scholarly journals Biology of t(6;11) Fusion Proteins and Their Role in MLL-Rearranged Acute Leukemia Lineage Determination

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5033-5033
Author(s):  
Arpita Kundu ◽  
Eric Kowarz ◽  
Jennifer Reis ◽  
Rolf Marschalek
Keyword(s):  
Gene Expression ◽  
Acute Lymphoblastic Leukemia ◽  
High Risk ◽  
Acute Leukemia ◽  
Fusion Proteins ◽  
Lymphoblastic Leukemia ◽  
Chromosomal Translocation ◽  
Fusion Genes ◽  
Disease Phenotype ◽  
Acute Leukemias

Chromosomal translocations are genetic rearrangements where a chromosomal segment is transferred to a non-homologous chromosome which give rise to novel chimeras. Chromosomal rearrangements play a significant role in the development of acute leukemias (acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML)). Chromosomal translocation events occurring at 11q23 involving the KMT2A or Mixed-Lineage Leukemia (MLL) gene (n=102) can be diagnosed in about 5-10% of all acute leukemia patients (Marschalek Ann Lab Med 2016), especially prevalent in infant acute leukemias (up to 70% of cases). Different chromosomal translocation partner genes (such as AF4, AF6, AF9orENL and ELL) account for the majority of leukemia cases and have their genomic breakpoints within a major breakpoint cluster region (BCR intron 9-11; Meyer et. al. Leukemia 2018). Some rearrangements are specifically associated with particular disease phenotype e.g. the majority of ALL patients (~ 90%) are mainly caused by the following gene fusions, MLL-AF4, MLL-AF9, MLL-ENL. We are interested in a rare but yet drastic chromosomal translocation t(6;11)(q27;q23) which fuses KMT2A/MLL to Afadin (AFDN/AF6) gene. This chromosomal rearrangement has a very poor prognosis (survival-rate is ~10%) and is predominantly diagnosed in patients with high-risk AML. In this project, we investigate the molecular consequences of two different MLL-AF6 fusions and their corresponding reciprocal AF6-MLL fusions. MLL-AF6 fusions are mainly occurring within MLL intron 9 to 11 and are associated with an AML disease phenotype, while the same fusion occurring within the minor breakpoints region in MLL intron 21 until exon (ex) 24 are mainly diagnosed with T-ALL (T-cell acute lymphoblastic leukemia) disease phenotype. The molecular mechanism that determines the resulting disease phenotype is yet unknown. Therefore, we cloned all of these t(6;11) fusion proteins in order to investigate the functional consequences of the two different breakpoints (MLLex1-9::AF6ex2-30, AF6ex1::MLLex10-37; MLLex1-21::AF6ex2-30, AF6ex1::MLLex22-37). All 4 fusion genes were introduced into our inducible Sleeping Beauty system (Ivics et. al. Mobile DNA 2010; Kowarz et. al. Biotechnol J. 2015) and stably transfected reporter cell lines. Basically, these 4 fusion proteins differ only in the presence or absence of their Plant homeodomain 1-3/Bromodomain (PHD1-3/BD) domain (see Figure 1). The PHD domain regulates the epigenetic and transcriptional regulatory functions of wildtype MLL. Subsequently, we analyzed gene expression differences by the MACE-Seq (Massive Analyses of cDNA Ends). MACE data revealed fundamental differences in gene expression profiles when analyzing the two different sets of t(6;11) fusion genes. The resulting profiles have similarities to either AML or T-ALL and might give a rational explanation for the different lineages in these t(6;11) patients. Altogether, these results notably indicate that our study will provide a novel insight into this type of high-risk leukemia and subsequently will be useful for developing of novel and appropriate therapeutic strategies against acute leukemia. Disclosures No relevant conflicts of interest to declare.

