Project description:To investigate the genome-wide transcription targets of GR in renal cell carcinoma, cleavage under targets and tagmentation (CUT&Tag) was performed in Caki-1 cells using antibodies againstGR. Following CUT&Tag, DNAs were amplified using non-biased conditions, labeled, and sequenced with Illumina NovaSeq 150PE.
Project description:The FOXA1 pioneer factor is an essential mediator of steroid receptor function in multiple hormone dependent cancers, including breast and prostate cancers, enabling nuclear receptors such as ER and AR to activate lineage specific growth programs. . Analyzing data from loss-of-function screens, we identified a subset of NSCLC tumor lines where proliferation is FOXA1-dependent. Using rapid immunoprecipitation and mass spectrometry of endogenous protein (RIME) we identified chromatin-localized interaction between FOXA1 and glucocorticoid receptor (GR) in these tumor cells. Knockdown of GR inhibited proliferation of FOXA1-dependent, but not FOXA1-independent NSCLC cells. Here, we utilized ChIP-sequencing to identify a permissive set of genes potentially regulated by FOXA1 and GR to understand potential mechanisms underlying FOXA1-GR dependence in NSCLC.
Project description:Comparison of various inductibles constructions of arabidopsis treated by differents solutions. The aim of this project is to determine the primary and secondary targets of the LEC2 transcrition factor. The induction by the dexamethasone allows the expression of constructions LEC2:GR or ttg:GR introduced into transforming plants.The dexamethasone induces the expression of the contruct which carries the receptor to the glucocorticoïde (GR.). The cycloheximide is a inhibitor of the translation and allows, coupled with the dexamethasome, the identification of the primary targets only. The LEC2_GR25 and LEC2_GR31 constructs are two independents transforming plants of the cDNA-LEC2_GR construct. Both were used in order to have an idea of the variability of the data transcriptome obtained. The ttg_GR construct is used here as control ; ttg is another transcription factor, thus if induction with the dexamethasone works well, the targets induced in the two mutants will be different.
Project description:To compare the transcriptomic changes mediated by VHL knockout in Caki-1 cells, we carried out the next-generation sequencing (NGS)-derived transcriptomic profiling. We found significant enrichment of gene signatures involving IFNa/b signaling in VHL-KO Caki-1 cells compared to control cells. Our analysis also demonstrated that VHL deficiency induced the expression of genes associated with the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway involved in sensing the cytoplasmic presence of double-stranded DNA (dsDNA).
Project description:Exogenous glucocorticoids are widely used in the clinic for the treatment of inflammatory disorders and auto-immune diseases. Unfortunately, their use is hampered by many side effects and therapy resistance. Efforts to find more selective glucocorticoid receptor (GR) agonists and modulators (called SEGRAMs), able to separate anti-inflammatory effects via gene suppression from metabolic effects via gene activation, have been unsuccessful so far. In this study, we characterized a set of functionally diverse GR ligands in A549 cells, first using a panel of luciferase-based reporter gene assays evaluating GR-driven gene activation and gene suppression. We expanded this minimal assay set with novel luciferase-based read-outs monitoring GR protein levels, GR dimerization and GR Serine 211 (Ser211) phosphorylation status and compared their outcomes with compound effects on the mRNA levels of known GR target genes in A549 cells and primary hepatocytes. We found that luciferase reporters evaluating GR-driven gene activation and gene repression were not always reliable predictors for effects on endogenous target genes. Remarkably, our novel assay monitoring GR Ser211 phosphorylation levels proved to be the most reliable predictor for compound effects on almost all tested endogenous GR targets, both driven by gene activation and repression. The integration of this novel assay in existing screening platforms may therefore increase chances to find novel GR ligands with an improved therapeutic benefit.
Project description:A glucocorticoid-regulated BBM protein (35S:BBM-GR) was used in combination with microarray analysis to identify genes directly activated by BBM. We employed the system described by (Lloyd et al., 1994) in which dexamethasone (DEX) and cycloheximide (CHX) are applied together to respectively, induce nuclear localization of the BBM-GR protein and prevent translation of the primary targets mRNAs. In this way it is possible to identify direct targets of a transcriptional activator by comparing gene expression profiles between DEX+CHX-treated transgenic and wild-type tissues. The ability of the 35S:BBM GR construct to induce somatic embryogenesis in Arabidopsis seedlings was determined by phenotypic observation of 35S:BBM GR seeds germinated and grown in the presence of 10 µM dexamethasone (DEX). As in 35S:BBM seedlings, we observed somatic embryo formation on the cotyledons, first leaves and shoot meristem of DEX-treated 35S:BBM GR seedlings. We identified a set of 20 genes (including BBM itself) and our analysis indicates that BBM directly activates a signaling pathway comprising transcription factors and other signaling molecules, but which does not initially include genes known to induce somatic embryogenesis, such as LEC1, LEC2 or WUS. The functions of the BBM target genes are unknown, however a number of them have recently been identified in microarray screens for meristem-expressed genes. The identification of BBM-interacting partners and downstream targets provides new tools for unraveling pathways related to plant cell growth and organogenesis. Keywords: transcriptional activation