scholarly journals Genetic Characterization of B-Cell Prolymphocytic Leukemia (B-PLL): A Hierarchical Prognostic Model Involving MYC and TP53 Abnormalities. on Behalf of the Groupe Francophone De Cytogenetique Hematologique (GFCH) and the French Innovative Leukemia Organization (FILO) Group

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 943-943 ◽  
Author(s):  
Elise Chapiro ◽  
Damien Roos-Weil ◽  
Nadia Bougacha ◽  
Clementine Gabillaud ◽  
Clémentine Dillard ◽  
...  

Abstract B-PLL is defined by the presence of prolymphocytes in peripheral blood exceeding 55% of lymphoid cells. The diagnosis, mainly based on clinical and morphological data, can be difficult because of overlap with other B-cell malignancies. Because of the rarity of the disease, only case reports and small series describe its cytogenetic features. Few prognostic markers have been identified in this aggressive leukemia usually resistant to standard chemo-immuno therapy. We report here the cytogenetic and molecular findings in a large series of B-PLL. We also studied the in vitro response to novel targeted drugs on primary B-PLL cells. The study included 34 cases with a diagnosis of B-PLL validated by morphological review performed by three independent expert cytologists. The diagnosis of mantle cell lymphoma was excluded by karyotype (K) and FISH using CCND1, CCND2 and CCND3 probes. Median age at diagnosis was 72 years [46-88]. K was complex (≥3 abnormalities) in 73%, and highly complex (HCK≥5) in 45%. Combining K and FISH data, the most frequent chromosomal aberrations were: translocation targeting the MYC gene [t(MYC)] (21/34, 62%), 17p deletion including TP53 gene (13/34, 38%), trisomy 18/18q (10/33, 30%), 13q14 deletion (10/34, 29%), trisomy 3 (8/33, 24%), trisomy 12 (8/34, 24%) and 8p deletion (7/31, 23%). Whole-Exome Sequencing analysis of paired tumor-control DNA was performed in 16 patients. The most frequently mutated genes were TP53(6/16, 38%), associated with del17p in all, MYD88 (n=4), BCOR (n=4), MYC (n=3), SF3B1 (n=3), FAT1 (n=3), SETD2 (n=2), CHD2 (n=2), CXCR4 (n=2), BCLAF1 (n=2) and NFASC (n=2). Distribution of the chromosomal aberrations is shown in Fig 1. The main group of patients (21/34, 62%) had a t(MYC) that was associated with a higher % of prolymphocytes (86 vs 76, p=0.03), CD38 expression (90% vs 15%,p<0.001), and a lower K complexity (HCK≥5 : 20% vs 85%, p=0.0004). Mutations in MYC and in genes involved in RNA metabolism and chromatin remodeling were almost exclusively observed with t(MYC). Principal component analysis of gene expression data in 12 cases analyzed by RNA-Seq showed that the 7 patients with t(MYC) clustered together. These results suggest that t(MYC) form a homogeneous subgroup of B-PLL. A second group with MYC gain (5/34, 15%), was associated with HCK≥5 (100% vs 36%, p=0,01) and trisomy 3 (80% vs 14%, p=0,008). Altogether, 26/34 patients (76%) had a MYC activation, translocation or gain, that were mutually exclusive. The median overall survival (OS) for the entire cohort was 126 months with a median follow-up time of 47 months [ 0.2-141]. We found MYC activation (translocation or gain) to be associated with a shorter OS (p=0.03). Regarding MYC and del17p, we identified 3 distinct cytogenetic prognostic groups, with significant differences in OS (p=0.0006) (Fig 2). The patients without MYC activation had the lower risk (n=8, median not reached). Patients with a MYC activation without del17p had an intermediate risk (n=18, 125 months). The highest risk group corresponded to patients with both MYC and TP53 aberrations (n=7, 11 months). We performed drug response profiling on primary B-PLL cells using the ATP-based CellTiter Glo kit (Promega) (n=5). We observed that after 48h of exposure to increased doses, response was heterogeneous, with a majority of samples resistant to fludarabine (n=3), ibrutinib (n=3), idelalisib (n=4), venetoclax (n=3) and OTX015 (n=4). Annexin/PI assays using flow cytometry showed that the induced cell death could be increased by combination of ibrutinib or venetoclax with OTX015 or JQ1, two BET protein inhibitors that target MYC signaling (n=1/2). In summary, B-PLL have complex and highly complex K, a high frequency of MYC activation by translocation or gain, frequent 17p deletion, and frequent mutations in MYC, TP53, BCOR, and MYD88 genes. We identified 3 prognostic subgroups according to MYC and 17p status. Patients with MYC activation + 17p deletion have the shorter OS, and should be considered as a high-risk "double-hit" subgroup. Our results show that cytogenetic analysis is a useful diagnostic tool in B-PLL that improves prognostic stratification. We recommend to perform K and FISH (MYC and TP53) analyses systematically when a B-PLL is suspected. Our in vitro data suggest that drugs targeting the BCR and BCL2 in combination with MYC inhibition may be a therapeutic option in some patients. Disclosures Baseggio: Takeda Oncology: Honoraria.