The AF4·MLL fusion protein is capable of inducing ALL in mice without requirement of MLL·AF4

Blood ◽  
2010 ◽  
Vol 115 (17) ◽  
pp. 3570-3579 ◽  
Author(s):  
Adelheid Bursen ◽  
Karen Schwabe ◽  
Brigitte Rüster ◽  
Reinhard Henschler ◽  
Martin Ruthardt ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Fusion Protein ◽  
Fusion Proteins ◽  
Lymphoblastic Leukemia ◽  
Chromosomal Translocation ◽  
Disease Development ◽  
Fusion Genes ◽  
Genetic Aberration ◽  
Biphenotypic Acute Leukemia ◽  
Observation Period

Abstract The chromosomal translocation t(4;11)(q21;q23) is the most frequent genetic aberration of the human MLL gene, resulting in high-risk acute lymphoblastic leukemia (ALL). To elucidate the leukemogenic potential of the fusion proteins MLL·AF4 and AF4·MLL, Lin−/Sca1+ purified cells (LSPCs) were retrovirally transduced with either both fusion genes or with MLL·AF4 or AF4·MLL alone. Recipients of AF4·MLL- or double-transduced LSPCs developed pro-B ALL, B/T biphenotypic acute leukemia, or mixed lineage leukemia. Transplantation of MLL·AF4- or mock-transduced LSPCs did not result in disease development during an observation period of 13 months. These findings indicate that the expression of the AF4·MLL fusion protein is capable of inducing acute lymphoblastic leukemia even in the absence of the MLL·AF4 fusion protein. In view of recent findings, these results may imply that t(4;11) leukemia is based on 2 oncoproteins, providing an explanation for the very early onset of disease in humans.

Acute Leukemia

2016 ◽  
Author(s):  
Richard A. Larson ◽  
Roland B Walter
Keyword(s):  
Acute Myeloid Leukemia ◽  
Acute Lymphoblastic Leukemia ◽  
Acute Leukemia ◽  
Myeloid Leukemia ◽  
Who Classification ◽  
Lymphoblastic Leukemia ◽  
World Health ◽  
Acute Leukemias ◽  
Acute Myeloid

The acute leukemias are malignant clonal disorders characterized by aberrant differentiation and proliferation of transformed hematopoietic progenitor cells. These cells accumulate within the bone marrow and lead to suppression of the production of normal blood cells, with resulting symptoms from varying degrees of anemia, neutropenia, and thrombocytopenia or from infiltration into tissues. They are currently classified by their presumed cell of origin, although the field is moving rapidly to genetic subclassification. This review covers epidemiology; etiology; classification of leukemia by morphology, immunophenotyping, and cytogenetic/molecular abnormalities; cytogenetics of acute leukemia; general principles of therapy; acute myeloid leukemia; acute lymphoblastic leukemia; and future possibilities. The figure shows the incidence of acute leukemias in the United States. Tables list World Health Organization (WHO) classification of acute myeloid leukemia and related neoplasms, expression of cell surface and cytoplasmic markers for the diagnosis of acute myeloid leukemia and mixed-phenotype acute leukemia, WHO classification of acute lymphoblastic leukemia, WHO classification of acute leukemias of ambiguous lineage, WHO classification of myelodysplastic syndromes, European LeukemiaNet cytogenetic and molecular genetic subsets in acute myeloid leukemia with prognostic importance, cytogenetic and molecular subtypes of acute lymphoblastic leukemia, terminology used in leukemia treatment, and treatment outcome for adults with acute leukemia. This review contains 1 highly rendered figure, 9 tables, and 117 references.

scholarly journals Clonal Evolution of B-Cell Acute Lymphoblastic Leukemia with del(9)(p13p21) into Mixed Phenotype Acute Leukemia Presenting as an Isolated Testicular Relapse

Reports ◽  
2019 ◽  
Vol 2 (3) ◽  
pp. 18 ◽  
Author(s):  
Miller ◽  
Park ◽  
Saxe ◽  
Lew ◽  
Raikar
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Acute Leukemia ◽  
B Cell ◽  
Lymphoblastic Leukemia ◽  
Clonal Evolution ◽  
Acute Leukemias ◽  
Cytogenetic Aberrations ◽  
Mixed Phenotype Acute Leukemia ◽  
Cell Acute Lymphoblastic Leukemia ◽  
Mixed Phenotype

