scholarly journals p53 Abnormalities in B-Cell Prolymphocytic Leukemia

Blood ◽  
1997 ◽  
Vol 89 (6) ◽  
pp. 2015-2023 ◽  
Author(s):  
Daniela Lens ◽  
Pierre J.J.C. De Schouwer ◽  
Rifat A. Hamoudi ◽  
Munah Abdul-Rauf ◽  
Nahla Farahat ◽  
...  

Abstract B-cell prolymphocytic leukemia (B-PLL) is an aggressive disorder of mature B cells with distinct clinical and pathologic features. To determine the incidence of abnormalities of p53, we analyzed 19 cases of B-PLL by DNA blot to assess loss of heterozygosity (LOH) at 17p13.3, by immunocytochemistry to assess p53 expression, and by direct DNA sequencing of polymerase chain reaction-amplified exons 5 to 9 of the p53 gene. LOH was detected in 10 of 19 (53%) cases, p53 expression was detected in 8 of 17 (47%), and p53 mutations were detected in 10 of 19 (53%) cases. The pattern of mutations was distinct from that observed in other B-cell malignancies. Six cases exhibited missense mutations; 4 were transversions and 2 were transitions. The G:C → A:T transition at cathepsin G dinucleotides commonly reported in p53 mutations in chronic lymphocytic leukemia (CLL) and other hematologic malignancies was observed in only 1 case of B-PLL. Three cases exhibited deletions (ranging from 3 to 35 bp in length) and one case exhibited a 2-bp insertion. In 1 case, a 27-bp deletion resulted in the expression of a p53 protein lacking 9 amino acids from the DNA binding region. All samples with p53 mutation showed loss of germline p53 sequences. However, 3 of 10 showed no LOH by Southern blot, indicating a localized deletion around the p53 locus at 17p13.1. Five of the 10 cases with p53 mutation exhibited detectable p53 expression, including 4 cases with p53 missense mutation and 1 case with deletion. Two of 7 cases with no detectable mutation of p53 nevertheless overexpressed p53. Therefore, there was no correlation between protein expression and p53 mutation in B-PLL. Our data indicate that the overall abnormalities of p53 occurred in 14 of 19 (75%) cases of B-PLL. The frequency of p53 mutation (53%) in B-PLL is the highest reported in B-cell malignancies and may be responsible for the frequent resistance to therapy of this disease. In addition, the pattern of p53 mutation was different from that observed in CLL and other hematologic malignancies and may indicate that a distinct pathogenic mechanism operates in B-PLL.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 8064-8064
Author(s):  
Richard R. Furman ◽  
John C. Byrd ◽  
Roger G. Owen ◽  
Susan Mary O'Brien ◽  
Jennifer R. Brown ◽  
...  

8064 Background: Acala is a next-generation, highly selective, covalent Bruton tyrosine kinase inhibitor approved in the US for patients (pts) with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) and previously treated mantle cell lymphoma (MCL). We evaluated the safety profile of acala monotherapy (monotx) in multiple B cell malignancies. Methods: Data from pts with activated B-cell diffuse large B-cell lymphoma, CLL, follicular lymphoma, MCL, multiple myeloma, prolymphocytic leukemia, Richter syndrome, SLL, or Waldenström macroglobulinemia treated with ≥1 dose of acala monotx in 9 studies were pooled. Acala was administered at 100 mg BID in most pts (100–400 mg total dose daily). Adverse events (AE) were assessed. Results: A total of 1040 pts were included (median age: 67 y [range: 32–90]; ECOG status ≤1: 93%; median exposure duration: 24.6 mo [range: 0–58.5]). A total of 360 (34%) pts discontinued acala, most commonly due to progressive disease (PD; 17%). AEs led to acala discontinuation in 97 (9%) pts; those in > 2 pts were pneumonia (n = 5) and thrombocytopenia (n = 4). Incidence of AEs, including the most common (any grade and grade ≥3), are shown in the Table. Events of clinical interest (ECIs) included atrial fibrillation (afib) of any grade in 46 (4%) pts and grade ≥3 in 13 (1%) pts; major hemorrhage (any grade) in 37 (4%) pts; grade ≥3 infection in 183 (18%) pts; hypertension (any grade) in 79 (8%) pts and grade ≥3 in 36 (4%) pts; and second primary malignancies (SPM) excluding non-melanoma skin cancer (NMSC; any grade) in 68 (7%) pts. Median (range) time to first onset in days for each ECI (any grade) was: afib, 522 (8–1280); major hemorrhage, 293 (4–1327); infections, 92 (1–1317); hypertension, 157 (2–1345); SPM excluding NMSC, 339 (7–1499). Death was reported in 139 (13%) pts, most commonly due to PD (6%) and AEs (5%). Conclusions: Acala monotx has a favorable tolerability profile with increased exposure across multiple mature B cell malignancies. Additional analyses will further explore the longitudinal characteristics of AEs. [Table: see text]


