Longitudinal gene expression profiling identifies a poor risk subset of patients with ABC-type Diffuse Large B Cell Lymphoma
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ABSTRACT: Despite the effectiveness of immuno-chemotherapy, 40% of patients with diffuse large B-cell lymphoma (DLBCL) experience relapse or refractory disease. Longitudinal studies have previously focused on the mutational landscape of relapse but falling short of providing a consistent relapse-specific genetic signature. In our study, we have focussed attention on the changes in gene expression profile accompanying DLBCL relapse using archival paired diagnostic/relapse specimens from 38 de novo DLBCL patients. Cell of origin remained stable from diagnosis to relapse in 80% of patients, with only a single patient showing COO switching from ABC to GCB. Analysis of the transcriptomic changes that occur following relapse suggest ABC and GCB relapses are mediated via different mechanisms. We developed a 30-gene discriminator for ABC-DLBCLs derived from relapse-associated genes, that defined clinically distinct high and low risk subgroups in ABC-DLBCLs at diagnosis in datasets comprising both population-based and clinical trial cohorts. This signature also identified a population of <60-year-old patients with superior PFS and OS treated with Ibrutinib-R-CHOP as part of the PHOENIX trial. Altogether this new signature adds to the existing toolkit of putative genetic predictors now available in DLBCL that can be readily assessed as part of prospective clinical trials.
Project description:CD5-positive (CD5+) diffuse large B-cell lymphoma (DLBCL) has a poor prognosis and high incidence of central nervous system (CNS) relapse, even in the rituximab era. To determine the gene expression profile of CD5+ DLBCL, total RNA from 90 patients with DLBCL, including 33 CD5+ DLBCL and 57 CD5-negative (CD5-) DLBCL patients, was examined using Agilent human oligo microarrays. These cases were separated into 78 activated B-cell-like (ABC) DLBCLs and 12 germinal center B-cell-like (GCB) DLBCLs. All cases of CD5+ DLBCL were classified as ABC DLBCLs. The classifier based on gene expression used in a supervised analysis correctly identified CD5 expression in the DLBCL and ABC DLBCL samples. The gene most relevant to CD5 expression was SH3BP5. The enriched GO categories in the CD5+ ABC DLBCL signature gene set were multicellular organismal signaling, transmission of nerve impulse, and synaptic transmission. This present study, which includes the largest reported number of patients with CD5+ DLBCL, confirmed that most CD5+ DLBCLs are ABC DLBCLs, suggesting that therapeutic strategies for ABC DLBCL may be effective for the treatment of CD5+ DLBCL. Our CD5+ ABC DLBCL signature gene set may provide insights into the cause of the high frequency of CNS relapse in CD5+ DLBCL.
Project description:CD5-positive (CD5+) diffuse large B-cell lymphoma (DLBCL) has a poor prognosis and high incidence of central nervous system (CNS) relapse, even in the rituximab era. To determine the gene expression profile of CD5+ DLBCL, total RNA from 90 patients with DLBCL, including 33 CD5+ DLBCL and 57 CD5-negative (CD5-) DLBCL patients, was examined using Agilent human oligo microarrays. These cases were separated into 78 activated B-cell-like (ABC) DLBCLs and 12 germinal center B-cell-like (GCB) DLBCLs. All cases of CD5+ DLBCL were classified as ABC DLBCLs. The classifier based on gene expression used in a supervised analysis correctly identified CD5 expression in the DLBCL and ABC DLBCL samples. The gene most relevant to CD5 expression was SH3BP5. The enriched GO categories in the CD5+ ABC DLBCL signature gene set were multicellular organismal signaling, transmission of nerve impulse, and synaptic transmission. This present study, which includes the largest reported number of patients with CD5+ DLBCL, confirmed that most CD5+ DLBCLs are ABC DLBCLs, suggesting that therapeutic strategies for ABC DLBCL may be effective for the treatment of CD5+ DLBCL. Our CD5+ ABC DLBCL signature gene set may provide insights into the cause of the high frequency of CNS relapse in CD5+ DLBCL. This present study involved 90 cases (33 patients with CD5+ DLBCL and 57 with CD5- DLBCL) of de novo consecutive DLBCL diagnosed at Mie University Hospital with available frozen biopsy specimens and total RNA samples. Lymphoma tissue RNA from 90 patients was extracted for target preparation and hybridization onto Agilent microarrays. The expression of CD5 in tumor cells was confirmed by means of immunohistochemistry using frozen sections.