Lineage switch in acute leukemias is a well-reported occurrence; however, most of these cases involve a switch from either lymphoid to myeloid or myeloid to lymphoid lineage. Here, we report a case of a 14-year-old male with B-cell acute lymphoblastic leukemia (B-ALL) who initially responded well to standard chemotherapy but then later developed mixed phenotype acute leukemia (MPAL) at relapse, likely reflecting a clonal evolution of the original leukemia with a partial phenotypic shift. The patient had a del(9)(p13p21) in his leukemia blasts at diagnosis, and the deletion persisted at relapse along with multiple additional cytogenetic aberrations. Interestingly, the patient presented with an isolated testicular lesion at relapse, which on further analysis revealed both a lymphoid and myeloid component. Unfortunately, the patient did not respond well to treatment at relapse and eventually succumbed to his disease. To our knowledge, an isolated extramedullary MPAL at relapse in a patient with previously diagnosed B-ALL has not been reported in the literature before.

High CD45 (PTPRC) Expression Is Associated with An Overall Poor Outcome in Childhood Acute Lymphoblastic Leukemia Treated on the ALL-BFM 2000 Protocol and Exerts An Especially Pronounced Effect in Intermediate Risk Patients

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 742-742
Author(s):  
Gunnar Cario ◽  
Rita Mitlohner ◽  
Martin Zimmermann ◽  
Renja Romey ◽  
Peter Rhein ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Lymphoblastic Leukemia ◽  
High Risk ◽  
Protein Expression ◽  
Lymphoblastic Leukemia ◽  
Treatment Resistance ◽  
Intermediate Risk ◽  
Prognostic Relevance ◽  
Risk Patients ◽  
Low Expression

Abstract Abstract 742 Further improvement of outcome in childhood acute lymphoblastic leukemia (ALL) could be achieved by identifying additional high-risk (HR) patients who then may benefit from an intensified treatment. In trial ALL-BFM 2000, the HR group was defined by inadequate initial response to induction treatment [poor prednisone response on treatment day eight (PPR), non remission on treatment day 33, and/or a high load of minimal residual disease (MRD, ≥10E-3) after 12 weeks of treatment (TP2)] and/or by positive cytogenetics for a t(4;11) or t(9;22). No MRD already on treatment day 33 defined standard risk (SR) patients, a measurable MRD at a low level characterized the intermediate risk (IR) group. Of importance, the majority of relapses occurred within this heterogeneous group of patients. In order to identify potential new stratification markers we earlier compared gene expression profiles of MRD resistance (HR) and sensitive (SR) ALL in a case-control setting (Cario et al, Blood 2005). Subsequently, we aimed at confirming the potential prognostic relevance of genes identified and their respective proteins in representative study populations. CD45 (also PTPRC, protein-tyrosine phosphatase, receptor-type, C) was one of these candidate genes. In order to assess its prognostic relevance, CD45 gene expression was first analyzed by quantifiable RT-PCR in a set of 555 precursor B-ALL (pB-ALL); its protein expression subsequently in 422 pB-ALL patients by flow cytometry. About one third of patients were included in both study sets. Normalization of protein expression was done by assessing the density of surface expression relative to its density on normal lymphocytes. The 90th percentile was used as a cut-off to distinguish a CD45-high from a CD45-low expression group in both analyses. In gene expression analysis we observed a significant association of a high CD45 expression with a high white blood cell count at diagnosis (WBC) (P = 0.0004), NCI-HR (P = 0.03) as well as presence of the MLL-AF4 rearrangement (P < 0.0001). Moreover, a high CD45 expression was associated with in-vivo treatment resistance as defined by MRD (P = 0.0025). Analyzing CD45 protein expression confirmed the association of a high expression with a high WBC (P < 0.0001), NCI-HR (P = 0.0002) as well as presence of the MLL-AF4 rearrangement (P < 0.0001). Moreover, although the association to treatment resistance was lower (P = 0.055), patients with a high CD45 expression had a significantly worse 5-years EFS probability of 62±8% compared to 82±2% for those in the low-expression group (P=0.002). Focussing on the IR group, patients with a high CD45 expression had a very poor outcome (EFS 45±15%) as compared to those with a low expression (EFS 86±3%, P < 0.0001). This effect was mainly related to a higher cumulative relapse incidence (55±16% vs. 13±3%, P < 0.0001). Of interest, no significant differences in EFS were seen in HR patients. Based on our results, consideration of CD45 protein expression may serve as additional stratification tool in BFM-based protocols to further refine true non-high-risk patients with a low risk of relapse by identifying additional patients at high relapse risk. Of importance, in view of the fact that CD45 expression was not prognostic in the high-risk group, patients with a high CD45 expression currently treated on non high risk arms, may potentially benefit from an intensified treatment in the HR arm. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Key pathways are frequently mutated in high-risk childhood acute lymphoblastic leukemia: a report from the Children's Oncology Group