2005 ◽  
Vol 20 (suppl 1) ◽  
pp. 56-62
Author(s):  
Geraldo Barroso Cavalcanti Júnior ◽  
Valeria Soraya de Farias Sales ◽  
Dany Geraldo Kramer Cavalcanti e Silva ◽  
Maria Cleide de Araújo Lopes ◽  
Aldair de Souza Paiva ◽  
...  

PURPOSE: CD5 is a T cell marker, aberrantly express in B cell chronic lymphocytic leukemia (B-CLL) and mantle cell lymphoma (MCL). Other chronic B cell malignancies including hairy cell leukemia (HCL) and B cell prolymphocytic leukemia (B-PLL) are CD5 negative or express this antigen in a weak way. In this study, CD5 expression was investigated in leukemic cells from 42 patients with chronic B cell lymphoproliferative disease. METHODS: We studied the CD5 expression in leukemic cells from 42 patients with chronic B-cell malignancies by flow cytometry. Demographic features such as age, sex and clinical date were also analyzed. RESULTS: There were 22 males and 20 females. The immunophenotyping showed that 35 cases were B-CLL, 3 B-PLL and HCL and one patient was MCL. CD5 expression was present in all B-CLL and MCL. Low expression of CD5 was observed in one patient with B-PLL and negative in all cases of HCL. CONCLUSION: Our date demonstrated that CD5 expression can help distinguish among B-CLL from HCL and B-PLL, but is similar expressed in MCL.


Author(s):  
David P Ng ◽  
Lauren M Zuromski

Abstract Objectives Clinical flow cytometry is laborious, time-consuming, and expensive given the need for data review by highly trained personnel such as technologists and pathologists as well as the significant number of normal cases. Given these issues, automation in analysis and diagnosis holds the key to major efficiency gains. The objective was to design an automated pipeline for the diagnosis of B-cell malignancies in flow cytometry and evaluate its performance against our standard clinical diagnostic flow cytometry process. Methods Using 3,417 cases of peripheral blood data over 6 months from our 10-color B-cell screening tube, we used a newly described method for feature extraction and dimensionality reduction called UMAP on the raw flow cytometry data followed by random forest classification to classify cases without gating on specific population. Results Our automated classifier was able to achieve greater than 95% accuracy in diagnosing all B-cell malignancies, and even better performance for specific malignancies for which the panel was designed, such as chronic lymphocytic leukemia. By adjusting classifier cutoffs, 100% sensitivity could be achieved with an albeit low 14% specificity. Hypothetically, this would allow 11% of the cases to be autoverified without human intervention. Conclusions These results suggest that a clinical implementation of this pipeline can greatly assist in quality control, improve turnaround time, and decrease staff workloads.


1999 ◽  
Vol 17 (3) ◽  
pp. 791-791 ◽  
Author(s):  
John C. Byrd ◽  
Jamie K. Waselenko ◽  
Thomas J. Maneatis ◽  
Timothy Murphy ◽  
Frank T. Ward ◽  
...  

PURPOSE: Rituximab was recently approved for use in relapsed, low-grade non-Hodgkin's lymphoma; however, few data exist regarding the safety of this agent in patients with a high number of tumor cells in the blood. METHODS AND RESULTS: After the observation at our institution of a rapid reduction of peripheral-blood tumor cells with associated severe pulmonary infusion-related toxicity in two patients with refractory hematologic malignancies, data on three additional cases were collected from physician-submitted reports of adverse events related to rituximab treatment. Five patients with hematologic malignancies possessing a high number of blood tumor cells were treated with rituximab and developed rapid tumor clearance. The median age was 68 years (range, 26 to 78 years). Patients were diagnosed with B-cell prolymphocytic leukemia (n = 2), chronic lymphocytic leukemia (n = 2), or transformed non-Hodgkin's lymphoma (n = 1). All of these patients had bulky adenopathy or organomegaly. All five patients developed a unique syndrome of severe infusion-related reactions, thrombocytopenia, rapid decrement in circulating tumor cell load, and mild electrolyte evidence of tumor lysis, and all required hospitalization. In addition, one patient developed ascites. These events resolved, and four patients were subsequently treated with rituximab without significant complications. CONCLUSION: Rituximab administration in patients who have a high number of tumor cells in the blood may have an increased likelihood of severe initial infusion-related reactions. These data also suggest that rituximab may have activity in a variety of other lymphoid neoplasms, such as chronic lymphocytic leukemia and B-cell prolymphocytic leukemia.


