Project description:Classical NF-κB activity can be inhibited by overexpression of the IκBα super repressor (SR). To determine the role of NF-κB in rhabdomyosarcoma cells, we overexpressed the IκBα SR in RH30 rhabdomyosarcoma cells. IκBα SR was overexpressed in RH30 cells. RH30 vector cells were used as control group.
Project description:We used human Affymetrix microarrays to identify the up- or down-regulated gene expressions from MDA-MB-231 cells infected with control vector or Flag-SR-IkBa Experiment Overall Design: The pattern of gene expression from MDA-MB-231 cells transduced with retroviruses were analysed by RNA extraction and hybridization on Affymetrix microarrays. From expression profiles, we identified NF-kB target genes, and uncovered a novel and specific role of a gene in osteolytic bone metastasis.
Project description:We previously demonstrated that the NF-κB inhibitor IκBα binds the chromatin together with PRC2 to regulate a subset of developmental- and stem cell-related genes. This alternative function has been elusive in both physiological and disease conditions because of the predominant role of IκBα as a negative regulator of NF-κB. We here uniquely characterize specific residues of IκBα that allow the generation of separation-of-function (SOF) mutants that are defective for either NF-κBrelated (SOF DeltaNF-κB) or chromatin-related (SOF DeltaH2A,H4) activities. Expression of IκBα SOF DeltaNF-κB, but not SOF DeltaH2A/H4, is sufficient to negatively regulate a specific stemness program in intestinal cells, thus rescuing the differentiation blockage imposed by IκBα deficiency. . By ChIP assay we demonstrated IκBα binding to several stem cell genes that are transcriptionally repressed following IκBα SOF DeltaNF-κB induction. Our data indicate that SOF mutants represent an exclusive tool for studying IκBα functions in physiology and disease.
Project description:We previously demonstrated that the NF-κB inhibitor IκBα binds the chromatin together with PRC2 to regulate a subset of developmental- and stem cell-related genes. This alternative function has been elusive in both physiological and disease conditions because of the predominant role of IκBα as a negative regulator of NF-κB. We here uniquely characterize specific residues of IκBα that allow the generation of separation-of-function (SOF) mutants that are defective for either NF-κBrelated (SOF DeltaNF-κB) or chromatin-related (SOF DeltaH2A,H4) activities. Expression of IκBα SOF DeltaNF-κB, but not SOF DeltaH2A/H4, is sufficient to negatively regulate a specific stemness program in intestinal cells, thus rescuing the differentiation blockage imposed by IκBα deficiency. . By ChIP assay we demonstrated IκBα binding to several stem cell genes that are transcriptionally repressed following IκBα SOF DeltaNF-κB induction. Our data indicate that SOF mutants represent an exclusive tool for studying IκBα functions in physiology and disease.
Project description:Inflammatory signals are key in development and cell differentiation but their orchestration with pluripotency and stemness signals is poorly understood. Our previous work identified a chromatin function of IκBα, the NF-κB inhibitor, that is crucial for differentiation in different types of somatic stem cells. Here we demonstrate that deficiency of IκBα imposes a profound chromatin rewiring defect that impacts on DNA methylation, histone post-translational modifications and transcriptional regulation, stabilizing mouse embryonic stem cells (ESCs) in a ground state of pluripotency while preventing them from pluripotency exit and differentiation. By engineering separation-of-function mutants of IκBα with specific binding to either NF-κB or histones, we demonstrate that regulation of pluripotency state by IκBα is independent of NF-kB but requires the chromatin-related IκBα function.
Project description:Inflammatory signals are key in development and cell differentiation but their orchestration with pluripotency and stemness signals is poorly understood. Our previous work identified a chromatin function of IκBα, the NF-κB inhibitor, that is crucial for differentiation in different types of somatic stem cells. Here we demonstrate that deficiency of IκBα imposes a profound chromatin rewiring defect that impacts on DNA methylation, histone post-translational modifications and transcriptional regulation, stabilizing mouse embryonic stem cells (ESCs) in a ground state of pluripotency while preventing them from pluripotency exit and differentiation. By engineering separation-of-function mutants of IκBα with specific binding to either NF-κB or histones, we demonstrate that regulation of pluripotency state by IκBα is independent of NF-kB but requires the chromatin-related IκBα function.
Project description:We previously demonstrated that the NF-κB inhibitor IκBα binds the chromatin together with PRC2 to regulate a subset of developmental- and stem cell-related genes. This alternative function has been elusive in both physiological and disease conditions because of the predominant role of IκBα as a negative regulator of NF-κB. We here uniquely characterize specific residues of IκBα that allow the generation of separation-of-function (SOF) mutants that are defective for either NF-κBrelated (SOF DeltaNF-κB) or chromatin-related (SOF DeltaH2A,H4) activities. Expression of IκBα SOF DeltaNF-κB, but not SOF DeltaH2A/H4, is sufficient to negatively regulate a specific stemness program in intestinal cells, thus rescuing the differentiation blockage imposed by IκBα deficiency. . By ChIP assay we demonstrated IκBα binding to several stem cell genes that are transcriptionally repressed following IκBα SOF DeltaNF-κB induction. Our data indicate that SOF mutants represent an exclusive tool for studying IκBα functions in physiology and disease.
Project description:Melanoma patients with high mRNA levels of the HDL receptor SR-BI (SCARB1) reveal poor survival outcome. The aim of the study was to evaluate the role of SR-BI in cancer progression. Therefore, SR-BI was targeted either by siRNA or by using the SR-BI specific lipid transfer inhibitor BLT-1. The SR-BI knockdown specifically revealed reduced protein glycosylation, STAT5 target gene expression and EMT pathway activation. Thus, SR-BI target genes reflect the metastatic phenotype in melanoma cells. We used the transcriptome analysis to compare SR-BI depletion to BLT-1 treatment (which specifically blocks SR-BI mediated lipid transfer) in human melanoma cells.
Project description:Inflammatory signals are key in development and cell differentiation but their orchestration with pluripotency and stemness signals is poorly understood. Our previous work identified a chromatin function of IκBα, the NF-κB inhibitor, that is crucial for differentiation in different types of somatic stem cells. Here we demonstrate that deficiency of IκBα imposes a profound chromatin rewiring defect that impacts on DNA methylation, histone post-translational modifications and transcriptional regulation, stabilizing mouse embryonic stem cells (ESCs) in a ground state of pluripotency while preventing them from pluripotency exit and differentiation. By engineering separation-of-function mutants of IκBα with specific binding to either NF-κB or histones, we demonstrate that regulation of pluripotency state by IκBα is independent of NF-kB but requires the chromatin-related IκBα function.