Genome-Wide Analysis of Microdeletions and Identification of NF1 Inactivation in Acute Myelogenous Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 165-165
Author(s):  
Sami Malek ◽  
Peter Ouillette ◽  
Yin Wang ◽  
Yan Liu ◽  
Whitney Wright ◽  
...  
Keyword(s):  
Acute Myelogenous Leukemia ◽  
Copy Number ◽  
Research Funding ◽  
Normal Karyotype ◽  
B Cell Lymphoma ◽  
Myelogenous Leukemia ◽  
Acute Myelogenous ◽  
Copy Number Changes ◽  
Induced Apoptosis ◽  
High Level

Abstract Abstract 165 Genomic aberrations are of dominant importance to the biology and clinical outcome of patients with acute myelogenous leukemia (AML). To further our understanding of such aberrations in AML, we analyzed DNA from highly purified AML blasts and paired buccal cells from 95 patients for subchromosomal copy number changes and allele identities using ultra-high-density Affymetrix SNP 6.0 array-based genomic profiling. A total of 358 somatically acquired copy number changes were detected in 95 AML genomes. We detected 16 losses and 22 gains of entire chromosomes, 285 subchromosomal losses and 35 subchromosomal gains. No recurrent high-level amplifications or recurrent homozygous deletions were identified. Eight of the 34 AML cases (24%) with normal karyotype each had one lesion detected through 6.0 array profiling, all but one of which was less than 4Mb in length. Focusing on microdeletions as potential indicators of the locations of novel tumor suppressor genes or genes with importance to AML biology, we identified 60 deletions that were less than 1 Mb in length and 158 deletions of less than 5 Mb, the vast majority of which were undetectable by conventional cytogenetics. Through fine mapping of microdeletions on 17q, we identified Neurofibromin 1 (NF1) null states due to mutations or absent expression in ∼7% of AML. NF1 mutations were present in the hematopoetic stem cell compartment (CD34+/CD38- cell population) and siRNA-mediated NF1 suppression using recombinant lentiviruses significantly increased colony formation of primary AML blasts in methylcellulose. Further, AML blasts without functional NF1 displayed sensitivity to rapamycin-induced apoptosis, thus identifying a dependence on mTOR signaling for survival. As an additional validation of using microdeletions to guide pathogenetic gene discovery, we identified deletions involving RUNX1, IRF8, Core Binding Factor Beta (CBFB) and Casitas B-cell lymphoma B (CBLB), genes known to be altered in AML. IRF8 expression was found to be absent in ∼30% of all AML but sequencing of all coding exons of IRF8 of 48 AML cases did not disclose somatically acquired mutations. In summary, this comprehensive description of subchromosomal copy number changes and microdeletions in adult AML substantially adds to our knowledge of the pathological anatomy of the AML genome and should inform future searches for novel genes with importance to AML biology. Disclosures: Malek: Cephalon: Honoraria, Speakers Bureau; Celgene: Honoraria, Speakers Bureau; Affymetrix: Research Funding. Erba:Lilly: Research Funding; Antisoma: Research Funding; Wyeth: Research Funding; Cephalon: Honoraria, Research Funding; MGI Pharma: Honoraria; Pharmion: Honoraria; Celgene: Honoraria; BMS: Honoraria; Novartis: Honoraria, Research Funding; Genzyme: Consultancy, Honoraria, Research Funding; Gemin-X: Research Funding; Kanisa: Research Funding.

scholarly journals Irradiated B7-1 transduced primary acute myelogenous leukemia (AML) cells can be used as therapeutic vaccines in murine AML

Blood ◽  
1996 ◽  
Vol 87 (7) ◽  
pp. 2938-2946 ◽  
Author(s):  
K Dunussi-Joannopoulos ◽  
HJ Weinstein ◽  
PW Nickerson ◽  
TB Strom ◽  
SJ Burakoff ◽  
...  
Keyword(s):  
T Cell ◽  
Acute Myelogenous Leukemia ◽  
High Titer ◽  
Myelogenous Leukemia ◽  
Therapeutic Vaccines ◽  
Natural Ligand ◽  
Acute Myelogenous ◽  
High Level ◽  
Transformed Cell Lines

