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Few data exist regarding the tumor B-cell receptor (BCR) repertoire and lymphoid microenvironment in primary mediastinal B-cell lymphoma (PMBL). We applied 5' rapid amplification of cDNA ends (5'RACE) to tumor RNA samples from 137 PMBL patients with available gene expression profiling and next-generation sequencing data. We obtained 5'RACE results for 75/137 (54.7%) patients, with clinical characteristics as follows: median [min-max] age, 33 [18-64] years; female, 53.3%; ECOG score 0-1, 86.7%; stage I-II, 57.3%; 1st-line treatment with anti-CD20 plus ACVBP, 72%; CHOP14, 14.7%; CHOP21, 13.3%. Among the 60 biopsies that expressed a productive BCR, we highlighted a strong somatic hypermutation profile with 58 (96.7%) patients carrying mutated IgVH, defined as <98% identity to the germline sequence. We then identified a subgroup of 12/75 patients (16%) with a worse prognosis (progression-free survival (PFS): HR [95% CI]=17 [3.2-88]; overall survival (OS): HR=21 [2.1-210]) associated with the highest clonal dominance status (HCD), defined by the dominant clonotype representing >81.1% and >78.6% of all CDR3 sequences for IgVH and IgVL, respectively. Compared to other patients, this subgroup had similar clinical characteristics but a greater median allele frequency for all somatic variants, decreased BCR diversity, and greater expression of PDL1/PDL2 and MS4A1 genes, suggesting a greater tumoral infiltration. According to a multivariate model integrating AID expression and BCR diversity, only HCD status was associated with outcome (PFS: HR=14.6 [2.46-86.8]; OS: HR=11.4 [1-128.8]). We confirmed this poorer prognosis in an independent cohort, in which 6/37 (16%) patients exhibited HCD (PFS: HR=12 [3-46]; OS: HR=17 [1.8-170])., (Copyright © 2024 American Society of Hematology.)

Follicular lymphoma (FL) course is highly variable, making its clinical management challenging. In this incurable and recurring pathology, the interval between relapses tends to decrease while aggressiveness increases, sometimes resulting in the transformation to higher-grade lymphoma. These evolutions are particularly difficult to anticipate, resulting from complex clonal evolutions where multiple subclones compete and thrive due to their capacity to proliferate and resist therapies. Here, to apprehend further these processes, we used a high-throughput RNA sequencing approach to address simultaneously the B-cell immunoglobulin repertoires and T-cell immunoglobulin repertoires repertoires of lymphoma cells and their lymphoid microenvironment in a large cohort of 131 FL1/2-3A patients. Our data confirm the existence of a high degree of intra-clonal heterogeneity in this pathology, resulting from ongoing somatic hyper-mutation and class switch recombination. Through the evaluation of the Simpson ecological-diversity index, we show that the contribution of the cancerous cells increases during the course of the disease to the detriment of the reactive compartment, a phenomenon accompanied by a concomitant decrease in the diversity of the tumoral population. Clonal evolution in FL thus contrasts with many tumors, where clonal heterogeneity steadily increases over time and participates in treatment evasion. In this pathology, the selection of lymphoma subclones with proliferative advantages progressively outweighs clonal diversification, ultimately leading in extreme cases to transformation to high-grade lymphoma resulting from the rapid emergence of homogeneous subpopulations., Competing Interests: The authors declare no conflict of interest., (© 2024 The Authors. HemaSphere published by John Wiley & Sons Ltd on behalf of European Hematology Association.)

High-throughput sequencing plays a pivotal role in hematological malignancy diagnostics, but interpreting missense mutations remains challenging. In this study, we used the newly available AlphaMissense database to assess the efficacy of machine learning to predict missense mutation effects and its impact to improve our ability to interpret them. Based on the analysis of 2073 variants from 686 patients analyzed for clinical purpose, we confirmed the very high accuracy of AlphaMissense predictions in a large real-life data set of missense mutations (AUC of ROC curve 0.95), and provided a comprehensive analysis of the discrepancies between AlphaMissense predictions and state of the art clinical interpretation., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Primary mediastinal B-cell lymphoma (PMBL) is an uncommon entity of aggressive B-cell lymphoma with an unusually good prognosis, except for 10-15% of chemotherapy-refractory cases. To identify earlier these higher risk patients, we performed molecular characterization of a retrospective multicenter cohort of patients treated with firstline immunochemotherapy. The traits of the patients with gene-expression profiling data (n = 120) were as follows: median age of 34 years (range, 18-67 years); female sex, 58.3%; elevated lactate dehydrogenase, 82.5%; Eastern Cooperative Oncology Group performance status score of 0 to 1, 85.7%; Ann Arbor stage I/II, 55%; International Prognostic Index score of 1 to 2, 64.4%; and median metabolic tumor volume, 290.4 cm3 (range, 15.7-1147.5 cm3). Among all 137 markers tested for correlation with survival data, only programmed death-ligand (PDL) 1 and PDL2 expression showed a prognostic impact. Overall, both PDL1 and PDL2 genes were highly expressed in 37 patients (30.8%; PDL1high/PDL2high). The baseline clinical characteristics of patients with PDL1high/PDL2high were similar to those of other patients. In univariate analysis, PDL1high/PDL2high status was associated with poor progression-free survival (PFS) (hazard ratio [HR], 4.292) and overall survival (OS; HR, 8.24). In multivariate analysis, PDL1high/PDL2high status was an independent prognostic factor of adverse outcomes (PFS: HR, 5.22; OS: HR, 10.368). We validated these results in an independent cohort of 40 patients and confirmed the significant association between PDL1high/PDL2high status and inferior PFS (HR, 6.11). High PDL1/PDL2 gene expression defines a population with strong immune privilege and poorer outcomes from standard chemotherapy who might benefit from firstline checkpoint inhibitor therapy., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Aggressive large B-cell lymphoma (LBCL) has variable outcomes. Current prognostic tools use factors for risk stratification that inadequately identify patients at high risk of refractory disease or relapse before initial treatment. A model associating 2 risk factors, total metabolic tumor volume (TMTV) >220 cm3 (determined by fluorine-18 fluorodeoxyglucose positron emission tomography coupled with computed tomography) and performance status (PS) ≥2, identified as prognostic in 301 older patients in the REMARC trial (#NCT01122472), was validated in 2174 patients of all ages treated in 2 clinical trials, PETAL (Positron Emission Tomography-Guided Therapy of Aggressive Non-Hodgkin Lymphomas; N = 510) and GOYA (N = 1315), and in real-world clinics (N = 349) across Europe and the United States. Three risk categories, low (no factors), intermediate (1 risk factor), and high (2 risk factors), significantly discriminated outcome in most of the series. Patients with 2 risk factors had worse outcomes than patients with no risk factors in the PETAL, GOYA, and real-world series. Patients with intermediate risk also had significantly worse outcomes than patients with no risk factors. The TMTV/Eastern Cooperative Oncology Group-PS combination outperformed the International Prognostic Index with a positive C-index for progression-free survival and overall survival in most series. The combination of high TMTV > 220 cm3 and ECOG-PS ≥ 2 is a simple clinical model to identify aggressive LBCL risk categories before treatment. This combination addresses the unmet need to better predict before treatment initiation for aggressive LBCL the patients likely to benefit the most or not at all from therapy., (© 2022 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

