Project description:Bortezomib therapy has been proven successful for the treatment of relapsed and/or refractory multiple myeloma (MM). However, both intrinsic and acquired resistance has already been observed. In this study, we explored the relationship between CD9 expression and bortezomib sensitivity in MM Both intrinsic and acquired resistance has already been observed. In this study, we explored the relationship between CD9 expression and bortezomib sensitivity in MM. We found that down-regulation of CD9 by methylation decreased bortezomib sensitivity in multiple myeloma.
Project description:Bortezomib therapy has been proven successful for the treatment of relapsed and/or refractory multiple myeloma (MM). However, both intrinsic and acquired resistance has already been observed. In this study, we explored the relationship between CD9 expression and bortezomib sensitivity in MM Both intrinsic and acquired resistance has already been observed. In this study, we explored the relationship between CD9 expression and bortezomib sensitivity in MM. We found that down-regulation of CD9 by methylation decreased bortezomib sensitivity in multiple myeloma. A six chip study using total RNA recovered from three separate wild-type cultures of U266 cells and three separate cultures of U266 with CD9 overexpression. Each chip measures the expression level of 45,033 genes from Homo sapiens with fourteen 60-mer probe pairs (PM/MM) per gene, with three-fold technical redundancy.
Project description:Proteasome inhibitors are important chemotherapeutics in the treatment of multiple myeloma, but they are currently used empirically as no markers of sensitivity have been validated. We have identified expression of tight junction protein (TJP) 1 as being associated with sensitivity of plasma cells in vitro and in vivo to proteasome inhibitors. TJP1 suppressed expression of genes in the major histocompatibility class II region, including two catalytically active immunoproteasome subunits, thereby decreasing proteasome activity, a critical determinant of proteasome inhibitor sensitivity. This occurred through suppression by TJP1 of signaling through the epidermal growth factor receptor/Janus kinase 1/signal transducer and activator of transcription 3 pathway. In the clinic, high TJP1 expression in myeloma patients was associated with a significantly higher likelihood of responding to bortezomib, and with a longer time-to-progression after treatment. Taken together, these data support the use of TJP1 as a biomarker of sensitivity and resistance to proteasome inhibitors. To further elucidate mechanisms of bortezomib resistance, we developed human-derived multiple myeloma cell lines with a 4-fold or greater resistance to bortezomib. Then total RNA for bortezomib resistant (BR) and wild type (WT) was extracted and used for comparison by gene expression profiling.
Project description:The combination of bortezomib and dexamethasone should become the reference induction treatment for multiple myeloma patients younger than 65 years. Pharmacogenomic profiles of genes involved in response to treatment may help to understand resistance. We performed gene expression profiling in 9 myeloma cell lines, incubated or not with bortezomib and dexamethasone for 6 hours. Supervised analysis identified significantly up regulated genes involved in stress responses. We focused on REDD1 a gene known to be rapidly induced by a wide variety of stress conditions and DNA damages. REDD1 expression was early and highly induced after bortezomib exposure. REDD1 induction was associated with the dephosphorylation of P70 S6 ribosomal kinase (P70S6K), a key substrate of mTOR. These effects were dependent upon cell line. REDD1 was overexpressed within two hours in bortezomib resistant cell lines in association with a cell size decrease. In sensitive cell lines, neither REDD1 induction nor morphological changes occurred. RNA interference mediated inhibition of REDD1 induction abrogates P70S6K dephosphorylation, early transitory cell size reduction and enhances sensitivity to bortezomib - dexamethasone. Our results suggest that mTOR regulation could be a resistance mechanism mediated by REDD1 expression in myeloma cells. Nine cell lines of multiple myeloma studied, incubated or not with bortezomib and dexamethasone, examined with spotted cDNA nylon membrane. Cell line and Code : JJN3 = Vel_1x; L363 = Vel_2x; LP1 = Vel_3x; MDN = Vel_4x; NCI = Vel_5x; RPMI = Vel_6x; SBN = Vel_7x; U266 = Vel_8x; XG1 = Vel_9x.
