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1.
J Clin Invest ; 131(13)2021 07 01.
Article in English | MEDLINE | ID: mdl-34043588

ABSTRACT

Peripheral T cell lymphomas (PTCLs) represent a significant unmet medical need with dismal clinical outcomes. The T cell receptor (TCR) is emerging as a key driver of T lymphocyte transformation. However, the role of chronic TCR activation in lymphomagenesis and in lymphoma cell survival is still poorly understood. Using a mouse model, we report that chronic TCR stimulation drove T cell lymphomagenesis, whereas TCR signaling did not contribute to PTCL survival. The combination of kinome, transcriptome, and epigenome analyses of mouse PTCLs revealed a NK cell-like reprogramming of PTCL cells with expression of NK receptors (NKRs) and downstream signaling molecules such as Tyrobp and SYK. Activating NKRs were functional in PTCLs and dependent on SYK activity. In vivo blockade of NKR signaling prolonged mouse survival, demonstrating the addiction of PTCLs to NKRs and downstream SYK/mTOR activity for their survival. We studied a large collection of human primary samples and identified several PTCLs recapitulating the phenotype described in this model by their expression of SYK and the NKR, suggesting a similar mechanism of lymphomagenesis and establishing a rationale for clinical studies targeting such molecules.


Subject(s)
Lymphoma, T-Cell, Peripheral/immunology , Receptors, Antigen, T-Cell/immunology , Receptors, Natural Killer Cell/immunology , Animals , Carcinogenesis/genetics , Carcinogenesis/immunology , Cellular Reprogramming/genetics , Cellular Reprogramming/immunology , Epigenesis, Genetic , Gene Expression Regulation, Neoplastic , Genes, p53 , Humans , Killer Cells, Natural/immunology , Lymphoma, T-Cell, Peripheral/genetics , Lymphoma, T-Cell, Peripheral/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Neoplasms, Experimental/genetics , Neoplasms, Experimental/immunology , Neoplasms, Experimental/metabolism , Receptors, Antigen, T-Cell/genetics , Receptors, Natural Killer Cell/genetics , Signal Transduction/genetics , Signal Transduction/immunology , Syk Kinase/metabolism , T-Lymphocytes/immunology
2.
Hemasphere ; 5(2): e522, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33880432

ABSTRACT

RNA sequencing holds great promise to improve the diagnostic of hematological malignancies, because this technique enables to detect fusion transcripts, to look for somatic mutations in oncogenes, and to capture transcriptomic signatures of nosological entities. However, the analytical performances of targeted RNA sequencing have not been extensively described in diagnostic samples. Using a targeted panel of 1385 cancer-related genes in a series of 100 diagnosis samples and 8 controls, we detected all the already known fusion transcripts and also discovered unknown and/or unsuspected fusion transcripts in 12 samples. Regarding the analysis of transcriptomic profiles, we show that targeted RNA sequencing is performant to discriminate acute lymphoblastic leukemia entities driven by different oncogenic translocations. Additionally, we show that 86% of the mutations identified at the DNA level are also detectable at the messenger RNA (mRNA) level, except for nonsense mutations that are subjected to mRNA decay. We conclude that targeted RNA sequencing might improve the diagnosis of hematological malignancies. Standardization of the preanalytical steps and further refinements of the panel design and of the bioinformatical pipelines will be an important step towards its use in standard diagnostic procedures.

3.
BMC Bioinformatics ; 22(1): 120, 2021 Mar 12.
Article in English | MEDLINE | ID: mdl-33711922

ABSTRACT

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.


Subject(s)
Comparative Genomic Hybridization , DNA Copy Number Variations , High-Throughput Nucleotide Sequencing , Adult , Humans , Male , Middle Aged , Prospective Studies , Sequence Analysis, DNA
4.
Blood Adv ; 5(4): 1003-1016, 2021 02 23.
Article in English | MEDLINE | ID: mdl-33591326

