PAX5/TEL Causes Down Modulation of B-Lineage Specific Genes, and Enhances Migration to CXCL12 in preBI Cells.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 980-980
Author(s):  
Grazia Fazio ◽  
Chiara Palmi ◽  
Antonius G. Rolink ◽  
Giovanni Cazzaniga ◽  
Andrea Biondi
Keyword(s):  
B Cell ◽  
Target Genes ◽  
Fusion Gene ◽  
Wild Type Mouse ◽  
Leukemic Cells ◽  
Wild Type ◽  
Cell Precursor ◽  
Childhood All ◽  
B Lineage ◽  
Lineage Specific Genes

Abstract PAX5 is a transcription factor essential for B-cell development. Recently, it has been found as frequent target of abnormalities in childhood ALL (30% of B-cell precursor ALL cases), showing monoallelic loss, point mutations or chromosomal translocations. The role of these lesions is still poorly understood. We previously cloned the PAX5/TEL fusion gene in a patient affected by B-cell precursor ALL with t(9;12) translocation. We investigated the functional roles of PAX5/TEL protein in vitro, in murine wild type preBI cells, primary cells derived from a wild type mouse and positive for B220, cKIT and CD19 antigens.We demonstrated that the PAX5/TEL protein acts as a transcriptional repressor, down regulating not only CD19, but also other B-lineage specific genes, such as BLNK and MB-1. In addition, PAX5/TEL down regulates FLT3, B220 and μ heavy chain expression, and it does not activate MCSFR. Moreover in PAX5−/− preBI cells, PAX5/TEL did not restore CD19 expression. Comprehensively, these findings suggest that the fusion protein functions as a dominant repressor of transcription on many PAX5-target genes. It is known that CXCL12/SDF1 is a growth factor promoting B-cell progenitor proliferation, acting as a chemo attractant to the bone marrow. In several hematopoietic malignancies, tumor cells express CXCR4, and that the CXCL12-CXCR4 axis may influence the biology of tumor, favoring the metastasis process and the tumor proliferation. Indeed, we demonstrated that PAX5/TEL enhances cell migration towards CXCL12, with over-expression of CXCR4. These phenomena could indicate that leukemic cells carrying PAX5/TEL are able to access to niches that are normally restricted to progenitor cells, and thereby reside in a microenvironment that favours their growth and survival, although this finding must be proved in vivo. Together with previous evidences on the PAX5/TEL capacity to overcome IL7 withdrawal and to interfere with TGFbeta1 pathway, we conclude that PAX5/TEL induces resistance to apoptosis and interferes with the processes of B-cell differentiation and migration. Taken together, these phenomena likely represent key events in the process of B-cell transformation.

A novel PAX5-ELN fusion protein identified in B-cell acute lymphoblastic leukemia acts as a dominant negative on wild-type PAX5

Blood ◽  
2006 ◽  
Vol 109 (8) ◽  
pp. 3417-3423 ◽  
Author(s):  
Marina Bousquet ◽  
Cyril Broccardo ◽  
Cathy Quelen ◽  
Fabienne Meggetto ◽  
Emilienne Kuhlein ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
B Cell ◽  
Target Genes ◽  
Lymphoblastic Leukemia ◽  
Quantitative Polymerase Chain Reaction ◽  
Dominant Negative ◽  
Leukemic Cells ◽  
Dominant Negative Effect ◽  
Wild Type ◽  
Cell Acute Lymphoblastic Leukemia

Abstract We report a novel t(7;9)(q11;p13) translocation in 2 patients with B-cell acute lymphoblastic leukemia (B-ALL). By fluorescent in situ hybridization and 3′ rapid amplification of cDNA ends, we showed that the paired box domain of PAX5 was fused with the elastin (ELN) gene. After cloning the full-length cDNA of the chimeric gene, confocal microscopy of transfected NIH3T3 cells and Burkitt lymphoma cells (DG75) demonstrated that PAX5-ELN was localized in the nucleus. Chromatin immunoprecipitation clearly indicated that PAX5-ELN retained the capability to bind CD19 and BLK promoter sequences. To analyze the functions of the chimeric protein, HeLa cells were cotransfected with a luc-CD19 construct, pcDNA3-PAX5, and with increasing amounts of pcDNA3-PAX5-ELN. Thus, in vitro, PAX5-ELN was able to block CD19 transcription. Furthermore, real-time quantitative polymerase chain reaction (RQ-PCR) experiments showed that PAX5-ELN was able to affect the transcription of endogenous PAX5 target genes. Since PAX5 is essential for B-cell differentiation, this translocation may account for the blockage of leukemic cells at the pre–B-cell stage. The mechanism involved in this process appears to be, at least in part, through a dominant-negative effect of PAX5-ELN on the wild-type PAX5 in a setting ofPAX5 haploinsufficiency.

