Project description:In our genome-wide association study, we searched for an association of genetic variants with colorectal cancer, type 1 diabetes, Hodgkin lymphoma and Diffuse large B-cell lymphoma among Polish population.
Project description:Intra-tumour heterogeneity in lymphoid malignancies encompasses selection of genetic events and epigenetic regulation of transcriptional programs. Clonal-related neoplastic cell populations are unsteadily subjected to immune editing and metabolic adaptations within different tissue microenvironments. How tissue-specific mesenchymal cells impact on the diversification of aggressive lymphoma clones is still unknown. We investigated the intra-tumour heterogeneity and the specific mesenchymal modifications that are associated with A20 diffuse large B-cell lymphoma (DLBCL) cells seeding of different tissue microenvironments. We found that the tissue microenvironment casts a relevant influence over A20 transcriptional landscape also impacting on Myc and DNA damage response programs. Extending the investigation to mice deficient for the matricellular protein SPARC, a stromal prognostic factor in human DLBCL, we demonstrated a different immune imprint on A20 cells according to stromal Sparc proficiency.
Project description: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:Diffuse large B-cell lymphoma (DLBCL), the most common lymphoid malignancy in adults, is curable in less than 50% of patients. Prognostic models based on pre-treatment characteristics, such as the International Prognostic Index (IPI), are currently used to predict outcome in DLBCL. However, clinical outcome models identify neither the molecular basis of clinical heterogeneity, nor specific therapeutic targets. We analyzed the expression of 6,817 genes in diagnostic tumor specimens from DLBCL patients who received cyclophosphamide, adriamycin, vincristine and prednisone (CHOP)-based chemotherapy, and applied a supervised learning prediction method to identify cured versus fatal or refractory disease. The algorithm classified two categories of patients with very different five-year overall survival rates (70% versus 12%). The model also effectively delineated patients within specific IPI risk categories who were likely to be cured or to die of their disease. Genes implicated in DLBCL outcome included some that regulate responses to B-cell-receptor signaling, critical serine/threonine phosphorylation pathways and apoptosis. Our data indicate that supervised learning classification techniques can predict outcome in DLBCL and identify rational targets for intervention. golub-00095 Assay Type: Gene Expression Provider: Affymetrix Array Designs: Hu6800 Organism: Homo sapiens (ncbitax) Tissue Sites: Lymphoid tissue Material Types: synthetic_DNA, synthetic_RNA, organism_part Cell Types: B-Lymphocyte Disease States: Diffuse large B-cell Lymphoma, Follicular Lymphoma
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:This SuperSeries is composed of the following subset Series: GSE21846: Transcriptional profiling of 29 cases of diffuse large B cell lymphoma GSE21847: miRNA profiling of 29 cases of diffuse large B cell lymphoma GSE21848: miRNA profiling of 36 cases of diffuse large B cell lymphoma Refer to individual Series
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: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.