ABSTRACT

Although copy number alterations (CNAs) and translocations constitute the backbone of the diagnosis and prognostication of acute myeloid leukemia (AML), techniques used for their assessment in routine diagnostics have not been reconsidered for decades. We used a combination of 2 next-generation sequencing-based techniques to challenge the currently recommended conventional cytogenetic analysis (CCA), comparing the approaches in a series of 281 intensively treated patients with AML. Shallow whole-genome sequencing (sWGS) outperformed CCA in detecting European Leukemia Net (ELN)-defining CNAs and showed that CCA overestimated monosomies and suboptimally reported karyotype complexity. Still, the concordance between CCA and sWGS for all ELN CNA-related criteria was 94%. Moreover, using in silico dilution, we showed that 1 million reads per patient would be enough to accurately assess ELN-defining CNAs. Total genomic loss, defined as a total loss ≥200 Mb by sWGS, was found to be a better marker for genetic complexity and poor prognosis compared with the CCA-based definition of complex karyotype. For fusion detection, the concordance between CCA and whole-transcriptome sequencing (WTS) was 99%. WTS had better sensitivity in identifying inv(16) and KMT2A rearrangements while showing limitations in detecting lowly expressed PML-RARA fusions. Ligation-dependent reverse transcription polymerase chain reaction was used for validation and was shown to be a fast and reliable method for fusion detection. We conclude that a next-generation sequencing-based approach can replace conventional CCA for karyotyping, provided that efforts are made to cover lowly expressed fusion transcripts.


Subject(s)
Leukemia, Myeloid, Acute , Chromosome Aberrations , Cytogenetic Analysis , DNA Copy Number Variations , Humans , Karyotyping , Leukemia, Myeloid, Acute/diagnosis , Leukemia, Myeloid, Acute/genetics
5.
Blood Cancer J ; 10(6): 67, 2020 06 11.
Article in English | MEDLINE | ID: mdl-32527994

ABSTRACT

Relevant molecular tools for treatment stratification of patients ≥65 years with acute myeloid leukemia (AML) are lacking. We combined clinical data with targeted DNA- and full RNA-sequencing of 182 intensively and palliatively treated patients to predict complete remission (CR) and survival in AML patients ≥65 years. Intensively treated patients with NPM1 and IDH2R172 mutations had longer overall survival (OS), whereas mutated TP53 conferred lower CR rates and shorter OS. FLT3-ITD and TP53 mutations predicted worse OS in palliatively treated patients. Gene expression levels most predictive of CR were combined with somatic mutations for an integrated risk stratification that we externally validated using the beatAML cohort. We defined a high-risk group with a CR rate of 20% in patients with mutated TP53, compared to 97% CR in low-risk patients defined by high expression of ZBTB7A and EEPD1 without TP53 mutations. Patients without these criteria had a CR rate of 54% (intermediate risk). The difference in CR rates translated into significant OS differences that outperformed ELN stratification for OS prediction. The results suggest that an integrated molecular risk stratification can improve prediction of CR and OS and could be used to guide treatment in elderly AML patients.


Subject(s)
Leukemia, Myeloid, Acute/genetics , Mutation , Transcriptome , Age Factors , Aged , Aged, 80 and over , DNA-Binding Proteins/genetics , Endodeoxyribonucleases/genetics , Female , Gene Expression Regulation, Leukemic , Humans , Leukemia, Myeloid, Acute/epidemiology , Leukemia, Myeloid, Acute/therapy , Male , Nuclear Proteins/genetics , Nucleophosmin , Remission Induction , Survival Analysis , Transcription Factors/genetics , Tumor Suppressor Protein p53/genetics , fms-Like Tyrosine Kinase 3/genetics
6.
Clin Cancer Res ; 26(14): 3597-3607, 2020 07 15.
Article in English | MEDLINE | ID: mdl-32122925

ABSTRACT

PURPOSE: RNA splicing is a fundamental biological process that generates protein diversity from a finite set of genes. Recurrent somatic mutations of splicing factor genes are common in some hematologic cancers but are relatively uncommon in acute myeloid leukemia (AML, < 20% of patients). We examined whether RNA splicing differences exist in AML, even in the absence of splicing factor mutations. EXPERIMENTAL DESIGN: We developed a bioinformatics pipeline to study alternative RNA splicing in RNA-sequencing data from large cohorts of patients with AML. RESULTS: We have identified recurrent differential alternative splicing between patients with poor and good prognosis. These splicing events occurred even in patients without any discernible splicing factor mutations. Alternative splicing recurrently occurred in genes with specific molecular functions, primarily related to protein translation. Developing tools to predict the functional impact of alternative splicing on the translated protein, we discovered that approximately 45% of the splicing events directly affected highly conserved protein domains. Several splicing factors were themselves misspliced and the splicing of their target transcripts were altered. Studying differential gene expression in the same patients, we identified that alternative splicing of protein translation genes in ELNAdv patients resulted in the induction of an integrated stress response and upregulation of inflammation-related genes. Finally, using machine learning techniques, we identified a splicing signature of four genes which refine the accuracy of existing risk prognosis schemes and validated it in a completely independent cohort. CONCLUSIONS: Our discoveries therefore identify aberrant alternative splicing as a molecular feature of adverse AML with clinical relevance.See related commentary by Bowman, p. 3503.