Project description:Diffuse large B-cell lymphoma (DLBCL) comprises molecularly distinct subgroups such as activated B-cell-like (ABC) and germinal center B-cell-like (GCB) DLBCLs. We previously reported that CD5(+) and CD5(-)CD10(+) DLBCL constitute clinically relevant subgroups. To determine whether these 2 subgroups are related to ABC and GCB DLBCLs, we analyzed the genomic imbalance of 99 cases (36 CD5(+), 19 CD5(-)CD10(+), and 44 CD5(-)CD10(-)) using array-based comparative genomic hybridization (CGH). Forty-six of these cases (22 CD5(+), 9 CD5(-)CD10(+), 1 CD5 (-), and 14 CD5(-)CD10(-)) were subsequently subjected to gene-expression profiling, resulting in their division into 28 ABC (19 CD5(+) and 9 CD5(-)CD10(-)) and 18 GCB (3 CD5(+), 7 CD5(-)CD10(+), and 8 CD5(-)CD10(-)) types. A comparison of genome profiles of distinct subgroups of DLBCL demonstrated that (1) ABC DLBCL is characterized by gain of 3q, 18q, and 19q and loss of 6q and 9p21, and GCB DLBCL is characterized by gain of 1q, 2p, 7q, and 12q; (2) the genomic imbalances characteristic of the CD5(+) and CD5(-)CD10(+) groups were similar to those of the ABC and GCB types, respectively. These findings suggest that CD5(+) and CD5(-)CD10(+) subgroups are included, respectively, in the ABC and GCB types. Finally, when searching for genomic imbalances that affect patients' prognosis, we found that 9p21 loss (p16(INK4a) locus) marks the most aggressive type of DLBCL. Expression profiles in 46 patients with DLBCL and 8 for normal lymph node biopsy samples.
Project description:Diffuse large B-cell lymphoma (DLBCL) comprises molecularly distinct subgroups such as activated B-cell-like (ABC) and germinal center B-cell-like (GCB) DLBCLs. We previously reported that CD5(+) and CD5(-)CD10(+) DLBCL constitute clinically relevant subgroups. To determine whether these 2 subgroups are related to ABC and GCB DLBCLs, we analyzed the genomic imbalance of 99 cases (36 CD5(+), 19 CD5(-)CD10(+), and 44 CD5(-)CD10(-)) using array-based comparative genomic hybridization (CGH). Forty-six of these cases (22 CD5(+), 9 CD5(-)CD10(+), 1 CD5 (-), and 14 CD5(-)CD10(-)) were subsequently subjected to gene-expression profiling, resulting in their division into 28 ABC (19 CD5(+) and 9 CD5(-)CD10(-)) and 18 GCB (3 CD5(+), 7 CD5(-)CD10(+), and 8 CD5(-)CD10(-)) types. A comparison of genome profiles of distinct subgroups of DLBCL demonstrated that (1) ABC DLBCL is characterized by gain of 3q, 18q, and 19q and loss of 6q and 9p21, and GCB DLBCL is characterized by gain of 1q, 2p, 7q, and 12q; (2) the genomic imbalances characteristic of the CD5(+) and CD5(-)CD10(+) groups were similar to those of the ABC and GCB types, respectively. These findings suggest that CD5(+) and CD5(-)CD10(+) subgroups are included, respectively, in the ABC and GCB types. Finally, when searching for genomic imbalances that affect patients' prognosis, we found that 9p21 loss (p16(INK4a) locus) marks the most aggressive type of DLBCL.
Project description:B cell receptor (BCR) signaling has emerged as a therapeutic target in B cell lymphomas, but the precise deployment of inhibitors to target oncogenic BCR signaling requires detailed knowledge of the signaling cascades that the BCR triggers in individual tumors. Here, we have used CRISPR-Cas9 screens to investigate whether the ABC and GCB molecular subtypes of diffuse large B cell lymphoma (DLBCL) utilize distinct BCR signaling modes to sustain their proliferation and survival. Constitutive germinal center (GC) BCR signaling in GCB DLBCLs requires the BCR, CD19 and SYK engaging PI(3) kinase for survival. In ABC DLBCLs with oncogenic mutations in the BCR and MYD88, a novel BCR-TLR9-MYD88 signaling supercomplex is assembled on endolysosomal membranes that engages NF-kB. Our data explain why this subset of ABC DLBCL tumors respond frequently to ibrutinib, an inhibitor of BCR-dependent NF- kB activation, while GCB DLBCLs are insensitive, and thus provide a roadmap for the rational development of BCR pathway inhibitors in molecular subtypes of DLBCL.
