Background and Aim: Fra-1 (Fos-related antigen-1) is a member of the AP1 (activator protein-1) family of transcription factors. We have recently shown that Fra-1 is necessary for breast cancer cells to metastasize in vivo, and that breast cancer outcome can be predicted by a classifier comprising genes that are expressed in a Fra-1-dependent fashion. Here, we show that Fra-1 plays an important role also in colon cancer progression. Methods: We compared proliferation rates of parental and Fra-1-depleted colon cancer cells in vitro under 2D, 3D, and attachment-free conditions and in vivo upon subcutaneous and intravenous injections into mice. We also compared RNA expression profiles of colon cancer cells with and without Fra-1 expression. Results: Fra-1 depletion impair colony outgrowth of human colon cancer cells in soft agar and in suspension, whereas it does not affect proliferation on 2D culture plates. Consistent with this, upon subcutaneous injection into mice, tumors formed by Fra-1-depleted colon cancer cells are only three times smaller than those produced by control cells. In contrast, when injected intravenously, Fra-1 depletion causes 200-fold reduction in tumor burden. Consistent with the more aggressive characteristics of Fra-1-proficient tumors, the prognosis of colon cancer patients can be predicted by a Fra-1 classifier generated by comparing RNA profiles of parental and Fra-1-depleted colon cancer cells. Conclusions: Our results demonstrate that Fra-1 is an important determinant of the metastatic potential of human colon cancer cells, and suggest that a Fra-1 classifier can be used as a prognostic predictor in colon cancer patients. Overall design: HT29 cell line, two shRNAs against Fra-1, one empty vector control, three biological replicates
Fra-1 is a key driver of colon cancer metastasis and a Fra-1 classifier predicts disease-free survival.
No sample metadata fields
View SamplesHistone deacetylases (HDACs) and acetyltransferases control the epigenetic regulation of gene expression through modification of histone marks. Histone deacetylase inhibitors (HDACi) are small molecules that interfere with histone tail modification thus altering chromatin structure and epigenetically controlled pathways. They promote apoptosis in proliferating cells and are promising anti-cancer drugs. While some HDACis have already been approved for therapy and others are in different phases of clinical trials, the exact mechanism of action of this drug class remains elusive. Previous studies have shown that HDACis cause massive changes in chromatin structure but only moderate changes in gene expression. To which extent these changes manifest at the protein level has never been investigated on a proteome-wide scale. Here, we have studied HDACi-treated cells by large-scale mass spectrometry based proteomics. We show that HDACi treatment affects primarily the nuclear proteome and induces a selective decrease of bromodomain containing proteins (BCPs), the main readers of acetylated histone marks. By combining time-resolved proteome and transcriptome profiling, we show that BCPs are affected at the protein level as early as 12 hours after HDACi treatment and that their abundance is regulated by a combination of transcriptional and post-transcriptional mechanisms. Using gene silencing, we demonstrate that the decreased abundance of BCPs is sufficient to mediate important transcriptional changes induced by HDACi. Our data reveals a new aspect of the mechanism of action of HDACi that is mediated by an interplay between histone acetylation and the abundance of BCPs.
Histone Deacetylase Inhibitors (HDACi) Cause the Selective Depletion of Bromodomain Containing Proteins (BCPs).
Cell line, Treatment, Time
View SamplesAging is associated with the decline of protein, cell, and organ function. Here, we use an integrated approach to characterize gene expression, bulk translation, and cell biology in the brains and livers of young and old rats. We identify 468 differences in protein abundance between young and old animals. The majority are a consequence of altered translation output, that is, the combined effect of changes in transcript abundance and translation efficiency. In addition, we identify 130 proteins whose overall abundance remains unchanged but whose sub-cellular localization, phosphorylation state, or splice-form varies. While some protein-level differences appear to be a generic property of the rats' chronological age, the majority are specific to one organ. These may be a consequence of the organ's physiology or the chronological age of the cells within the tissue. Taken together, our study provides an initial view of the proteome at the molecular, sub-cellular, and organ level in young and old rats. Overall design: RNA-Seq and ribosome profiling from matched young and old rat liver and brain
Integrated Transcriptome and Proteome Analyses Reveal Organ-Specific Proteome Deterioration in Old Rats.
No sample metadata fields
View SamplesActivators of innate immunity may have potential to combat a broad range of infectious agents. We report that treatment with bacterial flagellin prevented rotavirus (RV) infection in mice and cured chronically RV-infected mice. Protection was independent of adaptive immunity and interferon (IFN, type I and II) and required flagellin receptors Toll-like receptor 5 (TLR5) and NOD-like receptor C4 (NLRC4). Flagellin-induced activation of TLR5 on dendritic cells elicited production of the cytokine interleukin (IL)-22, which induced a protective gene expression program in intestinal epithelial cells. Flagellin also induced NLRC4-dependent production of IL-18 and immediate elimination of RV-infected cells. Administration of IL-22 and IL-18 to mice fully recapitulated the capacity of flagellin to prevent or eliminate RV infection, and thus holds promise as a broad-spectrum antiviral agent. Overall design: Total mRNA from intestinal epithelial cells of Rag1-/- mice treated with PBS, IL-18, IL-22 or IL-22/IL-18 was assayed for RNA sequencing.
Viral infection. Prevention and cure of rotavirus infection via TLR5/NLRC4-mediated production of IL-22 and IL-18.
No sample metadata fields
View SamplesAryl hydrocarbon receptor (AHR) activation by tryptophan (Trp) catabolites enhances tumor malignancy and suppresses anti-tumor immunity. Hitherto, indoleamine-2,3-dioxygenase 1 (IDO1) or tryptophan- 2, 3-dioxygenase (TDO2) are recognized as the main Trp-catabolizing enzymes (TCEs) responsible for the generation of AHR agonists. Here, the ability of the aromatic L-amino acid oxidase, interleukin 4 induced 1 (IL4I1), to activate the AHR was investigated using IL4I1 knockout CAS-1 glioblastoma cells.
IL4I1 Is a Metabolic Immune Checkpoint that Activates the AHR and Promotes Tumor Progression.
Cell line
View SamplesAnalysis of the effect of IL4I1 on gene expression of CD8 T-cells in CLL
IL4I1 Is a Metabolic Immune Checkpoint that Activates the AHR and Promotes Tumor Progression.
Sex
View SamplesIndole-3-pyruvate (I3P), an endogenous metabolite derived from tryptophan by gut microbiota and IL4I1 enzyme in humans can potentially activate the transcriptional activity of the Aryl Hydrocarbon receptor. Here we test this by stimulating AHR proficient U-87MG cells with I3P alone or in combination with the AHR antagonist SR1.
IL4I1 Is a Metabolic Immune Checkpoint that Activates the AHR and Promotes Tumor Progression.
Cell line
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