Subject(s)
Biological Phenomena , Leukemia, Myeloid, Acute , Alternative Splicing , Humans , Leukemia, Myeloid, Acute/diagnosis , Leukemia, Myeloid, Acute/genetics , Mutation , Prognosis , RNA Splicing/genetics , RNA Splicing Factors/genetics
7.
EBioMedicine ; 48: 58-69, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31648986

ABSTRACT

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.


Subject(s)
Biomarkers, Tumor , Gene Expression Profiling , Lymphoma, Large B-Cell, Diffuse/diagnosis , Lymphoma, Large B-Cell, Diffuse/genetics , Transcriptome , Chromosome Mapping , Computational Biology/methods , DNA Copy Number Variations , Female , Gene Expression Profiling/methods , Genetic Association Studies , Genetic Predisposition to Disease , Humans , Immunohistochemistry , Male , Molecular Sequence Annotation
8.
Sci Rep ; 8(1): 11293, 2018 07 26.
Article in English | MEDLINE | ID: mdl-30050054

ABSTRACT

Alterations of RUNX1 in acute myeloid leukemia (AML) are associated with either a more favorable outcome in the case of the RUNX1/RUNX1T1 fusion or unfavorable prognosis in the case of point mutations. In this project we aimed to identify genes responsible for the observed differences in outcome that are common to both RUNX1 alterations. Analyzing four AML gene expression data sets (n = 1514), a total of 80 patients with RUNX1/RUNX1T1 and 156 patients with point mutations in RUNX1 were compared. Using the statistical tool of mediation analysis we identified the genes CD109, HOPX, and KIAA0125 as candidates for mediator genes. In an analysis of an independent validation cohort, KIAA0125 again showed a significant influence with respect to the impact of the RUNX1/RUNX1T1 fusion. While there were no significant results for the other two genes in this smaller validation cohort, the observed relations linked with mediation effects (i.e., those between alterations, gene expression and survival) were almost without exception as strong as in the main analysis. Our analysis demonstrates that mediation analysis is a powerful tool in the identification of regulative networks in AML subgroups and could be further used to characterize the influence of genetic alterations.


Subject(s)
Core Binding Factor Alpha 2 Subunit/genetics , Gene Fusion , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/pathology , Point Mutation , RUNX1 Translocation Partner 1 Protein/genetics , Biostatistics , Gene Expression Profiling , Humans
10.
J Mol Diagn ; 19(6): 892-904, 2017 11.
Article in English | MEDLINE | ID: mdl-29054399

ABSTRACT

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.


Subject(s)
Lymphoma, Large B-Cell, Diffuse/genetics , Multiplex Polymerase Chain Reaction/methods , Oligonucleotide Array Sequence Analysis/methods , Reverse Transcriptase Polymerase Chain Reaction/methods , Biomarkers, Tumor/genetics , Gene Expression Profiling , Gene Expression Regulation, Neoplastic/genetics , Humans , Lymphoma, Large B-Cell, Diffuse/classification , Lymphoma, Large B-Cell, Diffuse/diagnosis , Lymphoma, Large B-Cell, Diffuse/pathology , Mutation , Paraffin Embedding
11.
Oncotarget ; 8(29): 48157-48168, 2017 Jul 18.
Article in English | MEDLINE | ID: mdl-28636991

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.