Project description:Genome-wide analysis of gene expression in response to bortezomib treatment(33 nM) in cell lines before and after selection for resistance. Multiple myeloma (MM) is a hematologic malignancy characterized by the proliferation of neoplastic plasma cells in the bone marrow. While the first-to-market proteasome inhibitor bortezomib/VELCADE has been successfully used to treat myeloma patients, drug resistance remains an emerging problem. In this study, we identify signatures of bortezomib sensitivity and resistance by gene expression profiling (GEP) using pairs of bortezomib-sensitive and -resistant cell lines created from the Bcl-XL/Myc double transgenic mouse model of MM. Finally, these data reveal complex heterogeneity within MM and suggest resistance to one drug class reprograms resistant clones to make them more sensitive to a distinct class of drugs. This study represents an important next step in translating pharmacogenomic profiling and may be useful for understanding personalized pharmacotherapy of MM patients. Transcript profiling timecourses after treatment with Bortezomib treatment (33nm) in Multiple Myeloma derived cell lines.
Project description:Genome-wide analysis of gene expression in response to bortezomib treatment (33 nM) in cell lines before and after selection for resistance. Multiple myeloma (MM) is a hematologic malignancy characterized by the proliferation of neoplastic plasma cells in the bone marrow. While the first-to-market proteasome inhibitor bortezomib/VELCADE has been successfully used to treat myeloma patients, drug resistance remains an emerging problem. In this study, we identify signatures of bortezomib sensitivity and resistance by gene expression profiling (GEP) using pairs of bortezomib-sensitive and -resistant cell lines created from the Bcl-XL/Myc double transgenic mouse model of MM. Finally, these data reveal complex heterogeneity within MM and suggest resistance to one drug class reprograms resistant clones to make them more sensitive to a distinct class of drugs. This study represents an important next step in translating pharmacogenomic profiling and may be useful for understanding personalized pharmacotherapy of MM patients. Transcript profiling timecourses after treatment with Bortezomib treatment (33nm) in Multiple Myeloma derived cell lines.
Project description:Genome-wide analysis of gene expression in response to bortezomib treatment (33 nM) in cell lines before and after selection for resistance. Multiple myeloma (MM) is a hematologic malignancy characterized by the proliferation of neoplastic plasma cells in the bone marrow. While the first-to-market proteasome inhibitor bortezomib/VELCADE has been successfully used to treat myeloma patients, drug resistance remains an emerging problem. In this part of the study, we identify signatures of bortezomib sensitivity by gene expression profiling (GEP) using The human myeloma cell lines MM1.S and U266 (obtained from ATCC). Finally, these data reveal complex heterogeneity within MM and suggest resistance to one drug class reprograms resistant clones to make them more sensitive to a distinct class of drugs. This study represents an important next step in translating pharmacogenomic profiling and may be useful for understanding personalized pharmacotherapy of MM patients. Transcript profiling timecourses after treatment with Bortezomib treatment (33nm) in two myeloma cell lines.
Project description:The combination of bortezomib and dexamethasone should become the reference induction treatment for multiple myeloma patients younger than 65 years. Pharmacogenomic profiles of genes involved in response to treatment may help to understand resistance. We performed gene expression profiling in 9 myeloma cell lines, incubated or not with bortezomib and dexamethasone for 6 hours. Supervised analysis identified significantly up regulated genes involved in stress responses. We focused on REDD1 a gene known to be rapidly induced by a wide variety of stress conditions and DNA damages. REDD1 expression was early and highly induced after bortezomib exposure. REDD1 induction was associated with the dephosphorylation of P70 S6 ribosomal kinase (P70S6K), a key substrate of mTOR. These effects were dependent upon cell line. REDD1 was overexpressed within two hours in bortezomib resistant cell lines in association with a cell size decrease. In sensitive cell lines, neither REDD1 induction nor morphological changes occurred. RNA interference mediated inhibition of REDD1 induction abrogates P70S6K dephosphorylation, early transitory cell size reduction and enhances sensitivity to bortezomib - dexamethasone. Our results suggest that mTOR regulation could be a resistance mechanism mediated by REDD1 expression in myeloma cells.
Project description:To investigate the role of coculture treatment of multiple myeloma cells to bortezomib drug resistance, multiple myeloma cells were cocultured with bone marrow mesechymal stem cells
Project description:To investigate the role of iron(FeAc) on bortezomib-induced drug resistance of multiple myeloma cells, we administrated MM.1S with iron and bortezomib