Anti CD20 increases PD-L1 protein expression in a cell line of primary mediastinal B cell lymphoma through immunogenetic and micro RNA signaling
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ABSTRACT: Cell lines of mediastinal lymphomas, one each of primary mediastinal (thymic) large B cell lymphoma (PMBL), classic Hodgkin lymphoma (CHL), B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and CHL, and T-cell lymphoma were treated with rituximab (RmAb), brentuximab vedotin (BV), ibrutinib (IBR), prednisone (PRED) or untreated (UT) for 48 hours. Flow cytometry for PD-L1 protein was performed, and differential expression (DE) analysis of mRNA and miRNA performed by RNAseq. B-cell lines exhibited 2- fold increase in PD-L1 protein (p<.05) with RmAb compared to UT. Others showed no effect of RmAb, however, the T-cell line showed 2-fold increase on treatment with BV (P<.05). DE performed by limma showed no genomic level changes. ANOVA analysis of PMBL treated with RmAb, however, showed physiologic level DE involving >3000 genes involving multiple pathways associated with cell death and survival, protein degradation, mRNA translation, mRNA degradation, immunologic functions, and PD-1/PD-L1 immunotherapy. In the B cell lines, DE of CD274 (PD-L1) was decreased or not significant. MiRNA DE showed upregulation of 7 miRNAs, including miR-155-5p.
Project description:Primary mediastinal large B-cell lymphoma (PMBL) represents a clinically and pathologically distinct subtype of large B-cell lymphomas. Furthermore, molecular studies, including global gene expression profiling, have provided evidence that PMBL is more closely related to classical Hodgkin lymphoma (cHL). Although targeted sequencing studies have revealed a number of mutations involved in PMBL pathogenesis, a comprehensive description of disease-associated genetic alterations and perturbed pathways is still lacking. Here, we performed whole-exome sequencing of 95 PMBL tumors to inform on oncogenic driver genes and recurrent copy number alterations. The integration of somatic gene mutations with gene expression signatures provides further insights into genotype-phenotype interrelation in PMBL. We identified highly recurrent oncogenic mutations in the JAK-STAT and NF-kB pathways, and provide additional evidence of the importance of immune evasion in PMBL (CIITA, CD58, B2M, CD274, PDCD1LG2). Our analyses highlight the IRF-pathway as a putative novel hallmark with frequent alterations in multiple pathway members (IRF2BP2, IRF4, IRF8). In addition, our integrative analysis illustrates the importance of JAK1, RELB and EP300 mutations driving oncogenic signaling. The identified driver genes were significantly more frequently mutated in PMBL as compared to diffuse large B-cell lymphoma, whereas only a limited number of genes were significantly different between PMBL and cHL, emphasizing the close relationship between these entities. Our study, performed on a large cohort of PMBL, highlights the importance of distinctive genetic alterations for disease taxonomy with relevance for diagnostic work-up and therapeutic decision-making.
Project description:Primary Mediastinal large B-cell lymphoma (PMBL) is a rare form of non-Hodgkin lymphoma (NHL) representing 2% of mature B-cell NHL in patients less than 18 years of age.We compared the gene expression profiling between fully humanized anti-CD20 targeted monoclonal antibody recognizing a unique CD20 type II epitope, obinutuzumab and IgG or PBS treated Karpas Primary Mediastinal B-cell lymphoma (PMBL) cell line. -
Project description:The pathogenesis of classical Hodgkin lymphoma (cHL), the most common lymphoma in the young, is still enigmatic, largely because its Hodgkin and Reed-Sternberg (HRS) tumor cells are rare in the involved lymph node and therefore difficult to analyze. Here, by overcoming this technical challenge and performing for the first time a genome-wide transcriptional analysis of microdissected HRS cells in comparison to other B-cell lymphomas, cHL lines and normal B-cell subsets, we show that they differ extensively from the usually studied cHL cell lines, that the lost B-cell identity of cHLs is not linked to the acquisition of a plasma cell-like gene expression program, and that Epstein-Barr virus infection of HRS cells has a minor transcriptional influence on the established cHL clone. Moreover, although cHL appears a distinct lymphoma entity overall, HRS cells of its histological subtypes diverged in their similarity to other related lymphomas. Unexpectedly, we identified two molecular subgroups of cHL associated to differential strengths of the transcription factor activity of the NOTCH1, MYC and IRF4 proto-oncogenes. Finally, HRS cells display deregulated expression of several genes potentially highly relevant to lymphoma pathogenesis, including silencing of the apoptosis-inducer BIK and of INPP5D, an inhibitor of the PI3K-driven oncogenic pathway. The present study complements the GSE12453 and GSE14879 records by adding the following 10 samples: 5 primary tumor samples and 5 cell line samples. The 5 primary tumor samples represent 1000-2000 neoplastic cells microdissected from frozen biopsies of 5 cases of primary mediastinal B-cell lymphoma (PMBL). The 5 cell line samples represent 500-1000 living neoplastic cells isolated by fluorescence-activated cell sorting from growing cultures of the classical Hodgkin lymphoma (cHL) cell lines L1236, L428, KMH2 and HDLM2 and the lymphocyte-predominant Hodgkin lymphoma (lpHL) cell line DEV.
