Transcriptional responses by alpha-emitting radioimmunoconjugate Bi-213-CD20-rituximab
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PROVIDER: PRJNA98035 | ENA |
REPOSITORIES: ENA
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Project description:The possibility to deliver radioisotopes directly to tumor cells by using monoclonal antibodies has become a promising concept for the elimination of small tumor nodules or single disseminated tumor cells. The alpha-particle emitter Bismut-213 which has a high linear energy transfer and a very short path length appears to be able to kill cells by only few nuclear hits. Bismut-213 based alpha-immunotherapy treatment is currently proved in clinical trials for AML, NHL and preclinically for CLL and multiple myeloma. Because little is known about the biological effects of alpha radiation we examined the molecular effects of the alpha emitter Bismut-213 in malignant and normal B-cells. In this study, we used the cell line Karpas 422 (K422) which had been derived from a malignant B-cell Non-Hodgkin’s lymphoma as well as normal primary CD19+ B-cells which had been selected immunomagnetically from peripheral blood. For the delivery and binding of the alpha emitter we used the monoclonal antibody rituximab which targets the CD20 receptor of malignant and normal B-cells. The lymphoma cell line K422 was incubated in vitro with Bismut-213-CD20 with 100 µCi and 200 µCi respectively, for 46 min (1 half life time of the alpha emitter) or 24 h. Immunomagnetically isolated CD19+ cells from healthy donors were incubated in vitro with Bismut-213-CD20 with 100 µCi or 200 µCi, for 46 min. Gene expression profiles of irradiated cells were analysed using cDNA oligonucleotide arrays (Affymetrix Human Genome Focus Arrays) comprising 8,793 genes and compared with those from untreated control cells. Following normalization significantly altered genes were identified by using the variance stabilization normalization (VSN) method and the significance analysis of microarrays (SAM) algorithm. Differentially expressed genes were defined to exhibit a fold change of 1,4 and higher or 0,7 and lower and a q-value of 5% or lower compared to the genes of the untreated control cells. Irradiated K422 cells with 100 µCi showed 42 differential expressed genes after 46 minutes (one half life time) and 451 deregulated genes after exposure of 24 hours. A similar response could be observed at an exposure of 200 µCi (50 differentially expressed genes after 46 min; 485 genes after 24 h). Hence, a severe radiation induced response could not be detected before 24 hours. 200 µCi irradiated CD19+ cells showed 67 differentially expressed genes after 46 minutes compared to the untreated CD19+ cells (for 100 µCi: 42 differentially expressed genes). By performing cluster analyses the irradiated cells exhibited a distinct homogenous molecular phenotype in comparison to not irradiated cells. Alpha irradiated cells showed transcriptional activation of DNA repair genes. Furthermore, both examined cell types showed up-regulated genes which are known to play a role in general and oxidative stress response. Surprisingly, up-regulation of interferon-stimulated genes in K422 cells could be observed. Because of the transcriptional activation of genes regulating the G1-S- cell cycle transition the supposition came up that the irradiated K422 do progress into the S-phase of the cell cycle and arrest in the S- or G2/M-phase. In contrast to the K422 cells the primary CD19+ B-cells revealed transcriptional activation of cell cycle inhibitors which is an already known reaction following ionizing radiation but no apoptosis associated genes could be observed. In spite of the massive cytotoxic damages which are assumed referring to the gene expression data the K422 cells appear to be able to activate several defense mechanisms in a precise manner. Hence, the malignant K422 cells exhibit a larger amount as well as more various responses than the CD19+ cells. This might be due to the tumorigenic transformation of the malignant cells that exhibit probably more effective defense strategies than the CD19+ cells. The balance between the therapeutic effect of alpha radiation on malignant cells and the damaging effect on normal cells is an essential issue and it is of important clinical relevance concerning radioimmunotherapy with alpha radiation. Keywords: time course and dose dependency
2007-07-01 | GSE7291 | GEO
