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This table presents all variants identified among our cohort by Lymphopanel NGS. Variant type and variant allele frequency (VAF) are indicated.

This table presents all CNVs identified among our cohort using the ONCOCNV software. Duplication was considered when copy number was superior to 2 and deletion was considered when copy number was inferior to 2. False discovery rate (FDR) cutoff was set at 0.01.

Supplementary methods, figures, and tables Figure S1: Variant filters applied to Lymphopanel NGS data. Figure S2: Validation of variants according to SIFT and CADD scores. Figure S3: PMBL samples harbor more mutations than other DLBCL subtypes. Figure S4: Role of AID-induced SHM in DLBCL. Figure S5: Mutation frequency by subtype. Figure S6: Clustering of gene mutations according to subtype. Figure S7: Protein representations of observed mutations. Figure S8: Correlations between age and specific gene mutations. Figure S9: Prognosis according to IPI and subtype. Figure S10: Prognostic impact of gene mutations among the Lymphopanel. Table S1: Clinical characteristics of patients in our cohort. Table S2: Overview of the Lymphopanel used for NGS analysis. Table S3: Overview of pathway selection Table S4: Validation of variant filtering by an independent study of seven non-tumoral samples from DLBCL patients Table S5: Validated variants. Table S6: Lymphopanel NGS detection of genes with high AID target frequencies. Table S7: Prognostic impact of mutations in Lymphopanel genes

Supplementary Figures 1-10 Figure S1. MYD88 mutation VAF according to L265P or non-L265P variants. Figure S2. Age according to MYD88 mutation status and variant among ABC patients. Figure S3. Genomic profiles of DLBCL according to the presence of MYD88 L265P or non-L265P variants. Figure S4. Relative L265P allele expression level according to L265P VAF. Figure S5. Gene expression according to MYD88 status. Figure S6. NFkB pathway gene expression according to MYD88 mutational status. Figure S7. LPS score according to subtype and downstream NFkB alterations. Figure S8. Clustering according to expression levels of 27 genes involved in LPS response and differentially expressed according to MYD88 L265P. Figure S9. TNFAIP3 and CARD11 expression according to their copy number status. Figure S10. Additional survival analyses.

Clinical characteristics of the 17 patients with CNS relapse are provided, included time to CNS relapse, first-line treatment and response after first-line treatment. CR, Complete Response; PR, Partial Response; PD, Progressive Disease.

Purpose: Next-generation sequencing (NGS) has detailed the genomic characterization of diffuse large B-cell lymphoma (DLBCL) by identifying recurrent somatic mutations. We set out to design a clinically feasible NGS panel focusing on genes whose mutations hold potential therapeutic impact. Furthermore, for the first time, we evaluated the prognostic value of these mutations in prospective clinical trials.Experimental Design: A Lymphopanel was designed to identify mutations in 34 genes, selected according to literature and a whole exome sequencing study of relapsed/refractory DLBCL patients. The tumor DNA of 215 patients with CD20+de novo DLBCL in the prospective, multicenter, and randomized LNH-03B LYSA clinical trials was sequenced to deep, uniform coverage with the Lymphopanel. Cell-of-origin molecular classification was obtained through gene expression profiling with HGU133+2.0 Affymetrix GeneChip arrays.Results: The Lymphopanel was informative for 96% of patients. A clear depiction of DLBCL subtype molecular heterogeneity was uncovered with the Lymphopanel, confirming that activated B-cell–like (ABC), germinal center B-cell like (GCB), and primary mediastinal B-cell lymphoma (PMBL) are frequently affected by mutations in NF-κB, epigenetic, and JAK–STAT pathways, respectively. Novel truncating immunity pathway, ITPKB, MFHAS1, and XPO1 mutations were identified as highly enriched in PMBL. Notably, TNFAIP3 and GNA13 mutations in ABC patients treated with R-CHOP were associated with significantly less favorable prognoses.Conclusions: This study demonstrates the contribution of NGS with a consensus gene panel to personalized therapy in DLBCL, highlighting the molecular heterogeneity of subtypes and identifying somatic mutations with therapeutic and prognostic impact. Clin Cancer Res; 22(12); 2919–28. ©2016 AACR.See related commentary by Lim and Elenitoba-Johnson, p. 2829

All relevant clinical data is included. Immunohistochemical results for BCL2, CD10, BCL6, MUM1, FOXP1, IgM and MYC are transcribed: 0 indicates negativity and 1 indicates positivity. For BCL2 and MYC, positivity is according to a threshold of 50% or 40% respectively.

Purpose: MYD88 mutations, notably the recurrent gain-of-function L265P variant, are a distinguishing feature of activated B-cell like (ABC) diffuse large B-cell lymphoma (DLBCL), leading to constitutive NFκB pathway activation. The aim of this study was to examine the distinct genomic profiles of MYD88-mutant DLBCL, notably according to the presence of the L265P or other non-L265P MYD88 variants.Experimental Design: A cohort of 361 DLBCL cases (94 MYD88 mutant and 267 MYD88 wild-type) was submitted to next-generation sequencing (NGS) focusing on 34 genes to analyze associated mutations and copy number variations, as well as gene expression profiling, and clinical and prognostic analyses.Results: Importantly, we highlighted different genomic profiles for MYD88 L265P and MYD88 non-L265P–mutant DLBCL, shedding light on their divergent backgrounds. Clustering analysis also segregated subgroups according to associated genetic alterations among patients with the same MYD88 mutation. We showed that associated CD79B and MYD88 L265P mutations act synergistically to increase NFκB pathway activation, although the majority of MYD88 L265P–mutant cases harbors downstream NFκB alterations, which can predict BTK inhibitor resistance. Finally, although the MYD88 L265P variant was not an independent prognostic factor in ABC DLBCL, associated CD79B mutations significantly improved the survival of MYD88 L265P–mutant ABC DLBCL in our cohort.Conclusions: This study highlights the relative heterogeneity of MYD88-mutant DLBCL, adding to the field's knowledge of the theranostic importance of MYD88 mutations, but also of associated alterations, emphasizing the usefulness of genomic profiling to best stratify patients for targeted therapy. Clin Cancer Res; 23(9); 2232–44. ©2016 AACR.

Supplementary methods, supplementary figure & table legends, and supplementary tables 3, 4, 8 & 9. Table S3: Overview of the Lymphopanel used for NGS analysis. Table S4: Overview of pathway selection Table S8. Genes involved in the LPS score. Table S9. Expression levels of genes involved in response to LPS stimulation according to MYD88 L265P.

Statistically significant differences (p

COO information according to the three techniques used in this study is given according to the various MYD88 variants present in our cohort.

From a liquid biopsy, cell-free DNA (cfDNA) can provide information regarding basal tumoral genetic patterns and changes upon treatment. In a prospective cohort of 30 diffuse large B-cell lymphomas (DLBCL), we determined the clinical relevance of cfDNA using targeted next-generation sequencing and its correlation with PET scan imaging at the time of diagnosis and during treatment. Using a dedicated DLBCL panel, mutations were identified at baseline for 19 cfDNAs and profiles were consistent with expected DLBCL patterns. Tumor burden-related clinical and PET scan features (LDH, IPI, and metabolic tumor volume) were significantly correlated with the quantity of tumoral cfDNA. Among the four patients presenting additional mutations in their cfDNAs, three had high metabolic tumor volumes, suggesting that cfDNA more accurately reflects tumor heterogeneity than tissues biopsy itself. Mid-treatment, four patients still had basal mutations in their cfDNAs, including three in partial response according to their Deauville scores. Our study highlights the major interests in liquid biopsy, in particular in the context of bulky tumors where cfDNA allows capturing the entire tumoral mutation profile. Therefore, cfDNA analysis in DLBCL represents a complementary approach to PET scan imaging.

Little is known on the phylogenetic relationship between diagnostic and relapse clones of diffuse large B-cell lymphoma (DLBCL). We applied high throughput sequencing (HTS) of the VDJ locus of Immunoglobulin heavy chain (IGHV) on 14 DLBCL patients with serial samples, including tumor biopsies and/or peripheral blood mononuclear cells (PBMC). Phylogenetic data were consolidated with targeted sequencing and cytogenetics. Phylogeny clearly showed that DLBCL relapse could occur according either an early or a late divergent mode. These two modes of divergence were independent from the elapsed time between diagnosis and relapse. We found no significant features for antigen selection pressure in complementary determining region both at diagnosis and relapse for 9/12 pairs and a conserved negative selection pressure for the three remaining cases. Targeted HTS and conventional cytogenetics revealed a branched vs. linear evolution for 5/5 IGHV early divergent cases, but unexpected such "oncogenetic" branched evolution could be found in at least 2/7 IGHV late divergent cases. Thus, if BCR signaling is mandatory for DLBCL emergence, oncogenetic events under chemotherapy selection pressure may be the main driving forces at relapse. Finally, circulating subclones with divergent IGHV somatic hypermutations patterns from initial biopsy could be detected in PBMC at diagnosis for 4/6 patients and, for two of them, at least one was similar to the ones found at relapse. This study highlights that oncogenetic intraclonal diversity of DLBCL should be evaluated beyond the scope a single biopsy and represents a rationale for future investigations using peripheral blood for lymphoid malignancies genotyping. Am. J. Hematol. 92:68-76, 2017. © 2016 Wiley Periodicals, Inc.

