scholarly journals Rituximab regulates signaling pathways and alters gene expression associated with cell death and survival in diffuse large B-cell lymphoma

2011 ◽  
Vol 25 (4) ◽  
Author(s):  
Leppä
Keyword(s):  
Gene Expression ◽  
Cell Death ◽  
B Cell ◽  
Signaling Pathways ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Large B Cell Lymphoma ◽  
Large B Cell

scholarly journals Upregulation of Cereblon Expression By the DNA Methyltransferase Inhibitor Azacytidine Strongly Enhances Lenalidomide Cytotoxicity in Germinal Center B-Cell-like (GCB) and Activated B-Cell-like (ABC) Diffuse Large B-Cell Lymphoma (DLBCL)

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2253-2253 ◽  
Author(s):  
Silvia L Locatelli ◽  
Roberto Papait ◽  
Giuseppa Careddu ◽  
Ada Koschorke ◽  
Giuliano G Stirparo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Death ◽  
B Cell ◽  
Cell Lines ◽  
Germinal Center ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Large B Cell Lymphoma ◽  
Germinal Center B Cell ◽  
Large B Cell

Abstract INTRODUCTION: Lenalidomide monotherapy exerts clinical activity in relapsed/refractory Diffuse Large B-cell Lymphoma (DLBCL) with better response rate and progression-free survival being recorded in activated B-cell-like (ABC) rather than germinal center B-cell-like (GCB)-DLBCL. Reasons for such a difference are likely due to different expression of key molecules involved in mediating activity of Lenalidomide, such as Interferon regulatory factor 4(IRF4) and cereblon (CRBN). Evidences supporting the key role of DNA methylation and histone modifications in regulating genome stability and gene expression in DLBCL prompted us to investigate the capacity of Azacytidine in modulating Lenalidomide activity, thereby sensitizing GCB-DLBCL to Lenalidomide and enhancing Lenalidomide efficacy in ABC-DLBCL. METHODS: DLBCL cell lines with ABC (U-2932, RIVA) or GCB (SU-DHL4, SU-DHL6) genotype were used to investigate the effects of Lenalidomide and Azacytidine on cell growth and cell death. Western blotting (WB) and immunofluorescence analysis were used to assess modulating effects of the two-drug combination on molecular determinants of Lenalidomide activity. Additionally, we studied CRBN, IRF4 and CRBN binding proteins expression, such as Ikaros and Aiolos (IKZF1 and IKZF3) by real time polymerase chain reaction (RT-PCR) in response to drug treatment. RESULTS: Graded concentrations of Lenalidomide (0.1-100 µM) inhibited cell proliferation by 20% to 40% and increased cell death up to 30% to 40% in ABC-DLBCL cell lines, whereas had minimal effects on GCB-DLBCL cell lines. Untreated ABC-DLBCL but not GCB-DLBCL consistently showed a high expression of CRBN and IRF4. Upon Lenalidomide treatment (3 days) CRBN was significantly upregulated and IRF4 downregulated in ABC-DLBCL, but not GCB-DLBCL cells. Since DNA methylation regulates gene expression in DLBCL cell lines, we next examined whether Azacytdine could modulate CRBN and IRF4 expression and in turn enhance responsiveness to Lenalidomide. Exposure of both ABC- and GCB-DLBCL cell lines to Azacytidine (up to 72 hours) induced a marked increase of CRBN and IRF4 transcripts; addition of Lenalidomide strongly increased Azacytidine-induced increase of CRBN and significantly downregulated IRF4 expression; the combined treatment induced a marked downregulation of Ikaros and Aiolos protein levels. At the cellular level, the concomitant Azacytidine (10 μM)/Lenalidomide (10 μM) treatment inhibited in a synergistic manner the mean (±SEM) cell growth of both ABC-DLBCL (Lena: -16 ± 4%; AZA: -22 ± 2%; AZA/Lena: -70 ± 1%, P<0.001) and GCB-DLBCL (Lena: -17 ± 3%; AZA: -40 ± 4%; AZA/Lena: -82 ± 2%, P<0.001). Additionally, the two drug exposure was associated with a 3-fold decrease of S phase cells(Lena: 28 ± 2%; AZA: 22 ± 0.8%; AZA/Lena: 9 ± 1%, P<0.001); a marked p21 overexpression, and a 3- to 4-fold cell death increase (P<0.001) in both ABC- and GCB-DLBCL. CONCLUSIONS: Our results indicate that Azacytidine sensitizes GCB-DLBCL to the cytotoxic effects of Lenalidomide and enhances Lenalidomide efficacy against ABC-DLBCL resulting in synergistic anti-proliferative and pro-apoptotic effects in both ABC- and GCB-DLBCL cell lines. Cytotoxicity of the two drug combination is mediated by signaling events involving CRBN upregulation and IRF4 downregulation leading to CRBN-binding proteins downregulation. Azacytidine-dependent activation of CRBN and IRF4 expression allow to hypothesize a methylation-driven regulation of these genes. These results might provide a rationale for clinical studies using Azacytidine and Lenalidomide combination in ABC- and GCB-DLBCL. Disclosures No relevant conflicts of interest to declare.

scholarly journals Gene expression profiling-based risk prediction and profiles of immune infiltration in diffuse large B-cell lymphoma

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Selin Merdan ◽  
Kritika Subramanian ◽  
Turgay Ayer ◽  
Johan Van Weyenbergh ◽  
Andres Chang ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
B Cell ◽  
Risk Prediction ◽  
Expression Profiling ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Gene Signatures ◽  
Large B Cell Lymphoma ◽  
Large B Cell