Recent studies have shown that tumor cells genetically modified by transduction of B7–1, a natural ligand for the T-cell costimulatory molecules CD28 and CTLA-4, are rejected in syngeneic hosts. In these reports, transformed cell lines and drug-selected cells have been used for vaccinations. To determine the effectiveness of B7–1-transduced primary acute myelogenous leukemia (AML) cells on the induction of antitumor immunity, we have studied a murine AML model in which primary AML cells were retrovirally transduced with the murine B7–1 cDNA. A defective retroviral producer clone expressing B7–1 and secreting a high titer of virus was used for infection of AML cells. Unselected transduced AML cells, expressing a high level of B7–1, were used for in vivo vaccinations. Our results show that one intravenous (IV) injection of irradiated B7–1-positive (B7–1+) AML cells can provide long-lasting (5 to 6 months) systemic immunity against subsequent challenge with wild-type AML cells. Furthermore, one exposure to irradiated B7–1+ AML cells results in rejection of leukemia by leukemic mice when the vaccination occurs in the early stages of the disease. The antileukemia immunity is CD8+ T-cell-dependent and B7/CD28-mediated, since in vivo treatment of mice with anti-CD8 monoclonal antibody or CTLA-4 Ig leads to abrogation of the specific antileukemia immune response. These results emphasize that B7–1 vaccines may have therapeutic usefulness for patients with AML.

scholarly journals DNA copy number changes in diffuse large B-cell lymphoma--comparative genomic hybridization study

Blood ◽  
1996 ◽  
Vol 87 (12) ◽  
pp. 5269-5278 ◽  
Author(s):  
O Monni ◽  
H Joensuu ◽  
K Franssila ◽  
S Knuutila
Keyword(s):  
Comparative Genomic Hybridization ◽  
Copy Number ◽  
B Cell Lymphoma ◽  
Comparative Genomic ◽  
Genomic Hybridization ◽  
Primary Tumors ◽  
Large B Cell Lymphoma ◽  
Recurrent Tumors ◽  
Copy Number Changes ◽  
High Level

We studied DNA copy number changes in diffuse large B-cell lymphoma using comparative genomic hybridization analysis on 20 primary tumors and on 12 recurrent tumors excised after chemotherapy or radiotherapy. Twenty-nine (91%) of the cases showed abnormal copy number karyotypes. Chromosomal regions at X (41%), 1q (38%), 7 (31%), 3 (24%), 6p (21%), 11 (21%), 12 (21%), and 18 (21%) were most frequently gained, and the most common losses involved 6q (38%), X (21%), 1p (14%), and 8p (10%). High-level amplifications were observed at 6p23-ter, 10p12–14, 17p1l.2, 18q21-ter, and Xq22-ter, all but 18q appearing only in the recurrent tumors. Gains (median, 2; range, 0 to 10) were more frequent than losses (median, 1; range, 0 to 7; P = .0004). The median number of aberrations found in the recurrent tumors (6.5) was greater than that in the primary tumors (2; P = .01). The copy number changes found in the recurrent tumors were more random than those found in the primary tumors, which were mainly located in the most frequently affected regions. Our findings are in line with those observed using conventional cytogenetic analysis, but especially novel high-level amplifications were detected. Southern blot analysis showed BCL2 amplification, but not translocation t(14;18)(q32;q21), in cases in which a gain at 18q was detected by comparative genomic hybridization, which strongly suggests that, in addition to translocation, gene amplification is another mechanism for the overexpression of the BCL2 protein.

