Cross-Platform Assessment of Genomic Imbalance Confirms the Clinical Relevance of Genomic Complexity and Reveals Loci with Potential Pathogenic Roles in Diffuse Large B-Cell Lymphoma
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE74025 | GEO | 2015/12/01
SECONDARY ACCESSION(S): PRJNA302302
REPOSITORIES: GEO
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Project description:Richter syndrome (RS) occurs in up to 15% of patients with chronic lymphocytic leukemia (CLL). While RS, usually represented by the histologic transformation to a diffuse large B-cell lymphoma (DLBCL), is associated with a very poor outcome, especially when clonally related to the pre-existing CLL, mechanisms leading to RS have not been clarified yet. To better understand the pathogenesis of RS, we analyzed a series of cases including: 59 RS, 28 CLL-phase of RS, 315 CLL and 127 de novo DLBCL. RS demonstrated a genomic complexity intermediate between CLL and DLBCL. Cell cycle deregulation via inactivation of TP53 and of CDKN2A was a main mechanism in the histologic transformation from CLL-phase, being present in approximately half of the cases, and affected the outcome of the RS patients. A second major subgroup was characterized by the presence of trisomy 12 and comprised one third of the cases. While RS shared some of the lesions seen in de novo DLBCL, its genomic profile was clearly separate. The CLL-phase preceding RS had not a generalized increase in genomic complexity when compared with untransformed CLL, but it presented clear differences in the frequency of specific genetic lesions. Genomic profiling of Richter-syndrome Chronic Lymphocytic Leukemia
2013-09-20 | E-GEOD-50252 | biostudies-arrayexpress
Project description:Richter syndrome (RS) occurs in up to 15% of patients with chronic lymphocytic leukemia (CLL). While RS, usually represented by the histologic transformation to a diffuse large B-cell lymphoma (DLBCL), is associated with a very poor outcome, especially when clonally related to the pre-existing CLL, mechanisms leading to RS have not been clarified yet. To better understand the pathogenesis of RS, we analyzed a series of cases including: 59 RS, 28 CLL-phase of RS, 315 CLL and 127 de novo DLBCL. RS demonstrated a genomic complexity intermediate between CLL and DLBCL. Cell cycle deregulation via inactivation of TP53 and of CDKN2A was a main mechanism in the histologic transformation from CLL-phase, being present in approximately half of the cases, and affected the outcome of the RS patients. A second major subgroup was characterized by the presence of trisomy 12 and comprised one third of the cases. While RS shared some of the lesions seen in de novo DLBCL, its genomic profile was clearly separate. The CLL-phase preceding RS had not a generalized increase in genomic complexity when compared with untransformed CLL, but it presented clear differences in the frequency of specific genetic lesions.
2013-09-20 | GSE50252 | GEO
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>
| phs000450 | dbGaP
Project description:Molecular pathogenesis of posttransplant (PT) lymphoproliferative disorder, including the most prevalent diffuse large B cell lymphoma (DLBCL), is largely unknown. We have recently showed that Epstein-Barr Virus (EBV)+ and EBV- PT-DLBCL are biologically different, but gene expression profile of the latter lymphoma is similar to that of immunocompetent (IC) DLBCL. To validate these findings on a genomic level, we performed array CGH analysis of 21 EBV+ and 6 EBV- PT-DLBCL, and 11 control IC-DLBCL. Genomic and transcriptomic data were subsequently integrated. Notably, EBV+ and EBV- PT-DLBCL revealed only one shared recurrent imbalance, while EBV- PT-DLBCL displayed at least 10 aberrations recurrent in IC-DLBCL, among others gain of 3/3q and 18q, and loss of 6q23/TNFAIP3 and 9p21/CDKN2A. EBV+ PT-DLBCL showed distinct aberrations, including the most prevalent gain/amplification of 9p24.1 targeting PDCD1LG2/PDL2. Significant differential representation/expression of 3p13/FOXP1 and 9p21/CDKNA2 in EBV+ PT-DLBCL when compared with EBV- PT-/IC-DLBCL, suggests that the oncogene FOXP1 and the tumor suppressor gene CDKNA2 are not implicated in pathogenesis of EBV+ PT-DLBCL. In summary, genomic profiling of PT-/IC-DLBCL confirmed biological distinctness of EBV+ and EBV- PT-DLBCL, and relationship between EBV- PT-DLBCL and IC-DLBCL. These findings support the hypothesis that EBV- PT-DLBCL are coincidental lymphomas in transplant recipients
2015-06-02 | GSE69440 | GEO
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.
