Similar Datasets
Project description:Anti-CD38 monoclonal antibodies like Daratumumab (Dara) are effective in multiple myeloma (MM); however, drug resistance ultimately occurs and the mechanisms behind this are poorly understood. Here, we performed two in vitro genome-wide CRISPR screens to systematically discover the regulators of sensitivity to Dara-mediated antibody-dependent cellular cytotoxicity (ADCC) and identified KDM6A. The loss of KDM6A led to a marked downregulation in CD38 expression by increasing H3K27me3 on the CD38 promoter, resulting in resistance to Dara-mediated ADCC. Yet, adding back CD38 did not completely rescue this phenotype. In fact, KDM6A loss also downregulated CD48, which promoted Dara resistance by inhibiting natural killer cell activity. Lowering the H3K27me3 with an EZH2 inhibitor restored sensitivity to Dara through CD38 and CD48 upregulation. These findings suggest KDM6A loss as a mechanism of Dara resistance and explore the strategy of using an EZH2 inhibitor, one of which is already FDA-approved, to improve the response to Dara in MM.
2024-01-23 | GSE228769 | GEO
Project description:Anti-CD38 monoclonal antibodies like Daratumumab (Dara) are effective in multiple myeloma (MM); however, drug resistance ultimately occurs and the mechanisms behind this are poorly understood. Here, we performed two in vitro genome-wide CRISPR screens to systematically discover the regulators of sensitivity to Dara-mediated antibody-dependent cellular cytotoxicity (ADCC) and identified KDM6A. The loss of KDM6A led to a marked downregulation in CD38 expression by increasing H3K27me3 on the CD38 promoter, resulting in resistance to Dara-mediated ADCC. Yet, adding back CD38 did not completely rescue this phenotype. In fact, KDM6A loss also downregulated CD48, which promoted Dara resistance by inhibiting natural killer cell activity. Lowering the H3K27me3 with an EZH2 inhibitor restored sensitivity to Dara through CD38 and CD48 upregulation. These findings suggest KDM6A loss as a mechanism of Dara resistance and explore the strategy of using an EZH2 inhibitor, one of which is already FDA-approved, to improve the response to Dara in MM.
2024-01-23 | GSE228768 | GEO
Project description:Anti-CD38 monoclonal antibodies like Daratumumab (Dara) are effective in multiple myeloma (MM); however, drug resistance ultimately occurs and the mechanisms behind this are poorly understood. Here, we performed two in vitro genome-wide CRISPR screens to systematically discover the regulators of sensitivity to Dara-mediated antibody-dependent cellular cytotoxicity (ADCC) and identified KDM6A. The loss of KDM6A led to a marked downregulation in CD38 expression by increasing H3K27me3 on the CD38 promoter, resulting in resistance to Dara-mediated ADCC. Yet, adding back CD38 did not completely rescue this phenotype. In fact, KDM6A loss also downregulated CD48, which promoted Dara resistance by inhibiting natural killer cell activity. Lowering the H3K27me3 with an EZH2 inhibitor restored sensitivity to Dara through CD38 and CD48 upregulation. These findings suggest KDM6A loss as a mechanism of Dara resistance and explore the strategy of using an EZH2 inhibitor, one of which is already FDA-approved, to improve the response to Dara in MM.
2024-01-23 | GSE228766 | GEO
Project description:Anti-CD38 monoclonal antibodies like Daratumumab (Dara) are effective in multiple myeloma (MM); however, drug resistance ultimately occurs and the mechanisms behind this are poorly understood. Here, we performed two in vitro genome-wide CRISPR screens to systematically discover the regulators of sensitivity to Dara-mediated antibody-dependent cellular cytotoxicity (ADCC) and identified KDM6A. The loss of KDM6A led to a marked downregulation in CD38 expression by increasing H3K27me3 on the CD38 promoter, resulting in resistance to Dara-mediated ADCC. Yet, adding back CD38 did not completely rescue this phenotype. In fact, KDM6A loss also downregulated CD48, which promoted Dara resistance by inhibiting natural killer cell activity. Lowering the H3K27me3 with an EZH2 inhibitor restored sensitivity to Dara through CD38 and CD48 upregulation. These findings suggest KDM6A loss as a mechanism of Dara resistance and explore the strategy of using an EZH2 inhibitor, one of which is already FDA-approved, to improve the response to Dara in MM.
2024-01-23 | GSE228770 | GEO
Project description:Anti-CD38 monoclonal antibodies like Daratumumab (Dara) are effective in multiple myeloma (MM); however, drug resistance ultimately occurs and the mechanisms behind this are poorly understood. Here, we performed two in vitro genome-wide CRISPR screens to systematically discover the regulators of sensitivity to Dara-mediated antibody-dependent cellular cytotoxicity (ADCC) and identified KDM6A. The loss of KDM6A led to a marked downregulation in CD38 expression by increasing H3K27me3 on the CD38 promoter, resulting in resistance to Dara-mediated ADCC. Yet, adding back CD38 did not completely rescue this phenotype. In fact, KDM6A loss also downregulated CD48, which promoted Dara resistance by inhibiting natural killer cell activity. Lowering the H3K27me3 with an EZH2 inhibitor restored sensitivity to Dara through CD38 and CD48 upregulation. These findings suggest KDM6A loss as a mechanism of Dara resistance and explore the strategy of using an EZH2 inhibitor, one of which is already FDA-approved, to improve the response to Dara in MM.