Cytoplasmic Nucleophosmin in Acute Myelogenous Leukemia with a Normal Karyotype

2005 ◽  
Vol 352 (3) ◽  
pp. 254-266 ◽  
Author(s):  
Brunangelo Falini ◽  
Cristina Mecucci ◽  
Enrico Tiacci ◽  
Myriam Alcalay ◽  
Roberto Rosati ◽  
...  
Keyword(s):  
Acute Myelogenous Leukemia ◽  
Normal Karyotype ◽  
Myelogenous Leukemia ◽  
Acute Myelogenous

scholarly journals Mechanistic insight into WEB-2170-induced apoptosis in human acute myelogenous leukemia cells: The crucial role of PTEN

2009 ◽  
Vol 37 (10) ◽  
pp. 1176-1185.e21 ◽  
Author(s):  
Cristina Cellai ◽  
Anna Laurenzana ◽  
Elisa Bianchi ◽  
Sara Sdelci ◽  
Rossella Manfredini ◽  
...  
Keyword(s):  
Acute Myelogenous Leukemia ◽  
Crucial Role ◽  
Myelogenous Leukemia ◽  
Leukemia Cells ◽  
Mechanistic Insight ◽  
Acute Myelogenous ◽  
Induced Apoptosis ◽  
Insight Into

Azacitidine in the Treatment of Elderly Patients with Acute Myelogenous Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4164-4164
Author(s):  
Heather L. Benjamin ◽  
James M. Rossetti ◽  
Aaron J. Lampkin ◽  
Christie Hilton ◽  
Entezam Sahovic ◽  
...  
Keyword(s):  
Elderly Patients ◽  
Acute Myelogenous Leukemia ◽  
Research Funding ◽  
Myelogenous Leukemia ◽  
Open Label ◽  
Drug Induced ◽  
Acute Myelogenous ◽  
Prospective Phase ◽  
Blast Count ◽  
The Mean

Abstract Abstract 4164 BACKGROUND Effective treatment of the elderly patient with acute myelogenous leukemia (AML) remains a challenging task. Elderly patients with AML usually respond poorly to standard induction chemotherapy. Response rates in elderly patients are in the range of 30–50% compared to 80–90% in younger patients. Moreover, prolonged hospitalization with treatment related mortality as high as 30% is typical in this older population. In a prior retrospective analysis done at our institution, azacitidine showed an overall response rate of 60% with limited toxicity when administered to patients older than 55 years of age with AML. We present an interim analysis of the first 13 patients enrolled in our prospective, phase II open label study using single agent azacitidine for elderly patients with AML. METHODS This is a prospective, phase II open label study using azacitidine in patients ≥ 60 years with AML. Inclusion criteria: Newly diagnosed AML (de novo or secondary, WHO criteria) and ECOG≤ 2. Promyelocytic (M3) phenotype was excluded. Patients with circulating blast count ≥ 30,000/mcl were treated with hydroxyurea until < 30,000/mcl. Azacitidine was given at a dose of 100 mg/m2 subcutaneously for 5 consecutive days every 28 days until disease progression or significant toxicity. G-CSF was given to patients with neutropenia (ANC < 1000/mcl) during all cycles excluding cycle one. RESULTS Thirteen patients have been enrolled to date. The mean age of patients is 75 years (range: 66–84). The mean baseline ECOG performance score was 1 with a mean during treatment of 1. Mean baseline bone marrow blast count was 57% (range: 21–100%). Overall response rate using the NCI response criteria (IWG criteria for patients with hematological improvement (HI) only) was 46% (6/13): complete response (CR; n=3; 23%), partial response (PR; n=1; 8%), and HI (n=2; 15%). One additional patient had a 94% reduction in marrow blasts, but failed to achieve transfusion independence. The mean number of days on treatment was 171+ (range: 13–606). The mean number of days hospitalized for diagnosis plus treatment or disease related complication was 21 (range: 7–72) with the majority of therapy being given in the outpatient setting. One patient required prolonged hospitalization after going on to allogeneic transplantation. The mean overall survival from diagnosis for all patients was 246+ days (range: 13–606). The mean overall survival for responders was 399+ days (range: 212–606). One patient continues on therapy with azacitidine at 606 days (CR). Of the other responders, one progressed at 420 days and is considering other options (CR), one died from an intra-cranial hemorrhage after receiving Mylotarg for disease progression at 454 days (CR), one progressed at 119 days and went on to another clinical trial (PR), and two died with disease at 212 and 347 days (HI). Non-hematological toxicity was limited to mild injection site skin reaction and fatigue in 77% (10/13) each. No treatment related deaths were observed. The dose and schedule of therapy remained constant in all but three patients: One patient required a 25% dose reduction after cycle 3 followed by another 25% reduction after cycle 11 due to drug induced marrow suppression, one patient required a 25% dose reduction after cycle 2 due to drug induced marrow suppression, and one patient required and tolerated a 25% dose escalation to recapture a CR after cycle 15. CONCLUSION This interim analysis suggests that the administration of subcutaneous azacitidine in an accelerated dosing schedule to elderly patients with acute myelogenous leukemia is a feasible and well-tolerated alternative to standard induction chemotherapy. Disclosures: Benjamin: Celgene Corporation: Research Funding. Off Label Use: Use of azacitidine in AML.. Rossetti:Celgene Corporation: Honoraria, Research Funding, Speakers Bureau. Sahovic:Celgene Corporation: Honoraria, Research Funding, Speakers Bureau. Abdulhaq:Celgene Corporation: Research Funding. Shadduck:Celgene Corporation: Honoraria, Research Funding, Speakers Bureau. Lister:Celgene Corporation: Research Funding.