Blood ◽  
2011 ◽  
Vol 118 (11) ◽  
pp. 3080-3087 ◽  
Author(s):  
Jinghui Zhang ◽  
Charles G. Mullighan ◽  
Richard C. Harvey ◽  
Gang Wu ◽  
Xiang Chen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Lymphoblastic Leukemia ◽  
High Risk ◽  
B Cell ◽  
High Frequency ◽  
Lymphoblastic Leukemia ◽  
Cell Development ◽  
B Cell Development ◽  
Ras Signaling ◽  
Somatic Alterations

Abstract We sequenced 120 candidate genes in 187 high-risk childhood B-precursor acute lymphoblastic leukemias, the largest pediatric cancer genome sequencing effort reported to date. Integrated analysis of 179 validated somatic sequence mutations with genome-wide copy number alterations and gene expression profiles revealed a high frequency of recurrent somatic alterations in key signaling pathways, including B-cell development/differentiation (68% of cases), the TP53/RB tumor suppressor pathway (54%), Ras signaling (50%), and Janus kinases (11%). Recurrent mutations were also found in ETV6 (6 cases), TBL1XR1 (3), CREBBP (3), MUC4 (2), ASMTL (2), and ADARB2 (2). The frequency of mutations within the 4 major pathways varied markedly across genetic subtypes. Among 23 leukemias expressing a BCR-ABL1-like gene expression profile, 96% had somatic alterations in B-cell development/differentiation, 57% in JAK, and 52% in both pathways, whereas only 9% had Ras pathway mutations. In contrast, 21 cases defined by a distinct gene expression profile coupled with focal ERG deletion rarely had B-cell development/differentiation or JAK kinase alterations but had a high frequency (62%) of Ras signaling pathway mutations. These data extend the range of genes that are recurrently mutated in high-risk childhood B-precursor acute lymphoblastic leukemia and highlight important new therapeutic targets for selected patient subsets.

scholarly journals NUTM1 Is a Rare but Recurrent Fusion Gene Partner in B Cell Precursor Acute Lymphoblastic Leukemia Associated with Increased Expression of Genes on Cytoband 10p12.31

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2823-2823
Author(s):  
Femke M. Hormann ◽  
Alex Q. Hoogkamer ◽  
H. Berna Beverloo ◽  
Aurélie Boeree ◽  
Ronald W. Stam ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Lymphoblastic Leukemia ◽  
Rna Sequencing ◽  
Histone Acetyltransferase ◽  
Lymphoblastic Leukemia ◽  
Fusion Transcript ◽  
Population Based ◽  
Fusion Genes ◽  
Cell Precursor ◽  
Cytogenetic Aberration