The mutational status of the variable region of the immunoglobulin heavy chain gene (IGHV) is a very important biomarker for chronic lymphocytic leukemia (CLL) patients. However, the routine detection of IGHV mutational status is time-consuming and costly. Therefore, we performed 5' Rapid amplification of cDNA ends (5' RACE) in 81 CLL patients who previously underwent detection using Biomed-2. The agreement rate of these two methods was 93.8 %. Regarding the discordant cases, 5' RACE was more sensitive to identify unproductive and multiple rearrangements. Furthermore, 5' RACE can also be used to simultaneously sequence light chains. In most CLL cases, the mutational statuses of heavy and light chains are concordant, except in IGLV3-21. Most IGLV3-21 (24/25) rearrangement shared a similar LCDR3 (QVWDSSSDHPWV) and harbored a single point mutation, namely, IGLV3-21 R110 . Compared to mutated-CLL non IGLV3-2 R110 , IGLV3-21 R110 -CLL exhibited a shorter overall survival (OS) and time to first treatment (TTFT) (p = 0.05, p < 0.0001, respectively) even though 75 % (18/24) of these patients expressed mutated heavy chains. Altogether, IGLV3-21 R110 defines a CLL subgroup with specific biological features and an unfavorable prognosis independent of the IGHV mutational status and emphasizes the important value of the light chain. This study is the first to use 5' RACE to detect the mutational status of IGH in CLL. Here, 5' RACE was a reliable and effective method to test the mutational status of heavy and light chains. In addition, 5' RACE can be combined with other assays in the NGS workflow to obtain more detailed insight into subclonal architecture and intraclonal diversity., Competing Interests: Conflicts of Interest The authors declare no conflict of interest., (Copyright © 2022. Published by Elsevier Ltd.)

Background: The pathology-based diagnosis of cardiac antibody-mediated rejection (AMR) relies on the 2013 International Society for Heart and Lung Transplantation Working Formulation, in which microvascular inflammation (MVI) is considered as present or absent regardless of its extent. This work assessed the biological and clinical value of a semiquantitative evaluation of the extent of MVI in endomyocardial biopsies (EMBs)., Methods: We retrospectively graded the extent of MVI in 291 EMB from 291 patients according to a 4-point scale in which MVI scores of 0, 1, 2, and 3 represented 0%, 1%-10%, 11%-50%, and >50% of the myocardial area, respectively. We analyzed the association between the MVI score and tissue rejection molecular activity assessed by microarrays or reverse transcriptase multiplex ligation-dependent probe amplification, current pathology classification (pathologic AMR [pAMR]), anti-HLA donor-specific antibodies, and graft dysfunction., Results: Overall, 172 (59.1%), 33 (11.4%), 42 (14.4%), and 44 (15.1%) EMB were given MVI scores of 0, 1, 2, and 3, respectively. pAMR1(H+) and pAMR2/3 categories were found to be heterogeneous in terms of MVI score. Acute cellular rejection grades did not influence the MVI score. In both molecular approaches, we observed a stepwise increase in the expression of AMR-related transcripts with increasing MVI scores, independent of the C4d or CD68 status (P < 0.001). Both the frequency and mean fluorescence intensity of donor-specific antibodies gradually increased with the MVI score (P < 0.001). Acute graft dysfunction was more frequent in MVI score 3 (P < 0.001)., Conclusions: The intensity of MVI in EMB, based on a semiquantitative evaluation of its extent, has biological and clinical importance., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Morphological, immunohistochemical, and molecular methods often need to be combined for accurate diagnosis and optimal clinical management of sarcomas. Here, we have developed, a new molecular diagnostic assay, for the detection of gene fusions in sarcomas. This targeted multiplexed next-generation sequencing (NGS)-based method utilizes ligation dependent reverse-transcriptase polymerase chain reaction (LD-RT-PCR-NGS) to detect oncogenic fusion transcripts involving 137 genes, leading to 139 gene fusions known to be recurrently rearranged in soft-tissue and bone tumors. 158 bone and soft-tissue tumors with previously identified fusion genes by fluorescent in situ hybridization (FISH) or RT-PCR were selected to test the specificity and the sensitivity of this assay. RNA were extracted from formalin-fixed paraffin-embedded (n = 143) or frozen (n = 15) material (specimen; n = 42 or core needle biopsies; n = 116). Tested tumors encompassed 23 major translocation-related sarcomas types, including Ewing and Ewing-like sarcomas, rhabdomyosarcomas, desmoplastic small round-cell tumors, clear-cell sarcomas, infantile fibrosarcomas, endometrial stromal sarcomas, epithelioid hemangioendotheliomas, alveolar soft-part sarcomas, biphenotypic sinonasal sarcomas, extraskeletal myxoid chondrosarcomas, myxoid/round-cell liposarcomas, dermatofibrosarcomas protuberans and solitary fibrous tumors. In-frame fusion transcripts were detected in 98.1% of cases (155/158). Gene fusion assay results correlated with conventional techniques (FISH and RT-PCR) in 155/158 tumors (98.1%). These data demonstrate that this assay is a rapid, robust, highly sensitive, and multiplexed targeted RNA sequencing assay for the detection of recurrent gene fusions on RNA extracted from routine clinical specimens of sarcomas (formalin-fixed paraffin-embedded or frozen). It facilitates the precise diagnosis and identification of tumors with potential targetable fusions. In addition, this assay can be easily customized to cover new fusions., (© 2022. The Author(s), under exclusive licence to United States & Canadian Academy of Pathology.)