2021 ◽  
Vol 11 ◽  
Author(s):  
Ilenia Sana ◽  
Maria Elena Mantione ◽  
Piera Angelillo ◽  
Marta Muzio

In recent years significant progress has been made in the clinical management of chronic lymphocytic leukemia (CLL) as well as other B-cell malignancies; targeting proximal B-cell receptor signaling molecules such as Bruton Tyrosine Kinase (BTK) and Phosphoinositide 3-kinase (PI3Kδ) has emerged as a successful treatment strategy. Unfortunately, a proportion of patients are still not cured with available therapeutic options, thus efforts devoted to studying and identifying new potential druggable targets are warranted. B-cell receptor stimulation triggers a complex cascade of signaling events that eventually drives the activation of downstream transcription factors including Nuclear Factor of Activated T cells (NFAT). In this review, we summarize the literature on the expression and function of NFAT family members in CLL where NFAT is not only overexpressed but also constitutively activated; NFAT controls B-cell anergy and targeting this molecule using specific inhibitors impacts on CLL cell viability. Next, we extend our analysis on other mature B-cell lymphomas where a distinct pattern of expression and activation of NFAT is reported. We discuss the therapeutic potential of strategies aimed at targeting NFAT in B-cell malignancies not overlooking the fact that NFAT may play additional roles regulating the inflammatory microenvironment.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 297-297
Author(s):  
Larry Mansouri ◽  
Lesley-Ann Sutton ◽  
Viktor Ljungstrom ◽  
Sina Bondza ◽  
Linda Arngarden ◽  
...  

Abstract Dysregulated NF-κB signaling appears to be particularly important in B-cell malignancies, with recurrent mutations identified within both the canonical and non-canonical NF-κB pathways, as well as in components of the B-cell receptor (BcR) and Toll-like receptor (TLR) signaling pathways. In chronic lymphocytic leukemia (CLL), although recurrent mutations have been identified in MYD88 (TLR signaling) and BIRC3 (non-canonical NF-κB pathway), their frequency is low (<3%) and hence the extent to which genetic aberrations may contribute to constitutional NF-κB activation remains largely unknown. To gain further insight into this issue, we designed a HaloPlex gene panel (Agilent Technologies) and performed targeted next-generation sequencing (NGS) (HiSeq 2000/Illumina) of 18 NF-κB genes in a discovery cohort of 124 CLL patients, intentionally biased towards poor-prognostic patients with either unmutated IGHV genes or high-risk genomic aberrations. Using a conservative cutoff of >10% for the mutant allele, we identified mutations (n=35) within 30/124 (24%) patients in 14/18 NF-κB genes analyzed. IκB genes, which encode for cytoplasmic inhibitor proteins, accounted for 20/35 (57%) mutations, with IκBε (encoded by NFKBIE) mutated in 8 patients; notably, 3/8 cases carried an identical 4bp deletion within exon 1 of NFKBIE. Prompted by these findings, we proceeded to validate our findings in an independent CLL cohort (n=168) using the same methodology as above and primarily focusing on cases with poor-prognostic features. We identified 30 mutations within 28 CLL patients in 11/18 NF-κB genes analyzed. Strikingly, 13/30 mutations were found within IκBε, with 10/13 patients carrying the same 4bp NFKBIE deletion. Notably, investigations into whether additional cases (within both the discovery and validation cohort) may harbor mutations of low clonal abundance (<10% mutant allele), led to the detection of the NFKBIE deletion in another 18 cases. Owing to the prevalence of this 4bp deletion within the NFKBIE gene, we developed a GeneScan assay and screened an additional 312 CLL cases. Collectively, 40/604 (6.6%) CLL patients were found to carry this frame-shift deletion within the NFKBIE gene, which is in line with a recent publication reporting that 10% of Binet stage B/C patients carried this mutation (Damm et al. Cancer Discovery 2014). Remarkably, the majority of these NFKBIE mutations (16/40) were found in a subgroup of patients that expressed highly similar or stereotyped BcRs and are known to have a particularly poor outcome, denoted as subset #1. This finding thus alludes to a subset-biased acquisition and/or selection of genomic aberrations, similar to what has been reported for subset #2 and SF3B1, perhaps as a result of particular modes of BcR/antigen interaction. We utilized proximity-ligation assays to test the functional impact of the NFKBIE deletion by investigating protein-protein interactions. This analysis revealed reduced interaction between the inhibitor IκBε and the transcription factor p65 in NFKBIE-deleted CLL cells; IκBε-knock-down shRNA experiments confirmed dysregulated apoptosis/NF-κB signaling. Finally, to assess whether the NFKBIE deletion could also be present in other B-cell malignancies, we screened 372 mature B-cell lymphoma cases using NGS or the GeneScan assay and found the deletion in 7/136 (5.1%) mantle cell lymphomas, 3/66 (4.5%) diffuse large B-cell lymphomas and 3/170 (1.8%) splenic marginal zone lymphomas. Taken together, our analysis revealed that inactivating mutations within the NFKBIE gene lead to NF-κB activation in CLL and potentially several other B-cell-derived malignancies. Considering the central role of BcR stimulation in the natural history of CLL, the functional loss of IκBε may significantly contribute to sustained CLL cell survival and shape the disease evolution. This novel data strongly indicates that components of the NF-κB signaling pathway may be prime targets for future targeted therapies not only in CLL but also other mature B-cell lymphomas. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
1988 ◽  
Vol 71 (1) ◽  
pp. 178-185
Author(s):  
JD Norton ◽  
J Pattinson ◽  
AV Hoffbrand ◽  
H Jani ◽  
JC Yaxley ◽  
...  

