BCL2 dependency in diffuse large B-cell lymphoma: it's a family affair.
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ABSTRACT:
SUBMITTER: Matulis SM
PROVIDER: S-EPMC7395263 | biostudies-literature | 2020 Aug
REPOSITORIES: biostudies-literature
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BCL2 dependency in diffuse large B-cell lymphoma: it's a family affair.
Matulis Shannon M SM Boise Lawrence H LH
Haematologica 20200801 8
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Project description:The BCL6 proto-oncogene encodes a transcriptional repressor that is required for germinal center (GC) formation and whose deregulation by genomic lesions is implicated in the pathogenesis of GC-derived diffuse large B cell lymphoma (DLBCL) and, less frequently, follicular lymphoma (FL). The biological function of BCL6 is only partially understood because no more than a few genes have been functionally characterized as direct targets of BCL6 transrepression activity. Here we report that the anti-apoptotic proto-oncogene BCL2 is a direct target of BCL6 in GC B cells. BCL6 binds to the BCL2 promoter region by interacting with the transcriptional activator Miz1 and suppresses Miz1-induced activation of BCL2 expression. BCL6-mediated suppression of BCL2 is lost in FL and DLBCL, where the 2 proteins are pathologically coexpressed, because of BCL2 chromosomal translocations and other mechanisms, including Miz1 deregulation and somatic mutations in the BCL2 promoter region. These results identify an important function for BCL6 in facilitating apoptosis of GC B cells via suppression of BCL2, and suggest that blocking this pathway is critical for lymphomagenesis.
| S-EPMC2708681 | biostudies-literature
Project description:High-grade B-cell lymphoma (HGBL) with translocations involving MYC and BCL2 or BCL6 comprises ∼10% of cases of diffuse large B-cell lymphoma (DLBCL) and carries a poor prognosis. The incidence, prognosis, and optimal therapy for DLBCL harboring extra copies of the genes MYC, BCL2, and BCL6, rather than their genetic translocations, are unknown. In this retrospective, single-center study we identified 144 DLBCL cases including 46 patients with classic HGBL with double-hit or triple-hit chromosomal translocations (DHL), 55 with extra copies of MYC in addition to aberrations (extra copies or translocations) of BCL2 and/or BCL6 but did not meet the criteria for HGBL (EC group), and 43 without any aberrations of MYC, BCL2, or BCL6 (wild type [WT]). Unfavorable baseline characteristics had similar frequency in the EC and WT groups, but were significantly more prevalent in the DHL group. With a median follow-up of 36 months, the 2-year event-free survival (EFS) was similar between the WT and EC groups at 77% (95% confidence interval [CI], 65-90) and 82% (95% CI, 72-93), respectively. In contrast, the 2-year EFS of the DHL group was 63% (95% CI, 51-79). The 2-year overall survival in the WT, EC, and DHL groups was 86% (95% CI, 76-97), 89% (95% CI, 81-98), and 74% (95% CI, 62-88), respectively. Among patients treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone), the EC group had outcomes similar to those of the WT group. Our results indicate that patients with DLBCL with extra gene copies of MYC, BCL2, and BCL6 fare differently from those with HGBL and respond well to standard R-CHOP therapy.
| S-EPMC7391142 | biostudies-literature
Project description: Not available
| S-EPMC8377611 | biostudies-literature
Project description:Gene expression profiling of diffuse large B-cell lymphoma (DLBCL) has revealed prognostically important subgroups: germinal center B-cell-like (GCB) DLBCL, activated B cell-like (ABC) DLBCL, and primary mediastinal large B-cell lymphoma. The t(14;18)(q32;q21) has been reported previously to define a unique subset within the GCB-DLBCL. We evaluated for the translocation in 141 cases of DLBCL that were successfully gene expression profiled. Using a dual-probe fluorescence in situ hybridization assay, we detected the t(14;18) in 17% of DLBCLs and in 34% of the GCB subgroup which contained the vast majority of positive cases. In addition, 12 t(14;18)-positive cases detected by polymerase chain reaction assays on additional samples were added to the fluorescence in situ hybridization-positive cases for subsequent analysis. Immunohistochemical data indicated that BCL2, BCL6, and CD10 protein were preferentially expressed in the t(14;18)-positive cases as compared to t(14;18)-negative cases. Within the GCB subgroup, the expression of BCL2 and CD10, but not BCL6, differed significantly between cases with or without the t(14;18): 88% versus 24% for BCL2 and 72% versus 32% for CD10, respectively. In the GCB-DLBCL subgroup, a heterogeneous group of genes is overexpressed in the t(14;18)-positive subset, among which BCL2 is a significant discriminator. Interestingly, the t(14;18)-negative subset is dominated by overexpression of cell cycle-associated genes, indicating that these tumors are significantly more proliferative, suggesting distinctive pathogenetic mechanisms. However, despite this higher proliferative activity, there was no significant difference in overall or failure-free survival between the t(14;18)-positive and -negative subsets within the GCB subgroup.