Project description:We performed DNA methylation (HELP) and gene expression profiling in 69 samples of diffuse large B cell lymphoma (DLBCL). First, by gene expression, two molecular subtypes of DLBCL termed as germinal center B cell-like (GCB) and activated B cell-like (ABC) DLBCL were assigned to the 69 DLBCL cases. Then, we performed supervised analysis using HELP data and defined DNA methylation signature differentiating 2 subgroups of DLBCLs. Keywords: DNA methylation profiling
Project description:<p>Diffuse large B-cell lymphoma (DLBCL), the most common lymphoid malignancy in adults, is a clinically and genetically heterogenous disease that is further classified into transcriptionally defined activated B-cell (ABC) and germinal center B-cell (GCB) subtypes. Here, we describe a comprehensive genetic analysis of DLBCLs that identifies low-frequency alterations, captures recurrent mutations, copy number alterations (CNAs) and structural variants (SVs) and characterizes coordinate genetic signatures in 304 primary DLBCLs with available outcome data. We integrated these genetic drivers using consensus clustering and identified 5 robust DLBCL subsets, including a previously unrecognized group of low-risk ABC-DLBCLs of extrafollicular/marginal zone origin; 2 distinct subsets of GCB-DLBCLs with different outcomes and targetable alterations; and an ABC/GCB-independent group with biallelic inactivation of TP53, CDKN2A loss and associated genomic instability. The genetic features of the newly identified subsets, their mutational signatures and the temporal ordering of identified alterations provide new insights into DLBCL pathogenesis. The coordinate genetic signatures also predict outcome independent of the clinical International Prognostic Index and suggest new combination treatment strategies. More broadly, these studies provide a roadmap for an actionable DLBCL classification. </p>
Project description:The activated B cell-like (ABC) subgroup of diffuse large B cell lymphoma (DLBCL) is characterized by constitutive activation of the NF-êB pathway. Here we show that the NF- êB pathway induces the expression of the cytokines IL-6 and IL-10 in ABC DLBCL cell lines, which also have high levels of total and phosphorylated STAT3 protein, suggesting autocrine signaling. Using RNA interference for STAT3, we defined a gene expression signature of IL-6 and IL-10 signaling through STAT3. Based on this signature, we constructed a molecular predictor of STAT3 signaling that defined a subset of ABC DLBCL tumors with high expression of STAT3, IL-6 and/or IL-10, and their downstream targets. Although the STAT3-high and STAT3-low subsets had equivalent expression of genes that distinguish ABC DLBCL from GCB DLBCL, STAT3-high ABC DLBCLs had higher expression of signatures that reflected NF-kB activity, proliferation, and glycolysis. A smallmolecule inhibitor of JAK signaling, which blocked STAT3 signature expression, was toxic only for ABC DLBCL lines, and synergized with an inhibitor of NF-kB signaling. These findings suggest that the biological interplay between the STAT3 and NF-kB pathways may be exploited for the treatments of a subset of ABC DLBCLs. Keywords: time series design
Project description:We performed DNA methylation (HELP) and gene expression profiling in 69 samples of diffuse large B cell lymphoma (DLBCL). First, by gene expression, two molecular subtypes of DLBCL termed as germinal center B cell-like (GCB) and activated B cell-like (ABC) DLBCL were assigned to the 69 DLBCL cases. Then, we performed supervised analysis using HELP data and defined DNA methylation signature differentiating 2 subgroups of DLBCLs. Keywords: DNA methylation profiling The retrospective study included DNA extracted from 69 clinical samples. [This Series represents the DNA methylation profiling component of the study.]
Project description:Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease, with at least one-third of its patients not responding to the current chemotherapy regimen, R-CHOP. By gene expression profiling, patients with DLBCL can be categorized into two clinically relevant subtypes: activated B-cell (ABC) DLBCL and germinal center B-cell (GCB). Patients with ABC DLBCL have a worse prognosis, and are defined by chronic, overactive signaling through the B-cell receptor and NF-κB pathways. We examined the effects of the Src family kinase (SFK) inhibitor dasatinib in a panel of ABC and GCB DLBCL cell lines, and found that the ABC DLBCL cell lines are much more sensitive to dasatinib than the GCB DLBCL cell lines. However, using multiplexed inhibitor bead coupled to mass spectrometry (MIB/MS) kinome profiling competition and western blot analysis, both subtypes display inhibition of the SFKs in response to dasatinib after both short- and long-term treatment. MIB/MS analyses revealed several cell cycle kinases, including CDK4, CDK6, and the Aurora kinases, are inhibited by dasatinib treatment in the ABC DLBCL subtype, but not in the GCB DLBCL subtype. The present findings have important implications for the clinical use of dasatinib for the treatment of ABC DLBCL, either alone or in combination with other agents.