Fifty-nine patients with B cell chronic lymphocytic leukemia (B-CLL) were screened for clonal rearrangement of T cell receptor (TCR) beta and gamma chain genes. Four were found with rearranged TCR beta genes, but none had detectable rearrangement of TCR gamma genes. One typical patient with B-CLL had a TCR beta gene structure consistent with a variable-diversity-joining rearrangement into the C beta 2 gene on one allele. An apparently identical rearrangement pattern was seen in a second patient, which suggested that there may be a restriction on the repertoire of possible TCR beta gene recombinations in mature B cells. Two further patients had a simple deletion of sequences, consistent with a diversity-joining rearrangement into C beta 2 on one allele. All four patients had rearrangements of immunoglobulin heavy- and light- chain genes typical of mature B cell malignancies. However, on review of clinical, morphological, and immunophenotype data, two had features consistent with B cell prolymphocytic leukemia or B lymphoma, and a third had progressed to a prolymphocytic transformation. Low-level expression of a predominantly 1.0- to 1.2-kilobase germ line TCR beta gene transcript was detected in several B-CLLs and at a comparable level in the four with rearranged TCR beta genes. This, together with the low frequency of TCR gene rearrangement, suggests that most B-CLL cases arise at a developmental stage when factors required for TCR gene activity are not operative.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4170-4170
Author(s):  
Simone C. Oostindie ◽  
Hilma J. Van Der Horst ◽  
Marije B. Overdijk ◽  
Kristin Strumane ◽  
Sandra Verploegen ◽  
...  