Clonal Origins of 'late' Relapses in ETV6-RUNX1 Acute Lymphoblastic Leukemia..

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1583-1583
Author(s):  
Frederik W van Delft ◽  
Sharon W Horsley ◽  
Kristina Anderson ◽  
Caroline M Bateman ◽  
Susan Colman ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
B Cell ◽  
Copy Number ◽  
Conflicts Of Interest ◽  
Fusion Gene ◽  
Lymphoblastic Leukemia ◽  
Leukemic Cells ◽  
Childhood All ◽  
Remission Duration ◽  
Clonal Origin

Abstract Abstract 1583 Poster Board I-609 Approximately a quarter of B cell precursor childhood acute lymphoblastic leukemia (ALL) is characterized by an ETV6-RUNX1 (TEL-AML1) fusion gene and has an overall good prognosis. The majority of these children will be treated on the standard risk arm of the United Kingdom ALL treatment protocols. Relapse usually occurs after cessation of treatment but remarkably can present many years later. The incidence of ETV6-RUNX1 at relapse has been reported to be less than or similar to de novo ALL. Molecular studies on neonatal bloodspots and on twins with concordant ALL have demonstrated the prenatal origin of major subtypes of childhood ALL, including most ETV6-RUNX1 fusion gene positive cases. In addition these investigations have suggested the existence of a preleukaemic stem cell requiring additional mutations or ‘hits’ in order to develop frank leukemia. To understand the genetic basis and clonal origin of late relapses we have compared the profiles of genome-wide copy number alterations (CNA) at relapse versus presentation in samples matched with remission DNA from 24 patients. The selected samples had tumor cell purity >75% before DNA extraction. DNA copy number alteration data was generated using the Affymetrix 500K SNP arrays. LOH analysis was performed using CNAG 3.0 and dCHIP 2008. Overall we identified 168 CNA at presentation and 252 at relapse (excluding deletions at IgH and TCR loci), equating to 6.96 and 10.3 CNA at presentation and relapse respectively. Although the number of CNA increased at relapse, no single gene or pathway was uniquely targeted in relapse. The most frequent alterations involved loss of 12p3.2 (ETV6), 9p21.3 (CDKN2A/B), 6q16.2-3 and gain of 21q22.1-22.12. A novel observation was gain of part or whole of chromosome 16 (2 patients at presentation, 5 at relapse) and deletion of the oncogene Plasmocytoma Variant Translocation 1 (PVT1) in 3 patients. Pathway analysis demonstrated frequent involvement at presentation and relapse of genes implicated in both B cell development (44 versus 46%) and cell cycle control (46 versus 71%). In order to study the clonal origin of relapse, we devised a classification describing the change in CNA between presentation and relapse in each individual patient. The clonal relationship between the presentation and relapse clone was established by the persistence of both the ETV6-RUNX1 fusion and at least 1 Ig and/or TCR rearrangement. We used a classification focussed on ‘driver’ CNA, defined as CNA that target genes functionally involved in leukemogenesis or CNA that are recurrently targeted as described in the literature. The four categories of relapse were type 1 (the dominant clone at presentation presented unchanged at relapse), type 2 (the relapse clone was derived from the major subclone at presentation with additional CNA), type 3 (the relapse clone was derived from a minor clone at presentation with gains and losses of CNA) and type 4 (the relapse clone is derived from an ancestral or preleukemic clone at initial presentation with all CNA gained). Twenty-one of the 24 patients were classifiable in this way (Figure 1). Although comparative relapse / presentation CNA profiles cannot identify precise clonal origins of relapse, the data indicate that irrespective of time to relapse (<2 to 9.9 years), the relapse clone appeared to be derived from either a major or minor clone at diagnosis with none (0/6) of the very late relapses (>5 years) derived from pre-leukemic cells lacking CNA. This data indicate diverse clonal origins of relapse and extended periods of dormancy, possibly via quiescence, for stem cells in ETV6-RUNX1+ ALL. Relapse type Remission duration (years) < 2 2 - 5 > 5 1 • • 2 • ••••••• •• 3 •• •• ••• 4 •• Figure 1. Each patient is represented by a black dot. Each patient is classified on the basis of the relapse type and remission duration. Disclosures No relevant conflicts of interest to declare.