AbstractThe clinical risk stratification of diffuse large B-cell lymphoma (DLBCL) relies on the International Prognostic Index (IPI) for the identification of high-risk disease. Recent studies suggest that the immune microenvironment plays a role in treatment response prediction and survival in DLBCL. This study developed a risk prediction model and evaluated the model’s biological implications in association with the estimated profiles of immune infiltration. Gene-expression profiling of 718 patients with DLBCL was done, for which RNA sequencing data and clinical covariates were obtained from Reddy et al. (2017). Using unsupervised and supervised machine learning methods to identify survival-associated gene signatures, a multivariable model of survival was constructed. Tumor-infiltrating immune cell compositions were enumerated using CIBERSORT deconvolution analysis. A four gene-signature-based score was developed that separated patients into high- and low-risk groups. The combination of the gene-expression-based score with the IPI improved the discrimination on the validation and complete sets. The gene signatures were successfully validated with the deconvolution output. Correlating the deconvolution findings with the gene signatures and risk score, CD8+ T-cells and naïve CD4+ T-cells were associated with favorable prognosis. By analyzing the gene-expression data with a systematic approach, a risk prediction model that outperforms the existing risk assessment methods was developed and validated.

scholarly journals Genome-wide DNA methylation and RNA-seq analyses identify genes and pathways associated with doxorubicin resistance in a canine diffuse large B-cell lymphoma cell line

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0250013
Author(s):  
Chia-Hsin Hsu ◽  
Hirotaka Tomiyasu ◽  
Chi-Hsun Liao ◽  
Chen-Si Lin
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
B Cell ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Rna Seq ◽  
Doxorubicin Resistance ◽  
Large B Cell Lymphoma ◽  
Genome Wide ◽  
Large B Cell

Doxorubicin resistance is a major challenge in the successful treatment of canine diffuse large B-cell lymphoma (cDLBCL). In the present study, MethylCap-seq and RNA-seq were performed to characterize the genome-wide DNA methylation and differential gene expression patterns respectively in CLBL-1 8.0, a doxorubicin-resistant cDLBCL cell line, and in CLBL-1 as control, to investigate the underlying mechanisms of doxorubicin resistance in cDLBCL. A total of 20289 hypermethylated differentially methylated regions (DMRs) were detected. Among these, 1339 hypermethylated DMRs were in promoter regions, of which 24 genes showed an inverse correlation between methylation and gene expression. These 24 genes were involved in cell migration, according to gene ontology (GO) analysis. Also, 12855 hypermethylated DMRs were in gene-body regions. Among these, 353 genes showed a positive correlation between methylation and gene expression. Functional analysis of these 353 genes highlighted that TGF-β and lysosome-mediated signal pathways are significantly associated with the drug resistance of CLBL-1. The tumorigenic role of TGF-β signaling pathway in CLBL-1 8.0 was further validated by treating the cells with a TGF-β inhibitor(s) to show the increased chemo-sensitivity and intracellular doxorubicin accumulation, as well as decreased p-glycoprotein expression. In summary, the present study performed an integrative analysis of DNA methylation and gene expression in CLBL-1 8.0 and CLBL-1. The candidate genes and pathways identified in this study hold potential promise for overcoming doxorubicin resistance in cDLBCL.

scholarly journals An NCCN-IPI based immune-related gene prognostic model for diffuse large B-cell lymphoma

2021 ◽  
Author(s):  
Shidai Mu ◽  
Deyao Shi ◽  
Lisha Ai ◽  
Fengjuan Fan ◽  
Fei Peng ◽  
...  
Keyword(s):  
Gene Expression ◽  
B Cell ◽  
Prognostic Model ◽  
Cell Lymphoma ◽  
International Prognostic Index ◽  
Prognostic Significance ◽  
B Cell Lymphoma ◽  
Large B Cell Lymphoma ◽  
Risk Patients ◽  
Large B Cell

AbstractBackgroundAn enhanced International Prognostic Index (NCCN-IPI) was built to better discriminate diffuse large B-cell lymphoma (DLBCL) patients in the rituximab era. However, there is an urgent need to identify novel valuable biomarkers in the context of targeted therapies, such as immune checkpoint blockade (ICB) therapy.MethodsGene expression data and clinical information were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets. 73 immune-related hub genes in DLBCL patients with different IPI levels were identified by weighted gene co-expression network analysis (WGCNA), and 4 genes were selected to construct an IPI-based immune-related prognostic model (IPI-IPM). Afterward, the genetic, somatic mutational and molecular profiles of IPI-IPM subgroups were analyzed, as well as the potential clinical response of ICB in different IPI-IPM subgroups.ResultsThe IPI-IPM was constructed base on the expression of LCN2, CD5L, NLRP11 and SERPINB2, where high-risk patients had shorter overall survival (OS) than low-risk patients, consistent with the results in the GEO cohorts. The comprehensive results showed that a high IPI-IPM risk score was correlated with immune-related signaling pathways, high KMT2D and CD79B mutation rates, high infiltration of CD8+ T cells and macrophages (M1, M2), as well as up-regulation of inhibitory immune checkpoints including PD-L1, LAG3 and BTLA, indicating more potential response to ICB therapy.ConclusionThe IPI-IPM has independent prognostic significance for DLBCL patients, which provides an immunological perspective to elucidate the mechanisms on tumor progression and drug resistance, also sheds a light on developing immunotherapy for DLBCL.

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