Project description:Long non-coding RNAs have been implicated in many of the hallmarks of cancer. We previously annotated lncRNA152 (lnc152; a.k.a. DRAIC) and demonstrated its roles in proliferation, cell cycle progression, and regulation of the estrogen signaling pathway in breast cancer cells. Herein, we found that lnc152 is highly upregulated in luminal breast cancers, but is downregulated in triple-negative breast cancers (TNBC). Using a set of complementary experimental approaches, we found that knockdown of lnc152 promotes cell migration and invasion in luminal breast cancer cell lines. In contrast, ectopic expression of lnc152 inhibits growth, migration, invasion, and angiogenesis in TNBC cell lines. In xenograft studies in mice, lnc152 inhibited the growth and metastasis of TNBC cells. Transcriptome analysis of the xenografts indicated that lnc152 downregulates genes regulating cancer-related phenotypes, including angiogenesis. Using RNA-pull down assays coupled with LC-MS/MS analysis, we identified RBM47, a known tumor suppressor protein in breast cancer, as a lnc152-interacting protein. We found that lnc152 suppresses the aggressive phenotypes of TNBC cells by regulating the expression of RBM47. Collectively, our results demonstrate that lnc152 is an angiogenesis-inhibiting tumor suppressor that attenuates the aggressive cancer-related phenotypes found in TNBC.
Project description:Multiple sclerosis (MS) is characterized by a targeted attack on oligodendroglia (OLG) and myelin by immune cells, which are thought to be the main drivers of MS susceptibility. We found that immune genes exhibit a primed chromatin state in single mouse and human OLG in a non-disease context, compatible with transitions to immune-competent states in MS. We identified transcription factors as BACH1 and STAT1 involved in immune gene regulation in oligodendrocyte precursor cells (OPCs). A subset of immune genes present bivalency of H3K4me3/H3K27me3 in OPCs, with Polycomb inhibition leading to their increased activation upon interferon-gamma (IFN) treatment. Some MS susceptibility single-nucleotide polymorphisms (SNPs) overlap with these regulatory regions in mouse and human OLG. Treatment of mouse OPCs with IFN leads to chromatin architecture remodeling at these loci and altered expression of interacting genes. Thus, susceptibility for MS may involve OLG, which therefore constitute novel targets for immunological-based therapies for MS.
Project description:Multiple sclerosis (MS) is characterized by a targeted attack on oligodendroglia (OLG) and myelin by immune cells, which are thought to be the main drivers of MS susceptibility. We found that immune genes exhibit a primed chromatin state in single mouse and human OLG in a non-disease context, compatible with transitions to immune-competent states in MS. We identified transcription factors as BACH1 and STAT1 involved in immune gene regulation in oligodendrocyte precursor cells (OPCs). A subset of immune genes present bivalency of H3K4me3/H3K27me3 in OPCs, with Polycomb inhibition leading to their increased activation upon interferon-gamma (IFN) treatment. Some MS susceptibility single-nucleotide polymorphisms (SNPs) overlap with these regulatory regions in mouse and human OLG. Treatment of mouse OPCs with IFN leads to chromatin architecture remodeling at these loci and altered expression of interacting genes. Thus, susceptibility for MS may involve OLG, which therefore constitute novel targets for immunological-based therapies for MS.
Project description:Multiple sclerosis (MS) is characterized by a targeted attack on oligodendroglia (OLG) and myelin by immune cells, which are thought to be the main drivers of MS susceptibility. We found that immune genes exhibit a primed chromatin state in single mouse and human OLG in a non-disease context, compatible with transitions to immune-competent states in MS. We identified transcription factors as BACH1 and STAT1 involved in immune gene regulation in oligodendrocyte precursor cells (OPCs). A subset of immune genes present bivalency of H3K4me3/H3K27me3 in OPCs, with Polycomb inhibition leading to their increased activation upon interferon-gamma (IFN) treatment. Some MS susceptibility single-nucleotide polymorphisms (SNPs) overlap with these regulatory regions in mouse and human OLG. Treatment of mouse OPCs with IFN leads to chromatin architecture remodeling at these loci and altered expression of interacting genes. Thus, susceptibility for MS may involve OLG, which therefore constitute novel targets for immunological-based therapies for MS.
Project description:Unveiling the regulatory pathways maintaining hepatic stellate cells (HSC) in a quiescent (q) phenotype is essential to develop new therapeutic strategies to treat fibrogenic diseases. To uncover the miRNA-mRNAs regulatory interactions in qHSCs, HSCs were FACS-sorted from healthy livers and activated HSCs were generated in vitro. MiRNA Taqman array analysis showed HSCs expressed a low number of miRNA, from which 46 were down-regulated and 212 up-regulated upon activation. Computational integration of miRNA and gene expression profiles revealed that 66% of qHSCs miRNAs correlated with more than 6 altered targeted mRNAs (17,28±10,7 targets/miRNA), whereas aHSC-associated miRNAs had an average of 1,49 targeted genes. Interestingly, interaction networks generated by miRNA-targeted genes in qHSCs were associated with key HSCs activation processes. Next, selected miRNAs were validated in healthy and cirrhotic human livers and miR-192 was chosen for functional analysis. Down-regulation of miR-192 in HSC was found to be an early event during fibrosis progression in mouse models of liver injury. Moreover, mimic assays for miR-192 in HSCs revealed its role in HSC activation, proliferation and migration. Together, these results uncover the importance of miRNAs in the maintenance of qHSC phenotype and form the basis for understanding the regulatory networks in HSCs. Transcriptomic profile derived from four quiescent hepatic stellate (QHSC), four activated hepatic stellate (AHSC), three liver sinusoidal endothelial (LSEC) and two hepatocytes cells (HEP).
Project description:Acetaminophen (N-acetyl-p-aminophenol; APAP) is a mild analgesic and antipyretic used commonly worldwide. Although APAP is considered a safe and effective over-the-counter medication, it is also the leading cause of drug-induced acute liver failure. Its hepatotoxicity has been linked to the covalent binding of its reactive metabolite, N-acetyl p-benzoquinone imine (NAPQI), to proteins. The aim of this in vivo study was to identify APAP-protein targets in both rat and mouse liver, and to compare the results from both species, using bottom-up proteomics and targeted multiple reaction monitoring (MRM) experiments. Livers from rats and mice, treated with APAP, were homogenized and digested by trypsin. Digests were then fractionated by mixed-mode solid-phase extraction prior to liquid chromatography-tandem mass spectrometry (LC-MS/MS) using scheduled multiple reaction monitoring (MRM) acquisition. The targeted assays were optimized based on high-resolution MS/MS data from information-dependent acquisition (IDA) using control liver homogenates treated with a custom alkylating reagent forming a positional isomer of the APAP modification on all cysteine residues, in order to build an in-house modified peptide database for targeted analysis. A list of putative in vivo targets of APAP were screened from previous in vitro studies, data-dependent high-resolution MS/MS analyses of liver digests, as well as selected proteins from the target protein database (TPDB), an online resource which references previous reports of proteins found to be modified by acetaminophen. Multiple protein targets of APAP in each species were found, while confirming modification sites.