Primary mediastinal B-cell lymphoma (PMBL) is an entity of B-cell lymphoma distinct from the other molecular subtypes of diffuse large B-cell lymphoma (DLBCL). We investigated the prevalence, specificity, and clinical relevance of mutations of XPO1, which encodes a member of the karyopherin-β nuclear transporters, in a large cohort of PMBL. PMBL cases defined histologically or by gene expression profiling (GEP) were sequenced and the XPO1 mutational status was correlated to genetic and clinical characteristics. The XPO1 mutational status was also assessed in DLBCL, Hodgkin lymphoma (HL) and mediastinal gray-zone lymphoma (MGZL).The biological impact of the mutation on Selective Inhibitor of Nuclear Export (SINE) compounds (KPT-185/330) sensitivity was investigated in vitro. XPO1 mutations were present in 28/117 (24%) PMBL cases and in 5/19 (26%) HL cases but absent/rare in MGZL (0/20) or DLBCL (3/197). A higher prevalence (50%) of the recurrent codon 571 variant (p.E571K) was observed in GEP-defined PMBL and was associated with shorter PFS. Age, International Prognostic Index and bulky mass were similar in XPO1 mutant and wild-type cases. KPT-185 induced a dose-dependent decrease in cell proliferation and increased cell-death in PMBL cell lines harboring wild type or XPO1 E571K mutant alleles. Experiments in transfected U2OS cells further confirmed that the XPO1 E571K mutation does not have a drastic impact on KPT-330 binding. To conclude the XPO1 E571K mutation represents a genetic hallmark of the PMBL subtype and serves as a new relevant PMBL biomarker. SINE compounds appear active for both mutated and wild-type protein.

HECT domain and ankyrin repeat containing E3 ubiquitin protein ligase 1, HACE1, located on chromosome 6q, encodes an E3 ubiquitin ligase and is downregulated in many human tumors. Here, we report HACE1 as a candidate tumor suppressor gene down-regulated by a combination of deletion and epigenetic mechanisms. HACE1 deletions were observed in 40% of B-cell lymphoma tumors. Hypermethylation of the HACE1 promoter CpG177 island was found in 60% (68/111) of cases and in all tested B-cell lymphoma lines. Using HDAC inhibitors, we observed predominantly inactive chromatin conformation (methylated H3 histones H3K9me2) in HACE1 gene promoter region. We demonstrated in Ramos and Raji cells that down-regulation of HACE1 expression was associated with a significant decrease in apoptosis and an accumulation of cells in the S and G2/M phases. Our experiments indicate that HACE1 can act as a haploinsufficient tumor suppressor gene in most B-cell lymphomas and can be downregulated by deacetylation of its promoter region chromatin, which makes HACE1 a potential target for HDAC inhibitors.

Classical Hodgkin lymphoma (cHL) accounts for 30% of all lymphomas [1]. Currently, 20–25% of cHL cases relapse or are refractory after first-line standard treatments, leading to the need to better ...

International audience; Classical hairy cell leukemia (HCL-c) is a rare lymphoid neoplasm. BRAFV600E mutation, detected in more than 80% of the cases, is described as a driver mutation, but additional genetic abnormalities appear to be necessary for the disease progression. For cases of HCL-c harboring a wild-type BRAF gene, the differential diagnosis of the variant form of HCL (HCL-v) or splenic diffuse red pulp lymphoma (SDRPL) is complex. We selected a panel of 21 relevant genes based on a literature review of whole exome sequencing studies (BRAF, MAP2K1, DUSP2, MAPK15, ARID1A, ARID1B, EZH2, KDM6A, CREBBP, TP53, CDKN1B, XPO1, KLF2, CXCR4, NOTH1, NOTCH2, MYD88, ANXA1, U2AF1, BCOR, and ABCA8). We analyzed 20 HCL-c and 4 HCL-v patients. The analysis of diagnostic samples mutations in BRAF (n = 18), KLF2 (n = 4), MAP2K1 (n = 3), KDM6A (n = 2), CDKN1B (n = 2), ARID1A (n = 2), CREBBP (n = 2) NOTCH1 (n = 1) and ARID1B (n = 1). BRAFV600E was found in 90% (18/20) of HCL-c patients. In HCL-c patients with BRAFV600E , other mutations were found in 33% (6/18) of cases. All 4 HCL-v patients had mutations in epigenetic regulatory genes: KDM6A (n = 2), CREBBP (n = 1) or ARID1A (n = 1). The analysis of sequential samples (at diagnosis and relapse) from 5 patients (2 HCL-c and 3 HCL-v), showed the presence of 2 new subclonal mutations (BCORE1430X and XPO1E571K ) in one patient and variations of the mutated allele frequency in 2 other cases. In the HCL-v disease, we described new mutations targeting KDM6A that encode a lysine demethylase protein. This opens new perspectives for personalized medicine for this group of patients.

Despite the many efforts already spent to enumerate somatic mutations in diffuse large B-cell lymphoma (DLBCL), previous whole-genome and whole-exome studies conducted on patients of mixed outcomes failed at characterizing the 30% of patients who will relapse or resist current immunochemotherapies. To address this issue, we performed whole-exome sequencing of normal/tumoral DNA pairs in 14 relapsed/refractory (R/R) patients subclassified by full-transcriptome arrays (six activated B-cell like, three germinal center B-cell like, and five primary mediastinal B-cell lymphomas), from the LNH-03 LYSA clinical trial program. Aside from well-known DLBCL features, gene and pathway level recurrence analyses proposed several interesting leads including TBL1XR1 and activating mutations in IRF4 or in the insulin regulation pathway. Sequencing-based copy number analysis defined 23 short recurrently altered regions involving genes such as REL, CDKN2A, HYAL2, and TP53. Moreover, it highlighted mutations in genes such as GNA13, CARD11, MFHAS1, and PCLO as associated with secondary variant allele amplification events. The five primary mediastinal B-cell lymphomas (PMBL), while unexpected in a R/R cohort, showed a significantly higher mutation rate (P = 0.003) and provided many insights on this classical Hodgkin lymphoma related subtype. Novel genes such as XPO1, MFHAS1, and ITPKB were found particularly mutated, along with various cytokine-based signaling pathways. Among these analyses, somatic events in the NF-κB pathway were found preponderant in the three DLBCL subtypes, confirming its major implication in DLBCL aggressiveness and pinpointing several new candidate genes.

// Maxime Fontanilles 1, 2 , Florent Marguet 3, 4 , Elodie Bohers 2 , Pierre-Julien Viailly 2 , Sydney Dubois 2 , Philippe Bertrand 2 , Vincent Camus 1, 2 , Sylvain Mareschal 2 , Philippe Ruminy 2 , Catherine Maingonnat 2 , Stephane Lepretre 1 , Elena-Liana Veresezan 5 , Stephane Derrey 6 , Herve Tilly 1, 2 , Jean-Michel Picquenot 5 , Annie Laquerriere 3, 4 and Fabrice Jardin 1, 2 1 Department of Hematology, Cancer Center Henri Becquerel, 76000 Rouen, France 2 INSERM U1245, Cancer Center Henri Becquerel, Institute of Research and Innovation in Biomedicine (IRIB), University of Normandy, UNIVROUEN, 76000 Rouen, France 3 INSERM U1245 and Hopital Charles Nicolle, NeoVasc Team, University of Normandy, UNIVROUEN, CHU-Hopitaux de Rouen, 76031 Rouen, France 4 Department of Neuropathology, Hopital Charles Nicolle, Normandy Center for Genomic and Personalized Medicine, CHU-Hopitaux de Rouen, 76031 Rouen, France 5 Department of Pathology, Cancer Center Henri Becquerel, 76000 Rouen, France 6 Department of Neurosurgery, Hopital Charles Nicolle, CHU-Hopitaux de Rouen, 76031 Rouen, France Correspondence to: Fabrice Jardin, email: fabrice.jardin@chb.unicancer.fr Keywords: primary central nervous system lymphoma, circulating cell-free tumor DNA, somatic mutation, liquid biopsy, next-generation sequencing Received: March 08, 2017 Accepted: May 03, 2017 Published: June 01, 2017 ABSTRACT Purpose: Primary central nervous system lymphomas (PCNSL) have recurrent genomic alterations. The main objective of our study was to demonstrate that targeted sequencing of circulating cell-free DNA (cfDNA) released by PCNSL at the time of diagnosis could identify somatic mutations by next-generation sequencing (NGS). Patients and Methods: PlasmacfDNA and matched tumor DNA (tDNA) from 25 PCNSL patients were sequenced using an Ion Torrent Personal Genome Machine (Life Technologies ® ). First, patient-specific targeted sequencing of identified somatic mutations in tDNA was performed. Then, a second sequencing targeting MYD88 c.T778C was performed and compared to plasma samples from 25 age-matched control patients suffering from other types of cancer. Results: According to the patient-specific targeted sequencing, eight patients (32% [95% CI 15-54%]) had detectable somatic mutations in cfDNA. Considering MYD88 sequencing, six patients had the specific c.T778C alteration detected in plasma. Using a control group, the sensitivity was 24% [9-45%] and the specificity was 100%. Tumor volume or deep brain structure involvement did not influence the detection of somatic mutations in plasma. Conclusion: This pilot study provided evidence that somatic mutations can be detected by NGS in the cfDNA of a subset of patients suffering from PCNSL.