Hairy cell leukemia (cHCL) patients have, in most cases, a specific clinical and biological presentation with splenomegaly, anemia, leukopenia, neutropenia, monocytopenia and/or thrombocytopenia, identification of hairy cells that express CD103, CD123, CD25, CD11c and identification of the V600E mutation in the B-Raf proto-oncogene ( BRAF ) in 90% of cases. Monocytopenia is absent in vHCL and SDRPL patients and the abnormal cells do not express CD25 or CD123 and do not present the BRAF V600E mutation. Ten percent of cHCL patients are BRAF WT and the distinction between cHCL and HCL-like disorders including the variant form of HCL (vHCL) and splenic diffuse red pulp lymphoma (SDRPL) can be challenging. We performed deep sequencing in a large cohort of 84 cHCL and 16 HCL-like disorders to improve insights into the pathogenesis of the diseases. BRAF mutations were detected in 76/82 patients of cHCL (93%) and additional mutations were identified in Krüppel-like Factor 2 ( KLF2 ) in 19 patients (23%) or CDKN1B in 6 patients (7.5%). Some KLF2 genetic alterations were localized on the cytidine deaminase (AID) consensus motif, suggesting AID-induced mutations. When analyzing sequential samples, a clonal evolution was identified in half of the cHCL patients (6/12 pts). Among the 16 patients with HCL-like disorders, we observed an enrichment of MAP2K1 mutations in vHCL/SDRPL (3/5 pts) and genes involved in the epigenetic regulation ( KDM6A, EZH2, CREBBP, ARID1A ) (3/5 pts). Furthermore, MAP2K1 mutations were associated with a bad prognosis and a shorter time to next treatment (TTNT) and progression-free survival (PFS), independently of the HCL classification.

Few data exist concerning circulating tumor DNA (ctDNA) relevance in primary mediastinal B-cell lymphoma (PMBL). To explore this topic, we applied a 9-gene next-generation sequencing pipeline to samples from forty-four PMBL patients (median age 36.5 years). The primary endpoint was a similarity between paired biopsy/plasma mutational profiles. We detected at least one variant in 32 plasma samples (80%). The similarity between the biopsy and ctDNA genetic profiles for the 30 patients with paired mutated biopsy/plasma samples was greater than or equal to 80% in 19 patients (63.3%). We then compared PMBL ctDNA features with those of a cohort of Hodgkin lymphoma patients ( n  = 60). The top three mutated genes were SOCS1, TNFAIP3, and B2M in both lymphoma types. PMBL displayed more alterations in TNFAIP3 (71.9% vs. 46.3%, p  = 0.029) and GNA13 (46.9% vs. 17.1%, p  = 0.013) than cHL. Our 9-gene set may delineate tumor genotypes using ctDNA samples from both lymphoma types.

The rapid transition from traditional sequencing methods to Next-Generation Sequencing (NGS) has allowed for a faster and more accurate detection of somatic variants (Single-Nucleotide Variant (SNV) and Copy Number Variation (CNV)) in tumor cells. NGS technologies require a succession of steps during which false variants can be silently added at low frequencies. Filtering these artifacts can be a rather difficult task especially when the experiments are designed to look for very low frequency variants. Recently, adding unique molecular barcodes called UMI (Unique Molecular Identifier) to the DNA fragments appears to be a very effective strategy to specifically filter out false variants from the variant calling results (Kukita et al. DNA Res 22(4):269-277, 2015; Newman et al. Nat Biotechnol 34(5):547-555, 2016; Schmitt et al. Proc Natl Acad Sci U S A 109(36):14508-14513). Here, we describe UMI-VarCal (Sater et al. Bioinformatics 36:2718-2724, 2020), which can use the UMI information from UMI-tagged reads to offer a faster and more accurate variant calling analysis., (© 2022. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Neoplasms involving plasmacytoid Dendritic Cells (pDCs) include Blastic pDC Neoplasms (BPDCN) and other pDC proliferations, where pDCs are associated with myeloid malignancies: most frequently Chronic MyeloMonocytic Leukemia (CMML) but also Acute Myeloid Leukemia (AML), hereafter named pDC-AML. We aimed to determine the reactive or neoplastic origin of pDCs in pDC-AML, and their link with the CD34+ blasts, monocytes or conventional DCs (cDCs) associated in the same sample, by phenotypic and molecular analyses (targeted NGS, 70 genes). We compared 15 pDC-AML at diagnosis with 21 BPDCN and 11 normal pDCs from healthy donors. CD45low CD34+ blasts were found in all cases (10-80% of medullar cells), associated with pDCs (4-36%), monocytes in 14 cases (1-10%) and cDCs (2 cases, 4.8-19%). pDCs in pDC-AML harbor a clearly different phenotype from BPDCN: CD4+ CD56- in 100% of cases, most frequently CD303+, CD304+ and CD34+; lower expression of cTCL1 and CD123 with isolated lymphoid markers (CD22/CD7/CD5) in some cases, suggesting a pre-pDC stage. In all cases, pDCs, monocytes and cDC are neoplastic since they harbor the same mutations as CD34+ blasts. RUNX1 is the most commonly mutated gene: detected in all AML with minimal differentiation (M0-AML) but not in the other cases. Despite low number of cases, the systematic association between M0-AML, RUNX1 mutations and an excess of pDC is puzzling. Further evaluation in a larger cohort is required to confirm RUNX1 mutations in pDC-AML with minimal differentiation and to investigate whether it represents a proliferation of blasts with macrophage and DC progenitor potential.