Abstract CD37 is a tetraspanin plasma membrane protein abundantly expressed on B-cells and represents a promising therapeutic target for the treatment of B-cell malignancies. Although complement-dependent cytotoxicity (CDC) has proven to be a powerful Fc-mediated effector function for killing hematological cancer cells, CD37 antibody-based therapeutics currently in clinical development are poor inducers of CDC. Here we present DuoHexaBody-CD37, a novel humanized IgG1 bispecific antibody targeting two different CD37 epitopes, with an E430G hexamerization-enhancing mutation, for the potential treatment of B-cell malignancies. The natural process of antibody hexamer formation through intermolecular Fc-Fc interactions between IgG molecules after cell surface antigen binding can be improved by introducing a single point mutation such as E430G in the IgG Fc domain, thereby facilitating more efficient C1q binding and complement activation (Diebolder et al., Science 2014; de Jong et al., PLoS Biol 2016). The hexamerization-enhancing mutation E430G was introduced into two humanized CD37 monoclonal antibodies (mAbs) that bind non-overlapping CD37 epitopes. Different antibody formats and combinations, including the single antibodies, combinations of the mAbs and bispecific mAbs were tested for their capacity to induce CDC and antibody-dependent cellular cytotoxicity (ADCC). The bispecific hexamerization-enhanced antibody variant DuoHexaBody-CD37, showed superior CDC activity compared to the single hexamerization-enhanced mAbs and the combination thereof, both in vitro over a range of different B-cell lines, and ex vivo in tumor cell samples obtained from patients with chronic lymphocytic leukemia (CLL). In a CDC assay using tumor cells obtained from a relapsed/refractory CLL patient who received prior treatment with rituximab, ibrutinib and idelalisib, DuoHexaBody-CD37 induced almost complete lysis (84% lysis at a concentration 100 µg/mL), thereby outperforming the single HexaBody molecules (15% and 23% lysis) and the combination (57%) (Figure 1). In addition to its potent CDC activity, DuoHexaBody-CD37 was also capable of inducing potent ADCC of Daudi cells (EC50 = 12.3 ± 9.5 ng/mL), as assessed using peripheral blood mononuclear cells from 8 healthy human donors in a standard chromium release assay. In assays using whole blood from 6 healthy human donors, DuoHexaBody-CD37 showed efficient B-cell binding and potent and specific depletion of the B-cell population (98% ± 1.3% depletion at 10 µg/mL, EC50 = 0.85 ± 0.284 µg/mL). Furthermore, DuoHexaBody-CD37 induced significant inhibition of tumor growth in vivo in Daudi-luc Burkitt's lymphoma and JVM-3 CLL mouse xenograft models, at doses as low as 0.1 and 1 mg/kg (p<0.05), respectively. In summary, we present a novel therapeutic antibody that, for the first time, combines proprietary DuoBody® and HexaBody® platforms. DuoHexaBody-CD37 induced highly potent CDC and efficient ADCC in preclinical models, suggesting that DuoHexaBody-CD37 may serve as a potential therapeutic mAb for the treatment of human B-cell malignancies. Disclosures Oostindie: Genmab: Employment, Equity Ownership. Van Der Horst:Genmab: Research Funding. Overdijk:Genmab: Employment, Equity Ownership. Strumane:Genmab: Employment, Equity Ownership. Verploegen:Genmab: Employment, Equity Ownership. Lindorfer:Genmab: Research Funding. Cook:Genmab: Research Funding. Chamuleau:Gilead: Research Funding; BMS: Research Funding; celgene: Research Funding; Genmab: Research Funding. Mutis:Gilead: Research Funding; Celgene: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genmab: Research Funding; Novartis: Research Funding; OnkImmune: Research Funding. Schuurman:Genmab: Employment, Other: Warrants. Sasser:Genmab: Employment, Equity Ownership. Taylor:Genmab: Research Funding. Parren:Genmab: Equity Ownership; Lava Therapeutics: Employment. Beurskens:Genmab: Employment, Equity Ownership. Breij:Genmab: Employment, Equity Ownership.


Blood ◽  
2018 ◽  
Vol 132 (23) ◽  
pp. 2446-2455 ◽  
Author(s):  
Ian W. Flinn ◽  
Peter Hillmen ◽  
Marco Montillo ◽  
Zsolt Nagy ◽  
Árpád Illés ◽  
...  

Abstract Duvelisib (also known as IPI-145) is an oral, dual inhibitor of phosphatidylinositol 3-kinase δ and γ (PI3K-δ,γ) being developed for treatment of hematologic malignancies. PI3K-δ,γ signaling can promote B-cell proliferation and survival in clonal B-cell malignancies, such as chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). In a phase 1 study, duvelisib showed clinically meaningful activity and acceptable safety in CLL/SLL patients. We report here the results of DUO, a global phase 3 randomized study of duvelisib vs ofatumumab monotherapy for patients with relapsed or refractory (RR) CLL/SLL. Patients were randomized 1:1 to oral duvelisib 25 mg twice daily (n = 160) or ofatumumab IV (n = 159). The study met the primary study end point by significantly improving progression-free survival per independent review committee assessment compared with ofatumumab for all patients (median, 13.3 months vs 9.9 months; hazard ratio [HR] = 0.52; P &lt; .0001), including those with high-risk chromosome 17p13.1 deletions [del(17p)] and/or TP53 mutations (HR = 0.40; P = .0002). The overall response rate was significantly higher with duvelisib (74% vs 45%; P &lt; .0001) regardless of del(17p) status. The most common adverse events were diarrhea, neutropenia, pyrexia, nausea, anemia, and cough on the duvelisib arm, and neutropenia and infusion reactions on the ofatumumab arm. The DUO trial data support duvelisib as a potentially effective treatment option for patients with RR CLL/SLL. This trial was registered at www.clinicaltrials.gov as #NCT02004522.


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