International audience; Introduction: Primary cutaneous diffuse large B‐cell lymphoma leg‐type (PCLBCL‐LT) is recognized by the World Health Organization (WHO) classification as a rare and aggressive disease accounting for 5 to 10% of primary cutaneous lymphoma. It displays original clinical features occurring mostly in the elderly and preferentially involving the legs but date the genetic specificities of this entities, as compared to other B‐cell aggressive lymphoma is unknown.Methods: To determine whether the mutational profile of primary cutaneous diffuse large B‐cell lymphoma leg‐type (PCLBCL‐LT) is unique by comparison with other diffuse large B‐cell lymphoma (DLBCL) subtypes, we analyzed a total cohort of 28 PCLBCL‐LT cases by next generation sequencing with a Lymphopanel designed for DLBCL. We also analyzed 12 pairs of tumor and control DNA samples by whole exome sequencing which led us to perform resequencing of three selected genes not included in the Lymphopanel: TBL1XR1, KLHL6 and IKZF3. To pinpoint specificities, comparison with a cohort of DLBCL and Primary central nervous System lymphoma (PCNSL) analyzed by the same targeted panel was performed.Results: Our study clearly identifies an original mutational landscape of PCLBCL‐LT with a very restricted set of highly recurrent mutations (>40%) involving MYD88 (p.L265P variant), PIM1 and CD79B. Other genes involved in B‐cell signaling, NFKB activation or DNA modeling were found altered notably TBL1XR1 (33%), MYC (26%) CREBBP (26%) and IRF4 (21%) or HIST1H1E(41%). MYD88L265P variant was associated with copy number variations or copy neutral loss of heterozygosity in 60% of cases. The most frequent genetic losses involved CDKN2A/2B, TNFAIP3/A20, PRDM1, TCF3 and CIITA. The high recurrence of specific gene mutations such as MYD88 and the absence of mutations of KMT2D or FOXO1 are distinct features from nodal DLBCLs of either GC or ABC subtypes. Interestingly PCLBCL‐LT exhibits a mutational pattern that is closer to PCNSL than to ABC‐type nodal DLBCL but also has distinctive features, such as a very high mutational rate for PIM1, a higher rate of CD79B mutations and other original mutations such as CREBBP, MYC and IRF4 mutations (figure 1).Conclusion: This study describes for the first time the genomic landscape of a series of untreated PCLBCL‐LT. Our results obtained by WES and targeted sequencing underscore several similarities with ABC‐DBCL and more specifically with PCNSL subtypes. On the other hand, we pinpoint specificities that may sustain distinctive clinical features and guide therapeutic strategies according to an individual genetic analysis.

Introduction: MYD88 mutations, notably the recurrent gain-of-function L265P variant, are a distinguishing feature of Activated B-Cell like (ABC) Diffuse Large B Cell Lymphoma (DLBCL), leading to constitutive NFkB pathway activation. The frequency of MYD88 mutations in DLBCL and other hematologic malignancies is well described; however, there has not yet been a large-scale study of a MYD88 mutated patient cohort with additional Next Generation Sequencing (NGS), copy number variation (CNV), and gene expression data, in order to thoroughly characterize the associated genomic profiles of these patients. The aims of our study were to compare the L265P and non-L265P mutations in terms of pathological and genetic features, to better detail the genomic background associated with MYD88 mutations in order to delineate patients potentially sensitive to targeted therapies, and to define the prognostic value of MYD88 mutations according to different genomic contexts. Methods: A cohort of 361 DLBCL patients (94 MYD88 mutant and 267 MYD88 wild-type) was selected among the prospective, multicenter and randomized LNH-03B and LNH09-7B (NCT01195714) LYSA trials, as well as among patients sequenced at our institution as part of routine procedure. Cell of origin (COO) classification was obtained with HGU133+2.0 Affymetrix GeneChip arrays for 214 patients, with RT-MLPA for 77 patients1 and with Hans immunohistochemistry (IHC) method for 49 patients. All cases were submitted to next generation sequencing (NGS) focusing on 34 genes (Lymphopanel2) in order to analyze associated mutations and copy number variations (CNVs), as well as IHC, FISH, and clinical and prognostic analyses. Results: Importantly, we highlighted different genomic profiles for MYD88 L265P and MYD88 non-L265P mutant DLBCL, shedding light on their divergent backgrounds. Clustering analysis segregated subgroups according to associated genetic alterations among patients with either MYD88 L265P or non-L265P mutations. As such, clustering separated MYD88 L265P mutated DLBCL with associated PIM1 (52%), CD79B (52%), KMT2D (42%), and PRDM1 (32%) mutations, as well as MYD88 L265P mutated DLBCL with CDKN2A/B (67%/50%), PRDM1 (57%) and TNFAIP3 (52%) CNVs. We showed that associated CD79B and MYD88 L265P mutations act synergistically to increase NFkB pathway activation, although the majority of ABC MYD88 L265P mutant cases harbor downstream NFkB alterations, which can potentially predict BTK inhibitor resistance. Of note, although the MYD88 L265P variant was not an independent prognostic factor in ABC DLBCL, associated CD79B mutations significantly improved the survival of MYD88 L265P mutant ABC DLBCL in our cohort both in OS (p=0.02) and PFS (p=0.01), whereas the association of CARD11 or TNFAIP3 alterations did not impact survival. Interestingly, MYD88 mutant DLBCL cases were significantly more likely to experience central nervous system (CNS) relapse than MYD88 WT cases (p=0.02), as were MYD88 L265P mutant cases specifically (p=0.03). This result still tended toward statistical significance when considering only ABC patients (7 of 11 ABC CNS-relapsing cases were MYD88 mutant, p=0.1) but would have to be confirmed in a larger cohort. Conclusions: This study highlights the relative heterogeneity of MYD88 mutant DLBCBL, adding to the field's knowledge of the distinct genetic backgrounds of these subgroups. Our data highlights the theranostic and prognostic relevance of examining MYD88 and associated genomic alterations, emphasizing the usefulness of genomic profiling to best stratify patients for targeted therapy. 1. Mareschal S, Ruminy P, Bagacean C, et al. Accurate Classification of Germinal Center B-Cell-Like/Activated B-Cell-Like Diffuse Large B-Cell Lymphoma Using a Simple and Rapid Reverse Transcriptase-Multiplex Ligation-Dependent Probe Amplification Assay: A CALYM Study. The Journal of molecular diagnostics : JMD. 2015;17(3):273-283. 2. Dubois S, Viailly P-J, Mareschal S, et al. Next Generation Sequencing in Diffuse Large B Cell Lymphoma Highlights Molecular Divergence and Therapeutic Opportunities: a LYSA Study. Clinical cancer research : an official journal of the American Association for Cancer Research. 2016;22(12):2919-2928. Disclosures Salles: Novartis: Consultancy, Honoraria; Mundipharma: Honoraria; Amgen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Gilead: Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Roche/Genentech: Consultancy, Honoraria, Research Funding.

