Single cell profiling of CD4+ T cells from follicular lymphoma, diffuse large B cell lymphoma and tonsilar samples
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ABSTRACT: Tumor-infiltrating regulatory T cells contribute to an immunosuppressive tumor microenvironment. We applied single-cell RNA sequencing (scRNA-seq) , TCR sequencing combined with cellular indexing of transcriptomes and epitopes (CITE-seq) on CD4 T cells to decipher the heterogeneity of intratumoral Tregs in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL), compared with non-malignant tonsillar tissue.
Project description:Transformation of Follicular Lymphoma to Diffuse Large Cell Lymphoma: Alternative Patterns with Increased or Decreased Expression of c-myc and its Regulated genes The natural history of follicular lymphoma (FL) is frequently characterized by transformation to a more aggressive diffuse large B cell lymphoma (DLBCL). We compared the gene expression profiles between transformed DLBCL and their antecedent FL. No genes were observed to increase or decrease their expression in all the cases of histological transformation. However, two different gene expression profiles associated with the transformation process were defined, one in which c-myc and genes regulated by c-myc showed increased expression and one in which these same genes showed decreased expression. Further, there was a striking difference in gene expression profiles between transformed DLBCL and de novo DLBCL, since the gene expression profile of transformed DLBCL was more similar to their antecedent FL than to de novo DLBCL. The study demonstrates that transformation from FL to DLBCL can occur by alternative pathways and that transformed DLBCL and de novo DLBCL have very different gene expression profiles that may underlie the different clinical behaviors of these two types of morphologically similar lymphomas.
Project description:Copy number analysis was performed on EBV+ DLBCL samples compared with EBV- DLBCL. We analyzed the genomic DNA from 18 cases of EBV+ DLBCL, 21 cases of EBV- DLBCL, and 13 cases of nonneoplastic tonsillar tissues using OncoScan FFPE Express 2.0 (MIP). No technical replication were done.
Project description:The aggressive B cell lymphoma diffuse large B cell lymphoma (DLBCL) is a heterogeneous entity that requires more precise monitoring and prognosis molecular tools. Extracellular vesicles that are secreted by all cell types are currently recognized as serving as a proxy for the cell of origin. Utilizing cutting-edge mass spectrometry, the current study described and assessed the plasma small extracellular vesicles (sEVs) proteome's diagnostic and prognostic potential. The presence of DLBCL has a significant impact on the sEV proteome, and several proteins substantially correlate with DLBCL.Nevertheless, no proteins that highly correlated with non-GCB or GCB were found.
Project description:Diffuse large B-cell lymphoma (DLBCL), the most common subtype of non-Hodgkin's lymphoma, is clinically heterogeneous: 40% of patients respond well to current therapy and have prolonged survival, whereas the remainder succumb to the disease. We proposed that this variability in natural history reflects unrecognized molecular heterogeneity in the tumors. Using DNA microarrays, we have conducted a systematic characterization of gene expression in B-cell malignancies. Here we show that there is diversity in gene expression among the tumors of DLBCL patients, apparently reflecting the variation in tumor proliferation rate, host response and differentiation state of the tumor. We identified two molecularly distinct forms of DLBCL which had gene expression patterns indicative of different stages of B-cell differentiation. One type expressed genes characteristic of germinal center B cells ('germinal center B-like DLBCL'); the second type expressed genes normally induced during in vitro activation of peripheral blood B cells ('activated B-like DLBCL'). Patients with germinal center B-like DLBCL had a significantly better overall survival than those with activated B-like DLBCL. The molecular classification of tumors on the basis of gene expression can thus identify previously undetected and clinically significant subtypes of cancer. This study is described more fully in Alizadeh AA et al.(2000) Nature 403:503-11