| S-EPMC1618550 | biostudies-literature
Project description:The objective of this study was to create a bioclinical model, based on clinical and molecular predictors of event-free and overall survival for relapsed/refractory diffuse large B-cell lymphoma patients treated on the Canadian Cancer Trials Group (CCTG) LY12 prospective study. In 91 cases, sufficient histologic material was available to create tissue microarrays and perform immunohistochemistry staining for CD10, BCL6, MUM1/IRF4, FOXP1, LMO2, BCL2, MYC, P53 and phosphoSTAT3 (pySTAT3) expression. Sixty-seven cases had material sufficient for fluorescent in situ hybridization (FISH) for MYC and BCL2 In addition, 97 formalin-fixed, paraffin-embedded tissue samples underwent digital gene expression profiling (GEP) to evaluate BCL2, MYC, P53, and STAT3 expression, and to determine cell-of-origin (COO) using the Lymph2Cx assay. No method of determining COO predicted event-free survival (EFS) or overall survival (OS). Factors independently associated with survival outcomes in multivariate analysis included primary refractory disease, elevated serum lactate dehydrogenase (LDH) at relapse, and MYC or BCL2 protein or gene expression. A bioclinical score using these four factors predicted outcome with 3-year EFS for cases with 0-1 vs 2-4 factors of 55% vs 16% (P<0.0001), respectively, assessing MYC and BCL2 by immunohistochemistry, 46% vs. 5% (P<0.0001) assessing MYC and BCL2 messenger ribonucleic acid (mRNA) by digital gene expression, and 42% vs 21% (P=0.079) assessing MYC and BCL2 by FISH. This proposed bioclinical model should be further studied and validated in other datasets, but may discriminate relapsed/refractory diffuse large B-cell lymphoma (DLBCL) patients who could benefit from conventional salvage therapy from others who require novel approaches. The LY12 study; clinicaltrials.gov Identifier: 00078949.
| S-EPMC5792273 | biostudies-literature
Project description:BackgroundApproximately one-third of diffuse large B cell lymphoma (DLBCL) patients exhibit co-expression of MYC and BCL2 (double-expressor lymphoma, DEL) and have a dismal prognosis. Targeted inhibition of the anti-apoptotic protein BCL2 with venetoclax (ABT-199) has been approved in multiple B-cell malignancies and is currently being investigated in clinical trials for DLBCL. Whether BCL2 anti-apoptotic function represents a multifaceted vulnerability for DEL-DLBCL, affecting both lymphoma B cells and T cells within the tumor microenvironment, remains to be elucidated.MethodsHere, we present novel genetically engineered mice that preclinically recapitulate DEL-DLBCL lymphomagenesis, and evaluate their sensitivity ex vivo and in vivo to the promising combination of venetoclax with anti-CD20-based standard immunotherapy.ResultsVenetoclax treatment demonstrated specific killing of MYC+/BCL2+ lymphoma cells by licensing their intrinsically primed apoptosis, and showed previously unrecognized immunomodulatory activity by specifically enriching antigen-activated effector CD8 T cells infiltrating the tumors. Whereas DEL-DLBCL mice were refractory to venetoclax alone, inhibition of BCL2 significantly extended overall survival of mice that were simultaneously treated with a murine surrogate for anti-CD20 rituximab.ConclusionsThese results suggest that the combination of anti-CD20-based immunotherapy and BCL2 inhibition leads to cooperative immunomodulatory effects and improved preclinical responses, which may offer promising therapeutic opportunities for DEL-DLBCL patients.
| S-EPMC9980368 | biostudies-literature
Project description:Based on gene expression profiles, diffuse large B cell lymphoma (DLBCL) is sub-divided into germinal center B cell-like (GCB) and activated B cell-like (ABC) DLBCL. Two of the most common genomic aberrations in ABC-DLBCL are mutations in MYD88, as well as BCL2 copy number gains. Here, we employ immune phenotyping, RNA-Seq and whole exome sequencing to characterize a Myd88 and Bcl2-driven mouse model of ABC-DLBCL. We show that this model resembles features of human ABC-DLBCL. We further demonstrate an actionable dependence of our murine ABC-DLBCL model on BCL2. This BCL2 dependence was also detectable in human ABC-DLBCL cell lines. Moreover, human ABC-DLBCLs displayed increased PD-L1 expression, compared to GCB-DLBCL. In vivo experiments in our ABC-DLBCL model showed that combined venetoclax and RMP1-14 significantly increased the overall survival of lymphoma bearing animals, indicating that this combination may be a viable option for selected human ABC-DLBCL cases harboring MYD88 and BCL2 aberrations.