Presence of Preleukemic Clones at Birth in the Majority of Children with B-Lineage Acute Lymphoblastic Leukemia.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 88-88
Author(s):  
Bernd Gruhn ◽  
Nadine Pfaffendorf ◽  
Susan Wittig ◽  
Roland Zell ◽  
Ralf Häfer ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Mononuclear Cells ◽  
Germ Line ◽  
Fusion Gene ◽  
Lymphoblastic Leukemia ◽  
Leukemic Cells ◽  
Guthrie Card ◽  
Childhood All ◽  
Blood Spots ◽  
B Lineage

Abstract The proof for the prenatal origin of childhood acute lymphoblastic leukemia (ALL) comes from the detection of concordant leukemia in monozygotic twins and the identification of translocation breakpoint genomic sequences at birth in a limited number of ALL patients with t(4;11) or t(12;21) chromosomal translocation. However, most patients with childhood ALL lack leukemia-specific fusion gene sequences. Therefore, we have used the rearranged immunoglobulin heavy chain (IgH) genes as a marker for the detection of preleukemic clones at birth. Guthrie card blood spots of 32 children with B-lineage ALL treated at our institution were available for this retrospective study. The ALL patients had a median age of 5 years (range, 15 months to 14 years) and had median presenting white blood cell (WBC) counts of 10150/μl (range, 800 to 103800/μl). In all patients a monoclonal IgH gene rearrangement was obtained from diagnostic bone marrow and sequenced. Clone-specific primers were designed using the specific D-N-J and N-D-N sequences. A two-stage polymerase chain reaction (PCR) using a semi-nested approach was developed to improve sensitivity and specificity of amplification. In all 32 patients, one leukemic cell could be detected in a background of 105 normal blood mononuclear cells. Nineteen of the 32 patients (59%) had detectable IgH gene rearrangements at birth using the sensitive semi-nested PCR. Sequencing of the PCR products obtained from Guthrie card blood spots revealed the identical sequences identified from diagnostic leukemic cells. The fetal characteristics of the leukemic cells were indicated by the small numbers of nucleotides inserted into the N region and the shortened D germ line segments. Interestingly, five of the six children (83%) with hyperdiploid ALL had detectable preleukemic clones at birth. Four of the five children (80%) with pro-B ALL, 13 of the 21 children (62%) with cALL and only two of the six children (33%) with pre-B ALL had preleukemic clones on their cards. We did not observe any differences in age at diagnosis or presenting WBC count between the 19 patients with preleukemic clones at birth and the 13 patients whose Guthrie cards were tested negative. Our results suggest that the majority of children with B-lineage ALL has preleukemic clones already at birth indicating a prenatal origin of leukemia. In addition, postnatal factors are important in leukemogenesis as well because of the long latency periods until clinical diagnosis of leukemia.

scholarly journals NUTM1 is a recurrent fusion gene partner in B-cell precursor acute lymphoblastic leukemia associated with increased expression of genes on chromosome band 10p12.31-12.2

Haematologica ◽  
2019 ◽  
Vol 104 (10) ◽  
pp. e455-e459 ◽  
Author(s):  
Femke M. Hormann ◽  
Alex Q. Hoogkamer ◽  
H. Berna Beverloo ◽  
Aurélie Boeree ◽  
Ilse Dingjan ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
B Cell ◽  
Fusion Gene ◽  
Lymphoblastic Leukemia ◽  
Chromosome Band ◽  
Cell Precursor ◽  
Expression Of Genes

scholarly journals B-cell growth factor receptor expression and B-cell growth factor response of leukemic B cell precursors and B lineage lymphoid progenitor cells

Blood ◽  
1987 ◽  
Vol 70 (4) ◽  
pp. 1020-1034 ◽  
Author(s):  
FM Uckun ◽  
AS Fauci ◽  
NA Heerema ◽  
CW Song ◽  
SR Mehta ◽  
...  
Keyword(s):  
Growth Factor ◽  
Cell Growth ◽  
B Cell ◽  
Progenitor Cells ◽  
Stimulation Index ◽  
Receptor Expression ◽  
Cell Precursor ◽  
B Cell Growth Factor ◽  
B Lineage ◽  
B Cell Precursors

