Similar Datasets
Project description:CD20 protein-negative diseases were observed for a subset of patients with B-NHL that relapsed after initial responses to mosunetuzumab. For many of these tumors, whole exome (WES) and RNA-seq failed to detect any MS4A1 genetic variants or loss of CD20 mRNA, which could have explained the apparent loss of CD20 protein. For this study, we obtained formalin-fixed paraffin-embedded (FFPE) tumor samples from a similar cohort of four additional patients relapsing after mosunetuzumab, and performed RNA-seq to look for changes in the splicing pattern of CD20.
2023-12-08 | GSE243919 | GEO
Project description:The aim of this research was to further investigate the contribution of CD20 antigen expression to rituximab activity and define the mechanisms responsible for CD20 downregulation in rituximab-resistant cell lines (RRCL).Rituximab-sensitive cell lines, RRCL, and primary neoplastic B cells were evaluated by chromium-51 release assays, ImageStream image analysis, immunohistochemical staining, flow cytometric analysis, CD20 knockdown, promoter activity, chromatin immunoprecipitation (ChIP) analysis of CD20 promoter, and CD20 plasmid transfection experiments to identify mechanisms associated with CD20 regulation in RRCL.RRCL exhibited a gradual loss of CD20 surface expression with repeated exposure to rituximab. We identified a CD20 antigen surface threshold level required for effective rituximab-associated complement-mediated cytotoxicity (CMC). However, a direct correlation between CD20 surface expression and rituximab-CMC was observed only in rituximab-sensitive cell lines. CD20 promoter activity was decreased in RRCL. Detailed analysis of various CD20 promoter fragments suggested a lack of positive regulatory factors in RRCL. ChIP analysis showed reduced binding of several key positive regulatory proteins on CD20 promoter in RRCL. Interleukin-4 (IL-4) induced higher CD20 promoter activity and CD20 expression but modestly improved rituximab activity in RRCL and in primary B-cell lymphoma cells. Forced CD20 expression restored cytoplasmic but not surface CD20, suggesting the existence of a defect in CD20 protein transport in RRCL.We identified several mechanisms that alter CD20 expression in RRCL and showed that, whereas CD20 expression is important for rituximab activity, additional factors likely contribute to rituximab sensitivity in B-cell lymphoma.
| S-EPMC3288324 | biostudies-literature
Project description:Relationship between MBD2 depletion and gene expression in a normal human fibroblastic cell line, MRC5
2011-09-16 | E-MEXP-2916 | biostudies-arrayexpress
Project description:Adoptive immunotherapy with T cells expressing a tumor-specific chimeric T-cell receptor is a promising approach to cancer therapy that has not previously been explored for the treatment of lymphoma in human subjects. We report the results of a proof-of-concept clinical trial in which patients with relapsed or refractory indolent B-cell lymphoma or mantle cell lymphoma were treated with autologous T cells genetically modified by electroporation with a vector plasmid encoding a CD20-specific chimeric T-cell receptor and neomycin resistance gene. Transfected cells were immunophenotypically similar to CD8(+) effector cells and showed CD20-specific cytotoxicity in vitro. Seven patients received a total of 20 T-cell infusions, with minimal toxicities. Modified T cells persisted in vivo 1 to 3 weeks in the first 3 patients, who received T cells produced by limiting dilution methods, but persisted 5 to 9 weeks in the next 4 patients who received T cells produced in bulk cultures followed by 14 days of low-dose subcutaneous interleukin-2 (IL-2) injections. Of the 7 treated patients, 2 maintained a previous complete response, 1 achieved a partial response, and 4 had stable disease. These results show the safety, feasibility, and potential antitumor activity of adoptive T-cell therapy using this approach. This trial was registered at www.clinicaltrials.gov as #NCT00012207.
