STAT3 is a transcription factor playing a crucial role in inflammation, immunity and oncogenesis, able to induce distinct subsets of target genes in different cell types or under different conditions. Identification of direct transcriptional targets however has only defined a relatively limited set of genes, not sufficient to explain its variegated functions. In order to improve our understanding of the STAT3 transcriptional network we decided to develop a computational approach for the discovery of STAT3 functional binding sites. Upon generating a Positional Weight Matrix to define STAT3 binding sites, we applied a loglikelihood ratio scoring function and were able to assign affinity scores with very high specificity (93.5%) as measured by EMSA. STAT3 binding sites scoring above a stringent threshold have been identified genome-wide in Homo sapiens and Mus musculus and selected for phylogenetic conservation by genomic sequence alignment using eight vertebrate species. Validation was carried out on a subset of predicted
Genome-wide discovery of functional transcription factor binding sites by comparative genomics: the case of Stat3.
No sample metadata fields
View SamplesThirty-eight tumors from 17 patients treated with BRAF inhibitor (n=12) or combination BRAF/MEK inhibitors (n=5) with known PD-L1 expression were analyzed. RNA expression arrays were performed on all pre-treatment (PRE, n=17), early during treatment (EDT, n=8) and progression (PROG, n=13) biopsies. HLA-A/HLA-DPB1 expression was assessed by immunohistochemistry (IHC). Gene set enrichment analysis (GSEA) of PRE, EDT and PROG melanomas revealed that transcriptome signatures indicative of immune cell activation were strongly positively correlated with PD-L1 staining. In contrast, MAPK signaling and canonical Wnt/--catenin activity were negatively associated with PD-L1 melanoma expression. The expression of PD-L1 and immune activation signatures did not simply reflect the degree or type of immune cell infiltration, and was not sufficient for tumor response to MAPK inhibition.
PD-L1 Expression and Immune Escape in Melanoma Resistance to MAPK Inhibitors.
Specimen part
View SamplesVemurafenib is a BRAF inhibitor with specificity for the most common BRAF mutant encountered in melanomas (BRAFV600E). Vemurafenib suppresses the proliferation of BRAF mutant human melanoma cells by suppressing downstream activation of the MEK/ERK mitogen activated protein kinases.
Response of BRAF-mutant melanoma to BRAF inhibition is mediated by a network of transcriptional regulators of glycolysis.
Specimen part, Cell line
View SamplesExperiment with 6 hybridizations, using 30 samples of species [Homo sapiens], using 6 arrays of array design [Affymetrix GeneChip Human Genome HG-U133A [HG-U133A]], producing 6 raw data files and 6 transformed and/or normalized data files.
Hypoxia modifies the transcriptome of primary human monocytes: modulation of novel immune-related genes and identification of CC-chemokine ligand 20 as a new hypoxia-inducible gene.
Specimen part, Disease
View SamplesResistance to platinum-based chemotherapy is a clinical challenge in the treatment of ovarian cancer (OC) and limits survival. Therefore, innovative drugs against platinum-resistance are urgently needed. Our therapeutic concept is based on the conjugation of two chemotherapeutic compounds to a monotherapeutic pro-drug, which is taken up by cancer cells and cleaved into active cytostatic metabolites. Here, we explore the activity of the duplex-prodrug 5-FdU-ECyd, covalently linking 2''-deoxy-5-fluorouridine (5-FdU) and 3''-C-ethynylcytidine (ECyd), on platinum-resistant OC cells. RNA-Sequencing was used for characterization of 5-FdU-ECyd treated platinum-sensitive A2780 and isogenic platinum-resistant A2780cis. Overall design: Platinum-sensitive A2780 and platinum resistant-cells A2780cis were treated with 5-FdU-Ecyd for 6h and 12h, there are also 6h and 12h untreated controls, all groups are in triplicates
The conjugated antimetabolite 5-FdU-ECyd and its cellular and molecular effects on platinum-sensitive vs. -resistant ovarian cancer cells <i>in vitro</i>.
Cell line, Subject, Time
View SamplesDendritic cells (DCs) are professional antigen-presenting cells whose activity is intrinsically linked to the microenvironment. Hypoxia is a condition of low oxygen tension occurring in inflammatory tissues that creates a special microenvironment conditioning cell physiology. We studied the effects of hypoxia on the differentiation of human monocytes into DCs. Immature DCs were differentiated in vitro from human monocytes under normoxic (iDCs) or hypoxic (Hi-DCs) conditions and the gene expression profile was determined. Hi-DCs expressed novel hypoxia-inducible genes and were characterized by up-regulation of pathways associated with cell movement/migration.
Transcriptome of hypoxic immature dendritic cells: modulation of chemokine/receptor expression.
No sample metadata fields
View SamplesHypoxia is a low oxygen condition that occurs in the developing tumor mass and that is associated with poor prognosis and resistance to chemo- and radio-therapy. The definition of the hypoxia gene signature is fundamental for the understanding of tumor biology, as in the case of neuroblastoma, the most common pediatric solid tumor. The issue of identifying a significant group of variables in microarray gene expression experiments is particularly difficult due to the typical high dimensional nature of the data and great effort has been spent in the development of feature selection techniques.
A biology-driven approach identifies the hypoxia gene signature as a predictor of the outcome of neuroblastoma patients.
Cell line
View SamplesHIF-1 plays a crucial role in sustaining glioblastoma (GBM) cell growth and the maintenance of their undifferentiated phenotype. However, HIF-1 has been suggested to interplay with Wnt signaling components, thus activating a neuronal differentiation process in both GBM and normal brain. Here, we show that a -catenin/TCF1/HIF-1 complex directly controls the transcription of neuronal differentiation genes in hypoxia. Conversely, at higher oxygen levels, the increased expression of TCF4 exerts a transcriptional inhibitory function on the same genomic regions, thus counteracting differentiation. Moreover, we demonstrate the existence of a positive correlation between HIF-1, TCF1 and neuronal phenotype in GBM tumors, accompanied by the over-expression of several Wnt signaling components, finally impacting on patient prognosis. In conclusion, we unveil a mechanism by which TCF1 and HIF-1 induce a reminiscent neuronal differentiation of hypoxic GBM cells, which is hampered, in normoxia, by high levels of TCF4, thus de facto sustaining cell aggressiveness.
HIF-1α/Wnt signaling-dependent control of gene transcription regulates neuronal differentiation of glioblastoma stem cells.
Specimen part
View SamplesGlioblastoma (GBM) is the most devastating tumour of the brain, endowed with a fatal prognosis. Indeed, the complete eradication of cancer cell disseminated outside the GBM mass still remains a crucial issue. Given the reported strong association existing between Annexin 2A (ANXA2) expression and cell dissemination in many cancers, we evaluated the effects exerted by the modulation of ANXA2 levels in GBM cells and assessed its potential in predicting patient outcome. Here, we show that expression of ANXA2 positively correlates with metastatic gene signatures and demonstrates to be prognostic by itself. Indeed, we prove that ANXA2 is involved in cell migration, invasion, cytoskeletal remodeling and proliferation in GBM cells. Moreover, we were able to construct a gene signature representative of ANXA2 inhibition, which showed a significant prognostic potential in different GBM patient cohorts.
Annexin 2A sustains glioblastoma cell dissemination and proliferation.
Specimen part
View Samplesphenotypic reprogramming ability of teh zebtafish brain microenviroment on GBM derived cells controlled by the activation of endogenous Wnt pathway
Wnt activation promotes neuronal differentiation of glioblastoma.
Specimen part, Time
View Samples