Project description:Previous study demonstrated that HDAC3 has a critical role in MM proliferation; however, the underlying mechanism has not yet been elucidated. We identify that HDAC3 inhibition targets DNMT1 through dual regulations. We demonstrate that knockdown of DNMT1 leads to apoptosis and significant growth inhibition in myeloma cells. HDAC3 inhibition by gene silencing or HDAC3 selective inhibitor BG45 downregulates an oncoprotein c-Myc through its acetylation. c-Myc directly regulates DNMT1 expression at its enhancer region. Furthermore, HDAC3 directly regulates the stability of DNMT1 protein through its acetylation. Pharmaceutical inhibition of HDAC3 and DNMT1 synergistically induce MM growth inhibition in in vitro and in vivo settings. The goal of this analysis is to identify genes whose expression changes after shRNA-mediated knockdown of HDAC3 or DNMT1 using the human U133 plus 2.0 Affymetrix GeneChip in myeloma cell line (MM.1S).
Project description:This study provides a genome-wide map of changes in histone mark modifications and HDAC3 binding in response to protesome inhibition in the multiple myeloma cell line MM.1S. Chromatin immunoprecipitation assays were carried out to determine the genomic locations of histone modifications (H3K27ac, H3K4me1, H3K4me3) and histone deacetylase 3 (HDAC3) binding locations in multiple myeloma cells following proteasome inhibition with either lactacystin, bortezomib or carfilzomib. In addition, we report the effects of the overexpression of the E3-ubiquitin ligase Siah2 and the impact of HDAC3 knockdown on H3K27 acetylation levels in multiple myeloma cells treated with lactacystin. Our global ChIP-seq analysis of histone marks showed that enhancer and promoter marks (H3K4me1 and H3K4me3, respectively) present little response to proteasome inhibition, while the acetylation of histone H3K27 was significantly up- or down-regulated after three-hour treatment with proteasome inhibitors. Treatment of the cells with lactacystin, bortezomib or carfilzomib strongly increased HDAC3 recruitment at cell cycle and mitochondrial promoters, indicating that proteasome inhibition stabilized HDAC3 locally at the promoter of these genes to induce their repression. Furthermore, genome-wide ChIP-seq analysis of H3K27ac profiles showed that overexpression of Siah2 enhanced H3K27 acetylation levels at cell cycle and mitochondrial promoters.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Multiple myeloma (MM) evolves from highly prevalent premalignant condition termed Monoclonal Gammopathy of Undetermined Significance (MGUS). We report an MGUS-MM phenotype arising in transgenic mice with Emu-directed expression of the unfolded protein/ER stress response and plasma cell development spliced isoform factor XBP-1s. Emu-XBP-1s elicited elevated serum Ig and IL-6 levels, skin alterations and with advancing age, a significant proportion of Emu-xbp-1s transgenic mice develop features diagnostic of human MM including bone lytic lesions. Transcriptional profiles of Emu-xbp-1s B lymphoid and MM cells show aberrant expression of genes known to be dysregulated in human MM including Cyclin D1, MAF, MAFB, and APRIL. This genetic model coupled with documented frequent XBP-1s overexpression in human MM serve to implicate chronic XBP-1s dysregulation in the development of this common and lethal malignancy. Keywords: XBP-1, MGUS, multiple myeloma, transgenic mouse
Project description:Multiple myeloma (MM) evolves from highly prevalent premalignant condition termed Monoclonal Gammopathy of Undetermined Significance (MGUS). We report an MGUS-MM phenotype arising in transgenic mice with Emu-directed expression of the unfolded protein/ER stress response and plasma cell development spliced isoform factor XBP-1s. Emu-XBP-1s elicited elevated serum Ig and IL-6 levels, skin alterations and with advancing age, a significant proportion of Emu-xbp-1s transgenic mice develop features diagnostic of human MM including bone lytic lesions. Transcriptional profiles of Emu-xbp-1s B lymphoid and MM cells show aberrant expression of genes known to be dysregulated in human MM including Cyclin D1, MAF, MAFB, and APRIL. This genetic model coupled with documented frequent XBP-1s overexpression in human MM serve to implicate chronic XBP-1s dysregulation in the development of this common and lethal malignancy. Experiment Overall Design: In this study, we have explored the biological impact of sustained XBP-1s expression in the lymphoid system, anticipating that this genetic event would be a necessary component along with other MM-relevant oncogenes and tumor suppressor gene manipulations to generate a MM-prone mouse model. Unexpectedly, XBP-1s overexpression alone yielded an MGUS-MM disease bearing many features classical of the human disease on the clinical, pathological and molecular levels. Experiment Overall Design: We performed expression analysis of B cells derived from the spleen of 20-week old Emu-xbp-1s mice (n=5) and non-transgenic mice (n=5). Additionally, we analyzed the expression profiles from MM tumor cells arising in Emu-xbp-1s mice (n=6).
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:The transcriptional profile of the human multiple myeloma (MM) cell line MM.1S treated with MLN4924 vs control MM.1S cells was characterized by oligonucleotide microarray analysis, using the human U133 plus 2.0 Affymetrix GeneChip, according to previously described protocols for total RNA extraction and purification; cDNA synthesis; in vitro transcription reaction for production of biotin-labeled cRNA; hybridization of cRNA with U133plus2.0 Affymetrix gene chips; and scanning of image output files. Scanned image output files were analyzed using DNA-Chip Analyzer (dChip) (www.dchip.org), including conversion to DCP files, normalization and modeling. The gene expression profile of MM.1S cells for each time point of MLN4924 treatment was compared to the profile of control MM.1S cells. The NEDD8 activating enzyme (NAE) is upstream of the 20S proteasome in the ubiquitin/proteasome pathway and catalyzes the first step in the neddylation pathway. NEDD8 modification of cullins is required for ubiquitination of cullin-ring ligases (CRLs), which regulate degradation of a distinct subset of proteins. The more targeted impact of NAE on protein degradation prompted us to study MLN4924, an investigational NAE inhibitor, in preclinical multiple myeloma (MM) models. In vitro treatment with MLN4924 led to dose-dependent decrease of viability in a panel of human MM cell lines. In this analysis, we evaluated the molecular changes triggered in MM.1S myeloma cells by their in vitro treatment with MLN4924. The transcriptional profiles of each experimental condition were characterized by oligonucleotide microarray analysis, using the human U133 plus 2.0 Affymetrix GeneChip. The human multiple myeloma (MM) cells MM.1S were cultured in vitro in the presence or absence of the NEDD8 activating enzyme (NAE) inhibitor MLN4924 for 8, 16 or 24hrs. The gene expression profiles of drug treated cells were compared with the profiles of control MM.1S cells.