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:This study performed an in-depth investigation of the immune-molecular profiles of an unique cohort of extranodal diffuse large B-cell lymphoma (DLBCL) of the bone, with single primary bone (PB-)DLBCL and multiple localizations (polyostotic-DLBCL). A similar DLBCL cohort with nodal localizations only and germinal center B-cell (GCB) phenotype (nodal-DLBCL-GCB) was used as comparator. With comprehensive genomic mutational and gene gene-expression profiling (GEP), in total 103 DLBCLS were analyzed. Both molecular techniques revealed a shared mutational genomic and gene-expression transcriptomic profile for PB-DLBCL (n=51) and polyostotic-DLBCL (n=18), justifying a collective analysis as bone-DLBCL. Differential incidences of EZH2, IRF8, and HIST1H1E, and MYC mutations/rearrangements (p<0.05) confirmed the distinct oncogenic evolution of bone-DLBCL and nodal-DLBCL-GCB (n=34). Bone-DLBCL primarily exhibited an intermediate/rich immune TME GEP signature (p≤<0.005), based on published gene sets. Further unsupervised clustering identified two distinct groups, establishing a notable ‘immune-rich’ cluster dominated by bone-DLBCL (754%, p=0.0062). This immune-rich cluster demonstrated superior survival (p=≤0.0263) compared to the ‘immune-low’ cluster, which consisted mostly of nodal-DLBCL-GCB cases (61%). Gene-set enrichment analysis illustrated variations in cell proliferation and immune systemreceptor pathways for the immune-rich cluster (p<0.001), indicating a crucial role for the tumor microenvironment (TME) in disease behavior and outcome. Further supported by deconvolution applications (CIBERSORTx and single-sample gene-set enrichment analysis), The immune-rich cluster highlighted highlighting an abundantmainly regulatory T cells in immune-rich and cell proliferation in immune-low. infiltrate of NK/T, Treg, TFH and follicular dendritic cells (p<0.001). Conclusively, PB-DLBCL and polyostotic-DLBCL shared similar TME features and immune-molecular profiles. This study delineates tThe distinct immune-rich TME profile of bone-DLBCL, which is associated with a superior survival. These findings suggest that bone-DLBCL patients with immune-rich GEP might benefit from less intensive polychemotherapies and this could further shape targeted immunomodulatory strategies.
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:We studied 498 de-novo adult DLBCL cases, which had been diagnosed between January 2002 and October 2009, as part of the International DLBCL Rituximab-CHOP Consortium Program Study We perform global gene expression profiling from formalin fixed paraffin embedded 498 DLBCL tissues RNA by SPIA mediated microarray detection and identified the distinct subgroups of the disease within DLBCL, known as germinal-center-B-cell-like (GCB), activated B-cell-like (ABC), and unclassified DLBCL (UC).