Abstract INTRODUCTION In 20-25% of the pediatric B cell precursor acute lymphoblastic leukemia (BCP-ALL) patients, the driving cytogenetic aberration is unknown. It is important to identify more primary lesions in this remaining B-other group to provide better risk stratification and identify possible treatment options. In this study, we aimed to identify novel recurrent fusion genes in BCP-ALL through RNA sequencing. METHODS We used paired-end total RNA Illumina sequencing to detect fusion genes with STAR-fusion and FusionCatcher in a population-based ALL cohort (n=71). We used Affymetrix U133 Plus2 expression arrays in a larger population-based ALL cohort (n=661) and an infant ALL cohort (n=70) to compare gene expression levels. Fluorescent in situ hybridization (FISH) was performed using Cytocell NUTM1 break-apart probe set MPH4800. RESULTS We identified an in-frame SLC12A6-NUTM1 fusion transcript composed of exons 1-2 of SLC12A6 fused to exons 3 to 8 of NUTM1 by RNA sequencing. Both genes are located on 15q14 within 5.3 Kb distance on opposite strands, and the fusion could result from an inversion. The fusion transcript is predicted to encode almost the total NUTM1 protein including the acidic binding domain for the histone acetyltransferase EP300. The SLC12A6-NUTM1 fusion case showed high NUTM1 expression, while NUTM1 expression was absent in the remaining cases. Using gene expression profiling, we identified four additional pediatric and two non-KMT2A-rearranged infant BCP-ALL cases with high NUTM1 expression. In the population-based cohort reflecting all different cytogenetic subtypes, these cases were restricted to the B-other group without known sentinel cytogenetic abnormalities. FISH showed a NUTM1 break apart pattern in all four tested NUTM1-positive cases indicative of a balanced translocation. RNA sequencing confirmed an ACIN1-NUTM1 fusion in one of the infant cases. We conclude that NUTM1 is normally not expressed in leukemic lymphoblasts, and that its expression can be induced by a gene fusion. The karyotypes of the predicted NUTM1 fusion cases combined with RNA sequencing data suggest that different chromosomal rearrangements are involved, likely resulting in different NUTM1 fusion partners. In literature, BRD9-NUTM1, IKZF1-NUTM1, and CUX1-NUTM1 fusions were reported in pediatric B-other cases, and BRD9-NUTM1 and ACIN1-NUTM1 fusions were reported in non-KMT2A-rearranged infants. Our combined aberrant gene expression and FISH results indicate that NUTM1 fusions occur in 2.4% (5/210) of pediatric and in 28% (2/7) of infant BCP-ALL cases without a sentinel cytogenetic aberration. The recurrence of NUTM1 aberrations in BCP-ALL cases without a known driver and the resulting expression of NUTM1 suggests that this fusion could be a new oncogenic driver in leukemia. All seven patients with a NUTM1 fusion achieved continuous complete remission with a median follow-up time of 8.3 years (range 4.8-13.8 years), suggesting that NUTM1 fusions in BCP-ALL have a favorable prognosis. To get an insight in the underlying biology, we compared gene expression between NUTM1-positive and NUTM1-negative pediatric B-other cases. We identified 130 differentially expressed probe sets (FDR ≤0.01) with a peculiar enrichment of those located on chromosome band 10p12.31 (Bonferroni adjusted p=4.05E-04). The genes in cytoband 10p12.31, including BMI1, were variably upregulated in 6/7 NUTM1-positive cases and positively correlated to NUTM1 expression levels. The NUTM1 protein is capable of binding and hereby stimulating the histone acetyltransferase activity of the EP300 protein. The EP300 protein preferentially binds a risk allele of BMI1 associated with increased risk for BCP-ALL. The BMI1 protein has been shown to convert BCR-ABL1-positive progenitor cells into BCR-ABL1-positive BCP-ALL cells. Hence, we postulate that NUTM1 fusion proteins contribute to leukemogenesis by stimulating EP300, leading to upregulation of BMI1 and other 10p12.31 genes in BCP-ALL. CONCLUSION NUTM1 fusions are a rare but recurrent event in BCP-ALL that seems to have a good prognosis. The NUTM1 fusions result in expression of the normally silent NUTM1 gene and are associated with upregulation of a cluster of genes on 10p12.31 including the leukemogenic BMI1 gene. Disclosures No relevant conflicts of interest to declare.

scholarly journals High-Risk Subtype of Ph-like Acute Lymphoblastic Leukemia (ALL) in Adults: Dismal Outcomes of CRLF2+ ALL Patients Treated with Intensive Chemotherapy

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1082-1082 ◽  
Author(s):  
Nitin Jain ◽  
Kathryn G. Roberts ◽  
Elias J. Jabbour ◽  
Keyur Patel ◽  
Karina Eterovic ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Lymphoblastic Leukemia ◽  
High Risk ◽  
Gene Expression Profiling ◽  
Expression Profiling ◽  
Research Funding ◽  
Lymphoblastic Leukemia ◽  
Adult Patients ◽  
Hispanic Ethnicity ◽  
Oncology Research