The purpose of this study was to analyze the expression of B cell growth factor (BCGF) receptors and to elucidate the biologic effects of biochemically purified natural BCGF at the B cell precursor stage of human B lineage lymphoid differentiation. The specific binding of radioiodinated high-mol-wt BCGF (125I-HMW-BCGF) and low-molecular-wt BCGF (125I-LMW-BCGF) to fresh marrow blasts from B cell precursor acute lymphoblastic leukemia (ALL) patients was initially investigated. The estimated number of radioiodinated BCGF molecules bound per blast ranged from undetectable to 24.3 X 10(3) for HMW-BCGF, and from 11.5 X 10(3) to 457.8 X 10(3) for LMW-BCGF. In 3H-TdR incorporation assays, 75% of cases showed a significant response to LMW-BCGF with a median stimulation index of 9.3. By comparison, only 33% of cases showed a significant response to HMW-BCGF with a median stimulation index of 2.4. Subsequently, B cell precursor colony assays were performed to assess and compare the biologic effects of BCGF on leukemic B lineage lymphoid progenitor cells. Among 28 cases studied, 57% responded to both HMW-BCGF and LMW-BCGF, 21% responded only to LMW-BCGF, and the remaining cases showed no proliferative response to either growth factor. The response patterns of virtually pure populations of FACS- sorted leukemic B cell precursors were essentially identical to the proliferative responses of unsorted leukemic B-cell precursors. Synergistic effects between HMW-BCGF and LMW-BCGF were observed in 80% of the cases that responded to both. The numbers of cell-bound radioiodinated BCGF molecules, the stimulation indices, as well as the number of B cell precursor colonies in BCGF-stimulated cultures showed a marked interpatient variation. Patients with structural chromosomal abnormalities (SCAs) involving 12p11–13 or patients with a Philadelphia chromosome showed a greater HMW-BCGF response at the level of leukemic progenitor cells than did other patients (P = .02). The LMW-BCGF response was significantly greater for patients with SCA than for patients without SCA (P = .04). The response of leukemic progenitor cells to HMW-BCGF or LMW-BCGF did not correlate with sex, age, disease status, FAB morphology, WBC at diagnosis, or immunophenotype. To our knowledge, this study represents the first detailed analyses of BCGF receptor expression and BCGF effects in B cell precursor ALL. The data presented provide direct evidence for the expression of functional receptors for both HMW-BCGF and LMW-BCGF in B cell precursor ALL.

scholarly journals Low molecular weight B cell growth factor induces proliferation of human B cell precursor acute lymphoblastic leukemias

Blood ◽  
1987 ◽  
Vol 70 (1) ◽  
pp. 132-138 ◽  
Author(s):  
B Wormann ◽  
SR Mehta ◽  
AL Maizel ◽  
TW LeBien
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Growth Factor ◽  
Cell Growth ◽  
B Cell ◽  
Lymphoblastic Leukemia ◽  
Leukemic Cells ◽  
Cell Precursor ◽  
B Cell Growth Factor ◽  
B Cell Precursors

Experiments were conducted to determine the effect of low mol wt B cell growth factor (L-BCGF) on B cell precursor acute lymphoblastic leukemia (ALL). L-BCGF induced a significant increase in 3H-TdR incorporation in 28 of 37 bone marrow aspirates from patients with B cell precursor ALL, with stimulation indices ranging from 2 to 129. Fluorescence-activated cell sorting confirmed that in five of seven patients the common acute lymphoblastic leukemia antigen (CALLA)/CD10 positive leukemic cells were responding directly to L-BCGF. L-BCGF was capable of inducing, in some patients, an increase in absolute viable cells and could also induce colony formation in vitro. The response of B cell precursor ALL was not attributable to beta IL 1, IL 2, or gamma interferon. These results indicate that the majority of B cell precursor ALL undergo a proliferative response to L-BCGF, suggesting a regulatory role for this lymphokine in the growth of B cell precursors.

scholarly journals mb-1: a new marker for B-lineage lymphoblastic leukemia

Blood ◽  
1993 ◽  
Vol 82 (3) ◽  
pp. 853-857 ◽  
Author(s):  
V Buccheri ◽  
B Mihaljevic ◽  
E Matutes ◽  
MJ Dyer ◽  
DY Mason ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
B Cell ◽  
Heavy Chain ◽  
Single Case ◽  
Lymphoblastic Leukemia ◽  
Cell Precursor ◽  
B Lineage ◽  
Ig Heavy Chain ◽  
Specific Reagent