Project description:The possibility to deliver radioisotopes directly to tumor cells by using monoclonal antibodies has become a promising concept for the elimination of small tumor nodules or single disseminated tumor cells. The alpha-particle emitter Bismut-213 which has a high linear energy transfer and a very short path length appears to be able to kill cells by only few nuclear hits. Bismut-213 based alpha-immunotherapy treatment is currently proved in clinical trials for AML, NHL and preclinically for CLL and multiple myeloma. Because little is known about the biological effects of alpha radiation we examined the molecular effects of the alpha emitter Bismut-213 in malignant and normal B-cells. In this study, we used the cell line Karpas 422 (K422) which had been derived from a malignant B-cell Non-Hodgkin’s lymphoma as well as normal primary CD19+ B-cells which had been selected immunomagnetically from peripheral blood. For the delivery and binding of the alpha emitter we used the monoclonal antibody rituximab which targets the CD20 receptor of malignant and normal B-cells. The lymphoma cell line K422 was incubated in vitro with Bismut-213-CD20 with 100 µCi and 200 µCi respectively, for 46 min (1 half life time of the alpha emitter) or 24 h. Immunomagnetically isolated CD19+ cells from healthy donors were incubated in vitro with Bismut-213-CD20 with 100 µCi or 200 µCi, for 46 min. Gene expression profiles of irradiated cells were analysed using cDNA oligonucleotide arrays (Affymetrix Human Genome Focus Arrays) comprising 8,793 genes and compared with those from untreated control cells. Following normalization significantly altered genes were identified by using the variance stabilization normalization (VSN) method and the significance analysis of microarrays (SAM) algorithm. Differentially expressed genes were defined to exhibit a fold change of 1,4 and higher or 0,7 and lower and a q-value of 5% or lower compared to the genes of the untreated control cells. Irradiated K422 cells with 100 µCi showed 42 differential expressed genes after 46 minutes (one half life time) and 451 deregulated genes after exposure of 24 hours. A similar response could be observed at an exposure of 200 µCi (50 differentially expressed genes after 46 min; 485 genes after 24 h). Hence, a severe radiation induced response could not be detected before 24 hours. 200 µCi irradiated CD19+ cells showed 67 differentially expressed genes after 46 minutes compared to the untreated CD19+ cells (for 100 µCi: 42 differentially expressed genes). By performing cluster analyses the irradiated cells exhibited a distinct homogenous molecular phenotype in comparison to not irradiated cells. Alpha irradiated cells showed transcriptional activation of DNA repair genes. Furthermore, both examined cell types showed up-regulated genes which are known to play a role in general and oxidative stress response. Surprisingly, up-regulation of interferon-stimulated genes in K422 cells could be observed. Because of the transcriptional activation of genes regulating the G1-S- cell cycle transition the supposition came up that the irradiated K422 do progress into the S-phase of the cell cycle and arrest in the S- or G2/M-phase. In contrast to the K422 cells the primary CD19+ B-cells revealed transcriptional activation of cell cycle inhibitors which is an already known reaction following ionizing radiation but no apoptosis associated genes could be observed. In spite of the massive cytotoxic damages which are assumed referring to the gene expression data the K422 cells appear to be able to activate several defense mechanisms in a precise manner. Hence, the malignant K422 cells exhibit a larger amount as well as more various responses than the CD19+ cells. This might be due to the tumorigenic transformation of the malignant cells that exhibit probably more effective defense strategies than the CD19+ cells. The balance between the therapeutic effect of alpha radiation on malignant cells and the damaging effect on normal cells is an essential issue and it is of important clinical relevance concerning radioimmunotherapy with alpha radiation. Keywords: time course and dose dependency
2007-07-01 | GSE7292 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below.
2007-07-01 | GSE7322 | GEO
Project description:Transcriptional responses in B-cell lymphomas by the alpha-emitting radioimmunoconjugate Bi-213-CD20-rituximab
| PRJNA104065 | ENA
Project description:Transcriptional responses in primary CD19+ B-cells by the alpha-emitting radioimmunoconjugate Bi-213-CD20-rituximab
| PRJNA104067 | ENA
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
2014-09-01 | E-GEOD-54201 | biostudies-arrayexpress
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.
2014-09-01 | GSE54201 | GEO
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.
2014-12-31 | GSE54169 | GEO
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
2014-12-31 | GSE50929 | GEO
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.
2006-03-07 | GSE4351 | GEO