Abstract Background:Ph-like acute lymphoblastic leukemia (ALL) is a high-risk subtype of ALL in children. There are limited and conflicted data on the incidence and prognosis of Ph-like ALL in adults. Methods:Patients with newly-diagnosed B-ALL who received frontline chemotherapy at MD Anderson Cancer Center underwent gene expression profiling of leukemic cells to identify Ph-like ALL. Gene expression profiling was performed on 148 RNA samples using either U133 Plus 2.0 microarrays, or a customized Taqman low density array (LDA) card to identify patients with the Ph-like ALL gene signature (Roberts et al. NEJM 2014). An additional 7 previously untreated patients were found to have CRLF2 overexpression by multicolor flow-cytometry (MFC), and received induction chemotherapy at MDACC were included in the outcome analysis (but not for subtype frequency calculation). We performed targeted sequencing of 303 recurrently mutated genes (L300 panel, MDACC) in 40 patients with CRFL2 rearrangements (15 with matched germline control). Minimal residual disease (MRD) was assessed by MFC, with a sensitivity of 0.01%. Results:Of 148 patients, 49 (33.1%) were Ph-like, 46 patients (31.1%) were Ph+, and 53 patients (35.8%) were of other B-ALL subtypes (B-other). The median age of Ph-like cohort was 33.5 years (range, 15-71), Ph+ cohort was 49 years (range, 22-84), and B-other was 38 years (range, 15-79). Within the Ph-like ALL cohort, 61% had overexpression of CRLF2. Patients received hyper-CVAD (80%) or an augmented-BFM regimen (20%). The rate of CR/CRp was similar in the 3 disease subgroups (Ph-like ALL 89%, Ph+ ALL 93%, B-other 94%, p = 0.57). However, patients with Ph-like ALL were significantly less likely to achieve MRD-negative remission (30% vs. 56% for Ph+ ALL vs. 87% for B-other, p <0.001). Patients with Ph-like ALL had significantly worse overall survival (OS) and event-free survival (EFS) compared to B-other with a 5-year survival of 23% (vs. 59% for B-other, p=0.006) (Figure 1A). The poor outcomes of Ph-like ALL were also observed when only hyper-CVAD treated patients were considered. Interestingly, 68% of the patients with Ph-like ALL (78% among the CRLF2+ cohort) were of Hispanic ethnicity. This was significantly higher compared to Ph+ ALL (35%) and B-other (30%), p <0.001. Patients with CRLF2 overexpression had significantly inferior OS, EFS, and remission duration when compared to other genomic subgroups, including the Ph-like non-CRLF2 group (Figure 1B). Notably, 5-year survival in the CRLF2+ group was <20%. The following were independently associated with inferior OS on multivariable analysis: age (hazard ratio [HR] 2.474, p<0.001); WBC count (HR 1.183, p=0.007); platelet count (HR 4.283, p<0.001) and Ph-like ALL (HR 1.579, p=0.04) (Table 1). The most common mutations by L300 sequencing of 40 patients with CRLF2 were JAK2 (n=19, 47.5%), KRAS (n=10, 25%), CRLF2 (n=7, 17.5%), NRAS (n=5, 12.5%), PAX5 (n=5, 12.5%), JAK1 (n=4, 10%) (Figure 2). The CRLF2 F232C mutation, noted in 7 (17.5%) patients in this study, appears more frequent than in pediatric patients (3/134, 2.2%, Chen et al. Blood 2012), and in range with a smaller adult series (3/14, 21.4%, Yoda et al. PNAS 2010). CRLF2 F232C mutations were mutually exclusive with JAK2/JAK1 mutations (except in one patient). Conclusions:Our findings show a high frequency of Ph-like ALL in adults; an increased frequency of Ph-like ALL in adults with Hispanic ethnicity; significantly inferior outcomes of adult patients with Ph-like ALL; and significantly worse outcomes in Ph-like ALL patients with CRLF2 overexpression. The frequency of CRLF2 F232C mutation appears to be higher in adult patients with B-ALL than in the children. Ph-like ALL represents a high-risk disease subtype of adult B-ALL. Novel strategies are needed to improve the outcome of these patients. Disclosures Jain: Pharmacyclics: Consultancy, Honoraria, Research Funding; Genentech: Research Funding; Incyte: Research Funding; BMS: Research Funding; Abbvie: Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Celgene: Research Funding; ADC Therapeutics: Consultancy, Honoraria, Research Funding; Seattle Genetics: Research Funding; Servier: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Infinity: Research Funding; Novimmune: Consultancy, Honoraria. Jabbour:ARIAD: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Novartis: Research Funding; BMS: Consultancy. Cortes:ARIAD: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Teva: Research Funding. O'Brien:Pharmacyclics, LLC, an AbbVie Company: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria. Mullighan:Incyte: Membership on an entity's Board of Directors or advisory committees; Amgen: Speakers Bureau; Loxo Oncology: Research Funding. Konopleva:Reata Pharmaceuticals: Equity Ownership; Abbvie: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Stemline: Consultancy, Research Funding; Eli Lilly: Research Funding; Cellectis: Research Funding; Calithera: Research Funding.