International audience; To determine whether the mutational profile of primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL-LT) is unique by comparison with other diffuse large B-cell lymphoma subtypes, we analyzed a total cohort of 20 PCLBCL-LT patients by using next-generation sequencing with a lymphoma panel designed for diffuse large B-cell lymphoma. We also analyzed 12 pairs of tumor and control DNA samples by whole-exome sequencing, which led us to perform resequencing of three selected genes not included in the lymphoma panel: TBL1XR1, KLHL6, and IKZF3. Our study clearly identifies an original mutational landscape of PCLBCL-LT with a very restricted set of highly recurrent mutations (>40%) involving MYD88 (p.L265P variant), PIM1, and CD79B. Other genes involved in B-cell signaling, NF-κB activation, or DNA modeling were found altered, notably TBL1XR1 (33%), MYC (26%) CREBBP (26%), and IRF4 (21%) or HIST1H1E (41%). MYD88L265P variant was associated with copy number variations or copy neutral loss of heterozygosity in 60% of patients. The most frequent genetic losses involved CDKN2A/2B, TNFAIP3/A20, PRDM1, TCF3, and CIITA. Together, these results show that PCLBCL-LT exhibits a unique mutational landscape, combining highly recurrent hotspot mutations in genes involved in NF-kB and B-cell signaling pathways, which provides a rationale for using selective inhibitors of the B-cell receptor.

Diffuse large B cell lymphoma (DLBCL) is an aggressive and heterogeneous malignancy that can be divided in two major subgroups, germinal center B-cell-like (GCB) and activated B-cell-like (ABC). Activating mutations of genes involved in the BCR and NF-κB pathways (CD79A, CD79B, MYD88, and CARD11) or in epigenetic regulation (EZH2) have been recently reported, preferentially in one of the two DLBCL subtypes. We analyzed the mutational status of these five recurrently mutated genes in a cohort of 161 untreated de novo DLBCL. Overall, 93 mutations were detected, in 61 (38%) of the patients. The L265P MYD88 mutation was the most frequent MYD88 variant (n = 18), observed exclusively in the ABC subtype. CD79A/CD79B ITAM domains were targeted in ABC DLBCL (12/77; 16%), whereas CARD11 mutations were equally distributed in the two subtypes. The EZH2 Y641 substitution was found almost exclusively in the GCB subgroup (15/62; 24%). Twenty cases (12%) displayed two activating mutations, including the most frequent CD79/MYD88 variants combination (n = 8) which is observed exclusively in the ABC subtype. When considering only ABC DLBCL patients treated by rituximab plus chemotherapy, the presence of an activating NF-κB mutation was associated with an unfavorable outcome (3-years OS 26% for mutated cases versus 67% for the cases without mutations, P = 0.0337). Our study demonstrates that activating and targetable mutations are observed at a very high frequency in DLBCL at the time of diagnosis, indicating that sequencing of a limited number of genes could help tailor an optimal treatment strategy in DLBCL.

International audience; Classical Hodgkin lymphoma is one of the most common lymphomas and shares clinical and genetic features with primary mediastinal B-cell lymphoma. In this retrospective study, we analyzed the recurrent hotspot mutation of the exportin 1 (XPO1, p.E571K) gene, previously identified in primary mediastinal B-cell lymphoma, in biopsies and plasma circulating cell-free DNA from patients with classical Hodgkin lymphoma using a highly sensitive digital PCR technique. A total of 94 patients were included in the present study. This widely expressed XPO1 E571K mutation is present in one quarter of classical Hodgkin lymphoma patients (24.2%). Mutated and wild-type classical Hodgkin lymphomas were similar regarding the main clinical features. Patients with a detectable XPO1 mutation at the end of treatment displayed a tendency toward shorter progression-free survival, as compared to patients with undetectable mutation in plasma cell-free DNA (2-year progression-free survival: 57.1%, 95% confidence interval: 30.1-100% versus 2-year progression-free survival: 90.5%, 95% confidence interval: 78.8-100%, respectively, P=0.0601). To conclude, the detection of the XPO1 E571K mutation in biopsy and plasma cell-free DNA by digital PCR may be used as a novel biomarker in classical Hodgkin lymphoma for both diagnosis and minimal residual disease, and pinpoints a crucial role of XPO1 in classical Hodgkin lymphoma pathogenesis. The detection of somatic mutation in the plasma cell-free DNA of patients represents a major technological advance in the context of liquid biopsies and noninvasive management of classical Hodgkin lymphoma.

Little is known on the phylogenetic relationship between diagnostic and relapse clones of diffuse large B-cell lymphoma (DLBCL). We applied high throughput sequencing (HTS) of the VDJ locus of Immunoglobulin heavy chain (IGHV) on 14 DLBCL patients with serial samples, including tumor biopsies and/or peripheral blood mononuclear cells (PBMC). Phylogenetic data were consolidated with targeted sequencing and cytogenetics. Phylogeny clearly showed that DLBCL relapse could occur according either an early or a late divergent mode. These two modes of divergence were independent from the elapsed time between diagnosis and relapse. We found no significant features for antigen selection pressure in complementary determining region both at diagnosis and relapse for 9/12 pairs and a conserved negative selection pressure for the three remaining cases. Targeted HTS and conventional cytogenetics revealed a branched vs. linear evolution for 5/5 IGHV early divergent cases, but unexpected such "oncogenetic" branched evolution could be found in at least 2/7 IGHV late divergent cases. Thus, if BCR signaling is mandatory for DLBCL emergence, oncogenetic events under chemotherapy selection pressure may be the main driving forces at relapse. Finally, circulating subclones with divergent IGHV somatic hypermutations patterns from initial biopsy could be detected in PBMC at diagnosis for 4/6 patients and, for two of them, at least one was similar to the ones found at relapse. This study highlights that oncogenetic intraclonal diversity of DLBCL should be evaluated beyond the scope a single biopsy and represents a rationale for future investigations using peripheral blood for lymphoid malignancies genotyping. Am. J. Hematol. 92:68-76, 2017. © 2016 Wiley Periodicals, Inc.

Very few recurrent chromosomal abnormalities have been identified in T-cell non-Hodgkin lymphomas. These involve the TRA@/TRD@ gene at chromosome band 14q11 in up to 15% of cases. We recently reported a novel and recurrent translocation, t(14;19)(q11;q13), in peripheral T-cell lymphoma (PTCL). Fluorescence in situ hybridization analysis performed in three cases suggested an involvement of the TRA@/TRD@ locus at 14q11 and of a region telomeric to BCL3 on 19q13. We now report the molecular cloning of these translocations. Sequence analysis confirmed the involvement of the TRA@/TRD@ and indicated that the breakpoints were located mainly in the TRAJ region. On chromosome 19, our results revealed a new clustering of breakpoints outside the region involved in t(14;19)(q32;q13)-positive B-cell malignancies. Remarkably, all three breaks were located downstream or within the PVRL2 gene, in a small 10.3 kb interval, suggesting a nonrandom location of the breakpoints. For two patients, a high mRNA expression of both PVRL2 and BCL3 was found. In conclusion, we identified PVRL2 as a new recurrent partner gene of the TRA@ locus in PTCL. These results suggest that both BCL3 and PVRL2 may participate in the pathogenesis of these PTCLs, but further studies should be undertaken to investigate the precise role of these genes.

Diffuse large B-cell lymphoma (DLBCL) is an aggressive and heterogeneous malignancy harboring frequent targetable activating somatic mutations. Emerging evidence suggests that circulating cell-free DNA (cfDNA) can be used to detect somatic variants in DLBCL using Next-Generation Sequencing (NGS) experiments. In this proof-of-concept study, we chose to develop simple and valuable digital PCR (dPCR) assays for the detection of recurrent exportin-1 (XPO1) E571K, EZH2 Y641N, and MYD88 L265P mutations in DLBCL patients, thereby identifying patients most likely to potentially benefit from targeted therapies. We demonstrated that our dPCR assays were sufficiently sensitive to detect rare XPO1, EZH2, and MYD88 mutations in plasma cfDNA, with a sensitivity of 0.05%. cfDNA somatic mutation detection by dPCR seems to be a promising technique in the management of DLBCL, in addition to NGS experiments.

