Background and aims: Dysregulation of intestinal epithelial cells performance associates with an array of pathologies whose onset mechanisms are incompletely understood. The aim of the present study was to provide a map of gene expresssion patterns along the human healthy adult gastro-intestinal tract and to implement a new procedure for microarray data noise filtering that would allow their use as a reference when screening for pathological deviations, such as inflammatory bowel disease (IBD). Methods: Gene expression profiles in antrum, duodenum, jejunum, ileum and transverse colon biopsies were measured with the Affymetrix U133A array and principal component analysis was used to identify region-selective biomarkers. These data were intersected with highly variable genes from a public dataset of gene expression in the ileal and colonic healthy regions of UC and Crohns disease patients. Moreover, gene sets covering gut functions not entirely accounted for by the available public tools were constructed to monitor their expression along the GI tract. Results: 166 genes were found to be responsible for distinguishing the five regions considered. Fourteen had never been described in the GI tract, including a semaphorin probably implicated in pathogen invasion, and six other novel genes. Similar analysis of the IBD datasets revealed that samples stratify based on disease rather than on the intestinal region. This withstanding, eleven genes were identified as possible early predictors of Crohns and/or UC in ileum and/or colon. These include CLCA4 and SLC26A2, both implicated in ion transport. Conclusions: This novel approach, validated by retrieving known gene profiles, allowed the identification of promising new leads both in health and IBD state.
Biomarkers of human gastrointestinal tract regions.
Age
View SamplesFor this study we selected a gene, -synuclein (SNCA), that is consistently under-expressed in MCF7 cells and breast tumors. Following transfection with an SNCA expression construct, two stable MCF7 clones (named MCF7-SNCA #1 and 2) were selected and examined for expression differences relative to the parental MCF7 cells.
Cancer develops, progresses and responds to therapies through restricted perturbation of the protein-protein interaction network.
Specimen part, Cell line
View SamplesNeuroblastoma (NB) is a neoplasm of the sympathetic nervous system, and is the most common solid tumor of infancy. NBs are very heterogeneous, with a clinical course ranging from spontaneous regression to resistance to all current forms of treatment. High-risk patients need intense chemotherapy, and only 30-40% will be cured. Relapsed or metastatic tumors acquire multi-drug resistance, raising the need for alternative treatments. Owing to the diverse mechanisms that are responsible of NB chemoresistance, we aimed to target epigenetic factors that control multiple pathways to bypass therapy resistance. We found that the SWI/SNF-related, matrix-associated, actin- dependent regulator of chromatin, subfamily a, member 4 (SMARCA4/BRG1) was consistently upregulated in advanced stages of NB, with high BRG1 levels being indicative of poor outcome. Loss-of-function experiments in vitro and in vivo showed that BRG1 is essential for the proliferation of NB cells. Furthermore, whole genome transcriptome analysis revealed that BRG1 controls the expression of key elements of oncogenic pathways such as PI3K/AKT and BCL2, which offers a promising new combination therapy for high-risk NB
BRG1/SMARCA4 is essential for neuroblastoma cell viability through modulation of cell death and survival pathways.
Cell line
View SamplesOncogene-induced senescence (OIS) is a p53-dependent defence mechanism against uncontrolled proliferation. Consequently, many human tumours harbour p53 mutations while others show a dysfunctional p53 pathway, frequently by unknown mechanisms. We identified BRD7, a bromodomain-containing protein whose inhibition allows full neoplastic transformation in the presence of wild-type p53. Intriguingly, in human breast tumours harbouring wild-type, but not mutant p53, the BRD7 gene locus was frequently deleted and low BRD7 expression was found in a subgroup of tumours. Functionally, BRD7 is required for efficient p53-mediated transcription of a subset of target genes. BRD7 interacts with p53 and p300, and is recruited to target gene promoters, affecting histone acetylation, p53 acetylation, and promoter activity. Thus, BRD7 suppresses tumourigenicity by serving as a p53 cofactor required for efficient induction of p53-dependent OIS.