Project description:The classical Hodgkin lymphoma (cHL) environment is comprised of a rich and varied immune cell infiltrate that is co-opted to support the survival and growth of malignant Hodgkin-Reed-Sternberg (HRS) cells. Several lines of evidence support the notion that, despite the immune suppressive environment that characterizes this disease, HRS cells are actively surveilled by endogenous T cells. For instance, HRS cells recurrently acquire genetic lesions associated with impaired antigen presentation and PD-L1 upregulation. Moreoever, cHL is particularly vulnerable to anti-PD-1/PD-L1 immunotherapy, which indicates that T cells can recognize and eliminate HRS cells when dominant immune checkpoints are disabled. However, the T cells that drive responses to anti-PD-1 therapy in cHL have not been defined. Furthermore, there is a paucity of data linking phenotypic and functional T cell states with clonality at the single cell level in cHL. To address this knowledge gap, we performed paired single cell RNA and T cell receptor sequencing (scRNA/TCR-seq) on 14 cHL and 5 reactive lymphoid tissue (RLT) specimens. Recurrent and significant clonal expansion within effector and exhausted CD8+ T cell and regulatory T (TREG) cell clusters was uniquely observed in most cHL specimens. Surprisingly, CD8+ T cells exhibiting transcriptional features of exhaustion were relatively uncommon in cHL specimens. Multi-plex flow cytometric analysis revealed maintained effector cytokine secretion by most conventional lymphoma-infiltrating T cells upon ex vivo restimulation, which argued against a profound T cell dysfunctional state in cHL, and suggested that lymphoma-iniltrating T cells, when removed from the immune suppressive cHL environment, are capable of exerting effector functions. Finally, these results raise new questions about the nature of the T cells that mediate response to PD-1 blockade therapy in patients with cHL.
Project description:Primary mediastinal B-cell lymphoma (PMBL) and classical Hodgkin lymphoma (cHL) share a frequent constitutive activation of Janus-activated kinase (JAK) / signal transducer and activator of transcription (STAT) signaling pathway. Due to complex non-linear relations within the pathway, key dynamic properties remained to be identified to predict possible strategies for intervention. To untangle these features, we used dynamic pathway modeling that employs model development and calibration based on extensive quantitative data generation. Quantitative data were collected on JAK/STAT pathway signaling components in two lymphoma-derived cell lines, MedB-1 and L1236, representative of PMBL and cHL, respectively. We showed that the amounts of STAT5 and STAT6 are higher whereas the amount of SHP1 is lower in the two lymphoma cell lines compared to B cells from healthy donors. Distinctively, L1236 cells harbor more JAK2 and less SHP1 molecules per cell than MedB-1 or control cells. In our experimental setting interleukin-13 (IL13) stimulation levels remained constant over time. In MedB-1 cells surface IL13 receptor alpha 2 had a strong IL13-sequestering/decoy function. In both lymphoma cell lines we observed IL13-induced activation of interleukin-4 receptor alpha, JAK2 and STAT5, but not of STAT6, which was highly phosphorylated even without stimulus. Furthermore, the known STAT-inducible negative regulators CISH and SOCS3 were up-regulated within 2 hours in MedB-1 but not in L1236 cells. Global transcription profiling revealed 11 early and 16 sustained common genes up-regulated by IL13 in both lymphoma cell lines. Based on this detailed information we established two individual mathematical models, MedB-1 and L1236 model, which were able to describe the respective experimental data. Sensitivity analysis of the model identified six possible therapeutic targets able to reduce gene expression levels in L1236 cells and three in MedB-1 cells. By inhibition of STAT5 phosphorylation we successfully validated one of the predicted targets demonstrating the potential of the approach in guiding target identification for highly deregulated signaling networks in cancer cells. We established mathematical models of the JAK/STAT pathway in two lymphoma cell types (PMBL and cHL), able to reproduce experimental data and to predict possible therapeutic targets. Cells from two lymphoma-derived cell lines, MedB-1 and L1236, were used for a time-course microarray analysis comprising stimulations with IL13 for 0, 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 h and unstimulated controls (0, 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 h), for a total of 20 microarrays per cell line.
Project description:Diffuse large B-cell lymphoma (DLBCL) is currently divided into three main molecular subtypes, defined by gene expression profiling (GEP): Germinal Center B-cell like (GCB), Activated B-Cell like (ABC), and Primary Mediastinal B-cell Lymphoma (PMBL). DLBCL subtypes were determined according to patients' gene expression profiles.