The pp90rsk-CREB Signaling Pathway Regulates Apoptosis In Acute Myelogenous Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3801-3801
Author(s):  
Bryan Mitton ◽  
Ritika Dutta ◽  
Yu-Chiao Hsu ◽  
Rachel Ochoa ◽  
Elliot Landaw ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cell Apoptosis ◽  
Acute Myelogenous Leukemia ◽  
Myelogenous Leukemia ◽  
Expression Level ◽  
Acute Myelogenous ◽  
Targeted Inhibition ◽  
Induced Apoptosis ◽  
Pharmacologic Inhibition

Abstract CREB (cAMP Response-Element Binding Protein) is a nuclear transcription factor critical for hematopoietic cell proliferation, differentiation, and survival. We previously demonstrated that 60% of patients with Acute Myelogenous Leukemia (AML) overexpress CREB in leukemic blasts, and CREB overexpression in these patients was associated with an increased risk of relapse and decreased event-free survival. Previous studies have suggested that CREB may play an important role in the regulation of apoptosis in a wide variety of cancers. Specifically, CREB has been shown to up-regulate members the anti-apoptotic protein family such as Bcl-2, Bcl-XL and Mcl-1, leading to chemotherapy resistance in vitro. CREB-mediated resistance to apoptosis may underlie the increased rate of relapse and poor survival of AML patients with CREB overexpression. Thus, we hypothesized that targeted inhibition of CREB in AML cells would promote AML cell apoptosis. To test this hypothesis, we developed a small-molecule inhibitor of CREB function, XX-650-23. This molecule disrupts the interaction between CREB and its binding partner CBP (CREB-Binding Protein), which is required for full activation of CREB-mediated gene transcription. Treatment of primary AML patient bone marrow samples with XX-650-23 induced apoptosis and cell death at a dose of 2 uM. The degree of apoptosis varied with the expression level of CREB in primary AML cells tested. Higher CREB levels correlated with higher sensitivity to XX-650-23. In non-leukemic primary patient bone marrow samples, CREB levels were very low, and XX-650-23 did not induce apoptosis in these cells. AML cell lines (KG-1 and HL-60) also underwent apoptosis following CREB inhibition, in proportion to CREB expression level. CREB knockdown or overexpression in KG-1 cells decreased and increased susceptibility to apoptosis, respectively. Mechanistically, the onset of apoptosis in AML cells occurred simultaneously with down-regulation of Bcl-2, a validated CREB-regulated gene. Inhibition of Bcl-2 function using the specific Bcl-2 inhibitor ABT-737 (100 nM) induced apoptosis similar to XX-650-23, indicating that Bcl-2 inhibition alone is sufficient to cause apoptosis. Thus, targeted inhibition of CREB results in Bcl-2 downregulation and is sufficient to induce apoptosis in AML cells. Proteomic analysis using Mass Cytometry-Time of Flight (CyTOF) revealed that one compensatory cellular response to CREB inhibition is increased phosphorylation of CREB. This phosphorylation decreased in the presence of BI-D1870, a specific inhibitor of the pp90RSK kinase (RSK), but not by pharmacologic inhibition of the p38 or ERK kinases, using SB202190 or U0126, respectively. We therefore examined the role of pp90RSK in the regulation of apoptosis in AML cells. Pharmacologic inhibition of RSK independently lead to AML cell apoptosis (BI-D1870, IC50=3.3 uM), in part due to blockade of CREB phosphorylation. In summary, our data provide the first evidence that inhibition of CREB, or its chief activator RSK, is sufficient to induce apoptosis in AML cells. Current work focuses on defining CREB target genes mediating XX-650-23 response using chromatin-immunoprecipitation with massively parallel DNA sequencing (ChIP-Seq), and defining the RSK kinome in AML cells using 2-dimensional gel phosphoprotein profiling. These studies will more fully define the role of the RSK-CREB signaling axis in AML proliferation, survival, and apoptosis. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Blockade of MEK signaling potentiates 5-Aza-2′-deoxycytidine-induced apoptosis and upregulation of p21waf1 in acute myelogenous leukemia cells