Background and aim of the study Primary mediastinal B-cell lymphoma (PMBL) is an entity of aggressive B-cell lymphoma that is clinically and biologically distinct from the other molecular subtypes of diffuse large B-cell lymphoma (DLBCL). We recently detected by Whole exome sequencing a recurrent point mutation in the XPO1 (exportin 1) gene (also referred to as chromosome region maintenance 1; CRM1), which resulted in the Glu571Lys (p.E571K) missense substitution in 2 refractory/relapsed PMBL (Dubois et al., ICML 2015; Mareschal et al. AACR 2015). XPO1 is a member of the Karyopherin-b superfamily of nuclear transport proteins. XPO1 mediates the nuclear export of numerous RNAs and cellular regulatory proteins, including tumor suppressor proteins. This mutation is in the hydrophobic groove of XPO1 that binds to the leucine-rich nuclear export signal (NES) of cargo proteins. In this study, we investigated the prevalence, specificity, and biological / clinical relevance of XPO1 mutations in PMBL. Patients and methods High-throughput targeted or Sanger sequencing of 117 PMBL patients and 3 PMBL cell lines were performed. PMBL cases were defined either molecularly by gene expression profile (mPMBL cohort) or by standard histological method (hPMBL cohort) and enrolled in various LYSA (LYmphoma Study Association) clinical trials. To assess the frequency and specificity of XPO1 mutations, cases of classical Hodgkin lymphoma (cHL) and primary mediastinal grey zone lymphoma (MGZL) were analysed. Cell experiments were performed to assess the impact of the E571 mutation on the activity of selective inhibitor of nuclear export (SINE) molecules. Results XPO1 mutations were present in 28/117 (24%) PMBL cases but were rare in cHL cases (1/19, 5%) and absent from MGZL cases (0/20). A higher prevalence (50%) of the recurrent codon 571 variant (p.E571K) was observed in PMBL cases defined by gene expression profiling (n = 32), as compared to hPMBL cases (n = 85, 13%). No difference in age, International Prognostic Index (IPI) or bulky mass was observed between the PMBL patients harboring mutant and wild-type XPO1 in the overall cohort whereas a female predominance was noticed in the mPMBL cohort. Based on a median follow-up duration of 42 months, XPO1 mutant patients exhibited significantly decreased PFS (3y PFS = 74% [CI95% 55-100]) compared to wild-type patients (3y PFS = 94% [CI95% 83-100], p=0.049) in the mPMBL cohort. In 4/4 tested cases, the E571K variant was also detected in cell-free circulating plasmatic DNA, suggesting that the mutation can be used as a biomarker at the time of diagnosis and during follow-up. Importantly, the E571K variant was detected as a heterozygous mutation in MedB-1, a PMBL-derived cell line, whereas the two other PMBL cell lines tested, Karpas1106 and U-2940, did not display any variants in XPO1 exon 15. KPT-185, the SINE compound that blocks XPO1-dependent nuclear export, induced a dose-dependent decrease in cell proliferation and increased cell death in the PMBL cell lines harbouring wild type or mutated alleles. To test directly if XPO1 mutation from E571 to E571K alters XPO1 inhibition by SINE compounds, the mutated protein was tested in vitro. The E571XPO1 mutated allele was transiently transfected into osteosarcoma U2OS cells which stably express the fluorescently labelled XPO1 cargo REV. Cells were treated with the clinical SINE compound selinexor, which is currently in phase I/II clinical trials and nuclear localization of REV-GFP was analysed in red transfected cells. The results showed that the nuclear export of the mutated XPO1 protein was inhibited by selinexor similarly to the wild-type XPO1 protein (Figure 1). Conclusion Although the oncogenic properties of XPO1 mutations remain to be determined, their recurrent selection in PMBL strongly supports their involvement in the pathogenesis of this curable aggressive B-cell lymphoma. XPO1 mutations were primarily observed in young female patients who displayed a typical PMBL molecular signature. The E571K XPO1 mutation represents a novel hallmark of PMBL but does not seem to interfere with SINE activity. Rev-GFP (green fluorescent) expressing U2OS cells were transfected with wild type XPO1-RFP (red fluorescent protein), XPO1-C528S-RFP, XPO1-E571K-mCherry, and XPO1-E571G-mCherry. The cells were then treated with 1µM KPT-330 for 8 hours. Figure 1. Rev-GFP expressing U2OS cells transfected with XPO1 variants. Figure 1. Rev-GFP expressing U2OS cells transfected with XPO1 variants. Disclosures Landesman: Karyopharm Therapeutics: Employment. Senapedis:Karyopharm Therapeutics, Inc.: Employment, Patents & Royalties. Argueta:Karyopharm Therapeutics: Employment. Milpied:Celgene: Honoraria, Research Funding.

// Sydney Dubois 1 , Sylvain Mareschal 1 , Jean-Michel Picquenot 1, 2 , Pierre-Julien Viailly 1 , Elodie Bohers 1 , Marie Cornic 2 , Philippe Bertrand 1 , Elena Liana Veresezan 1, 2 , Philippe Ruminy 1 , Catherine Maingonnat 1 , Vinciane Marchand 1 , Helene Lanic 1, 3 , Dominique Penther 1 , Christian Bastard 1 , Herve Tilly 1, 3 , Fabrice Jardin 1, 3 1 INSERM U918, Centre Henri Becquerel, Universite de Rouen, IRIB, Rouen, France 2 Department of Pathology, Centre Henri Becquerel, Rouen, France 3 Department of Clinical Hematology, Centre Henri Becquerel, Rouen, France Correspondence to: Fabrice Jardin, e-mail: fabrice.jardin@chb.unicancer.fr Keywords: DLBCL, EZH2, Methylation, Immunohistochemistry, NGS Received: October 20, 2014 Accepted: January 15, 2015 Published: February 05, 2015 ABSTRACT Enhancer of Zeste Homolog 2 (EZH2) plays an essential epigenetic role in Diffuse Large B Cell Lymphoma (DLBCL) development. Recurrent somatic heterozygous gain-of-function mutations of EZH2 have been identified in DLBCL, most notably affecting tyrosine 641 (Y641), inducing hyper-trimethylation of H3K27 (H3K27me3). Novel EZH2 inhibitors are being tested in phase 1 and 2 clinical trials but no study has examined which patients would most benefit from this treatment. We evaluated the immunohistochemical (IHC) methylation profiles of 82 patients with DLBCL, as well as the mutational profiles of 32 patients with DLBCL using NGS analysis of a panel of 34 genes involved in lymphomagenesis. A novel IHC score based on H3K27me2 and H3K27me3 expression was developed, capable of distinguishing patients with wild-type (WT) EZH2 and patients with EZH2 Y641 mutations ( p = 10 −5 ). NGS analysis revealed a subclonal EZH2 mutation pattern in EZH2 mutant patients with WT-like IHC methylation profiles, while associated mutations capable of upregulating EZH2 were detected in WT EZH2 patients with mutant-like IHC methylation profiles. IHC and mutational profiles highlight in vivo hyper-H3K27me3 and hypo-H3K27me2 status, pinpoint associated activating mutations and determine EZH2 mutation clonality, maximizing EZH2 inhibitor potential by identifying patients most likely to benefit from treatment.

Diffuse large B-cell lymphoma (DLBCL) is the most common form of lymphoma, accounting for 30–40% of newly diagnosed cases of non-Hodgkin lymphomas. The molecular heterogeneity of DLBCL has been deciphered by gene expression profiling, and DLBCL have been divided into three main molecular subtypes: the germinal center B-cell-like (GCB) subtype, the activated B-cell-like (ABC) subtype, and the primary mediastinal B-cell lymphoma subtype with distinct clinical outcomes and responses to immunochemotherapy. Next-generation sequencing (NGS) technologies, which allow for massive, parallel, high-throughput DNA sequencing, have emerged over the past decade and have provided new insights into the genomic characterization of DLBCL. Recurrent single nucleotide variants (SNV) are now well defined and provide new therapeutic opportunities for the three molecular subtypes. The SNV target genes play a crucial role in several pathways, including B-cell receptor signaling (CD79A/CD79B), NFκ-B (CARD11), Toll-like receptor signaling (MYD88), immunity (CD58, TNFSRF14, B2M), cell cycle/apoptosis (TP53, BCL2) and epigenetic regulation (EZH2,CREBBP, MLL2).1,2

The involvement of hyaluronic acid (HA) oligosaccharides and blood-derived mononuclear cells in inflammatory processes prompted us to determine whether peripheral blood mononuclear cells (PBMC) possess hyaluronidase activity. PBMC were incubated with macromolecular-tritiated HA at pH 3.8 and supernatants were analysed by size exclusion chromatography to reveal digestion of HA. This digestion was due to the CD14-positive (CD14+), adherent, non-specific esterase-positive, subpopulation of PBMC. Hyaluronidase activity (72 kDa) was found in aqueous and non-ionic detergent PBMC extracts but not in the medium in which the cells had been cultured. These results indicate that hyaluronidase is, at least in part, linked to the membrane rather than excreted. Hence, monocytes have one or more hyaluronidases that can generate a pool of active HA fragments within tissues. Hyaluronidase activity was also found in 3/3 myelomonocytic lineage leukaemias but not in 3/3 lymphoblastic leukaemias.