The genetic basis of peripheral T-cell lymphoma (PTCL) is complex and encompasses several recurrent fusion transcripts discovered over the past years by means of massive parallel sequencing. However, there is currently no affordable and rapid technology for their simultaneous detection in clinical samples. Herein, we developed a multiplex ligation-dependent RT-PCR-based assay, followed by high-throughput sequencing, to detect 33 known PTCL-associated fusion transcripts. Anaplastic lymphoma kinase (ALK) fusion transcripts were detected in 15 of 16 ALK-positive anaplastic large-cell lymphomas. The latter case was further characterized by a novel SATB1&#95;ALK fusion transcript. Among 239 other PTCLs, representative of nine entities, non-ALK fusion transcripts were detected in 24 samples, mostly of follicular helper T-cell (TFH) derivation. The most frequent non-ALK fusion transcript was ICOS&#95;CD28 in nine TFH-PTCLs, one PTCL not otherwise specified, and one adult T-cell leukemia/lymphoma, followed by VAV1 rearrangements with multiple partners (STAP2, THAP4, MYO1F, and CD28) in five samples (three PTCL not otherwise specified and two TFH-PTCLs). The other rearrangements were CTLA4&#95;CD28 (one TFH-PTCL), ITK&#95;SYK (two TFH-PTCLs), ITK&#95;FER (one TFH-PTCL), IKZF2&#95;ERBB4 (one TFH-PTCL and one adult T-cell leukemia/lymphoma), and TP63&#95;TBL1XR1 (one ALK-negative anaplastic large-cell lymphoma). All fusions detected by our assay were validated by conventional RT-PCR and Sanger sequencing in 30 samples with adequate material. The simplicity and robustness of this targeted multiplex assay make it an attractive tool for the characterization of these heterogeneous diseases., (Copyright © 2021 Association for Molecular Pathology and American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

In the era of precision medicine, it is crucial to identify molecular alterations that will guide the therapeutic management of patients. In this context, circulating tumoral DNA (ctDNA) released by the tumor in body fluids, like blood, and carrying its molecular characteristics is becoming a powerful biomarker for non-invasive detection and monitoring of cancer. Major recent technological advances, especially in terms of sequencing, have made possible its analysis, the challenge still being its reliable early detection. Different parameters, from the pre-analytical phase to the choice of sequencing technology and bioinformatic tools can influence the sensitivity of ctDNA detection.

Background: Recently, copy number variations (CNV) impacting genes involved in oncogenic pathways have attracted an increasing attention to manage disease susceptibility. CNV is one of the most important somatic aberrations in the genome of tumor cells. Oncogene activation and tumor suppressor gene inactivation are often attributed to copy number gain/amplification or deletion, respectively, in many cancer types and stages. Recent advances in next generation sequencing protocols allow for the addition of unique molecular identifiers (UMI) to each read. Each targeted DNA fragment is labeled with a unique random nucleotide sequence added to sequencing primers. UMI are especially useful for CNV detection by making each DNA molecule in a population of reads distinct., Results: Here, we present molecular Copy Number Alteration (mCNA), a new methodology allowing the detection of copy number changes using UMI. The algorithm is composed of four main steps: the construction of UMI count matrices, the use of control samples to construct a pseudo-reference, the computation of log-ratios, the segmentation and finally the statistical inference of abnormal segmented breaks. We demonstrate the success of mCNA on a dataset of patients suffering from Diffuse Large B-cell Lymphoma and we highlight that mCNA results have a strong correlation with comparative genomic hybridization., Conclusion: We provide mCNA, a new approach for CNV detection, freely available at https://gitlab.com/pierrejulien.viailly/mcna/ under MIT license. mCNA can significantly improve detection accuracy of CNV changes by using UMI.

Oncogenesis and ontogeny of blastic plasmacytoid dendritic cell neoplasm (BPDCN) remain uncertain, between canonical plasmacytoid dendritic cells (pDCs) and AXL+ SIGLEC6+ DCs (AS-DCs). We compared 12 BPDCN to 164 acute leukemia by Affymetrix HG-U133 Plus 2.0 arrays: BPDCN were closer to B-cell acute lymphoblastic leukemia (ALL), with enrichment in pDC, B-cell signatures, vesicular transport, deubiquitination pathways, and AS-DC signatures, but only in some cases. Importantly, 1 T-cell ALL clustered with BPDCN, with compatible morphology, immunophenotype (cCD3+ sCD3- CD123+ cTCL1+ CD304+), and genetics. Many oncogenetic pathways are deregulated in BPDCN compared with normal pDC, such as cell-cycle kinases, and importantly, the transcription factor SOX4, involved in B ontogeny, pDC ontogeny, and cancer cell invasion. High-throughput sequencing (HaloPlex) showed myeloid mutations (TET2, 62%; ASXL1, 46%; ZRSR2, 31%) associated with lymphoid mutations (IKZF1), whereas single-nucleotide polymorphism (SNP) array (Affymetrix SNP array 6.0) revealed frequent losses (mean: 9 per patient) involving key hematological oncogenes (RB1, IKZF1/2/3, ETV6, NR3C1, CDKN2A/B, TP53) and immune response genes (IFNGR, TGFB, CLEC4C, IFNA cluster). Various markers suggest an AS-DC origin, but not in all patients, and some of these abnormalities are related to the leukemogenesis process, such as the 9p deletion, leading to decreased expression of genes encoding type I interferons. In addition, the AS-DC profile is only found in a subgroup of patients. Overall, the cellular ontogenic origin of BPDCN remains to be characterized, and these results highlight the heterogeneity of BPDCN, with a risk of a diagnostic trap., (© 2021 by The American Society of Hematology.)

In ribosomopathies, the Diamond-Blackfan anemia (DBA) or 5q- syndrome, ribosomal protein (RP) genes are affected by mutation or deletion, resulting in bone marrow erythroid hypoplasia. Unbalanced production of ribosomal subunits leading to a limited ribosome cellular content regulates translation at the expense of the master erythroid transcription factor GATA1. In RPS14-deficient cells mimicking 5q- syndrome erythroid defects, we show that the transcript length, codon bias of the coding sequence (CDS) and 3’UTR (untranslated region) structure are the key determinants of translation. In these cells, short transcripts with a structured 3’UTR and high codon adaptation index (CAI) showed a decreased translation efficiency. Quantitative analysis of the whole proteome confirmed that the post-transcriptional changes depended on the transcript characteristics that governed the translation efficiency in conditions of low ribosome availability. In addition, proteins involved in normal erythroid differentiation share most determinants of translation selectivity. Our findings thus indicate that impaired erythroid maturation due to 5q- syndrome may proceed from a translational selectivity at the expense of the erythroid differentiation program, and suggest that an interplay between the CDS and UTR may regulate mRNA translation.