BRD7 is a candidate tumour suppressor gene required for p53 function.
Specimen part, Disease, Cell line
View SamplesWe found that the non-essential amino acid L-Proline (L-Pro) acts as a signaling molecule that promotes the conversion of embryonic stem cells (ESCs) into mesenchymal-like, spindle-shaped, highly motile, invasive pluripotent stem cells. This embryonic stem cell-to-mesenchymal-like transition (esMT) is accompanied by a genome-wide remodeling of the transcriptome
L-Proline induces a mesenchymal-like invasive program in embryonic stem cells by remodeling H3K9 and H3K36 methylation.
Cell line
View SamplesWe used siRNA to knockdown lambda light chain expression in ALMC1 cells that express an intact IgG lambda monoclonal protein.
One siRNA pool targeting the λ constant region stops λ light-chain production and causes terminal endoplasmic reticulum stress.
Specimen part, Cell line
View SamplesThe SV40 large (LT) and small (st) antigens are produced from a single alternatively spliced pre-mRNA, that when co-expressed, transform a variety of cells in vitro and in vivo. However, 17kT, a relatively uncharacterized third protein that is co-linear with LT for the first 131 amino acids, is also produced from the early viral pre-mRNA by removal of an additional intron from the LT transcript. Here we report a line of transgenic mice expressing a liver-specific dox-inducible viral transcript that fails to yield any detectable LT protein, yet produces abundant 17kT. Comparative analysis of livers of transgenic mice expressing either 17kT or LT demonstrates that while 17kT is a potent stimulator of cell proliferation, it is ineffective at inducing liver tumor development, due in part, to the failure of 17kT to effectively induce the expression of growth regulators and reactivate expression of imprinted and developmentally regulated hepatic genes. These studies highlight key functional differences between LT and 17kT in their ability to transform quiescent primary epithelial cells in vivo, and demonstrate how specific functional domains within LT impact cell-specific gene expression to promote oncogenesis.
Comparative analysis of SV40 17kT and LT function in vivo demonstrates that LT's C-terminus re-programs hepatic gene expression and is necessary for tumorigenesis in the liver.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Tumor entrained neutrophils inhibit seeding in the premetastatic lung.
Sex, Specimen part, Disease, Treatment
View SamplesPrimary tumors have been shown to prepare distal organs for later colonization of metastatic cells by stimulating organ-specific infiltration of bone marrow-derived cells. Here we demonstrate that neutrophils accumulate in the lung prior to the arrival of metastatic cells in mouse models of breast cancer. Tumor-entrained neutrophils (TENs) inhibit metastatic seeding in the lungs by generating H2O2, and tumor-secreted CCL2 is a critical mediator of optimal anti-metastatic entrainment of G-CSF-stimulated neutrophils. TENs are present in the peripheral blood of breast cancer patients prior to surgical resection but not in healthy individuals. Thus, while tumor-secreted factors contribute to tumor progression at the primary site, they concomitantly induce a neutrophil-mediated inhibitory process at the metastatic site.
Tumor entrained neutrophils inhibit seeding in the premetastatic lung.
Sex, Specimen part, Disease
View SamplesPrimary tumors have been shown to prepare distal organs for later colonization of metastatic cells by stimulating organ-specific infiltration of bone marrow-derived cells. Here we demonstrate that neutrophils accumulate in the lung prior to the arrival of metastatic cells in mouse models of breast cancer. Tumor-entrained neutrophils (TENs) inhibit metastatic seeding in the lungs by generating H2O2, and tumor-secreted CCL2 is a critical mediator of optimal anti-metastatic entrainment of G-CSF-stimulated neutrophils. TENs are present in the peripheral blood of breast cancer patients prior to surgical resection but not in healthy individuals. Thus, while tumor-secreted factors contribute to tumor progression at the primary site, they concomitantly induce a neutrophil-mediated inhibitory process at the metastatic site.
Tumor entrained neutrophils inhibit seeding in the premetastatic lung.
Sex, Specimen part, Treatment
View Samples