Colorectal cancer cells with TP53 mutation are highly resistant to chemotherapeutics. In order to identify potential chemo-resistance signatures, here; we explored the global gene expression profiles of drug resistant colorectal cancer cell line SW480 upon Floxuridine (FdUrd) treatment using Illumina Human HT-12 v4.0 Expression Beadchip Array. Further, significantly altered genes were subjected to the pathway analysis in GeneCodis3 and crucial signaling pathways were found to be enriched. Upon further functional validations, these pathways could be targeted to enhance therapy in human cancers harboring mutant p53.
Transcriptome profiling identifies genes and pathways deregulated upon floxuridine treatment in colorectal cancer cells harboring GOF mutant p53.
Sex, Age, Specimen part, Cell line, Treatment
View SamplesThe transcription factor Meis1 is preferentially expressed in hematopoietic stem cells (HSCs) and over-expressed in certain leukemias. However, the functions of Meis1 in hematopoiesis remain largely unknown. Using inducible knock-out mice, we found that Meis1 is required for the maintenance of hematopoiesis under stress and over long term while steady-state hematopoiesis was sustained in the absence of Meis1. Bone marrow cells of Meis1 deficient mice showed reduced colony formation, contained significantly fewer numbers of long- term HSCs and these Meis1-deficient HSCs exhibited loss of quiescence. Further, we found that Meis1 deletion led to the accumulation of reactive oxygen species (ROS) in HSCs and decreased expression of genes implicated in hypoxia response. Finally, ROS scavenging by N-acetyl cysteine or stabilization of hypoxia-signaling by knockdown of the VHL protein led to reversal of the effects of Meis1-deletion. Taken together, these results demonstrate that Meis1 protects and preserves HSCs by restricting oxidative metabolism.
Meis1 preserves hematopoietic stem cells in mice by limiting oxidative stress.
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View SamplesAPE1 regulates a vast majority of genes by acting as a transcriptional co-activator or as a co-repressor. It is overexpressed in diverse cancer tissues and is associated with their drug resistance. It is essential for cell proliferation. APE1 is post-translationally acetylated by HAT p300 at its N-terminal Lys 6 and 7 residues. We examined APE1 and its acetylation-dependent gene expression profile of lung cancer cells which would contribute to sustained proliferation of lung cancer cells.
Regulation of limited N-terminal proteolysis of APE1 in tumor via acetylation and its role in cell proliferation.
Cell line
View SamplesThe pathogenesis of MLL-fusion gene leukemias has been linked to upregulated expression of HOX genes and of the HOX-cofactor Meis1.The functions of the HOX/MEIS1 complex in leukemia however remain unclear. Here, we used inducible MEIS1-knockout mice coupled with MLL-AF9 knockin mice to decipher the role of MEIS1 in leukemia. We found that MEIS1 was critically required for established leukemia. Further, MEIS1 loss led to increased oxygen flux and apoptosis, while hypoxia reversed these effects. Finally, we identify HLF as a downstream mediator of MEIS1 in leukemia. Overexpression of HLF prevents oxygen flux and rescues the leukemia phenotype in MEIS1-deficient cells. Thus, the oncogenic effects of MEIS1 are at least partly mediated by an HLF-driven hypoxic state. Overall design: Mouse bone marrow MLL-AF9 knockin cells of conditional Meis1f/f or control genotypes were treated with vehicle or 1000 nM of 4-hydroxy tamoxifen for 24 hours in IMDM with 10% FBA and 10 ng/ml of murine GM-CSF, IL-3, IL-6, SCF. RNA was isolated from treated cells and submitted to gene expression and sequencing core of Cincinnati Children''s Hospital & Medical Center. A total of four samples were included, and two groups were assisgned. Comparison comprises mRNA expression profile of vehicle and 4-OHT treatment in control cells versus Meis1-deleted cells.
MEIS1 regulates an HLF-oxidative stress axis in MLL-fusion gene leukemia.
No sample metadata fields
View SamplesCancer cells must evade immune responses at distant sites to establish metastases. The lung is a frequent site for metastasis. We hypothesized that lung-specific immunoregulatory mechanisms create an immunologically permissive environment for tumor colonization. We found that T cell-intrinsic expression of the oxygen-sensing prolyl-hydroxylase (PHD) proteins is required to maintain local tolerance against innocuous antigens in the lung, but powerfully licenses colonization by circulating tumor cells. PHD proteins limit pulmonary type helper (Th)-1 responses, promote CD4+-regulatory T (Treg) cell induction, and restrain CD8+ T cell effector function. Tumor colonization is accompanied by PHD protein-dependent induction of pulmonary Treg cells and suppression of IFN-g-dependent tumor clearance. T cell-intrinsic deletion or pharmacological inhibition of PHD proteins limits tumor colonization of the lung and improves the efficacy of adoptive cell transfer immunotherapy. Collectively, PHD proteins function in T cells to coordinate distinct immunoregulatory programs within the lung that are permissive to cancer metastasis. Overall design: RNA expression was measured by RNA-Seq at day 4 following stimulation of naïve FACS-sorted CD4+ T cells with anti-CD3 and anti-CD28 antibodies in the presence of indicated doses of TGF-b. Gene expression was analysed separately in control Cd4Cre (WT) and Egln1fl/fl Egln2fl/fl Egln3fl/fl Cd4Cre (tKO) cells, or in cells treated with the pharmacological PHD inhibitor dimethyloxaloylglycine (DMOG) and control vehicle-treated cells.
Oxygen Sensing by T Cells Establishes an Immunologically Tolerant Metastatic Niche.