Blood ◽  
1985 ◽  
Vol 66 (4) ◽  
pp. 824-829
Author(s):  
BS Wilson ◽  
JL Platt ◽  
NE Kay

Several mouse monoclonal IgG antibodies (AB1, AB2, AB3, and AB5) were developed that reacted with a 140,000 mol wt glycoprotein on the surface of cultured RAJI B lymphoid cells. The antibodies reacted with purified normal human peripheral blood B cells and CLL Ig+ B cells and showed specific germinal center and mantle zone staining in tissue sections of secondary lymphoid organs. Immunodepletion studies using 125I surface-labeled Raji cell membrane antigens demonstrated that the antigen identified by AB5 is the same 140,000 mol wt glycoprotein detected by anti-B2 that has recently been shown to react with the C3d fragment or CR2 receptor. (Iida et al: J Exp Med 158:1021, 1983). Addition of the AB series and anti-B2 monoclonal antibodies to cultures of purified human peripheral blood B cells resulted in the uptake of 3H- thymidine at two to six times background control levels provided that irradiated autologous T cells were added to the culture. Stimulation was not evoked by other monoclonal antibodies to B cell surface molecules (ie, B1, BA-1, BA-2, and HLA-DR). Pepsin-generated F(ab')2 fragments of anti-CR2 antibodies were essentially as effective as the intact IgG molecule in stimulating B cells. Induction of B cell proliferation by antibody binding to CR2 suggests that the C3d receptor may have an integral role in regulation of humoral immune response.


1976 ◽  
Vol 143 (2) ◽  
pp. 444-449 ◽  
Author(s):  
L Hudson ◽  
J Sprent

Evidence is presented to support the contention that IgM demonstrable by surface immunofluorescent staining on H-2-activated T cells represents specifically adsorbed B-cell-derived alloantibody. T cells activated to H-2 determinants expressed surface IgM only when the progenitor cell populations contained B lymphocytes. IgM was not detected on T cells activated to determinants which fail to stimulate alloantibody production (e.g., M-locus determinants). In addition, IgM-negative H-2 activated T cells (derived from B-cell-depleted lymphoid cells), unlike M-locus-activated T cells, adsorbed IgM in a specific manner when incubated in vitro with "early bleed" antisera raised against the activating H-2 determinants.


