leukemia

Blood ◽  
2020 ◽  
Vol 135 (26) ◽  
pp. 2337-2353 ◽  
Author(s):  
Tun Kiat Ko ◽  
Asif Javed ◽  
Kian Leong Lee ◽  
Thushangi N. Pathiraja ◽  
Xingliang Liu ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Tumor Suppressor ◽  
Myeloid Leukemia ◽  
High Throughput Sequencing ◽  
Kinase Inhibitors ◽  
Blast Crisis ◽  
Chronic Phase ◽  
Integrative Model ◽  
Dna Hypermethylation ◽  
Molecular Alterations

Abstract Targeted therapies against the BCR-ABL1 kinase have revolutionized treatment of chronic phase (CP) chronic myeloid leukemia (CML). In contrast, management of blast crisis (BC) CML remains challenging because BC cells acquire complex molecular alterations that confer stemness features to progenitor populations and resistance to BCR-ABL1 tyrosine kinase inhibitors. Comprehensive models of BC transformation have proved elusive because of the rarity and genetic heterogeneity of BC, but are important for developing biomarkers predicting BC progression and effective therapies. To better understand BC, we performed an integrated multiomics analysis of 74 CP and BC samples using whole-genome and exome sequencing, transcriptome and methylome profiling, and chromatin immunoprecipitation followed by high-throughput sequencing. Employing pathway-based analysis, we found the BC genome was significantly enriched for mutations affecting components of the polycomb repressive complex (PRC) pathway. While transcriptomically, BC progenitors were enriched and depleted for PRC1- and PRC2-related gene sets respectively. By integrating our data sets, we determined that BC progenitors undergo PRC-driven epigenetic reprogramming toward a convergent transcriptomic state. Specifically, PRC2 directs BC DNA hypermethylation, which in turn silences key genes involved in myeloid differentiation and tumor suppressor function via so-called epigenetic switching, whereas PRC1 represses an overlapping and distinct set of genes, including novel BC tumor suppressors. On the basis of these observations, we developed an integrated model of BC that facilitated the identification of combinatorial therapies capable of reversing BC reprogramming (decitabine+PRC1 inhibitors), novel PRC-silenced tumor suppressor genes (NR4A2), and gene expression signatures predictive of disease progression and drug resistance in CP.

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 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.

scholarly journals Molecular biology of bcr-abl1–positive chronic myeloid leukemia

Blood ◽  
2009 ◽  
Vol 113 (8) ◽  
pp. 1619-1630 ◽  
Author(s):  
Alfonso Quintás-Cardama ◽  
Jorge Cortes
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Kinase Inhibitors ◽  
Current Knowledge ◽  
Blast Crisis ◽  
Chronic Phase ◽  
Oncogenic Signaling ◽  
Stem Cell Quiescence ◽  
Oncogenic Signaling Pathways

Abstract Chronic myeloid leukemia (CML) has been regarded as the paradigmatic example of a malignancy defined by a unique molecular event, the BCR-ABL1 oncogene. Decades of research zeroing in on the role of BCR-ABL1 kinase in the pathogenesis of CML have culminated in the development of highly efficacious therapeutics that, like imatinib mesylate, target the oncogenic kinase activity of BCR-ABL1. In recent years, most research efforts in CML have been devoted to developing novel tyrosine kinase inhibitors (TKIs) as well as to elucidating the mechanisms of resistance to imatinib and other TKIs. Nonetheless, primordial aspects of the pathogenesis of CML, such as the mechanisms responsible for the transition from chronic phase to blast crisis, the causes of genomic instability and faulty DNA repair, the phenomenon of stem cell quiescence, the role of tumor suppressors in TKI resistance and CML progression, or the cross-talk between BCR-ABL1 and other oncogenic signaling pathways, still remain poorly understood. Herein, we synthesize the most relevant and current knowledge on such areas of the pathogenesis of CML.

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