The relevance of circulating tumor DNA (ctDNA) analysis as a liquid biopsy and minimal residual disease tool in the management of classical Hodgkin Lymphoma (cHL) patients was demonstrated in retrospective settings and remains to be confirmed in a prospective setting. We developed a targeted Next-Generation sequencing (NGS) panel for fast analysis (AmpliSeq technology) of nine commonly mutated genes in biopies and ctDNA of cHL patients. We then conducted a prospective trial to assess ctDNA follow up at diagnosis and after 2 cycles of chemotherapy (C2). Sixty cHL patients treated by first line conventional chemotherapy (BEACOPPescalated [21.3%], ABVD/ABVD-like [73.5%] and other regimens [5.2%, for elderly patients] were assessed in this non-interventional study. Median age of the patients was 33.5 years (range 20-86). Variants were identified in 42 (70%) patients. Mutations of NFKBIE, TNFAIP3, STAT6, PTPN1, B2M, XPO1, ITPKB, GNA13 and SOCS1 were found in 13.3%, 31.7%, 23.3%, 5%, 33.3%, 10%, 23.3%, 13.3% and 50% of patients, respectively. ctDNA concentration and genotype are correlated with clinical characteristics and presentation. Regarding early therapeutic response, 45 patients (83%, NA=6) had a negative positron emission tomography (PET) after C2 (Deauville Score 1-3). Mean of DeltaSUVmax after C2 was -78.8%. We analyzed ctDNA after C2 for 54 patients (90%). ctDNA became rapidly undetectable in all cases after C2. Variant detection in ctDNA is suitable to depict the genetic features of cHL at diagnosis and may help to assess early treatment response, in association with PET. Clinical Trial reference: NCT02815137.

Background: 18 F-FDG PET/CT is a standard for many B cell malignancies, while blood DNA measurements are emerging tools. Our objective was to evaluate the correlations between baseline PET parameters and circulating DNA in diffuse large B cell lymphoma (DLBCL) and classical Hodgkin lymphoma (cHL)., Methods: Twenty-seven DLBCL and forty-eight cHL were prospectively included. Twelve PET parameters were analysed. Spearman's correlations were used to compare PET parameters each other and to circulating cell-free DNA ([cfDNA]) and circulating tumour DNA ([ctDNA]). p values were controlled by Benjamini-Hochberg correction., Results: Among the PET parameters, three different clusters for tumour burden, fragmentation/massiveness and dispersion parameters were observed. Some PET parameters were significantly correlated with blood DNA parameters, including the total metabolic tumour surface (TMTS) describing the tumour-host interface (e.g. ρ = 0.81 p < 0.001 for [ctDNA] of DLBLC), the tumour median distance between the periphery and the centroid (medPCD) describing the tumour's massiveness (e.g. ρ = 0.81 p < 0.001 for [ctDNA] of DLBLC) and the volume of the bounding box including tumours (TumBB) describing the disease's dispersion (e.g. ρ = 0.83 p < 0.001 for [ctDNA] of DLBLC)., Conclusions: Some PET parameters describing tumour burden, fragmentation/massiveness and dispersion are significantly correlated with circulating DNA parameters of DLBCL and cHL patients. These results could help to understand the pathophysiology of B cell malignancies.

The XPO1 gene encodes exportin 1 (XPO1) that controls the nuclear export of cargo proteins and RNAs. Almost 25% of primary mediastinal B-cell lymphoma (PMBL) and classical Hodgkin lymphoma (cHL) cases harboured a recurrent XPO1 point mutation (NM&#95;003400, chr2:g61718472C>T) resulting in the E571K substitution within the hydrophobic groove of the protein, the site of cargo binding. We investigated the impact of the XPO1 E571K mutation using PMBL/cHL cells having various XPO1 statuses and CRISPR-Cas9-edited cells in which the E571K mutation was either introduced or knocked-out. We first confirmed that the mutation was present in both XPO1 mRNA and protein. We observed that the mutation did not modify the export capacity but rather the subcellular localisation of XPO1 itself. In particular, mutant XPO1 bound to importin β1 modified the nuclear export/import dynamics of relevant cargoes.

Motivation: With Next Generation Sequencing becoming more affordable every year, NGS technologies asserted themselves as the fastest and most reliable way to detect Single Nucleotide Variants (SNV) and Copy Number Variations (CNV) in cancer patients. These technologies can be used to sequence DNA at very high depths thus allowing to detect abnormalities in tumor cells with very low frequencies. Multiple variant callers are publicly available and are usually efficient at calling out variants. However, when frequencies begin to drop under 1%, the specificity of these tools suffers greatly as true variants at very low frequencies can be easily confused with sequencing or PCR artifacts. The recent use of Unique Molecular Identifiers (UMI) in NGS experiments has offered a way to accurately separate true variants from artifacts. UMI-based variant callers are slowly replacing raw-read based variant callers as the standard method for an accurate detection of variants at very low frequencies. However, benchmarking done in the tools publication are usually realized on real biological data in which real variants are not known, making it difficult to assess their accuracy., Results: We present UMI-Gen, a UMI-based read simulator for targeted sequencing paired-end data. UMI-Gen generates reference reads covering the targeted regions at a user customizable depth. After that, using a number of control files, it estimates the background error rate at each position and then modifies the generated reads to mimic real biological data. Finally, it will insert real variants in the reads from a list provided by the user., Availability: The entire pipeline is available at https://gitlab.com/vincent-sater/umigen under MIT license., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2020 The Authors.)

Peripheral T-cell lymphoma comprises a heterogeneous group of mature non-Hodgkin lymphomas. Their diagnosis is challenging, with up to 30% of cases remaining unclassifiable and referred to as "not otherwise specified". We developed a reverse transcriptase-multiplex ligation-dependent probe amplification gene expression profiling assay to differentiate the main T-cell lymphoma entities and to study the heterogeneity of the "not specified" category. The test evaluates the expression of 20 genes, including 17 markers relevant to T-cell immunology and lymphoma biopathology, one Epstein-Barr virus-related transcript, and variants of RHOA (G17V) and IDH2 (R172K/T). By unsupervised hierarchical clustering, our assay accurately identified 21 of 21 ALK-positive anaplastic large cell lymphomas, 16 of 16 extranodal natural killer (NK)/T-cell lymphomas, 6 of 6 hepatosplenic T-cell lymphomas, and 13 of 13 adult T-cell leukemia/lymphomas. ALK-negative anaplastic lymphomas (n=34) segregated into one cytotoxic cluster (n=10) and one non-cytotoxic cluster expressing Th2 markers (n=24) and enriched in DUSP22 -rearranged cases. The 63 T FH -derived lymphomas divided into two subgroups according to a predominant T FH (n=50) or an enrichment in Th2 (n=13) signatures. We next developed a support vector machine predictor which attributed a molecular class to 27 of 77 not specified T-cell lymphomas: 17 T FH , five cytotoxic ALK-negative anaplastic and five NK/T-cell lymphomas. Among the remaining cases, we identified two cell-of-origin subgroups corresponding to cytotoxic/Th1 (n=19) and Th2 (n=24) signatures. A reproducibility test on 40 cases yielded a 90% concordance between three independent laboratories. This study demonstrates the applicability of a simple gene expression assay for the classification of peripheral T-cell lymphomas. Its applicability to routinely-fixed samples makes it an attractive adjunct in diagnostic practice., (Copyright© 2020 Ferrata Storti Foundation.)

