Lucile Baseggio

CD5 expression identifies a subset of splenic marginal zone lymphomas with higher lymphocytosis: a clinico-pathological, cytogenetic and molecular study of 24 cases

Background Classically, splenic marginal zone B-cell lymphoma is characterized by the absence of CD5 expression. Cases of apparent splenic marginal zone B-cell lymphoma showing CD5 expression, as diagnosed by blood studies, have been described; however, in the absence of histological evidence, the correct diagnosis of these cases is controversial because of possible confusion with other CD5-positive small B-cell neoplasms. Design and Methods We report a series of 24 CD5-positive, t(11;14)-negative cases of splenic marginal zone B-cell lymphoma diagnosed by flow cytometry studies of blood and histologically proven on spleen sections. Clinical data as well as morphological, immunological, cytogenetic and molecular characteristics were assessed to evaluate the similarities and differences of these cases with those of classical CD5-negative splenic marginal zone B-cell lymphoma. Results The CD5 expression detected in blood by flow cytometry was confirmed in most cases by immunohistochemistry on spleen sections. In general, cases of CD5-positive and CD5-negative splenic marginal zone B-cell lymphoma did not appear different and, in particular, they showed similar karyotypic changes such as 7q deletion, trisomy 3, trisomy 18 and biased IGHV usage (i.e. VH1-2). The main differences were a higher lymphocyte count at diagnosis (8.15×109/L versus 3.90×109/L; P=0.005) and more frequent diffuse bone marrow infiltration (34% versus 8%; P=0.03) in the CD5-positive group. A tendency to a more mutated IGHV status in the CD5 positive cases was observed (80% versus 54.5%; (P=0.11). No significant differences in outcome were found in relation to CD5 expression. Conclusions This study confirms the existence of cases of CD5-positive splenic marginal zone B-cell lymphoma and shows that these cases are closely related to classical splenic marginal zone lymphoma. Whether or not CD5-positive splenic marginal zone B-cell lymphoma constitutes a true subset obviously requires the study of more cases.

Clinicopathologic characteristics and outcome of diffuse large B-cell lymphomas presenting with an associated low-grade component at diagnosis.

PURPOSE Some diffuse large B-cell lymphomas (DLBCL) present at diagnosis with associated morphologic features of small B-cell non-Hodgkins lymphoma (NHL) and may arise from the transformation of a previously unknown indolent low-grade lymphoma. The characteristics and prognosis of these particular DLBCL are not well known. PATIENTS AND METHODS The strict morphologic review of consecutive DLBCL patients diagnosed over 12 years in our department (Hematology Department, Centre Hospitalier Lyon-Sud, Lyon, France) allowed to retrieve 60 DLBCL that could be have occurred from the transformation of marginal zone B-cell NHL (32 patients), follicular NHL (22 patients), and small lymphocytic NHL (6 patients). We compared them to 180 matched patients of de novo DLBCL. RESULTS Patients median age was 55 years and presented the following clinical characteristics: poor performance status in 33%, disseminated disease in 97%, more than one extranodal site in 50%, and increased lactate dehydrogenase level in 55%. Complete remission with multidrug chemotherapy regimens was achieved in 60% of the patients, but 48% relapsed: 28% with aggressive and 20% with indolent histology, respectively. Overall survival (OS) and freedom-from-progression rates at 5 years were 57% and 33%, respectively. The matched-control analysis showed that patients with transformed NHL at diagnosis had lower complete response to chemotherapy (P = .004) and higher progression rate (P = .03), whereas no difference was observed in OS (P = .21). CONCLUSION Compared to de novo DLBCL, transformed NHL at diagnosis have similar overall survival but lower complete response to initial treatment and higher risk of indolent relapses.

Transcriptional Activation of hTERT, the Human Telomerase Reverse Transcriptase, by Nuclear Factor of Activated T Cells