| S-EPMC7806186 | biostudies-literature
Project description:Aberrant expression of CD5 has been reported in 5-10% of diffuse large B-cell lymphomas (DLBCLs). CD5+ DLBCL had been recognized as an aggressive immunophenotypic subgroup of DLBCL in the 2008 WHO classification of haematolymphoid neoplasm; however, it was eliminated from the list of subgroups of DLBCLs in the revised 2016 classification. Nevertheless, there is much controversy regarding the clinical significance of CD5 expression, and many researchers still assert that this subgroup exhibits an extremely unfavorable prognosis with frequent treatment failure. We retrospectively investigated 405 DLBCLs recruited from three university hospitals in Korea from 1997 to 2013. The clinical profile, immunophenotype, and chromosomal structural alterations of the BCL2 and MYC genes were compared according to CD5 expression. A total of 29 cases of de novo CD5+ DLBCL were identified out of 405 in our series (7.4%). Clinicopathologic correlation was performed in all 29 CD5+ DLBCLs and 166 CD5- DLBCLs which were eligible for full clinical review and further pathologic examination. Compared with CD5- counterparts, CD5+ DLBCLs showed female preponderance, frequent bone marrow involvement, higher lactate dehydrogenase level, advanced Ann Arbor stages and poorer prognosis (all p<0.05). Pathologically, the expression of CD5 positively correlated with that of BCL2, MYC and Ki-67 (all p<0.05). Coexpression of BCL2 and MYC, which is referred to as a double-expressor, was relatively more common in CD5+ DLBCL, whereas translocation or amplification of these genes was very rare. in conclusion, the expression of CD5 is an independent poor prognostic factor of DLBCLs, and this subgroup displays unique clinicopathologic features. Although the exact mechanism remains uncertain, consistent activation of BCL2 and MYC by alternative pathways other than chromosomal translocation may contribute to the pathogenesis.
| S-EPMC6808439 | biostudies-literature
Project description:PurposeWe have previously shown the prognostic significance of BCL2 expression in the activated B-cell-like diffuse large B-cell lymphoma (ABC-DLBCL) patients treated with cyclophosphamide-Adriamycin-vincristine-prednisone (CHOP) or CHOP-like therapy. However, after the inclusion of rituximab (R) in the CHOP regimen, several conflicting observations about the prognostic value of BCL2 expression have been reported.Experimental designWe evaluated the R-CHOP cohort of 221 DLBCL cases with gene expression profiling data. BCL2 protein (n = 169), mRNA (n = 221) expression, and t(14;18) (n = 144) were correlated with clinical outcome. The CHOP cohort (n = 181) was used for comparative analysis.ResultsBCL2 protein expression has significant impact on overall survival (OS) and event-free survival (EFS) in DLBCL (OS, P = 0.009; EFS, P = 0.001) and GCB-DLBCL (OS, P = 0.03; EFS, P = 0.002) but not in ABC-DLBCL in the R-CHOP cohort. The survival differences for EFS in GCB-DLBCL were still observed in multivariate analysis. At the mRNA level, this correlation was observed in EFS in DLBCL (P = 0.006), but only a trend was observed in GCB-DLBCL (P = 0.09). The t(14;18) was detected in 34% of GCB-DLBCL but was not associated with significant differences in survival. Gene enrichment analysis identified significant enrichment of the DLBCL "stromal-1" signatures and hypoxia-inducible factor 1 (HIF1-α) signature in BCL2(-)GCB-DLBCL, whereas T(FH) cell signatures were enriched in BCL2(+)GCB-DLBCL.ConclusionThe prognostic significance of BCL2 has changed after inclusion of rituximab in the treatment protocol and is observed in the GCB-DLBCL rather than the ABC-DLBCL. Although rituximab has benefited patients in both DLBCL subgroups, the BCL2(+)GCB-DLBCL seems to receive less benefit from this treatment and may require other novel therapeutic intervention.
| S-EPMC7394278 | biostudies-literature
Project description:Diffuse large B-cell lymphoma (DLBCL) comprises a heterogeneous group with pathophysiological, genetic and clinical features. Many patients can be cured with R-CHOP therapy, which is the current standard regimen. Despite recent progress in improving patient survival, the 40% survival of DLBCL patients remains poor. Therefore, the most important issue for patients with DLBCL remains the development of a new front-line therapy. Several studies have reported that intensified chemotherapy with dose-adjusted EPOCH-R or R-ACVBP was superior to R-CHOP. Gene expression profiling has identified two distinct forms of DLBCL: activated B cell-like (ABC) and germinal center B-cell-like (GCB) types. ABC DLBCL exhibits a worse prognosis than GCB DLBCL by molecular diagnosis after R-CHOP therapy. Next-generation sequencing has identified unique oncogenic mechanisms and genetic complexity, which has provided rational therapeutic targets. There are also a number of biomarkers, including CD5, and prognostic factors. Efforts to distinguish many biomarkers will be crucial for individualized treatment in the future.
| S-EPMC6144206 | biostudies-literature