Non-Hodgkin B-cell lymphomas (B-NHLs) are a highly heterogeneous group of mature B-cell malignancies. Their classification thus requires skillful evaluation by expert hematopathologists, but the risk of error remains higher in these tumors than in many other areas of pathology. To facilitate diagnosis, we have thus developed a gene expression assay able to discriminate the seven most frequent B-cell NHL categories. This assay relies on the combination of ligation-dependent RT-PCR and next-generation sequencing, and addresses the expression of more than 130 genetic markers. It was designed to retrieve the main gene expression signatures of B-NHL cells and their microenvironment. The classification is handled by a random forest algorithm which we trained and validated on a large cohort of more than 400 annotated cases of different histology. Its clinical relevance was verified through its capacity to prevent important misclassification in low grade lymphomas and to retrieve clinically important characteristics in high grade lymphomas including the cell-of-origin signatures and the MYC and BCL2 expression levels. This accurate pan-B-NHL predictor, which allows a systematic evaluation of numerous diagnostic and prognostic markers, could thus be proposed as a complement to conventional histology to guide the management of patients and facilitate their stratification into clinical trials.

Motivation: Next-generation sequencing has become the go-to standard method for the detection of single-nucleotide variants in tumor cells. The use of such technologies requires a PCR amplification step and a sequencing step, steps in which artifacts are introduced at very low frequencies. These artifacts are often confused with true low-frequency variants that can be found in tumor cells and cell-free DNA. The recent use of unique molecular identifiers (UMI) in targeted sequencing protocols has offered a trustworthy approach to filter out artefactual variants and accurately call low-frequency variants. However, the integration of UMI analysis in the variant calling process led to developing tools that are significantly slower and more memory consuming than raw-reads-based variant callers., Results: We present UMI-VarCal, a UMI-based variant caller for targeted sequencing data with better sensitivity compared to other variant callers. Being developed with performance in mind, UMI-VarCal stands out from the crowd by being one of the few variant callers that do not rely on SAMtools to do their pileup. Instead, at its core runs an innovative homemade pileup algorithm specifically designed to treat the UMI tags in the reads. After the pileup, a Poisson statistical test is applied at every position to determine if the frequency of the variant is significantly higher than the background error noise. Finally, an analysis of UMI tags is performed, a strand bias and a homopolymer length filter are applied to achieve better accuracy. We illustrate the results obtained using UMI-VarCal through the sequencing of tumor samples and we show how UMI-VarCal is both faster and more sensitive than other publicly available solutions., Availability and Implementation: The entire pipeline is available at https://gitlab.com/vincent-sater/umi-varcal-master under MIT license., Supplementary Information: Supplementary data are available at Bioinformatics online., (© The Author(s) 2020. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Epidermal growth factor receptor (EGFR) amplification and EGFR variant III (EGFRvIII, deletion of exons 2-7) are of clinical interest for glioblastoma. The aim was to develop a digital PCR (dPCR)-based method using locked nucleic acid (LNA)-based hydrolysis probes, allowing the simultaneous detection of the EGFR amplification and EGFRvIII variant. Sixty-two patients were included. An exploratory cohort (n = 19) was used to develop the dPCR assay using three selected amplicons within the EGFR gene, targeting intron 1 (EGFR1), junction of exon 3 and intron 3 (EGFR2) and intron 22 (EGFR3). The copy number of EGFR was estimated by the relative quantification of EGFR1, EGFR2 and EGFR3 amplicon droplets compared to the droplets of a reference gene. EGFRvIII was identified by comparing the copy number of the EGFR2 amplicon to either the EGFR1 or EGFR3 amplicon. dPCR results were compared to fluorescence in situ hybridization (FISH) and next-generation sequencing for amplification; and to RT-PCR-based method for EGFRvIII. The dPCR assay was then tested in a validation cohort (n = 43). A total of 8/19 EGFR-amplified and 5/19 EGFRvIII-positive tumors were identified in the exploratory cohort. Compared to FISH, the EGFR3 dPCR assay detected all EGFR-amplified tumors (8/8, 100%) and had the highest concordance with the copy number estimation by NGS. The concordance between RT-PCR and dPCR was also 100% for detecting EGFRvIII using an absolute difference of 10.8 for the copy number between EGFR2 and EGFR3 probes. In the validation cohort, the sensitivity and specificity of dPCR using EGFR3 probes were 100% for the EGFR amplification detection compared to FISH (19/19). EGFRvIII was detected by dPCR in 8 EGFR-amplified patients and confirmed by RT-PCR. Compared to FISH, the EGFR2/EGFR3 dPCR assay was estimated with a one-half cost value. These results highlight that dPCR allowed the simultaneous detection of EGFR amplification and EGFRvIII for glioblastoma.

Background: Molecular biology has emerged as a potential companion to histology for the diagnosis of rejection after heart transplantation. Reverse transcriptase multiplex ligation-dependent probe amplification (RT-MLPA) is a technique of targeted gene expression analysis suitable for formalin-fixed paraffin-embedded (FFPE) biopsies. Our aim was to assess RT-MLPA for the diagnosis of allograft rejection in heart transplantation., Methods: We performed a cross-sectional, case-control, multicenter study. After the selection of a 14-transcript panel (endothelial burden, Natural killer cells, interferon-γ pathway, effector T-cells, and antigen presentation), RT-MLPA was applied to 183 FFPE endomyocardial biopsies (EMB), randomized into a training (n = 113) and a validation (n = 70) series. A two-step class prediction analysis was developed (Linear prediction score-LPS1: rejection vs non-rejection; LPS2: antibody-mediated rejection [AMR] vs acute cellular rejection [ACR]). A study of the agreement between pathology and RT-MLPA was performed., Results: Overall, 48 ACR, 82 AMR, 5 mixed rejection, and 48 non-rejection EMBs were analyzed. Three molecular clusters were delineated by unsupervised hierarchical analysis (molecular non-rejection, ACR, and AMR). AMR was characterized by the high expression of CCL4, GNLY, FCGR3, CXCL11 and ACR by the high expression of CCL18 and ADAMdec. RT-MLPA and histopathology agreed in the final diagnosis in 82.2%, 67.7%, and 76.8% of the EMB in the test, validation, and overall cohort, respectively. Disagreement cases were more common in the case of histologic low-grade rejection and early post-transplant EMB., Conclusions: RT-MLPA is a suitable technique for targeted gene expression analysis on FFPE EMB with a good overall agreement with the histologic diagnosis of heart allograft rejection., (Copyright © 2019. Published by Elsevier Inc.)

Primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL-LT) preferentially involves the lower limb in elderly subjects. A combination of polychemotherapy and rituximab has improved prognosis. However, about 50% of patients will experience progression or relapse without any predictive biologic marker of therapeutic response. The mutational profile of PCLBCL-LT has highlighted mutations contributing to constitutive NF-κB and B-cell receptor (BCR) signaling pathways but has not demonstrated clinical utility. Therefore, the mutational status of 32 patients with PCLBCL-LT (14 patients with complete durable response and 18 patients with relapsing or refractory disease) was determined with a dedicated lymphopanel. Tumor pairs at diagnosis and relapse or progression were analyzed in 14 relapsing or refractory patients. Patients with PCLBCL-LT harboring one mutation that targets one of the BCR signaling genes, CD79A/B or CARD11, displayed a reduced progression-free survival and specific survival (median 18 months, P = 0.002 and 51 months, P = 0.03, respectively, whereas median duration in the wild-type group was not reached) and were associated with therapeutic resistance (P = 0.0006). Longitudinal analyses revealed that MYD88 and CD79B were the earliest and among the most mutated genes. Our data suggest that evaluating BCR mutations in patients with PCLBCL-LT may help to predict first-line therapeutic response and to select targeted therapies., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Gene expression profiling (GEP), next-generation sequencing (NGS) and copy number variation (CNV) analysis have led to an increasingly detailed characterization of the genomic profiles of DLBCL. The aim of this study was to perform a fully integrated analysis of mutational, genomic, and expression profiles to refine DLBCL subtypes. A comparison of our model with two recently published integrative DLBCL classifiers was carried out, in order to best reflect the current state of genomic subtypes., Methods: 223 patients with de novo DLBCL from the prospective, multicenter and randomized LNH-03B LYSA clinical trials were included. GEP data was obtained using Affymetrix GeneChip arrays, mutational profiles were established by Lymphopanel NGS targeting 34 key genes, CNV analysis was obtained by array CGH, and FISH and IHC were performed. Unsupervised independent component analysis (ICA) was applied to GEP data and integrated analysis of multi-level molecular data associated with each component (gene signature) was performed., Findings: ICA identified 38 components reflecting transcriptomic variability across our DLBCL cohort. Many of the components were closely related to well-known DLBCL features such as cell-of-origin, stromal and MYC signatures. A component linked to gain of 19q13 locus, among other genomic alterations, was significantly correlated with poor OS and PFS. Through this integrated analysis, a high degree of heterogeneity was highlighted among previously described DLBCL subtypes., Interpretation: The results of this integrated analysis enable a global and multi-level view of DLBCL, as well as improve our understanding of DLBCL subgroups., (Copyright © 2019 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objective: Anti-transcription intermediary factor 1γ (anti-TIF1γ) antibodies are the main predictors of cancer in dermatomyositis (DM). Yet, a substantial proportion of anti-TIF1γ-positive DM patients do not develop cancer. This study was undertaken to identify biomarkers to better evaluate the risk of cancer and mortality in DM., Methods: This multicenter study was conducted in adult anti-TIF1γ-positive DM patients from August 2013 to August 2017. Anti-TIF1γ autoantibody levels and IgG subclasses were identified using a newly developed quantitative immunoassay. Age, sex, DM signs and activity, malignancy, and creatine kinase (CK) level were recorded. Risk factors were determined by univariate and multivariate analysis according to a Cox proportional hazards regression model., Results: Among the 51 adult patients enrolled (mean ± SD age 61 ± 17 years; ratio of men to women 0.65), 40 (78%) had cancer and 21 (41%) died, with a mean ± SD survival time of 10 ± 6 months. Detection of anti-TIF1γ IgG2 was significantly associated with mortality (P = 0.0011) and occurrence of cancer during follow-up (P < 0.0001), with a 100% positive predictive value for cancer when the mean fluorescence intensity of anti-TIF1γ IgG2 was >385. None of the patients developed cancer after 24 months of follow-up. Univariate survival analyses showed that mortality was also associated with age >60 years (P = 0.0003), active DM (P = 0.0042), cancer (P = 0.0031), male sex (P = 0.011), and CK level >1,084 units/liter (P = 0.005). Multivariate analysis revealed that age >60 years (P = 0.015) and the presence of anti-TIF1γ IgG2 (P = 0.048) were independently associated with mortality., Conclusion: Our findings indicate that anti-TIF1γ IgG2 is a potential new biomarker of cancer that should be helpful in identifying the risk of mortality in anti-TIF1γ-positive DM patients., (© 2019, American College of Rheumatology.)

Burkitt lymphoma (BL) is characterized by a translocation of the MYC oncogene that leads to the upregulation of MYC expression, cell growth and proliferation. It is well-established that MYC translocation is not a sufficient genetic event to cause BL. Next-generation sequencing has recently provided a comprehensive analysis of the landscape of additional genetic events that contribute to BL lymphomagenesis. Refractory BL or relapsing BL are almost always incurable as a result of the selection of a highly chemoresistant clonally related cell population. Conversely, a few BL recurrence cases arising from clonally distinct tumors have been reported and were associated with a favorable outcome similar to that reported for first-line treatment. Here, we used an unusual case of recurrent but clonally distinct EBV+ BL to highlight the key genetic events that drive BL lymphomagenesis. By whole exome sequencing, we established that ID3 gene was targeted by distinct mutations in the two clonally unrelated diseases, highlighting the crucial role of this gene during lymphomagenesis. We also detected a heterozygous E1021K PIK3CD mutation, thus increasing the spectrum of somatic mutations altering the PI3K signaling pathway in BL. Interestingly, this mutation is known to be associated with activated phosphoinositide 3-kinase delta syndrome (APDS). Finally, we also identified an inherited heterozygous truncating c.5791CT FANCM mutation that may contribute to the unusual recurrence of BL., (© 2019 The Authors. Genes, Chromosomes & Cancer published by Wiley Periodicals, Inc.)