Subject(s)
Central Nervous System Neoplasms/genetics , DNA Mutational Analysis , High-Throughput Nucleotide Sequencing , Lymphoma/genetics , Mutation , Aged , Aged, 80 and over , Alleles , Biopsy , Case-Control Studies , Central Nervous System Neoplasms/diagnosis , Central Nervous System Neoplasms/therapy , DNA Mutational Analysis/methods , DNA, Circular , DNA, Neoplasm , Female , Gene Frequency , Genomics/methods , High-Throughput Nucleotide Sequencing/methods , Humans , Lymphoma/diagnosis , Lymphoma/therapy , Magnetic Resonance Imaging , Male , Middle Aged , Sensitivity and Specificity
12.
J Invest Dermatol ; 137(9): 1984-1994, 2017 09.
Article in English | MEDLINE | ID: mdl-28479318

ABSTRACT

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.


Subject(s)
DNA Copy Number Variations , Gene Expression Regulation, Neoplastic , Lymphoma, Large B-Cell, Diffuse/genetics , Myeloid Differentiation Factor 88/genetics , Skin Neoplasms/genetics , Aged , Aged, 80 and over , Cohort Studies , Female , Genetic Association Studies , High-Throughput Nucleotide Sequencing/methods , Humans , Leg , Lymphoma, Large B-Cell, Diffuse/pathology , Male , Middle Aged , Mutation , Skin Neoplasms/pathology
13.
Bioinformatics ; 33(19): 2977-2985, 2017 Oct 01.
Article in English | MEDLINE | ID: mdl-28481978

ABSTRACT

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.


Subject(s)
Comparative Genomic Hybridization , Lymphoma, Large B-Cell, Diffuse/genetics , Algorithms , Genomics , Humans , Polymorphism, Genetic , Software
14.
Clin Cancer Res ; 23(9): 2232-2244, 2017 May 01.
Article in English | MEDLINE | ID: mdl-27923841

ABSTRACT

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.


Subject(s)
Genetic Heterogeneity , Lymphoma, Large B-Cell, Diffuse/genetics , Myeloid Differentiation Factor 88/genetics , Prognosis , Adolescent , Adult , Aged , Aged, 80 and over , DNA Copy Number Variations/genetics , Female , Genome, Human , Genomics , High-Throughput Nucleotide Sequencing , Humans , Lymphoma, Large B-Cell, Diffuse/pathology , Male , Middle Aged , Mutation , NF-kappa B/genetics , Signal Transduction/genetics
15.
Am J Hematol ; 92(1): 68-76, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27737507

ABSTRACT

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.


Subject(s)
Clonal Evolution , Immunoglobulin Heavy Chains/genetics , Lymphoma, Large B-Cell, Diffuse/genetics , Neoplasm Recurrence, Local/genetics , V(D)J Recombination , Genes, Immunoglobulin Heavy Chain , High-Throughput Nucleotide Sequencing , Humans , Lymphoma, Large B-Cell, Diffuse/blood , Lymphoma, Large B-Cell, Diffuse/immunology , Lymphoma, Large B-Cell, Diffuse/pathology , Neoplasm Recurrence, Local/immunology , Phylogeny , Retrospective Studies , Sequence Analysis, DNA
16.
Haematologica ; 101(9): 1094-101, 2016 09.
Article in English | MEDLINE | ID: mdl-27479820

ABSTRACT

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.


Subject(s)
DNA, Neoplasm/genetics , Hodgkin Disease/diagnosis , Hodgkin Disease/genetics , Karyopherins/genetics , Mutation , Neoplasms/diagnosis , Neoplasms/genetics , Receptors, Cytoplasmic and Nuclear/genetics , Adult , Amino Acid Substitution , Biomarkers, Tumor , Cell Line, Tumor , Codon , Combined Modality Therapy , DNA, Neoplasm/blood , Female , High-Throughput Nucleotide Sequencing , Hodgkin Disease/mortality , Hodgkin Disease/therapy , Humans , Male , Middle Aged , Neoplasm Staging , Neoplasms/mortality , Neoplasms/therapy , Positron Emission Tomography Computed Tomography , Prognosis , Recurrence , Retrospective Studies , Survival Analysis , Treatment Outcome , Tumor Burden , Young Adult , Exportin 1 Protein
18.
Am J Hematol ; 91(9): 923-30, 2016 09.
Article in English | MEDLINE | ID: mdl-27312795

ABSTRACT

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-ß 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.