2009 ◽  
Vol 125 (5) ◽  
pp. 1168-1176 ◽  
Author(s):  
Chie Nishioka ◽  
Takayuki Ikezoe ◽  
Jing Yang ◽  
Naoki Komatsu ◽  
H. Phillip Koeffler ◽  
...  
Keyword(s):  
Acute Myelogenous Leukemia ◽  
Myelogenous Leukemia ◽  
Leukemia Cells ◽  
Acute Myelogenous ◽  
Induced Apoptosis

Caspase 2 and Caspase 3 Protein Levels as Predictors of Survival in Acute Myelogenous Leukemia

Blood ◽  
1998 ◽  
Vol 92 (9) ◽  
pp. 3090-3097 ◽  
Author(s):  
Zeev Estrov ◽  
Peter F. Thall ◽  
Moshe Talpaz ◽  
Elihu H. Estey ◽  
Hagop M. Kantarjian ◽  
...  
Keyword(s):  
Peripheral Blood ◽  
Acute Myelogenous Leukemia ◽  
Caspase 3 ◽  
Myelogenous Leukemia ◽  
Prognostic Variables ◽  
Normal Peripheral Blood ◽  
Protein Levels ◽  
Acute Myelogenous ◽  
Caspase 2 ◽  
High Level

Abstract Because caspase activation is an essential step in programmed cell death (apoptosis) and cytotoxic drug-induced apoptosis is mediated by caspase 2 and caspase 3, we hypothesized that caspase 2 and 3 levels predict clinical outcome in acute myelogenous leukemia (AML). Using quantitative Western blot analysis, we studied the levels of nonactivated (uncleaved) caspase 2 and 3 in peripheral blood low-density cells from 185 patients with newly diagnosed AML. We also measured the level of activated (cleaved) caspase 3 in 41 randomly selected samples from the 185 patients. Finally, we analyzed the effect of caspase 2 and 3 levels and other prognostic variables on patient survival using a multivariate Cox model. We found that median levels of nonactivated caspase 2 and 3 were higher in AML than in normal peripheral blood cells (P &lt; .001 and P &lt;.02, respectively). There was no association between caspase level and either the percentage of peripheral blasts or any specific type of leukemia cell cytogenetic abnormalities. When the effect of each uncleaved caspase was considered individually, a high level of uncleaved caspase 3 (P = .04), but not of caspase 2 (P = .16), was associated with decreased survival. Conversely, a high level of cleaved caspase 3 denoted improved survival and correlated with the inactivation of the DNA-repair enzyme poly(ADP-ribose) polymerase. Thus, cleaved caspase 3 could stimulate the apoptotic cascade further, and lack of its activation likely caused an accumulation of the uncleaved caspase. Although uncleaved caspase 2 level per se had no prognostic significance, the interactive effect of high levels of both uncleaved caspase 2 and 3 denoted very poor survival (P &lt; .001) and had the largest effect of all prognostic variables (P &lt; .001; estimated relative risk, 2.49; 95% confidence interval, 1.59 to 3.90). Taken together, caspase 2 and caspase 3 protein levels obtained at diagnosis may constitute a reliable prognostic factor in AML. © 1998 by The American Society of Hematology.

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