Project description:Rituximab alone or in combination with chemotherapeutics is the first-line therapy for variety of lymphoproliferative disorders including low- and high grade non-Hodgkin’s lymphomas (NHL). Although the complete response rate is quite impressive, vast majority of patient presents recurrent disease. The association between CD20 expression and clinical outcome in patients strongly suggests that reduced CD20 expression leads to inferior response to RCHOP (rituximab, cyclophosphamide, vincristine, doxorubicin and prednisone). In order to understand how loss of CD20 leads to development of RCHOP resistance, we developed rituximab resistant DOHH2 model in vivo by chronic exposure to rituximab. Characterization of several resistant in vivo xenografts revealed one model that maintained resistance to an acute dose of rituximab and demonstrated loss of CD20. Further characterization of the model demonstrated a loss of CD20 is associated with over expression of BCL2 and BIM. In vivo efficacy studies showed resistant line is insensitive to acute dose of RCHOP and treatment with an inhibitor of BCL2 (ABT199) in combination with chemotherapy resulted in better efficacy than RCHOP alone. We have identified an in vivo model of DLBCL where loss of CD20 and over expression of anti-apoptotic protein BCL2 leads to RCHOP resistance. These data suggest the addition of BCL2 inhibitor to chemotherapy might be effective in treating CD20 negative lymphomas. mRNA profiles of parental and rituximab resistant DOHH2 xenograft were generated by deep sequencing using Illumina HiSeq
Project description:Rituximab alone or in combination with chemotherapeutics is the first-line therapy for variety of lymphoproliferative disorders including low- and high grade non-Hodgkin’s lymphomas (NHL). Although the complete response rate is quite impressive, vast majority of patient presents recurrent disease. The association between CD20 expression and clinical outcome in patients strongly suggests that reduced CD20 expression leads to inferior response to RCHOP (rituximab, cyclophosphamide, vincristine, doxorubicin and prednisone). In order to understand how loss of CD20 leads to development of RCHOP resistance, we developed rituximab resistant DOHH2 model in vivo by chronic exposure to rituximab. Characterization of several resistant in vivo xenografts revealed one model that maintained resistance to an acute dose of rituximab and demonstrated loss of CD20. Further characterization of the model demonstrated a loss of CD20 is associated with over expression of BCL2 and BIM. In vivo efficacy studies showed resistant line is insensitive to acute dose of RCHOP and treatment with an inhibitor of BCL2 (ABT199) in combination with chemotherapy resulted in better efficacy than RCHOP alone. We have identified an in vivo model of DLBCL where loss of CD20 and over expression of anti-apoptotic protein BCL2 leads to RCHOP resistance. These data suggest the addition of BCL2 inhibitor to chemotherapy might be effective in treating CD20 negative lymphomas.
Project description:SUMOylation is a reversible post-translational modification that has been implicated in the regulation of various cellular processes including inflammatory responses and expression of Type I interferons (IFN1). In this report, we have explored the activity of the selective small molecule SUMOylation inhibitor TAK-981 in promoting antitumor innate immune responses. We demonstrate that treatment with TAK-981 results in IFN1-dependent macrophage and NK cell activation, promoting macrophage phagocytosis and NK cell cytotoxicity in ex vivo assays. Furthermore, pre-treatment with TAK-981 enhanced macrophage phagocytosis or NK cell cytotoxicity against CD20-positive target cells in combination with the anti-CD20 antibody rituximab. In vivo studies demonstrated synergistic antitumor activity of TAK-981 and rituximab in CD20-positive lymphoma xenograft models. TAK-981 is currently being studied in phase 1 clinical trials (NCT03648372, NCT04074330, NCT04776018, and NCT04381650) for the treatment of patients with lymphomas and solid tumors.
Project description:Abstract: Analysis of the patterns of gene expression in follicular lymphomas from 24 patients suggested that two groups of tumors might be distinguished. All patients, whose biopsies were obtained before any treatment, were treated with rituximab, a monoclonal antibody directed against the B cell antigen, CD20. Gene expression patterns in the tumors that subsequently failed to respond to rituximab appeared more similar to those of normal lymphoid tissues than to gene expression patterns of tumors from rituximab responders. These findings suggest the possibility that the response of follicular lymphoma to rituximab treatment may be predicted from the gene expression pattern of tumors. This SuperSeries is composed of the SubSeries listed below.
Project description:CD20 is an integrate membrane protein expressed on the surface of normal and malignant B-cells. It is an excellent molecular target for monoclonal antibodies (mAbs) that are widely used in the treatment of non-Hodgkin’s lymphomas (NHL) and chronic lymphocytic leukemia (CLL). Anti-CD20-directed therapies are the most effective, successful and widely used therapeutic monoclonal antibodies, routinely incorporated into all phases of conventional treatment, including first-line, maintenance and salvage treatment. Nonetheless, the overall response rates to treatment have been reported to be 46-67% for rituximab, and in patients relapsing after initial rituximab treatment the response rate is ~40%. A number of mechanisms have been proposed to account for this inefficiency, including modulation of surface CD20 levels, occurring due to both transcriptional and posttranscriptional regulations. Our observations strongly imply that the observed CD20 down-regulation relies on transcriptional mechanism and delineate new perspectives in the field of CD20 regulation. Since many of the new therapeutic agents selectively inhibit specific signaling pathways, combining the compounds that target different mechanisms of cell growth and survival is a particularly attractive approach. However, optimal combinations of novel treatment modalities with already existing ones should take into account potential ”off-target” activity yet to be identified that could unexpectedly result in high toxicity and/or impaired outcomes of treatment
Project description:This SuperSeries is composed of the following subset Series: GSE3646: Follicular lymphoma and normal lymphoid tissue comparisons GSE3647: Follicular lymphoma lymph node Abstract: Analysis of the patterns of gene expression in follicular lymphomas from 24 patients suggested that two groups of tumors might be distinguished. All patients, whose biopsies were obtained before any treatment, were treated with rituximab, a monoclonal antibody directed against the B cell antigen, CD20. Gene expression patterns in the tumors that subsequently failed to respond to rituximab appeared more similar to those of normal lymphoid tissues than to gene expression patterns of tumors from rituximab responders. These findings suggest the possibility that the response of follicular lymphoma to rituximab treatment may be predicted from the gene expression pattern of tumors. Refer to individual Series
Project description:We investigated the differential regulation patterns of type I anti-CD20 monoclonal antibody (mAb) rituximab and type II obinutuzumab on a transcriptional level. Using a panel of MCL cell lines, we determined the effects of obinutuzumab and rituximab as monotherapies as well as in combination on cell viability and proliferation. Obinutuzumab induced a higher reduction in cell proliferation in each mantle cell lymphoma cell line than rituximab did. Results indicate a common pattern of expression changes after binding of anti-CD20 mAbs, but also reveal a significant difference between type I and type II treatment. Combination treatment resulted in a rituximab-like expression pattern. Many deregulated genes were associated with stress signalling, cell death, immune response and other functional clusters. Our analyses identified different and antibody-specific downstream expression patterns of obinutuzumab and rituximab, which may represent the molecular basis of the superior effect of obinutuzumab in comparison to rituximab.
Project description:Phosphopeptides of CARs in 14g2a-based anti-GD2, Leu16 anti-CD20, rituximab anti-CD20, and RFR-LCDR anti-CD20 CAR-T cells without antigen stimulation