scholarly journals Intracellular Lysozyme in Mature Neutrophils and Blast Cells in Acute Leukemia

Blood ◽  
1974 ◽  
Vol 44 (2) ◽  
pp. 247-255 ◽  
Author(s):  
Hans Karle ◽  
Niels Ebbe Hansen ◽  
Sven-Aage Killmann
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Acute Leukemia ◽  
Lymphoblastic Leukemia ◽  
Cell Mass ◽  
Leukemic Cell ◽  
High Plasma ◽  
Lysozyme Activity ◽  
Neutrophilic Granulocytes ◽  
Acute Leukemias ◽  
Myelomonocytic Leukemia

Abstract Intracellular lysozyme (muramidase) activity was measured in leukemic blasts and mature neutrophilic granulocytes from 20 patients with acute myeloblastic and myelomonocytic leukemia and in 11 patients with acute lymphoblastic leukemia after differential centrifugation of cells in Ficoll and extraction of lysozyme with n-butanol. Considerable abnormalities in cellular lysozyme activity were found both in qualitative and quantitative terms. In contrast to normal myeloblasts, leukemic blasts of the myeloid series contained lysozyme in a considerable number of cases. Although no clear-cut distinction was seen, those patients with positive blast lysozyme reactivity tended to have the highest plasma lysozyme levels, whereas no good correlation was found between morphologic differentiation along myeloblastic or monocytoblastic lines of blasts and lysozyme reactivity. Calculations of the magnitude of lysozyme production in acute leukemias with high plasma lysozyme concentration was compatible with the hypothesis that in these cases lysozyme must be secreted by intact blasts and that, consequently, plasma lysozyme activity reflects the total leukemic cell mass. In mature neutrophilic granulocytes from patients with acute myeloblastic and myelomonocytic leukemia in relapse, the mean lysozyme activity was significantly decreased, although a great deal of variation was found. In remission, neutrophil lysozyme activity seemed to increase; among several possibilities this might be a reflection of different clones being operative in relapse and remission. In acute lymphoblastic leukemia, lysozyme activity in neutrophils was constantly low in relapse and increased to normal following induction of remission, which may be the main explanation of the low plasma lysozyme activity found in this type of acute leukemia. It is unexplained and puzzling why intraneutrophil lysozyme activity is low in a leukemic type where the myeloid cells are not believed to be primarily leukemic; one possible reason might be an effect of cell-to-cell interaction with the leukemic cell population.

The Heterogeneous Fusion Gene Landscape in Pediatric Acute Lymphoblastic Leukemia

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4081-4081
Author(s):  
Yanara Marincevic-Zuniga ◽  
Johan Dahlberg ◽  
Sara Nilsson ◽  
Amanda Raine ◽  
Jonas Abrahamsson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Acute Lymphoblastic Leukemia ◽  
Gene Fusion ◽  
Conflicts Of Interest ◽  
Fusion Gene ◽  
Lymphoblastic Leukemia ◽  
Fusion Genes ◽  
Fusion Transcripts ◽  
Pediatric All