Blood ◽  
1994 ◽  
Vol 83 (1) ◽  
pp. 26-32 ◽  
Author(s):  
T Miki ◽  
N Kawamata ◽  
S Hirosawa ◽  
N Aoki

Abstract Chromosomal translocations involving band 3q27 are the recently described nonrandom cytogenetic abnormalities in B-cell malignancies. We have previously cloned the breakpoint region of 3q27, designated as the BCL5 locus, from the B-cell line carrying the t(3;22). The cDNA for the BCL5 gene was cloned from the human liver cDNA library. The nucleotide sequencing analysis showed that the BCL5 gene encodes a potential transcription factor containing six repeats of the Cys2-His2 zinc-finger motif resembling the Drosophila segmentation gene Kruppel. The calculated molecular weight was 78.8 kD, which was supported by an in vitro transcription and translation experiment. A part of the sequence was essentially identical to that of a genomic fragment, ZNF51, previously reported to be located at 3qter. The translocation occurred in the 5′ region of the BCL5 gene, and the protein-coding exons were fused to the Ig-lambda gene in a head-to-head configuration in the cell line carrying t(3;22). The BCL5 cDNA probe detected a major transcript of 3.8 kb in Burkitt's lymphoma cell lines and an aberrant transcript in the t(3;22) cell line, whereas no transcript was detected in myeloid, monocytoid, erythroid, T-lymphoid, and Epstein-Barr virus- immortalized B-lymphoblastoid cell lines.


Blood ◽  
2006 ◽  
Vol 107 (12) ◽  
pp. 4898-4906 ◽  
Author(s):  
Andrea Hoelbl ◽  
Boris Kovacic ◽  
Marc A. Kerenyi ◽  
Olivia Simma ◽  
Wolfgang Warsch ◽  
...  

AbstractThe Stat5 transcription factors Stat5a and Stat5b have been implicated in lymphoid development and transformation. Most studies have employed Stat5a/b-deficient mice where gene targeting disrupted the first protein-coding exon, resulting in the expression of N-terminally truncated forms of Stat5a/b (Stat5a/bΔN/ΔN mice). We have now reanalyzed lymphoid development in Stat5a/bnull/null mice having a complete deletion of the Stat5a/b gene locus. The few surviving Stat5a/bnull/null mice lacked CD8+ T lymphocytes. A massive reduction of CD8+ T cells was also found in Stat5a/bfl/fllck-cre transgenic animals. While γδ T-cell receptor–positive (γδTCR+) cells were expressed at normal levels in Stat5a/bΔN/ΔN mice, they were completely absent in Stat5a/bnull/null animals. Moreover, B-cell maturation was abrogated at the pre–pro-B-cell stage in Stat5a/bnull/null mice, whereas Stat5a/bΔN/ΔN B-lymphoid cells developed to the early pro-B-cell stage. In vitro assays using fetal liver-cell cultures confirmed this observation. Most strikingly, Stat5a/bnull/null cells were resistant to transformation and leukemia development induced by Abelson oncogenes, whereas Stat5a/bΔN/ΔN-derived cells readily transformed. These findings show distinct lymphoid defects for Stat5a/bΔN/ΔN and Stat5a/bnull/null mice and define a novel functional role for the N-termini of Stat5a/b in B-lymphoid transformation.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1479-1479
Author(s):  
Marina Deschamps ◽  
Carole Henry ◽  
Eric Robinet ◽  
Francine Garnache-Ottou ◽  
Jean-Paul Remy-Martin ◽  
...  