Diff use large B-cell lymphoma (DLBCL) is the most common form of lymphoma, accounting for 30 - 40% of newly diagnosed non-Hodgkin lymphomas. Historically, DLBCL has been thought to involve recurrent translocations of the immunoglobulin heavy (IGH) locus and the deregulation of rearranged oncogenes. Whole exome sequencing (WES) of more than 200 DLBCLs has completely redefi ned the genetic landscape of the disease by identifying recurrent single nucleotide variants and providing new therapeutic opportunities in DLBCL molecular subtypes. Some of these somatic mutations target genes that play a crucial role in B-cell function (B cell receptor (BCR) signaling, nuclear factor κ B (NF- κ B) pathway, Toll-like receptor (TLR) signaling and phosphatidylinositol 3-kinase (PI3K) pathway), immunity, cell cycle/apoptosis or chromatin modifi cation. In this review, following an overview of the somatic mutations reported in DLBCL, we focus on activating and clustered mutations targeting genes including MYD88 , CD79A/B , EZH2 and CARD11 and discuss their clinical and therapeutic relevance in the precision medicine era.

CD70 is a co-stimulatory molecule involved in the immune response and also in cancer development and progression. Recent studies show that high CD70 expression in cancer cells may inhibit the anti-tumor response. Furthermore, CD70 expression has been reported as a predictive marker of resistance to chemotherapy in ovarian cancers. Some in vitro studies have shown that CD70 expression is epigenetically down-regulated through hypermethylation of its promoter during tumoral progression. This study evaluated the level of CD70 expression in surgical samples of breast invasive tumors and determined its correlation with CD70 promoter methylation. Twenty "luminal A" and 20 "basal-like" frozen samples from early breast tumors were retrospectively selected. CD70 expression was evaluated by quantitative real-time PCR. Total DNA was bisulfite-treated, and methylation levels of 5 consecutive CG sites present in the proximal region (-464, -421) of the promoter were assessed by pyrosequencing analysis. Statistical analyses were performed using the Mann-Whitney test. The median relative CD70 expression level was 0.37 and was significantly higher in the basal-like group (0.78 [0.24-31.7]) compared to the luminal A group (0.25 [0.03-1.83], p=0.0001). The median methylation level was 61%, with no significant difference between the basal-like (63%) and luminal A (58%) groups. No correlation was found between CD70 expression and CD70 methylation level. In this study, higher CD70 expression was observed in the basal-like group, but this expression was not related to promoter methylation. The higher expression in the poor-prognosis subgroup of patients makes CD70 a potential target for emerging anti-CD70 therapies.

To approach the question of hyaluronan catabolism in tumours, we have selected the cancer cell line H460M, a highly metastatic cell line in the nude mouse. H460M cells release hyaluronidase in culture media at a high rate of 57 pU/cell/h, without producing hyaluronan. Hyaluronidase was measured in the H460M cell culture medium at the optimum pH 3.8, and was not found above pH 4.5, with the enzyme-linked sorbent assay technique and zymography. Tritiated hyaluronan was digested at pH 3.8 by cells or cell membranes as shown by gel permeation chromatography, but no activity was recorded at pH 7 with this technique. Hyaluronan was digested in culture medium by tumour slices, prepared from tumours developed in nude mice grafted with H460M cells, showing that hyaluronan could be digested in complex tissue at physiological pH. Culture of tumour slices with tritiated acetate resulted in the accumulation within 2 days of radioactive macromolecules in the culture medium. The radioactive macromolecular material was mostly digested by Streptomyces hyaluronidase, showing that hyaluronan was its main component and that hyaluronan synthesis occurred together with its digestion. These results demonstrate that the membrane-associated hyaluronidase of H460M cells can act in vivo, and that hyaluronan, which is synthesised by the tumour stroma, can be made soluble and reduced to a smaller size by tumour cells before being internalised and further digested.

Resume L'activite hyaluronidasique de cellules cancereuses humaines a ete recherchee dans les milieux de culture de huit lignees etablies a partir de tumeurs primaires et de quatre lignees etablies a partir de metastases. Elle a ete retrouvee dans huit milieux de culture. Dans trois lignees cellulaires issues de tumeurs primaires l'activite etait inferieure a 0,035 pU/cellule/heure. Elle etait 5 a 100 fois superieure dans les milieux de culture de trois lignees derivees de metastases et 1 000 fois plus elevee dans le cas d'une lignee d'hepatome. L'activite optimale de l'enzyme se situait entre pH 3,6 et 4. L'hyaluronidase de ces lignees ne degradait pas exclusivement l'hyaluronane mais aussi les chondroitines sulfates. La proteine PH20, une proteine de spermatozoide possedant des homologies avec l'hyaluronidase de venin d'abeille, n'est pas exprimee dans ces cultures.

Diffuse large B cell lymphoma (DLBCL) is an aggressive and heterogeneous malignancy that can be divided in two major subgroups, germinal center B-cell-like (GCB) and activated B-cell-like (ABC). Activating mutations of genes involved in the BCR and NF-κB pathways (CD79A, CD79B, MYD88, and CARD11) or in epigenetic regulation (EZH2) have been recently reported, preferentially in one of the two DLBCL subtypes. We analyzed the mutational status of these five recurrently mutated genes in a cohort of 161 untreated de novo DLBCL. Overall, 93 mutations were detected, in 61 (38%) of the patients. The L265P MYD88 mutation was the most frequent MYD88 variant (n = 18), observed exclusively in the ABC subtype. CD79A/CD79B ITAM domains were targeted in ABC DLBCL (12/77; 16%), whereas CARD11 mutations were equally distributed in the two subtypes. The EZH2 Y641 substitution was found almost exclusively in the GCB subgroup (15/62; 24%). Twenty cases (12%) displayed two activating mutations, including the most frequent CD79/MYD88 variants combination (n = 8) which is observed exclusively in the ABC subtype. When considering only ABC DLBCL patients treated by rituximab plus chemotherapy, the presence of an activating NF-κB mutation was associated with an unfavorable outcome (3-years OS 26% for mutated cases versus 67% for the cases without mutations, P = 0.0337). Our study demonstrates that activating and targetable mutations are observed at a very high frequency in DLBCL at the time of diagnosis, indicating that sequencing of a limited number of genes could help tailor an optimal treatment strategy in DLBCL.

The molecular heterogeneity of diffuse large B-cell lymphoma (DLBCL) has been highlighted by gene expression profiling (GEP), dividing DLBCL into the following three main molecular subtypes with different clinical outcomes and responses to immunochemotherapy: the germinal center B-cell-like (GCB) subtype, the activated B-cell-like (ABC) subtype and the primary mediastinal B-cell lymphoma (PMBL) subtype. Despite frequent translocations involving the IGH (heavy chain) locus, B-cell receptor (BCR) expression is retained in almost all DLBCL, indicating that BCR signaling is crucial for the survival of malignant cells. Furthermore, DLBCL are characterized by recurrent somatic mutations that are supposed to be oncogenic drivers. Here, with the aim to more accurately define the DLBCL pathogenic subgroups, we report a detailed immunogenetic analysis of IGH rearrangements in a well-defined GEP DLBCL cohort and correlate these features with the somatic mutation status of recurrently mutated genes involved in lymphomagenesis. Methods: 204 DLBCL enrolled in the prospective LYSA LNH03 trial program were classified into molecular subtypes by GEP using Affymetrix arrays [82 ABC (40.2%), 77 GCB (37.7%), 29 (14.2%) unclassified and 16 PMBL (7.8%)]. The amplification of complete VDJ rearrangements was realized using BIOMED-2 protocols. Somatic hypermutation (SHM) characteristics were studied (mutation rate, glycosylation N-X-S/T sites, RGYW hotspots, composition of CDR3) and correlated with the molecular subtypes. To obtain a more comprehensive molecular portrait of the DLBCL cases, GEP and IGH VDJ analyses were correlated with the mutational status of a panel of 34 recurrently mutated genes in DLBCL such as MYD88, EZH2, CD79B, TNFAIP3, CARD11 and GNA13 (Dubois et al. Clinical Cancer Research 2016). Results: A total of 153/204 (75%) clonal VDJ rearrangements were successfully determined. Failures to detect clonotypic sequences were predominantly seen in PMBL (56%) and unclassified (31%) cases. The ABC subtype display a significantly lower SHM rate than the 3 other subtypes, especially in contrast to the PMBL subgroup that was characterized by a higher SHM rate (p Disclosures Haioun: Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sandoz: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees. Salles:Mundipharma: Honoraria; Janssen: Consultancy, Honoraria; Gilead: Honoraria, Research Funding; Novartis: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Roche/Genentech: Consultancy, Honoraria, Research Funding.