Project description:Diffuse large B-cell lymphoma (DLBCL), the most common subtype of non-Hodgkin's lymphoma, is clinically heterogeneous: 40% of patients respond well to current therapy and have prolonged survival, whereas the remainder succumb to the disease. We proposed that this variability in natural history reflects unrecognized molecular heterogeneity in the tumors. Using DNA microarrays, we have conducted a systematic characterization of gene expression in B-cell malignancies. Here we show that there is diversity in gene expression among the tumors of DLBCL patients, apparently reflecting the variation in tumor proliferation rate, host response and differentiation state of the tumor. We identified two molecularly distinct forms of DLBCL which had gene expression patterns indicative of different stages of B-cell differentiation. One type expressed genes characteristic of germinal center B cells ('germinal center B-like DLBCL'); the second type expressed genes normally induced during in vitro activation of peripheral blood B cells ('activated B-like DLBCL'). Patients with germinal center B-like DLBCL had a significantly better overall survival than those with activated B-like DLBCL. The molecular classification of tumors on the basis of gene expression can thus identify previously undetected and clinically significant subtypes of cancer. This study is described more fully in Alizadeh AA et al.(2000) Nature 403:503-11 Keywords: other
Project description:Diffuse large B-cell lymphoma (DLBCL), the most common form of lymphoma in adulthood, comprises multiple biologically and clinically distinct subtypes including germinal center B cell-like (GCB) and activated B cell like (ABC) DLBCL. Gene expression profile studies have shown that its most aggressive subtype, ABC-DLBCL, is associated with constitutive activation of the NF-kB transcription complex. However, except for a small fraction of cases, it remains unclear whether NF-kB activation in these tumors represents an intrinsic program of the tumor cell of origin or a pathogenetic event. Here we show that >50% of ABC-DLBCL and a smaller fraction of GCB-DLBCL carry somatic mutations at multiple genes, including negative (TNFAIP3/A20) and positive (CARD11, TRAF2, TRAF5, MAP3K7/TAK1 and TNFRSF11A/RANK) regulators of NF-kB. Of these, the A20 gene, which encodes for a ubiquitin-modifying enzyme involved in termination of NF-kB responses, is the most commonly affected one, with ~30% of the patients displaying biallelic inactivation by mutations and/or deletions, suggesting a tumor suppressor role. Less frequently, missense mutations of TRAF2 and CARD11 produce molecules with significantly enhanced ability to activate NF-kB. Thus, our results demonstrate that NF-kB activation in DLBCL is caused by genetic lesions affecting multiple genes, whose loss or activation may promote lymphomagenesis by leading to abnormally prolonged NF-kB responses. We show that most ABC-DLBCL and a smaller fraction of GCB-DLBCL display genetic lesions affecting multiple NFkB pathway genes, with A20 representing the most frequently mutated gene Experiment Overall Design: DLBCL biopsies from 73 patients were collected from the archives of the Departments of Pathology at Columbia University and Weill Cornell Medical College. Total RNA was extracted from frozen tumor biopsies and processed according to Affymetrix standard protocols. Purified tonsillar geminal center cells (centroblasts and centrocytes, 5 samples each from different individuals) were purified by magnetic cell separation as described in Klein et al, PNAS 2003.
Project description:Comparison of gene expression profiles from diagnostic samples of diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) to a patient case withsamples of primary and relapsed transformed FL
Project description:Comparison of gene expression profiles from diagnostic samples of diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) to a patient case withsamples of primary and relapsed transformed FL.
Project description:Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma, including two main molecular subtypes termed activated B cell-like (ABC) and germinal center B cell-like (GCB). ABC DLBCL is less curable and identification of new molecular targets is needed for the development of effective therapeutic agents. Here, we focused on EGR1, a transcription factor that is regulated by the B cell receptor and JAK1/STAT3 signaling pathway in ABC DLBCL. ChIP-Seq and RNA-Seq analyses revealed that gene regulation by EGR1 in ABC DLBCL accentuates multiple oncogenic pathways, including MYC and E2F, while dampening the lethal type I IFN pathway.
Project description:Cellular Indexing of Transcriptomes and Epitopes by sequencing (CITE-seq) used to dissect myeloid cell identities and states in murine experimental gliomas (GL261).