Abstract The human CD20 molecule (hCD20) is a B-cell lineage specific marker expressed by normal and leukemic B cells from the pre-B to the plasma-cell stages and a target for Rituximab (Rx) immunotherapy. During the course of a CD20 RTPCR on B-cell line cDNA, we unexpectedly obtained a shorter PCR product (ΔCD20) in addition to the expected 894bp PCR product (wtCD20). Sequencing analysis revealed that this additional fragment was identical to Genbank published CD20 sequence, but lacked 501bp. In silico analysis of the wtCD20 sequence, using Genesplicer and NetGene 2 softwares, showed donor and acceptor sites (nt112 & nt611 respectively, from ATG codon) matching the newly identified spliced DCD20 form and a branched site located in nt595 exon 3 of the gene respectively. The CD20 spliced mRNA form links part of the end of exon 3 to that of exon 7. The truncated sequence is on the reading frame and can code a putative protein of 130 amino-acids (~15KD) including the intracellular C- terminal domain with part of the transmembrane 1 (TM1) domain and the end of the N-terminal intracellular domain. The extracellular domain and large parts of the 4 TM segments are deleted suggesting that the putative ΔCD20 may be a non-anchored membrane protein. Using CD20 PCR assays amplifying either both wtCD20 and ΔCD20 forms or ΔCD20 alone, we detected the truncated mRNA DCD20 form in different B cell lines (n=12) but not in different T-cell lines (n=4). With a QPCR assay allowing for the specific quantification of either wtCD20 or truncated DCD20 mRNA we also detected the ΔCD20 spliced form [expressed as relative % of ΔCD20: R = (ΔCD20/wtCD20+ΔCD20) × 100] in in-vitro EBV-transformed B-cell lines (2.9 ± 4.51%, n=6); as well as in CD19+ cell sorted cells from tonsillectomy samples (9 ± 2.2%, n=7) and in-vitro B blast cells (14 ± 7.8%, n=5). Interestingly, screening of a panel of B-cell hematologic malignancies showed that the spliced form is detectable at various levels. We found a mean of 3.6 ± 5.1% in B-ALL (n=27); 3.9 ± 5.3% in follicular lymphomas (n=5); 2.9 ± 4.5% in mantle lymphomas (n=6); 3.2 ± 2.2% in high grade lymphomas (n=5); and 0.1 ± 0.2% in B-CLL (n=8). However, this spliced form was not detected in peripheral blood mononuclear cells or in immunomagnetically-sorted CD19+ or CD20+ blood cells from healthy donors. To explore clinical relevance, molecular monitoring of ΔCD20 in the marrow was performed in 2 patients. A 1rst patient with mantle lymphoma, showed an R of 4.2% at diagnosis (diag). After chemotherapy (VAD + chloraminophen) + Rx, R was 2.2% at +12 mo (×1.9 decrease from diag) and 1.8% at +18mo (×1.3 decrease/+12mo). This was in accordance with the cytological (absence of lymphoma cells) and the molecular response (absence of cyclinD1 overexpression). A second patient, with a Phi+ B-ALL, showed an ×13.7 R-decrease compared to diag (from 4.1% to 0.3%) following treatment according to the molecular response. Interestingly, R increased up to 2.6% at +8 months (×8.6/6mo) and 3% (×1.1/8mo) at +12 months after treatment, while molecular and cytological relapse was evidenced only 12 mo after treatment. In conclusion, we report evidence of a novel alternatively spliced transcript of the hCD20 gene, specifically expressed at detectable levels in leukemic, lymphoma, activated or EBV-transformed B cells, but not in normal resting B cells. Further experiments will determine whether the ΔCD20 mRNA spliced form modulates wtCD20 expression and thus influences the response to Rx treatment in hematologic B diseases. However, our initial results suggest that DCD20 quantification may be an indicator of minimal residual disease, as a potential predictive marker of relapse, especially in patients with no other molecular marker.


1977 ◽  
Vol 32 (1) ◽  
pp. 23-35 ◽  
Author(s):  
Dennis W. Metzger ◽  
Robert L. Hendricks ◽  
Marius Teodorescu ◽  
Sheldon Dray

Blood ◽  
1991 ◽  
Vol 78 (3) ◽  
pp. 703-710 ◽  
Author(s):  
CL Law ◽  
RJ Armitage ◽  
JG Villablanca ◽  
TW LeBien

