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:Cross-species comparative gene expression profiling was performed to identify differentially expressed genes conserved in aggressive B lymphomas. Whole genome expression arrays from mouse B220+ splenic B cells (wild-type C57BL/6, B6) were compared to whole tumors (approximately >75% neoplastic cells) from B6.iMyc mice. Correspondingly, isolated human peripheral blood B cells were compared to human diffuse large B cell (DLBCL) whole tumors (approximately >75% neoplastic cells) DLBCL.
Project description:In this study, we present the first comparison of global transcriptional changes taking place in canine lymphoma and human diffuse large B-cell lymphoma (DLBCL), with particular reference to the nuclear factor-kappaB (NF-?B) pathway. Microarray data generated from lymph nodes diagnosed with canine DLBCL and healthy lymph nodes were used for differential expression analysis, co-expression analysis and pathway analysis, and compared with analysis of publicly available microarray data from human healthy and DLBCL lymph nodes. The comparisons between species at gene level were performed by mapping the probesets in canine microarrays to orthologous genes in humans and vice versa. A considerable number of differentially expressed genes between canine lymphoma and healthy lymph node samples were also found differentially expressed between human DLBCL and healthy lymph node samples. Principal component analysis (PCA) using a literature derived 120 NF-?B target gene set mapped to 199 orthologous canine array probesets and 259 human array probesets clearly separated the healthy and cancer samples in both canine and human datasets. The analysis demonstrated that for both human and canine DLBCL there is activation of the NF-?B/p65 canonical pathway rather than the alternative pathway. This has therapeutic implications for the use of specific pathway inhibitors for the treatment of DLBCL for both species and also indicates that naturally occurring canine lymphoma could be used as a model to study therapeutic strategies for human lymphoma. The model was further validated by the identification of molecular signatures that could sub-classify canine DLBCL into activated B-cell-like (ABC) or germinal centre B-cell-like (GCB) types equivalent to human subtypes. Canine DLBCL patients were recruited via the clinical oncology service of the University of Edinburgh Royal (Dick) School of Veterinary Studies (DJA), and the University of Wisconsin-Madison School of Veterinary Medicine (DMV). Lymph node biopsy samples were taken, as part of normal diagnostic procedures, from dogs newly diagnosed with lymphoma (naïve) and samples from dogs that had relapsed following standard of care CHOP chemotherapy. Only dogs with confirmed DLBCL after pathological grading were used in this study. This included standard histopathological grading by two independent pathologists and CD3/PAX5 marker analysis. Normal lymph node samples were obtained from canines that were euthanized for non-lymphoma conditions. Microarray data were generated from 35 canine samples (25 DLBCL and 10 healthy) in total. However, data from 2 canine DLBCL samples did not meet our required quality and were removed from further analysis. Only data from 33 (23 DLBCL and 10 healthy) samples were used for analysis. The generated data were used for differential expression analysis, co-expression analysis and pathway analysis, and compared with analysis of publicly available microarray data (GSE12195) from human healthy and DLBCL lymph nodes. The comparisons between species at gene level were performed by mapping the probesets in canine microarrays to orthologous genes in humans and vice versa.
Project description:In this study, we present the first comparison of global transcriptional changes taking place in canine lymphoma and human diffuse large B-cell lymphoma (DLBCL), with particular reference to the nuclear factor-kappaB (NF-κB) pathway. Microarray data generated from lymph nodes diagnosed with canine DLBCL and healthy lymph nodes were used for differential expression analysis, co-expression analysis and pathway analysis, and compared with analysis of publicly available microarray data from human healthy and DLBCL lymph nodes. The comparisons between species at gene level were performed by mapping the probesets in canine microarrays to orthologous genes in humans and vice versa. A considerable number of differentially expressed genes between canine lymphoma and healthy lymph node samples were also found differentially expressed between human DLBCL and healthy lymph node samples. Principal component analysis (PCA) using a literature derived 120 NF-κB target gene set mapped to 199 orthologous canine array probesets and 259 human array probesets clearly separated the healthy and cancer samples in both canine and human datasets. The analysis demonstrated that for both human and canine DLBCL there is activation of the NF-κB/p65 canonical pathway rather than the alternative pathway. This has therapeutic implications for the use of specific pathway inhibitors for the treatment of DLBCL for both species and also indicates that naturally occurring canine lymphoma could be used as a model to study therapeutic strategies for human lymphoma. The model was further validated by the identification of molecular signatures that could sub-classify canine DLBCL into activated B-cell-like (ABC) or germinal centre B-cell-like (GCB) types equivalent to human subtypes.
Project description:Diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) are the most prevalent B-lymphocyte neoplasms in which abnormal activation of the Bruton’s tyrosine kinase (BTK)–mediated B-cell receptor (BCR) signaling pathway contributes to pathogenesis. Ibrutinib is an oral covalent BTK inhibitor that has shown some efficacy in both indications. To improve ibrutinib efficacy through combination therapy, we first investigated differential gene expression in parental and ibrutinib-resistant cell lines to better understand the mechanisms of resistance. Ibrutinib-resistant TMD8 cells had higher BCL2 gene expression and increased sensitivity to ABT-199, a BCL-2 inhibitor. Consistently, clinical samples from ABC-DLBCL patients who experienced poorer response to ibrutinib had higher BCL2 gene expression. We further demonstrated synergistic growth suppression by ibrutinib and ABT-199 in multiple ABC-DLBCL, GCB-DLBCL, and FL lymphoma cell lines. The combination of both drugs also reduced colony formation, increased apoptosis, and inhibited tumor growth in a TMD8 xenograft model. A synergistic combination effect was also found in ibrutinib-resistant cells generated by either genetic mutation or drug treatment. Together, these findings suggest a potential clinical benefit from ibrutinib and ABT-199 combination therapy.
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:We performed a veterinary clinical oncology trial in client-owned dogs to determine if immune modulating drugs could be combined in rational approaches to treat spontaneous canine diffuse large B cell lymphoma (DLBCL).