| S-EPMC2532803 | biostudies-literature
Project description:Although rituximab has revolutionized the treatment of hematological malignancies, the acquired resistance is one of the prime obstacles for cancer treatment, and development of novel CD20-targeting antibodies with potent anti-tumor activities and specificities is urgently needed. Emerging evidence has indicated that lysosomes can be considered as an "Achilles heel" for cancer cells, and might serve as an effective way to kill resistant cancer cells. HLA-DR antibody L243 has been recently reported to elicit potent lysosome-mediated cell death in lymphoma and leukemia cells, suggesting that HLA-DR could be used as a potential target against lymphoma. In this study, we generated a bispecific immunoglobulin G-like antibody targeting both CD20 and HLA-DR (CD20-243 CrossMab) through CrossMab technology. We found that the CrossMab could induce remarkably high levels of complement-dependent cytotoxicity, antibody-dependent cell-mediated cytotoxicity and anti-proliferative activity. Notably, although HLA-DR is expressed on normal and malignant cells, the CrossMab exhibited highly anti-tumor specificity, showing efficient eradication of hematological malignancies both in vitro and in vivo. Our data indicated that combined targeting of CD20 and HLA-DR could be an effective approach against malignancies, suggesting that CD20-243 CrossMab would be a promising therapeutic agent against lymphoma.
| S-EPMC4011918 | biostudies-literature
Project description:Resistance to enteric pathogens is a complex trait at the crossroads of multiple biological processes. We have previously shown in the Drosophila Genetic Reference Panel (DGRP) that resistance to infection is highly heritable, but our understanding of how the effects of genetic variants are channeled through distinct molecular layers is still limited. To address this, we employed a systems genetics approach on the gut transcriptomes from 38 control and orally-infected DGRP lines, identifying a large number of condition-specific expression quantitative trait loci (cis-eQTLs). By assessing the allelic imbalance in the transcriptomes of 19 F1 hybrid lines from a large round-robin design, we could independently attribute a robust cis-regulatory effect to only 10% of the detected cis-eQTLs. These results therefore suggest that many context-dependent eQTLs that are assumed to act in cis, may act in trans instead. Further comparison of the transcriptomes of resistant and susceptible DGRP lines revealed Nutcracker (ntc) as the only differentially expressed gene between resistance classes. Interestingly, we found that ntc is linked to infection-specific eQTLs that not only correlate with its expression level, but also to enteric infection susceptibility. This is consistent with our findings that ntc expression is induced upon infection, whereas loss of ntc confers an overall greater susceptibility to infection, including lower innate immune activation as well as impaired infection-induced stem cell activity. Further mechanistic analysis revealed one ntc eQTL that significantly decreases the binding affinity for the repressor Broad, resulting into an allele-specific ntc expression increase. Our collective findings therefore point to a large number of infection-specific cis and trans-acting eQTLs in the DGRP, including one common non-coding variant that lowers enteric infection susceptibility by modulating ntc gene regulation through altered Broad repressor binding.
2019-10-12 | GSE138801 | GEO
Project description:To assess a potential role of transcription factor CREM in the long-term detrimental effects of beta1-adrenoceptor overexpression, four mouse lines were generated and studied: wild-type mice (WT), Crem-normal beta1AR-transgenic mice (beta1ARTG), Crem-deficient non-transgenic mice (Crem-/-) and Crem-deficient beta1AR-transgenic mice (beta1ARTG/Crem-/-). We focused on genes up- or down-regulated in transgenic mice due to the lacking of CREM (beta1ARTG/Crem-/- vs. beta1ARTG).