Telomerase is essential for telomere maintenance, and its activation is thought to be a critical step in cellular immortalization and tumorigenesis. Human telomerase reverse transcriptase (hTERT) is a major component of telomerase activity. We show here that hTERT is expressed soon after lymphocyte activation and that its expression is inhibited by rapamycin, wortmannin, and FK506, which was the most potent inhibitor. These results suggest a potential role for the transcription factor nuclear factor of activated T cells (NFAT) in the regulation of hTERT expression. Five putative NFAT-binding sites were identified in the hTERT promoter. In luciferase assays, the hTERT promoter was activated by overexpressed NFAT1. Moreover, serial deletions revealed that the promoter activation was mainly due to a −40 NFAT1-binding site flanked by two SP1-binding sites. Mutation of the −40 NFAT-binding site caused a 53% reduction in the transcriptional activity of hTERT promoter. Simultaneous mutations of the −40 NFAT-responsive element together with one or both SP1-binding sites led to a more dramatic decrease in luciferase activity than single mutations, suggesting a functional synergy between NFAT1 and SP1 in hTERT transcriptional regulation. NFAT1 overexpression in MCF7 and Jurkat cell lines induced an increase in endogenous hTERT mRNA expression. Inversely, its down-regulation was induced by NFAT1 silencing. Furthermore, chromatin immunoprecipitation assay demonstrated that NFAT1 directly binds to two sites (−40 and −775) in the endogenous hTERT promoter. Thus, we show for the first time the direct involvement of NFAT1 in the transcriptional regulation of hTERT.

Long-term follow-up analysis of 100 patients with splenic marginal zone lymphoma treated with splenectomy as first-line treatment

Abstract Splenectomy is considered as one of the first-line treatments for symptomatic patients with splenic marginal zone lymphoma (SMZL). Between 1997 and 2012, 100 hepatitis C virus-negative patients with SMZL were treated by splenectomy as first-line treatment. At 6 months, all patients but three recovered from all cytopenias. The median lymphocyte count at 6 months and 1 year was 11.51 × 109/L and 6.9 × 109/L, respectively. Median progression-free survival (PFS) was 8.25 years. The 5-year and 10-year overall survival (OS) rates were 84% and 67%, respectively. Histological transformation occurred in 11% of patients, and was the only parameter significantly associated with a shorter time to progression (p = 0.0001). Significant prognostic factors for OS were age (p = 0.0356) and histological transformation (p = 0.0312). In this large retrospective cohort, we confirmed that splenectomy as first-line treatment in patients with SMZL corrected cytopenias and lymphocytosis within the first year and was associated with a good PFS.

Higher LPS-stimulated TNF-α mRNA levels in peripheral blood mononuclear cells from non-Hodgkin's lymphoma patients

OBJECTIVE The aim of the present study was to investigate the capacity of normal immune blood cells from non-Hodgkins lymphoma patients to produce tumor necrosis factor (TNF) after lipopolysaccharide (LPS) stimulation and the influence of the TNF (-308) polymorphism in this production. MATERIALS AND METHODS A whole peripheral blood cell assay was utilized following LPS stimulation. At selected incubation times, supernatants were harvested for protein dosage, while mRNA was extracted and reverse-transcribed. The amount of TNF mRNA was quantified using real-time quantitative polymerase chain reaction (PCR) and genomic DNA was typed for TNF (-308) polymorphism. RESULTS Upon LPS stimulation, TNF-secreted protein was slightly but not significantly increased in lymphoma patients when compared to controls. In contrast, the relative TNF mRNA amounts were significantly higher in lymphoma patients at 30 minutes (median 27.75 vs. 16.00; Mann-Whitney U-test p < 0.05), at 4 hours (52.00 vs. 31.00; p < 0.05), and at 24 hours (19.50 vs. 9.00; p < 0.05). In addition, patients carrying the variant TNF2 allele had higher relative TNF mRNA levels than TNF1 homozygotes (p = 0.02). CONCLUSION The LPS-induced TNF mRNA levels are higher in peripheral blood cells (PBC) from lymphoma patients than from controls, while TNF protein secretion is not strikingly different. Altered regulation of TNF mRNA translation or TNF protein secretion may contribute to these observations. Taken together, an increased susceptibility for TNF gene transcription after LPS stimulation was observed in PBC (mainly in monocytes) from lymphoma patients, and especially those carrying the TNF2 allele.

The genetic basis of hepatosplenic T-cell lymphoma

Hepatosplenic T-cell lymphoma (HSTL) is a rare and lethal lymphoma; the genetic drivers of this disease are unknown. Through whole-exome sequencing of 68 HSTLs, we define recurrently mutated driver genes and copy-number alterations in the disease. Chromatin-modifying genes, including SETD2, INO80, and ARID1B, were commonly mutated in HSTL, affecting 62% of cases. HSTLs manifest frequent mutations in STAT5B (31%), STAT3 (9%), and PIK3CD (9%), for which there currently exist potential targeted therapies. In addition, we noted less frequent events in EZH2, KRAS, and TP53SETD2 was the most frequently silenced gene in HSTL. We experimentally demonstrated that SETD2 acts as a tumor suppressor gene. In addition, we found that mutations in STAT5B and PIK3CD activate critical signaling pathways important to cell survival in HSTL. Our work thus defines the genetic landscape of HSTL and implicates gene mutations linked to HSTL pathogenesis and potential treatment targets.Significance: We report the first systematic application of whole-exome sequencing to define the genetic basis of HSTL, a rare but lethal disease. Our work defines SETD2 as a tumor suppressor gene in HSTL and implicates genes including INO80 and PIK3CD in the disease. Cancer Discov; 7(4); 369-79. ©2017 AACR.See related commentary by Yoshida and Weinstock, p. 352This article is highlighted in the In This Issue feature, p. 339.