2009-07-10 | E-GEOD-16920 | biostudies-arrayexpress
Project description:Copy number analysis can be useful for assessing prognosis in diffuse large B cell lymphoma (DLBCL). We analyzed copy number data from tumor samples of 60 patients diagnosed with DLBCL de novo and their matched normal samples. We detected a total of 63 recurrent copy number alterations (CNAs), including 33 gains, 30 losses, and nine recurrent acquired copy number neutral loss of heterozygosity (CNN-LOH). Interestingly, 20% of cases acquired CNN-LOH of 6p21 locus, which involves the HLA region. In normal cells there were no CNAs but we observed CNN-LOH involving some key lymphoma regions such as 6p21 and 9p24.1 (5%) and 17p13.1 (2.5%) in DLBCL patients. Furthermore, a model with some specific CNA was able to predict the subtype of DLBCL, 1p36.32 and 10q23.31 losses being restricted to germinal center B cell-like (GCB) DLBCL. In contrast, 8p23.3 losses and 11q24.3 gains were strongly associated with the non-GCB subtype. A poor prognosis was associated with biallelic inactivation of TP53 or 18p11.32 losses, while prognosis was better in cases carrying 11q24.3 gains, which includes ETS1 and FLI1 genes. In summary, CNA abnormalities identify specific DLBCL groups, and we describe CN-LOH in germline cells from DLBCL patients that are associated with genes that probably play a key role in DLBCL development.
2016-01-22 | GSE71389 | GEO
Project description:Copy number analysis can be useful for assessing prognosis in diffuse large B cell lymphoma (DLBCL). We analyzed copy number data from tumor samples of 60 patients diagnosed with DLBCL de novo and their matched normal samples. We detected a total of 63 recurrent copy number alterations (CNAs), including 33 gains, 30 losses, and nine recurrent acquired copy number neutral loss of heterozygosity (CNN-LOH). Interestingly, 20% of cases acquired CNN-LOH of 6p21 locus, which involves the HLA region. In normal cells there were no CNAs but we observed CNN-LOH involving some key lymphoma regions such as 6p21 and 9p24.1 (5%) and 17p13.1 (2.5%) in DLBCL patients. Furthermore, a model with some specific CNA was able to predict the subtype of DLBCL, 1p36.32 and 10q23.31 losses being restricted to germinal center B cell-like (GCB) DLBCL. In contrast, 8p23.3 losses and 11q24.3 gains were strongly associated with the non-GCB subtype. A poor prognosis was associated with biallelic inactivation of TP53 or 18p11.32 losses, while prognosis was better in cases carrying 11q24.3 gains, which includes ETS1 and FLI1 genes. In summary, CNA abnormalities identify specific DLBCL groups, and we describe CN-LOH in germline cells from DLBCL patients that are associated with genes that probably play a key role in DLBCL development.
2016-01-22 | GSE71386 | GEO
Project description:A better understanding of the pathogenesis of diffuse large B-cell lymphoma (DLBCL) has clarified its relationship to normal B-cells, pointed to distinct mechanisms of cell transformation, and facilitated the design of novel treatments. However, these data derive from mRNA genes studies, whereas genome-wide integrative investigations of the role of microRNAs (miRNAs) in DLBCL are still unavailable. We used array-CGH and microarray-based expression analyses to map the abnormalities targeting miRNAs in DLBCLs (n=86). Using training and validation DLBCL cohorts, we defined a collection of miRNAs that robustly segregates these tumors in three unique subsets. This miRNA-driven substructure appears to influence disease outcome, is independent of other mRNA-based DLBCL classifications, and stems from copy number changes targeting the miRNA genome, MYC activity, and the miRNA fingerprints of mature normal B-cells. Our data have uncovered clinically relevant additional molecular complexity in DLBCL and have established a blueprint for the detailed characterizations of miRNAs that are pertinent to B-cell lymphoma biology.
2009-03-13 | GSE15142 | GEO
Project description:A better understanding of the pathogenesis of diffuse large B-cell lymphoma (DLBCL) has clarified its relationship to normal B-cells, pointed to distinct mechanisms of cell transformation, and facilitated the design of novel treatments. However, these data derive from mRNA genes studies, whereas genome-wide integrative investigations of the role of microRNAs (miRNAs) in DLBCL are still unavailable. We used array-CGH and microarray-based expression analyses to map the abnormalities targeting miRNAs in DLBCLs (n=86). Using training and validation DLBCL cohorts, we defined a collection of miRNAs that robustly segregates these tumors in three unique subsets. This miRNA-driven substructure appears to influence disease outcome, is independent of other mRNA-based DLBCL classifications, and stems from copy number changes targeting the miRNA genome, MYC activity, and the miRNA fingerprints of mature normal B-cells. Our data have uncovered clinically relevant additional molecular complexity in DLBCL and have established a blueprint for the detailed characterizations of miRNAs that are pertinent to B-cell lymphoma biology.
2009-03-16 | GSE15177 | GEO
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.
2009-07-10 | GSE16920 | GEO