2024-01-23 | GSE228767 | GEO
Project description:Recently, the monoclonal antibody daratumumab was approved as a single agent for the treatment of patients with relapsed/refractory Multiple Myeloma (MM). Daratumumab is an antibody targeting surface molecule CD38 on myeloma cells and the agent is already widely being used based on its good tolerability and proven efficacy. We believe, however, that the efficacy of this drug and other anti-CD38 monoclonal antibodies can be further improved by combining it with other types of immunotherapies. Furthermore, surface molecule CD38 can be used as a target for immunotherapies other than just naked monoclonal antibodies. In this report, we review the expression pattern of CD38 among normal tissues and in different types of plasma cell dyscrasias including their progenitor cells, minimal residual disease, and circulating tumor cells. We summarize the physiological role of CD38 as well as its role in the pathophysiology of MM and we present the most recent clinical trials using CD38 as a target. In addition, we highlight possible combination immunotherapies incorporating anti-CD38 monoclonal antibodies and we demonstrate alternative immunotherapeutic approaches targeting the same antigen such as CD38-specific chimeric antigen receptor (CAR) T cells.
| S-EPMC5139636 | biostudies-literature
Project description:Epigenetic changes frequently occur during tumorigenesis and DNA hypermethylation may account for the inactivation of tumor suppressor genes in cancer cells. Studies in Multiple Myeloma (MM) have shown variable DNA methylation patterns with focal hypermethylation changes in clinically aggressive subtypes. We studied global methylation patterns in patients with relapsed/refractory MM and found that the majority of methylation peaks were located in the intronic and intragenic regions in MM samples. Therefore, we investigated the effect of methylation on miRNA regulation in MM. To date, the mechanism by which global miRNA suppression occurs in MM has not been fully described. In this study, we report hypermethylation of miRNAs in MM and perform confirmation in MM cell lines using bisulfite sequencing and methylation-specific PCR (MSP) in the presence or absence of the DNA demethylating agent 5-aza-2'-deoxycytidine. We further characterized the hypermethylation-dependent inhibition of miR-152, -10b-5p and -34c-3p which was shown to exert a putative tumor suppressive role in MM. These findings were corroborated by the demonstration that the same miRNAs were down-regulated in MM patients compared to healthy individuals, alongside enrichment of miR-152-, -10b-5p, and miR-34c-3p-predicted targets, as shown at the mRNA level in primary MM cells. Demethylation or gain of function studies of these specific miRNAs led to induction of apoptosis and inhibition of proliferation as well as down-regulation of putative oncogene targets of these miRNAs such as DNMT1, E2F3, BTRC and MYCBP. These findings provide the rationale for epigenetic therapeutic approaches in subgroups of MM.
| S-EPMC4201574 | biostudies-literature
Project description:Multiple myeloma (MM) is an incurable cancer characterized by the proliferation and accumulation of monoclonal plasma cells in the bone marrow. The monoclonal anti-CD38 daratumumab has taken a central place in the different treatment regimens for newly diagnosed and relapsed, refractory myeloma. In this study, we correlated the NK cell-mediated antibody-dependent cellular cytotoxicity (ADCC) and potential fratricide induced by daratumumab with CD38-expression levels on both effector and target cells. We show that CD38 expression can be modulated by adding all-trans retinoic acid (ATRA) or interferon-α to MM cells to further fine-tune these effects. In addition, we observed that ADCC becomes inefficient when fratricide occurs and both ADCC and fratricide depend on the balance between CD38 expression on effector and target cells. However, the addition of adjuvants (retinoic acid or interferon-α) to myeloma cells or the inhibition of fratricide using a CD38-blocking nanobody on NK-cells can reverse this balance towards ADCC and thus promote lysis of target cells by ADCC. ATRA and interferon-α increased the CD38 expression at the surface of MM cells about three-fold and two-fold, respectively. This increase was of interest for MM cells with low CD38 expression, that became susceptible to daratumumab-mediated ADCC after preincubation. A CD38-blocking nanobody prevented the binding of daratumumab to these NK-cells and blunted the fratricidal effect on effector NK cells. In conclusion, our study highlights the importance of a balanced CD38 expression on target and effector cells and attempts to alter this balance will affect the susceptibility of MM cells towards daratumumab-mediated ADCC.
| S-EPMC8234557 | biostudies-literature
Project description:The survival outcomes for multiple myeloma have improved several-fold in the past two decades, primarily due to the introduction of therapies with novel mechanisms of action including immunomodulatory agents, proteasome inhibitors, stem cell transplant and monoclonal antibodies in the schema of therapy. Antibody-based therapies targeting the surface marker CD38, namely daratumumab and isatuximab, have emerged as being highly effective as single agents as well as in combination regimens for both newly diagnosed and relapsed settings. Herein, the authors summarize the most recent data with both the current and emerging CD38-directed therapies in multiple myeloma.
| S-EPMC8254545 | biostudies-literature
Project description:Multiple myeloma (MM) is the second-most common hematologic malignancy after diffuse large B-cell lymphoma. Despite the improvement in response and survival rates following the introduction of novel therapies, only a few patients are cured, and the majority of MM patients experience several relapses and receive multiple lines of treatment. Currently, bortezomib and lenalidomide are the core component of treatment both at the time of diagnosis and at the relapse as well as the new proteasome inhibitors (PIs), such as carfilzomib and ixazomib, and the next-generation immunomodulatory drug, pomalidomide, are now available for patients in relapse. In addition, drugs with a different mechanism of action, such as the histone deacetylase inhibitor and the monoclonal antibodies (MoAb) targeting SLAMF7 or CD38, are a part of the anti-myeloma armamentarium and are very important for heavily pretreated or double refractory to a PI and IMiD patients. In this paper, we focus on the efficacy as well as toxicities of CD38 antibodies used both as a single agent and in combination as multiple myeloma treatment.
| S-EPMC6952883 | biostudies-literature