Several techniques for assaying and localizing hyaluronan (HA), all based on the affinity to hyaluronan of proteins isolated from cartilage, chondrosarcoma, or brain, have been proposed. We show here that a unique reagent, alkaline phosphatase-linked hyaluronectin, can be used to assay hyaluronan in biological fluids or tissue extracts (enzyme-linked sorbent assay method) and to characterize it in cells or tissue sections in two steps: reagent incubation and staining. Results of assays in biological fluids or tissue extracts showed a good correlation with results of the previously described technique using antibodies to detect hyaluronectin bound to a plastic microtest plate (B. Delpech et al., 1985, Anal. Biochem. 149, 555-565) for both low concentrations (1 mg/liter, r = 0.973, P0.001) and high concentrations (1 mg/liter, r = 0.953, P0.001). The interassay variations were 8.5% when the assay was performed at 4 degrees C and 18.5% at 37 degrees C. The intraassay variations under those conditions were, respectively, 14.4 and 6.5%. Tissue HA could be detected easily with the reagent, as shown in fetal tissues and in tumors. Specificity of the reaction was controlled either by blocking the reagent with an excess of hyaluronan (which was not possible with other glycosaminoglycans) or by destroying tissue hyaluronan with streptomyces hyaluronidase. Alkaline phosphatase-linked hyaluronectin was also used to assay hyaluronidase activity in several biological fluids. One-hour incubation of hyaluronidase preparations on HA-coated plates made it possible to detect as low as 1 mU bovine testis hyaluronidase and 0.1 mTRU streptomyces hyaluronidase. Four-hour incubation made it possible to detect activity in a 1/12,500 dilution of human serum.

[(18)F]-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging is essential to optimize the initial staging and to predict the prognosis of diffuse large B-cell lymphoma (DLBCL). To assess the relationship between the germinal center B cell-like/activated B cell-like (GCB/ABC) classification and PET scan features in DLBCL, 57 cases treated with rituximab and a cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP)/CHOP-like regimen were analyzed. The expression profile of 18 GCB/ABC related genes and five genes coding for glucose transporters (GLUTs) was determined from frozen tissues using DASL (cDNA-mediated Annealing, Selection, Ligation and extension) technology. According to the gene expression profile (GEP), 30 cases of DLBCL were classified as GCB subtype (2-year progression-free survival [PFS] 76%) and 27 cases as ABC subtype (2-year PFS 51%, p = 0.03). Using a semiquantitative assessment of the decrease in standard uptake value (SUV) at interim PET performed after 3-4 cycles of chemotherapy, we defined fast (n = 36) and slow (n = 9) metabolic responders. In multivariate analysis, GCB/ABC subtype, age-adjusted international prognostic index (aaIPI) and slow/fast metabolic response were independent variables that predicted outcome. A score incorporating aaIPI, fast/slow metabolic response and GCB/ABC classification was used to define two groups with highly significantly distinct outcomes. Our study suggests that the combination of GEP, aaIPI and interim PET more accurately predicts DLBCL prognosis and is therefore suitable for tailoring therapeutic strategies.

A new cell line, CB109, has been established from a human glioblastoma multiforme. The cytoskeleton was positive for glial fibrillary acidic protein, vimentin and fibronectin. Hyaluronan (HA) and the HA-binding protein hyaluronectin (HN) were expressed in the cell cytoplasm and in the extracellular matrix of spheroids and plated cells. Hyaluronidase did not prevent spheroid formation suggesting that HA was not involved in the cell-cell adhesion. HA precoating prevented cell adherence to the plates and favoured spheroid formation. HA was secreted in relatively large amounts into the culture medium. High performance liquid chromatography demonstrated that HA was in the high molecular weight form. The rate of HN secretion by cells was very low. Basic fibroblast growth factor significantly increased the proliferation in vitro and tumour growth after grafting into nude mice. The epidermal growth factor receptor was not expressed on cultivated CB109 cells. Cytogenetic analysis showed polysomy 7, structural rearrangement of chromosome 10 short arm and a translocation 13q13-q14 without detectable alteration of the RB gene.

1. A hyaluronic acid (HA)-binding glycoprotein from sheep brain was characterized. 2. The specific affinity for HA was shown in vitro by high performance liquid chromatography, polyacrylamide gel electrophoresis and ELISA methods. 3. The KD for high molecular weight HA was 5.4 10(-9) M at 37 degrees C and lower than 10(-10) M at 4 degrees C. 4. No link protein was found and HA molecules could bind up to 10 times their weight of the glycoprotein. 5. The specific site for interaction was the HA-derived decasaccharide HA10. 6. The protein is composed of one polypeptidic chain. Tryptophan and lysine play a prominent role in the conformation of the binding site to HA. 7. Enzyme analysis indicated that the protein different forms are due to differences in glycosylation and that N- and O-linkages coexist in the molecules. 8. Immunohistochemistry localized the glycoprotein at the nodes of Ranvier and at the periphery of neurons. The perineuronal labeling was seen around all neurons studied in the cerebellum whereas it was almost undetectable in the cerebral hemispheres. 9. HA is not saturated by hyaluronectin (HN) in the sheep nervous system. 10. The glycoprotein is largely similar to human brain HN, and different from the hyaluronate-binding protein characterized in the cartilage.

Characterization of three t(3;8)(q27;q24) translocations from diffuse large B-cell lymphomas

Hyaluronan was studied in extracts of the nervous system and in situ. Extraction yielded larger amounts at neutral or alkaline pH. Protease digestion enhanced the quantitative results obtained with an indirect enzyme immunological assay. It was shown that HA extracted from brain at neutral pH was bound to a glycoprotein component (hyaluronectin, HN) which is in part free at acid pH. Although HN is not restricted to nervous tissue it is mainly expressed in the central nervous system of adult mammals. Its main form has a molecular mass of 68 kDa and binds in vitro to HA and to HA-derived oligosaccharides down to HA10 with a Kd in the 10(-8) M range. HA-HN complexes were found in human cerebrospinal fluids. The HA concentration in cerebral tissue decreases from the fetus to the adult, whereas the HN concentration increases. HA is not however saturated by HN and still binds HN in vitro. In the rat HA decreases sharply at Days 10-11 after birth. In the rat embryo HA forms an extracellular component of the migration and proliferation areas of the cerebral cortex. In the adult typical locations were at the nodes of Ranvier and in perineuronal structures. HN was found in the same locations but seemed to be associated with a restricted category of neurons. In the cerebellum HA-HN was found mainly in the grey nuclei, the granular layer and around Purkinje cells. Cell bodies were not stained but in the electron microscope HN was seen in the cytoplasm and plasma membrane of the perisynaptic glial cell processes. A hypothesis has been proposed that HA-HN is involved in neural GABAergic transmission.