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.

Classical hairy cell leukemia (HCL-c) is a rare lymphoid neoplasm. BRAF V600E 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). BRAF V600E was found in 90% (18/20) of HCL-c patients. In HCL-c patients with BRAF V600E , 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 ( BCOR E1430X and XPO1 E571K ) 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., Competing Interests: CONFLICTS OF INTEREST All of the authors declare no conflicts of interest

Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma. It includes three major subtypes termed germinal center B-cell-like, activated B-cell-like, and primary mediastinal B-cell lymphoma. With the emergence of novel targeted therapies, accurate methods capable of interrogating this cell-of-origin classification should soon become essential in the clinics. To address this issue, we developed a novel gene expression profiling DLBCL classifier based on reverse transcriptase multiplex ligation-dependent probe amplification. This assay simultaneously evaluates the expression of 21 markers, to differentiate primary mediastinal B-cell lymphoma, activated B-cell-like, germinal center B-cell-like, and also Epstein-Barr virus-positive DLBCLs. It was trained using 70 paraffin-embedded biopsies and validated using >160 independent samples. Compared with a reference classification established from Affymetrix U133 + 2 data, reverse transcriptase multiplex ligation-dependent probe amplification classified 85.0% samples into the expected subtype, comparing favorably with current diagnostic methods. This assay also proved to be highly efficient in detecting the MYD88 L265P mutation, even in archival paraffin-embedded tissues. This reliable, rapid, and cost-effective method uses common instruments and reagents and could thus easily be implemented into routine diagnosis workflows, to improve the management of these aggressive tumors., (Copyright © 2017 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.)

Motivation: Although sequencing-based technologies are becoming the new reference in genome analysis, comparative genomic hybridization arrays (aCGH) still constitute a simple and reliable approach for copy number analysis. The most powerful algorithms to analyze such data have been freely provided by the scientific community for many years, but combining them is a complex scripting task., Results: The cghRA framework combines a user-friendly graphical interface and a powerful object-oriented command-line interface to handle a full aCGH analysis, as is illustrated in an original series of 107 Diffuse Large B-Cell Lymphomas. New algorithms for copy-number calling, polymorphism detection and minimal common region prioritization were also developed and validated. While their performances will only be demonstrated with aCGH, these algorithms could actually prove useful to any copy-number analysis, whatever the technique used., Availability and Implementation: R package and source for Linux, MS Windows and MacOS are freely available at http://bioinformatics.ovsa.fr/cghRA., Contact: mareschal@ovsa.fr or fabrice.jardin@chb.unicancer.fr., Supplementary Information: Supplementary data are available at Bioinformatics online., (© The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com)

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%). MYD88 L265P 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., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Mantle cell lymphoma (MCL) is a B-cell hemopathy characterized by the t(11;14) translocation and the aberrant overexpression of cyclin D1. This results in an unrestrained cell proliferation. Other genetic alterations are common in MCL cells such as SOX11 expression, mutations of ATM and/or TP53 genes, activation of the NF-κB signaling pathway and NOTCH receptors. These alterations lead to the deregulation of the apoptotic machinery and resistance to drugs. We observed that among a panel of MCL cell lines, REC1 cells were resistant towards genotoxic stress. We studied the molecular basis of this resistance., Methods: We analyzed the cell response regarding apoptosis, senescence, cell cycle arrest, DNA damage response and finally the 26S proteasome activity following a genotoxic treatment that causes double strand DNA breaks., Results: MCL cell lines displayed various sensitivity/resistance towards genotoxic stress and, in particular, REC1 cells did not enter apoptosis or senescence after an etoposide treatment. Moreover, the G2/M cell cycle checkpoint was deficient in REC1 cells. We observed that three main actors of apoptosis, senescence and cell cycle regulation (cyclin D1, MCL1 and CDC25A) failed to be degraded by the proteasome machinery in REC1 cells. We ruled out a default of the βTrCP E3-ubiquitine ligase but detected a lowered 26S proteasome activity in REC1 cells compared to other cell lines., Conclusion: The resistance of MCL cells to genotoxic stress correlates with a low 26S proteasome activity. This could represent a relevant biomarker for a subtype of MCL patients with a poor response to therapies and a high risk of relapse.

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.

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 ., (©2016 American Association for Cancer Research.)

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., (© 2016 Wiley Periodicals, Inc.)

Purpose: To assess the prognostic and predictive value of circulating ESR1 mutation and its kinetics before and after progression on aromatase inhibitor (AI) treatment., Patients and Methods: ESR1 circulating D538G and Y537S/N/C mutations were retrospectively analyzed by digital droplet PCR after first-line AI failure in patients treated consecutively from 2010 to 2012 for hormone receptor-positive metastatic breast cancer. Progression-free survival (PFS) and overall survival (OS) were analyzed according to circulating mutational status and subsequent lines of treatment. The kinetics of ESR1 mutation before (3 and 6 months) and after (3 months) AI progression were determined in the available archive plasmas., Results: Circulating ESR1 mutations were found at AI progression in 44/144 patients included (30.6%). Median follow-up from AI initiation was 40 months (range 4-94). The median OS was decreased in patients with circulating ESR1 mutation than in patients without mutation (15.5 versus 23.8 months, P=0.0006). The median PFS was also significantly decreased in patients with ESR1 mutation than in patients without mutation (5.9 vs 7 months, P=0.002). After AI failure, there was no difference in outcome for patients receiving chemotherapy (n = 58) versus non-AI endocrine therapy (n=51) in patients with and without ESR1 mutation. ESR1 circulating mutations were detectable in 75% of all cases before AI progression, whereas the kinetics 3 months after progression did not correlate with outcome., Conclusion: ESR1 circulating mutations are independent risk factors for poor outcome after AI failure, and are frequently detectable before clinical progression. Interventional studies based on ESR1 circulating status are warranted.

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. Am. J. Hematol. 91:923-930, 2016. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

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., (Copyright© Ferrata Storti Foundation.)

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.

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 AACRSee related commentary by Lim and Elenitoba-Johnson, p. 2829., (©2016 American Association for Cancer Research.)