Specimen part, Treatment, Subject
View SamplesTo better elucidate epigenetic mechanisms that correlate with the dynamic gene expression program observed after T cell activation, we investigated the genomic landscape of histone modifications in antigen-experienced CD8+ T cells. Using a ChIP-Seq approach coupled with global gene expression profiling, we generated genome-wide histone H3 lysine 4 (H3K4me3) and H3 lysine 27 (H3K27me3) trimethylation maps in distinct subsets of CD8+ T cells-nave, stem cell memory, central memory, and effector memory-to gain insight into how histone architecture is remodeled during the differentiation of activated T cells. We show that H3K4me3 histone modifications are associated with activation of genes, while H3K27me3 is negatively correlated with gene expression at canonical loci and enhancers regions associated with T cell metabolism, effector function, and memory. Our results also reveal histone modifications and gene expression signatures that distinguish the recently identified stem cell memory T cell from other antigen-experienced CD8+ T cell subsets. Taken together, our results suggest that antigen-experienced T cells may undergo chromatin remodeling in a progressive fashion that may have implications for our understanding of peripheral T cell ontogeny and the formation of immunological memory.
Lineage relationship of CD8(+) T cell subsets is revealed by progressive changes in the epigenetic landscape.
Specimen part
View SamplesZEB2 is a multi-zinc-finger transcription factor known to play a significant role in early neurogenesis and in EMT-dependent tumor metastasis. While the function of ZEB2 in T lymphocytes is unknown, activity of the closely related family member ZEB1 has been implicated in lymphocyte development. Here, we find that ZEB2 expression is upregulated by activated T cells, specifically in the KLRG1hi effector CD8+ T cell subset. Loss of ZEB2 expression results in a significant loss of antigen-specific CD8+ T cells following primary and secondary infection with a severe impairment in the generation of the KLRG1hi effector-memory cell population. We show that ZEB2, which can bind DNA at tandem, consensus E-box sites, regulates gene expression of several E-protein targets and may directly repress CD127 and IL-2 in CD8+ T cells responding to infection. Furthermore, we find that T-bet binds to highly conserved T-box-sites in the ZEB2 gene and that T-bet and ZEB2 regulate similar gene-expression programs in effector T cells, suggesting that T-bet acts upstream and through regulation of ZEB2. Taken together, we place ZEB2 in a larger transcriptional network that is responsible for the balance between terminal differentiation and formation of memory CD8+ T cells.
Transcriptional repressor ZEB2 promotes terminal differentiation of CD8+ effector and memory T cell populations during infection.
Sex, Age, Specimen part
View SamplesTumours progress despite being infiltrated by effector T cells. Tumour necrosis is associated with poor survival in a variety of cancers. Here, we report that that necrosis causes release of an intracellular ion, potassium, into the extracellular fluid of human and mouse tumours. Surprisingly, elevated extracellular potassium ([K+]e) was sufficient to profoundly suppress mouse and human T cell anti-tumour function. Elevations in [K+]e acted to acutely impair T cell receptor (TCR) dependent Akt-mTOR phosphorylation and effector function. Potassium mediated suppression of Akt-mTOR signalling and T cell effector function required intact activity of PP2A, a serine/threonine phosphatase. The suppressive effect mediated by elevated [K+]e required a T cell-intrinsic increase in intracellular potassium ([K+]i) and was independent of changes in plasma membrane potential (Vm). Finally, ionic reprogramming of tumour-specific T cells via over-expression of the voltage-gated potassium channel Kv1.3 lowered [K+]i and improved effector functions in vitro and in vivo, with this gain of function being dependent on intact channel function. Consequently, Kv1.3 T cell expression enhanced tumour clearance and the survival of melanoma-bearing mice. These results uncover a previously undescribed ionic checkpoint against T cell function within tumours and identify new strategies for cancer immunotherapy. Overall design: RNA expression was measured by RNA-Seq on day 5 of cultures, maintained in individual biologial triplicates which were stimulated with immobilized anti-CD3/28 antibodies or kept in complete media (no stim) - with equivalent conditions treated with isotonic media containing elevated potassium.
Ionic immune suppression within the tumour microenvironment limits T cell effector function.
Sex, Age, Specimen part, Cell line, Treatment, Subject
View SamplesSerial comparison between Th1 and Th17 tumor-specific cells cultured in vitro and ex vivo after transferred into sublethaly irradiated B6.PL mice. Th17-derived cells acquire Th1-like properties in vivo but maintain a distinct molecular profile.
Th17 cells are long lived and retain a stem cell-like molecular signature.
Specimen part, Treatment
View SamplesT cell receptor (TCR) signaling is a critical process in immunity to infectious disease and cancer. Recently, a genome-wide association study has implicated polymorphisms in the CISH locus with susceptibility to infectious diseases. However, the role of Cish in the immune responses and its molecular underpinnings remains unclear. Here we demonstrate that Cish deletion resulted in protection against viral infection and enhanced CD8+ T cell tumor immunity. Transcriptome profiling revealed a hyper-TCR activation signature in Cish-deficient CD8+ T cells. Subsequent analysis revealed an inhibitory role for Cish in PLC1 activation, ensuing Ca2+ release and downstream signaling. In the steady-state Cish was found to physically interact with PLC1, however, PLC1 was only found to be ubiquitinated after acute TCR stimulation in the presence of Cish. These data implicate Cish as a potent negative regulator of TCR signaling and T cell immunity to infection and cancer and may have significant clinical applications.
Cish actively silences TCR signaling in CD8+ T cells to maintain tumor tolerance.
Specimen part, Treatment
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