The expression of the Ig-linked mb-1 polypeptide was analyzed by immunocytochemistry (alkaline phosphatase anti-alkaline phosphatase technique) using a specific monoclonal antibody in 165 cases of acute leukemia, with 88 being lymphoblastic (ALL) and 77 myeloid (AML). The purpose of the study was to investigate the specificity of this reagent for B-lineage cases and its reactivity on leukemias that coexpress myeloid and B-cell antigens (biphenotypic). The majority (89%) of 72 B- cell precursor ALL patients were positive. Of these, mb-1 was expressed in all 9 patients with early-B-ALL (CD10-, c mu-), in all 11 patients with pre-B-ALL (c mu+) and in the single case of B-ALL (smIgM+). Forty- three of 51 patients with common-ALL (CD10+, c mu+) were also positive. All 16 T-lineage ALL patients and 72 (93.5%) of the AML patients examined were mb-1 negative. Four of the 5 mb-1-positive AML patients were considered biphenotypic and expressed other B-cell antigens such as CD10, CD19, and/or cCD22 and all showed rearrangement of the Ig heavy chain genes. Within the AML cases, mb-1 and cCD22 were more useful than other B-cell antigens in detecting biphenotypic cases, and mb-1 showed the highest correlation with the clonal rearrangement of Ig heavy chain genes. These results indicate that mb-1 is a sensitive and specific reagent for B-lineage blasts that will aid in the classification of B-cell precursor ALL and in the identification of biphenotypic leukemia presenting as AML.

scholarly journals ActivinA: a new leukemia-promoting factor conferring migratory advantage to B-cell precursor-acute lymphoblastic leukemic cells

Haematologica ◽  
2018 ◽  
Vol 104 (3) ◽  
pp. 533-545 ◽  
Author(s):  
Federica Portale ◽  
Giulia Cricrì ◽  
Silvia Bresolin ◽  
Monica Lupi ◽  
Stefania Gaspari ◽  
...  
Keyword(s):  
B Cell ◽  
Leukemic Cells ◽  
Cell Precursor

scholarly journals Spermine analogue-regulated expression of spermidine/spermine N1-acetyltransferase and its effects on depletion of intracellular polyamine pools in mouse fetal fibroblasts

2009 ◽  
Vol 422 (1) ◽  
pp. 101-109 ◽  
Author(s):  
Anne Uimari ◽  
Tuomo A. Keinänen ◽  
Anne Karppinen ◽  
Patrick Woster ◽  
Pekka Uimari ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Fusion Gene ◽  
Wild Type Mouse ◽  
Egfp Expression ◽  
Wild Type ◽  
Protein Fusion ◽  
Reverse Transcription Pcr ◽  
Fetal Fibroblasts ◽  
Spermine Analogues ◽  
Ssat Activity

SSAT (Spermidine/spermine N1-acetyltransferase, also known as SAT1), the key enzyme in the catabolism of polyamines, is turned over rapidly and there is only a low amount present in the cell. In the present study, the regulation of SSAT by spermine analogues, the inducers of the enzyme, was studied in wild-type mouse fetal fibroblasts, expressing endogenous SSAT, and in the SSAT-deficient mouse fetal fibroblasts transiently expressing an SSAT–EGFP (enhanced green fluorescent protein) fusion gene. In both cell lines treatments with DENSpm (N1,N11-diethylnorspermine), CPENSpm (N1-ethyl-N11-[(cyclopropyl)-methy]-4,8-diazaundecane) and CHENSpm (N1-ethyl-N11-[(cycloheptyl)methy]-4,8-diazaundecane) led to high, moderate or low induction of SSAT activity respectively. The level of activity detected correlated with the presence of SSAT and SSAT–EGFP proteins, the latter localizing both in the cytoplasm and nucleus. RT–PCR (reverse transcription–PCR) results suggested that the analogue-affected regulation of SSAT–EGFP expression occurred, mainly, after transcription. In wild-type cells, DENSpm increased the amount of SSAT mRNA, and both DENSpm and CHENSpm affected splicing of the SSAT pre-mRNA. Depleted intracellular spermidine and spermine levels inversely correlated with detected SSAT activity. Interestingly, the analogues also reduced polyamine levels in the SSAT-deficient cells expressing the EGFP control. The results from the present study show that the distinct SSAT regulation by different analogues involves regulatory actions at multiple levels, and that the spermine analogues, in addition to inducing SSAT, lower intracellular polyamine pools by SSAT-independent mechanisms.

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