Project description:Primary mediastinal B-cell lymphoma (PMBL) and classical Hodgkin lymphoma (cHL) share a frequent constitutive activation of Janus-activated kinase (JAK) / signal transducer and activator of transcription (STAT) signaling pathway. Due to complex non-linear relations within the pathway, key dynamic properties remained to be identified to predict possible strategies for intervention. To untangle these features, we used dynamic pathway modeling that employs model development and calibration based on extensive quantitative data generation. Quantitative data were collected on JAK/STAT pathway signaling components in two lymphoma-derived cell lines, MedB-1 and L1236, representative of PMBL and cHL, respectively. We showed that the amounts of STAT5 and STAT6 are higher whereas the amount of SHP1 is lower in the two lymphoma cell lines compared to B cells from healthy donors. Distinctively, L1236 cells harbor more JAK2 and less SHP1 molecules per cell than MedB-1 or control cells. In our experimental setting interleukin-13 (IL13) stimulation levels remained constant over time. In MedB-1 cells surface IL13 receptor alpha 2 had a strong IL13-sequestering/decoy function. In both lymphoma cell lines we observed IL13-induced activation of interleukin-4 receptor alpha, JAK2 and STAT5, but not of STAT6, which was highly phosphorylated even without stimulus. Furthermore, the known STAT-inducible negative regulators CISH and SOCS3 were up-regulated within 2 hours in MedB-1 but not in L1236 cells. Global transcription profiling revealed 11 early and 16 sustained common genes up-regulated by IL13 in both lymphoma cell lines. Based on this detailed information we established two individual mathematical models, MedB-1 and L1236 model, which were able to describe the respective experimental data. Sensitivity analysis of the model identified six possible therapeutic targets able to reduce gene expression levels in L1236 cells and three in MedB-1 cells. By inhibition of STAT5 phosphorylation we successfully validated one of the predicted targets demonstrating the potential of the approach in guiding target identification for highly deregulated signaling networks in cancer cells. We established mathematical models of the JAK/STAT pathway in two lymphoma cell types (PMBL and cHL), able to reproduce experimental data and to predict possible therapeutic targets.
Project description:Amplification of a ~2.5 megabase region on chromosome 9p24 is frequent in both primary mediastinal B-cell lymphoma (PMBL) and Hodgkin's lymphoma (HL). To identify the oncogenic genes in this interval, we created a RNA interference library targeting amplicon genes. A genetic screen using this library identified three genes that are essential for the proliferation and survival of PMBL and HL lines with this amplicon, which encode the kinase JAK2, the histone demethylase JMJD2C and a gene of unknown function, RANBP6. Inhibition of JAK2 and JMJD2C cooperated in killing these lymphomas and in remodeling their chromatin by globally increasing trimethylation of lysine 9 on histone H3 (H3K9me3) and heterochromatin formation. JAK2 and JMJD2C inhibition silenced MYC and its target genes, which coincided with an increase in H3K9me3 and the heterochromatin protein HP1alpha at the MYC locus. We conclude that amplification of JAK2 and JMJD2C cooperatively reprograms the PMBL and HL epigenome, sustaining their survival and proliferation.
Project description:We performed array comparative genomic hybridization (aCGH) and gene expression profiling in 203 samples of diffuse large B cell lymphoma (DLBCL). By gene expression, at least three molecular subtypes of DLBCL termed as germinal center B cell-like (GCB) DLBCL, activated B cell-like (ABC) DLBCL, and primary mediastinal B cell lymphoma (PMBL) can be distinguished. Combining gene expression profiling and aCGH, revealed copy number abnormalities that had strikingly different frequencies in the three molecular DLBCL subtypes. These data provide genetic evidence that the DLBCL subtypes are distinct diseases that utilize different oncogenic pathways. Keywords: clinical history design The retrospective study included RNA and DNA extracted from 203 clinical samples.
Project description:Amplification of a ~2.5 megabase region on chromosome 9p24 is frequent in both primary mediastinal B-cell lymphoma (PMBL) and Hodgkin's lymphoma (HL). To identify the oncogenic genes in this interval, we created a RNA interference library targeting amplicon genes. A genetic screen using this library identified three genes that are essential for the proliferation and survival of PMBL and HL lines with this amplicon, which encode the kinase JAK2, the histone demethylase JMJD2C and a gene of unknown function, RANBP6. Inhibition of JAK2 and JMJD2C cooperated in killing these lymphomas and in remodeling their chromatin by globally increasing trimethylation of lysine 9 on histone H3 (H3K9me3) and heterochromatin formation. JAK2 and JMJD2C inhibition silenced MYC and its target genes, which coincided with an increase in H3K9me3 and the heterochromatin protein HP1alpha at the MYC locus. We conclude that amplification of JAK2 and JMJD2C cooperatively reprograms the PMBL and HL epigenome, sustaining their survival and proliferation. Signal from untreated shRNA cells or DMSO control cells (Cy3) was compared to 4 dox-treated JAK2 shRNA cells, 4 dox-treated JMJD2C shRNA cells, or 8 JAK2 inhibitor-treated cells (Cy5).