Hairy cell leukaemia‐variant and splenic red pulp lymphoma: a single entity?

Supported in part by: Ministero della Salute (Ricerca Finalizzata I.R.C.C.S., ‘Alleanza Contro il Cancro’ and Rete Nazionale Bio-Informatica Oncologica/RN-BIO), Rome; Ricerca Scientifica Applicata, Regione Friuli Venezia Giulia, Trieste (‘Linfonet’ Project); Associazione Italiana contro le Leucemie, linfomi e mielomi (A.I.L.), Venezia Section, Pramaggiore Group; Novara-A.I.L. Onlus, Novara; Associazione Italiana per la Ricerca sul Cancro (A.I.R.C.; Investigator Grant IG-8701), Milan, Italy.

In non-follicular lymphoproliferative disorders, IGH/BCL2-fusion is not restricted to chronic lymphocytic leukaemia.

The translocation t(14;18) and its t(2;18) and t(18,22) variants, which involve the BCL2 genetic hallmark for follicular lymphoma (FL), have been reported in several cases of chronic B‐cell lymphoproliferative disease (CLPD) and frequently in chronic lymphocytic leukaemia (CLL). We describe here the clinical, morphological, immunological, cytogenetic and molecular findings from 37 cases of t(14;18)‐positive CLPD, identified from our series of non‐FL B‐cell neoplasms (n = 993) that were routinely analysed in peripheral blood by conventional cytogenetics analyses. The FL diagnosis was excluded by morphology and immunology (the samples were CD10 negative in all cases). The BCL2 translocations were observed in 22 CLL cases, including 7 monoclonal B‐cell lymphocytosis (MBL) cases re‐classified according to the new International Workshop on CLL criteria, six small lymphocytic lymphoma (SLL) cases, 1 splenic marginal zone lymphoma (SMZL) case and eight cases of unclassifiable CLPD with overlapping CLL/MZL features. In the CLL cases, the IGH/BCL2 fusion was remarkably associated with trisomy 12 (13/22) and mutated IGHV status (20/21) and did not affect the outcome. Moreover, most of these CLLs harboured a low mutation load of BCL6 gene and unmutated FAS (CD95) loci, which points to a post–germinal‐centre cellular origin.

Genetic polymorphisms in the proximal IL-10 promoter and susceptibility to non-Hodgkin lymphoma

Equipe Universitaire (JE 2267) Pathologie des Cellules Lymphoı̈des, Université Claude Bernard, Lyon, France, Department of Hematology, Medical University of Lodz, Poland, Service d’Hématologie, Centre-Hospitalier Lyon-Sud, Pierre-Bénite, France, Etablissement Français du Sang, Lyon, France, Service d’Anatomie Pathologique, Centre-Hospitalier Lyon-Sud, Pierre-Bénite, France, and Institute of Hematology and Blood Transfusion, Warsaw, Poland

Identification of proteomic signatures of mantle cell lymphoma, small lymphocytic lymphoma, and marginal zone lymphoma biopsies by surface enhanced laser desorption/ionization-time of flight mass spectrometry.

Mantle cell lymphoma (MCL), small lymphocytic lymphoma (SLL), and marginal zone lymphoma (MZL) are small B-cell non-Hodgkin lymphomas (NHLs) that may be difficult to distinguish. In order to identify specific proteomic biomarkers, differential proteomic analysis of these three NHLs was performed using surface enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF-MS). Whole cell lysates obtained from 18 MCL, 20 SLL, and 20 MZL biopsies were applied on two different ProteinChips (cationic and anionic). Hierarchical clustering and discriminating scores combined with an innovative bio-informatics microdissection strategy allowed us to distinguish specific lymphoma proteomic signatures based on the expression of 37 protein peaks. SELDI-assisted protein purification combined with nano-liquid chromatography (LC) quadrupole-time of flight tandem mass spectrometry (Q-TOF MS/MS) was used to identify proteins overexpressed in both MCL and SLL tumors. Among them two histones, H2B and H4, were identified in MCL tumor biopsies and the signal recognition particle 9 kDa protein, SRP9, in SLL tumor biopsies.