Subject(s)
Active Transport, Cell Nucleus/drug effects , Karyopherins/genetics , Lymphoma, B-Cell/genetics , Mutation , Receptors, Cytoplasmic and Nuclear/genetics , Acrylates/pharmacology , Adolescent , Adult , Aged , Biomarkers , Cell Line, Tumor , Female , Gene Expression Profiling , Hodgkin Disease/genetics , Humans , Hydrazines/pharmacology , Karyopherins/antagonists & inhibitors , Karyopherins/physiology , Lymphoma, B-Cell/mortality , Lymphoma, B-Cell/pathology , Male , Mediastinal Neoplasms/genetics , Mediastinal Neoplasms/mortality , Middle Aged , Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors , Receptors, Cytoplasmic and Nuclear/physiology , Sequence Analysis, DNA , Triazoles/pharmacology , Young Adult , Exportin 1 Protein
19.
Leuk Res ; 45: 90-100, 2016 06.
Article in English | MEDLINE | ID: mdl-27107267

ABSTRACT

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.


Subject(s)
Down-Regulation/genetics , Epigenesis, Genetic , Gene Deletion , Lymphoma, B-Cell/genetics , Ubiquitin-Protein Ligases/physiology , Acetylation , Apoptosis , Cell Cycle Checkpoints , Cell Line, Tumor , DNA Methylation , Gene Expression Regulation, Neoplastic , Genes, Tumor Suppressor , Histone Deacetylase Inhibitors/pharmacology , Humans , Promoter Regions, Genetic , Ubiquitin-Protein Ligases/genetics
20.
Clin Cancer Res ; 22(15): 3801-9, 2016 08 01.
Article in English | MEDLINE | ID: mdl-26936916

ABSTRACT

PURPOSE: The prognostic impact of total metabolic tumor volume (TMTV) measured on pretreatment (18)F-FDG PET/CT and its added value to molecular characteristics was investigated in patients with diffuse large B-cell lymphoma (DLBCL). EXPERIMENTAL DESIGN: For 81 newly diagnosed patients with DLBCL treated with rituximab and CHOP/CHOP-like regimen, TMTV was computed using the 41% SUVmax thresholding method. According to the gene expression profile, determined using DASL (cDNA-mediated Annealing, Selection, Ligation and extension) technology, a subset of 57 patients was classified in germinal center B (GCB) or activated B-cell (ABC) subtypes and MYC or BCL2 overexpressed. RESULTS: Median follow-up was 64 months. Five-year progression-free survival (PFS) and overall survival (OS) were 60% and 63% in the whole population. Median pretherapy TMTV was 320 cm(3) (25th-75th percentiles 106-668 cm(3)). With a 300 cm(3) cutoff, patients with high TMTV (n = 43) had a 5-year PFS and OS of 43% and 46% compared with 76% and 78% for patients with a low TMTV (P = 0.0023, P = 0.0047). ABC status, MYC, or BCL2 overexpression and both overexpression ("dual expressor," DE) were significantly associated with a worse PFS and OS. TMTV combined with molecular data allowed a significant better risk substratification of ABC/GCB patients, on PFS and OS. High TMTV individualized in molecular-low-risk patients a group with a poor outcome (MYC, PFS=51%, OS=55% BCL2, PFS=49%, OS=49% or DE PFS=50%, OS=50%) and a group with a good outcome (MYC, PFS=93%, OS=93% BCL2, PFS=86%, OS=86%, or DE PFS=81%, OS=81%). CONCLUSIONS: The combination of molecular and imaging characteristics at diagnosis could lead to a more accurate selection of patients, to increase tailor therapy. Clin Cancer Res; 22(15); 3801-9. ©2016 AACR.


Subject(s)
Biomarkers, Tumor , Fluorodeoxyglucose F18 , Gene Expression Profiling , Lymphoma, Large B-Cell, Diffuse/diagnosis , Lymphoma, Large B-Cell, Diffuse/genetics , Positron Emission Tomography Computed Tomography , Adult , Aged , Aged, 80 and over , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Female , Gene Expression Profiling/methods , Humans , Kaplan-Meier Estimate , Lymphoma, Large B-Cell, Diffuse/drug therapy , Lymphoma, Large B-Cell, Diffuse/mortality , Male , Middle Aged , Neoplasm Staging , Positron Emission Tomography Computed Tomography/methods , ROC Curve , Retrospective Studies , Treatment Outcome , Tumor Burden , Young Adult
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