Interleukin-4 (IL-4) regulates multiple stages of the antigen-dependent phase of B-cell development. However, its precise role in regulating B lymphopoiesis in bone marrow is not as well defined. We examined whether surface IgM- normal and leukemic human B-cell precursors (BCP) expressed IL-4 receptors using biotinylated IL-4. Constitutive expression of IL-4 receptors was detected on both normal and leukemic BCP. A higher percentage of normal BCP (82% +/- 15%) expressed IL-4 receptors compared with leukemic BCP (44% +/- 8%). Using mean fluorescent intensity as an indicator of receptor level on the IL-4 receptor positive cells, normal (91 +/- 41) and leukemic (44 +/- 37) BCP expressed comparable numbers of receptors. IL-4 induced the expression of CD23 on 30% of the leukemic BCP cases examined. IL-4 induced CD23 on surface IgM+ fetal bone marrow lymphoid cells but not on the surface IgM- normal BCP, despite the presence of detectable receptors on the surface IgM- cells. IL-4 did not stimulate proliferation of normal BCP, nor could it enhance the effect of recombinant IL-7 or low molecular weight B-cell growth factor. However, IL-4 increased the expression of surface IgM and surface Ig kappa on in vitro differentiated pre-B cells. Our collective results identify no role for IL-4 in the proliferation of normal or leukemic BCP, but identify a role in the enhancement of surface Ig expression during pre- B to B-cell differentiation.


Blood ◽  
1994 ◽  
Vol 83 (1) ◽  
pp. 26-32 ◽  
Author(s):  
T Miki ◽  
N Kawamata ◽  
S Hirosawa ◽  
N Aoki

Chromosomal translocations involving band 3q27 are the recently described nonrandom cytogenetic abnormalities in B-cell malignancies. We have previously cloned the breakpoint region of 3q27, designated as the BCL5 locus, from the B-cell line carrying the t(3;22). The cDNA for the BCL5 gene was cloned from the human liver cDNA library. The nucleotide sequencing analysis showed that the BCL5 gene encodes a potential transcription factor containing six repeats of the Cys2-His2 zinc-finger motif resembling the Drosophila segmentation gene Kruppel. The calculated molecular weight was 78.8 kD, which was supported by an in vitro transcription and translation experiment. A part of the sequence was essentially identical to that of a genomic fragment, ZNF51, previously reported to be located at 3qter. The translocation occurred in the 5′ region of the BCL5 gene, and the protein-coding exons were fused to the Ig-lambda gene in a head-to-head configuration in the cell line carrying t(3;22). The BCL5 cDNA probe detected a major transcript of 3.8 kb in Burkitt's lymphoma cell lines and an aberrant transcript in the t(3;22) cell line, whereas no transcript was detected in myeloid, monocytoid, erythroid, T-lymphoid, and Epstein-Barr virus- immortalized B-lymphoblastoid cell lines.


Blood ◽  
2003 ◽  
Vol 102 (12) ◽  
pp. 4159-4165 ◽  
Author(s):  
Agnieszka P. Szremska ◽  
Lukas Kenner ◽  
Eva Weisz ◽  
Rene G. Ott ◽  
Emmanuelle Passegué ◽  
...  

Abstract The activator protein 1 (AP-1) member JunB has recently been implicated in leukemogenesis. Here we surveyed human lymphoma samples for expression of JunB and other AP-1 members (c-Jun, c-Fos, Fra1, JunD). JunB was strongly expressed in T-cell lymphomas, but non-Hodgkin B-cell lymphomas do not or only weakly express JunB. We therefore asked whether JunB acted as a negative regulator of B-cell development, proliferation, and transformation. We used transgenic mice that expressed JunB under the control of the ubiquitin C promoter; these displayed increased JunB levels in both B- and T-lymphoid cells. JunB transgenic cells of B-lymphoid, but not of T-lymphoid, origin responded poorly to mitogenic stimuli. Furthermore, JunB transgenic cells were found to be less susceptible to the transforming potential of the Abelson oncogene in vitro. In addition, overexpression of JunB partially protected transgenic mice against the oncogenic challenge in vivo. However, transformed B cells eventually escaped from the inhibitory effect of JunB: the proliferative response was similar in explanted tumor-derived cells from transgenic animals and those from wild-type controls. Our results identify JunB as a novel regulator of B-cell proliferation and transformation. (Blood. 2003;102:4159-4165)


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