Abstract Background: Next generation sequencing allows for the detection of expressed fusion transcripts across the transcriptome and has spurred the discovery of many novel chimeric transcripts in various cancers. Structural chromosomal rearrangements that lead to fusion transcripts are a hallmark of acute lymphoblastic leukemia (ALL) and serve as markers for diagnosis and stratification of pediatric ALL patients into prognostically relevant subgroups. Improved delineation of structural alterations in ALL could provide additional information for prognosis in ALL and for improved stratification of patients into treatment groups. Methods: To identify novel fusion transcripts in primary pediatric ALL cells we performed whole transcriptome sequencing of 134 BCP and T-ALL patient samples collected at diagnosis. Our study include samples from patients with the well-known ALL subtypes t(12;21)ETV6-RUNX1, high hyperdiploid (51-67 chromosomes), t(9;22)BCR-ABL1, 11q23/MLL and dic(9;20), in addition to patients with undefined karyotype or non-recurrent cytogenetic aberrations ("undefined" and "other") (n=58). FusionCatcher was used for the detection of somatic fusion genes, followed by a stringent filtering pipeline including gene fusion validation by Sanger sequencing in order to reduce the number of false positives. Principal component analysis (PCA) of patients with fusion genes was performed using genome wide gene expression levels and DNA methylation levels (Infinium HumanMethylation450 bead array). Results: We identified and validated 60 unique fusion events in almost half of the analyzed patients (n=69). Of the identified fusion genes, 60% have not previously been reported in ALL or other forms of cancer. The majority of the fusion genes were found in a single patient, but 23% were recurrent, including known ALL fusion genes (n=10) and novel fusion genes (n=7). We found that BCP-ALL samples displayed a higher number of validated fusion genes (54%) compared to the T-ALL samples (28%) moreover in BCP-ALL patients with "other" and "undefined" karyotypes, we detected fusion genes in 71% and 61% of the samples, respectively. High hyperdiploid patients had the lowest rate of validated fusion genes (24%) compared to the other well-known subtypes, where we detected subtype-associated fusion genes in 97% of cases. We also identified promiscuous fusion gene partners, such as ETV6, RUNX1, PAX5 and ZNF384 that fused with up to five different genes. Interestingly, PCA revealed molecularly distinct gene expression and DNA methylation signatures associated with these fusion partners. Conclusion: RNA-sequencing of pediatric ALL cells revealed a detailed view of the heterogeneous fusion gene landscape, identifying both known and novel fusion genes. By grouping samples based on recurrent gene fusion partners we are able to find shared gene expression and DNA methylation patterns compared to other subtypes of ALL, suggesting a shared molecular etiology within these distinct subgroups, offering novel insights into the delineation of fusion genes in ALL. Disclosures No relevant conflicts of interest to declare.

scholarly journals Tyrosine kinome sequencing of pediatric acute lymphoblastic leukemia: a report from the Children's Oncology Group TARGET Project

Blood ◽  
2013 ◽  
Vol 121 (3) ◽  
pp. 485-488 ◽  
Author(s):  
Mignon L. Loh ◽  
Jinghui Zhang ◽  
Richard C. Harvey ◽  
Kathryn Roberts ◽  
Debbie Payne-Turner ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Lymphoblastic Leukemia ◽  
High Risk ◽  
Gene Expression Profile ◽  
Expression Profile ◽  
Tyrosine Kinases ◽  
Somatic Mutations ◽  
Lymphoblastic Leukemia ◽  
Kinase Signaling ◽  
Tyrosine Kinome

Abstract One recently identified subtype of pediatric B-precursor acute lymphoblastic leukemia (ALL) has been termed BCR-ABL1–like or Ph-like because of similarity of the gene expression profile to BCR-ABL1 positive ALL suggesting the presence of lesions activating tyrosine kinases, frequent alteration of IKZF1, and poor outcome. Prior studies demonstrated that approximately half of these patients had genomic lesions leading to CRLF2 overexpression, with half of such cases harboring somatic mutations in the Janus kinases JAK1 and JAK2. To determine whether mutations in other tyrosine kinases might also occur in ALL, we sequenced the tyrosine kinome and downstream signaling genes in 45 high-risk pediatric ALL cases with either a Ph-like gene expression profile or other alterations suggestive of activated kinase signaling. Aside from JAK mutations and 1 FLT3 mutation, no somatic mutations were found in any other tyrosine kinases, suggesting that alternative mechanisms are responsible for activated kinase signaling in high-risk ALL.

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