Introduction Diffuse Large B Cell Lymphoma (DLBCL) is the most common lymphoid malignancy, accounting for 30-40% of all Non Hodgkin Lymphomas. Gene expression profiling (GEP) has identified three main subtypes of DLBCL: Germinal Center B-cell like (GCB), Activated B-Cell like (ABC) and Primary Mediastinal B-cell Lymphoma (PMBL). Recently, Next Generation Sequencing (NGS) has enabled a more detailed characterization of DLBCL mutational profiles. Conventional techniques such as immunohistochemistry (IHC) and FISH are also widely used to describe DLBCL. However, no study has yet performed an integrative analysis of the mutational, gene expression, IHC and FISH profiles of DLBCL, in order to provide a comprehensive view of this disease. Methods 215 patients with de novo DLBCL in the prospective, multicenter and randomized LNH-03B clinical trials led by the LYmphoma Study Association (LYSA) were included in this study. Microarray-based GEP identified 81 ABC, 83 GCB, 18 PMBL and 33 other. Mutational profiles of patients' tumor DNA were established using Lymphopanel NGS, designed to identify mutations in 34 genes important for lymphomagenesis. For each recurrently mutated gene, we applied ROMER (Ritchie, Nucleic Acids Res, 2015) to perform gene set enrichment analysis on differential expression profiles of mutant and wild-type patients, using a multifactorial model accounting for subtype. The gene sets were obtained from the MSIGDB Hallmarks (Subramanian A, PNAS, 2005) and Signaturedb (Schaffer, Immunol Rev, 2006) collections. When possible, IHC was performed for IgM (n=150), MYC (n=140), BCL2 (n=148), BCL6 (n=146), CD10 (n=152), FOXP1 (n=147) and MUM1 (n=152); FISH was performed for MYC (n=131), BCL2 (n=133) and BCL6 (n=131). Results As expected, EZH2 mutations were significantly associated with upregulation of GCB gene expression (p An association between BCL6 translocations and ABC subtype was confirmed, via a correlation with ABC-enriched CD79B mutations (p=0.02), although interestingly not with MYD88 mutations. MYD88 mutations were correlated with an upregulation of genes involved in proliferation or repressed by PRDM1 (FDR=0.04 each), as well as with an upregulation of genes involved in checkpoint controls, such as E2F targets and genes involved in DNA repair (FDR=0.03 each). All MYD88 mutants expressed FOXP1 in IHC (p PMBL-enriched mutations in our cohort were frequently associated with IgM and FoxP1 negative IHC, as expected (WHO 2008 and Roschewski, Nat Rev Clin Onc). XPO1 and ITPKB mutations were correlated with JAK-STAT pathway activation in the total cohort, including upregulation of interferon-inducible genes for both gene mutations (FDR=0.02 and FDR=0.08 respectively) and upregulation of BCL6-repressed genes for XPO1 mutations only (FDR=0.02). Interestingly, CD58 mutations were significantly correlated with upregulation of Nfkb pathway target genes (FDR=0.06), perhaps due to their negative impact on CD2 activation and ROS production inhibition. Conclusion The results herein provide steps toward a comprehensive, multi-level overview of DLBCL. We highlight differential gene set expression linked to gene mutation status, as well as driver translocation-associated mutational profiles. By using an integrative analysis approach, this study broadens our understanding of DLBCL subtypes' diverse genetic backgrounds. Disclosures Briere: St. Louis Hospital, Paris, France: Employment. Salles:Celgene Corporation; Roche: Speakers Bureau; Calistoga Pharmaceuticals, Inc.; Celgene Corporation; Genentech, Inc.; Janssen Pharmaceutica Products, L.P.; Roche: Consultancy; Celgene Corporation; Roche and Gilead Sciences: Research Funding.

HACE1, located on chromosome 6q, encodes an E3 ubiquitin ligase and is downregulated in human tumors such as neuroblastomas and natural killer (NK) lymphomas. HACE1 has been shown to ubiquitylate Rac1, a protein involved in cell proliferation and G2/M cell cycle progression. The function of HACE1 and the factors involved in its transcriptional regulation are largely unknown in the context of B-cell lymphomas. We show here, by RT-qPCR, that HACE1 gene is constitutively expressed in Normal lymph nodes and in normal B-cells isolated from peripheral blood, contrasting with a strong downregulation of its expression in more than 70% (77/111) of diffuse large B-cell lymphoma (DLBCL) cases and in four tested B-Lymphoma cell lines. HACE1 gene copy number was assessed by quantitative multiplex PCR of short fluorescent fragments (QMPSF) and array for comparative genomic hybridization (aCGH) in 91 DLBCL cases. A HACE1 heterozygous deletion was observed in 38.1% and an homozygous deletion in 2.4% of cases. These deletions were associated with a significant gene expression decrease. The molecular epigenetic mechanisms underlying HACE1 downregulation were also investigated. Using pyrosequencing assays, as compared to normal B-cells, we observed an hypermethylation of HACE1 promoter CpG177 island in 60% (68/111) of DLBCL cases and in all tested B-Lymphoma cell lines. However, no significant correlation between promoter methylation status and gene expression level was demonstrated. Furthermore, RT-qPCR assays revealed that the demethylating agent 5′azacytidine (5′AZA) did not induce a HACE1 gene expression increase in the different cell lines. By contrast, the histone deacetylase inhibitors (HDACi) trichostatin A (TSA) and LBH589 strongly reactivated the expression of HACE1 in Ramos, Raji and RL cells in which the CpG 177 island was fully methylated. We next performed ChIP experiments to determine whether HACE1 locus chromatin was in an active or inactive conformation in Ramos cell line, the most sensitive cell line to TSA effect. We found that the chromatin of HACE1 gene promoter region was predominantly in the inactive conformation (methylated H3 histones). TSA treatment was able to reverse this pattern, switching the conformation of HACE1 promoter chromatin to an active one predominantly associated with acetylated H3 histones. The putative role of HACE1 in B-cell lymphomagenesis was further investigated using lentiviral transduction (shHACE1). We demonstrated in Ramos and Raji cells that a down-regulation of HACE1 expression was associated with a significant decrease of apoptosis level and cell cycle arrest in G2/M phase. To conclude, our experiments indicate that HACE1 can act as a haploinsufficient tumor suppressor gene in most B-cell lymphomas and be downregulated by deacetylation and methylation of its promoter region chromatin constituting a potential target for HDAC inhibitors. Citation Format: Abdelilah Bouzelfen, Marion Alcantara, Hafid Kora, Philippe Bertrand, Sylvain Mareschal, Elodie Bohers, Catherine Maingonnat, Philippe Ruminy, Sahil Adriouch, Gaetan Riou, Martin Figeac, Thierry Fest, Christian Bastard, Hervé Tilly, Jean-Baptiste Latouche, Fabrice Jardin. HACE1 is a putative tumor suppressor gene in B-cell lymphomagenesis down-regulated by both deletion and epigenetic mechanisms. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4947. doi:10.1158/1538-7445.AM2015-4947

S220 510 EZH2-Activating Mutations in DLBCL Are Easily Predictable by Routine Immunohistochemistry Analysis: a Tool to More Efficiently Define EZH2 Inhibitor-Sensitive Patients? Sydney Dubois, Sylvain Mareschal, Marie Cornic, Jean-Michel Picquenot, Elodie Bohers, Marion Alcantara, Catherine Maingonnat, Philippe Bertrand, Philippe Ruminy, Christian Bastard, Herve Tilly, Fabrice Jardin INSERM U918, Centre Henri Becquerel

Hyaluronectin (HN) is a glycoprotein with a high affinity to hyaluronic acid (HA) and known to be a component of the extracellular matrix of tumours. Clinical studies have shown that a low level of HN correlates to tumours with poor prognosis, whereas a high level of HN correlates to tumours with good prognosis. We previously demonstrated in vitro that hyaluronidase activity, which promotes tumour progression and metastatic spread by degradation of HA into angiogenic oligosaccharides, was inhibited or promoted by HN, according to the level of HN-expression. This raises the question of the role played by HN in cancer, and particularly if high and low levels of HN-expression could trigger opposite effects on tumour growth and/or metastatic spread. To address this issue, we used a model of spontaneous lung fluorescent metastases that we characterised previously. We stably transfected the human HN cDNA into fluorescent H460MGFP cells and selected two clones characterised by different levels of HN-expression: HN110 and HN704, with a high and a low level of HN-expression, respectively. In vitro, we demonstrated that HN704 cell migration was significantly increased. Inoculation of clones to nude mice had no significant effect on tumour growth, but clearly revealed opposite effects on metastatic spread: HN110 significantly decreased the number of fluorescent metastases whereas HN704 significantly increased it. We also analysed HN, HA and hyaluronidase contents in sera and tumours. These results demonstrate that HN can play a role as either a suppressor or promoter of metastatic spread.

Hyaluronidases and their substrate, hyaluronan (HA), were mainly explored in solid tumors but rarely in hematologic malignancies. While HA involvement was demonstrated in invasion and metastasis in most cases of solid tumors, the role of hyaluronidases in cancer progression remains controversial. One of the hyaluronidases, HYAL2, is suspected to be involved in the first step of HA degradation. In this work, HYAL2 mRNA, HA and total hyaluronidases expression were examined in lymphoma tissue extracts and correlated to the lymphoma subtype. Real-time RT-PCR was performed to evaluate HYAL2 mRNA. HA and hyaluronidase were assayed by enzyme-linked sorbent assay. Our results showed that HYAL2 mRNA expression was correlated to lymphoma diagnosis (p = 6 x 10(-3)) and was significantly lower in high-grade lymphoma, i.e., diffuse large B-cell diffuse lymphomas (DLBCLs). Several forms of hyaluronidase were detected by zymography and total hyaluronidase activity detected in tissue extracts was not significantly different according to tumor grade. HA levels also correlated to lymphoma subtype (p = 1 x 10(-5)) and were higher in DLBCLs. Moreover, HYAL2 mRNA and HA expressions were inversely correlated (p = 0.035). HYAL2 gene is localized on chromosome 3p21, which contains candidates tumor suppressor genes. Our results suggest that HYAL2 may have a prognostic significance in lymphomas and an antioncogenic activity. Conversely, HA overexpression in high-grade lymphomas is in favor of its involvement in tumor development and could provide a useful target for lymphoma therapy using HA-binding peptides.