2007-03-02 | E-MEXP-582 | biostudies-arrayexpress
Project description:OBJECTIVE:This study was designed to determine the safety, pharmacokinetics and biologic effects of a human-mouse chimeric anti-CD20 monoclonal antibody (SCT400) in Chinese patients with CD20-positive B-cell non-Hodgkin's lymphoma (CD20(+) B-cell NHL). SCT400 has an identical amino acid sequence as rituximab, with the exception of one amino acid in the CH1 domain of the heavy chain, which is common in Asians. METHODS:Fifteen patients with CD20(+) B-cell NHL received dose-escalating SCT400 infusions (250 mg/m(2): n=3; 375 mg/m(2): n=9; 500 mg/m(2): n=3) once weekly for 4 consecutive weeks with a 24-week follow-up period. The data of all patients were collected for pharmacokinetics and pharmacodynamics analyses. RESULTS:No dose-limiting toxicities were observed. Most drug-related adverse events were grade 1 or 2. Two patients had grade 3 or 4 neutropenia. Under premedication, the drug-related infusion reaction was mild. A rapid, profound and durable depletion of circulating B cells was observed in all dose groups without significant effects on T cell count, natural killer (NK) cell count or immunoglobulin levels. No patient developed anti-SCT400 antibodies during the course of the study. SCT400 serum half-life (T1/2), maximum concentration (Cmax) and area under the curve (AUC) generally increased between the first and fourth infusions (P<0.05). At the 375 mg/m(2) dose, the T1/2 was 122.5±46.7 h vs. 197.0±75.0 h, respectively, and the Cmax was 200.6±20.2 g/mL vs. 339.1±71.0 g/mL, respectively. From 250 mg/m(2) to 500 mg/m(2), the Cmax and AUC increased significantly in a dose-dependent manner (P<0.05). Patients with a high tumor burden had markedly lower serum SCT400 concentrations compared with those without or with a low tumor burden. Of the 9 assessable patients, 1 achieved complete response and 2 achieved partial responses. CONCLUSIONS:SCT400 is well-tolerated and has encouraging preliminary efficacy in Chinese patients with CD20(+) B-cell NHL.
| S-EPMC4865612 | biostudies-literature
Project description:CD20 has proven to be an excellent target for the treatment of B-cell lymphoma, first for the chimeric monoclonal antibody rituximab (Rituxan), and more recently for the radiolabelled antibodies Y-90 ibritumomab tiuxetan (Zevalin) and I-131 tositumomab (Bexxar). Radiation therapy effects are due to beta emissions with path lengths of 1-5 mm; gamma radiation emitted by I-131 is the only radiation safety issue for either product. Dose-limiting toxicity for both radiolabelled antibodies is reversible bone marrow suppression. They produce response rates of 70%-90% in low-grade and follicular lymphoma and 40%-50% in transformed low-grade or intermediate-grade lymphomas. Both products produce higher response rates than related unlabelled antibodies, and both are highly active in patients who are relatively resistant to rituximab-based therapy. Median duration of response to a single course of treatment is about 1 year with complete remission rates that last 2 years or longer in about 25% of patients. Clinical trials suggest that anti- CD20 radioimmunotherapy is superior to total body irradiation in patients undergoing stem cell supported therapy for B-cell lymphoma, and that it is a safe and efficacious modality when used as consolidation therapy following chemotherapy. Among cytotoxic treatment options, current evidence suggests that one course of anti-CD20 radioimmunotherapy is as efficacious as six to eight cycles of combination chemotherapy. A major question that persists is how effective these agents are in the setting of rituximab- refractory lymphoma. These products have been underutilised because of the complexity of treatment coordination and concerns regarding reimbursement.
| S-EPMC2779347 | biostudies-other
Project description:For the complete cure of tumors, it is essential to eliminate cancer-initiating cells (CICs). Immunohistochemically, most tumor cells were CD20 and/or CD138 positive in clinical samples of lymphoplasmacytic lymphoma (LPL), and CD20- CD138- cells were hardly detected. Therefore, useful positive markers expressing in a candidate of CICs of LPL are necessary. First, we performed gene expression microarray analysis between CD20- CD138- and CD20+ CD138+ subpopulations using sorted Waldenstrom macroglobulinemia cell line (MWCL-1).
2016-02-17 | GSE73756 | GEO