The Wilms tumor 1 gene (WT1) encodes a transcription factor involved in cell growth and development. As we previously reported WT1 expression is hardly detectable in normal hepatic tissue but is induced in liver cirrhosis. Although WT1 has been found to be overexpressed in a number of malignancies, the role of WT1 in hepatocarcinogenesis has not been clarified. We found that WT1 is expressed in several human hepatocellular carcinoma (HCC) cell lines including PLC/PRF/5 and HepG2, and in HCC tumor tissue in 42% of patients. WT1 small interfering RNAs did not affect proliferation rate of HCC cells but abrogated their resistance to anoikis. Transcriptome analysis of PLC/PRF/5 cells after WT1 knockdown demonstrated upregulation of 251 genes and downregulation of 321. Ninety per cent of the former corresponded to metabolic genes mostly those characterizing the mature hepatocyte phenotype. On the contrary, genes that decreased upon WT1 inhibition were mainly related to defense against apoptosis, cell cycle and tumor progression. In agreement with these findings WT1 expression increased the resistance of liver tumor cells to doxorubicin, a compound used to treat HCC. Interestingly, doxorubicin strongly enhanced WT1 expression in both HCC cells and normal human hepatocytes. Among different chemotherapeutics, induction of WT1 transcription was restricted to topoisomerase 2 inhibitors. When WT1 expression was prohibited doxorubicin caused a marked increase in caspase-3 activation. In conclusion, WT1 is expressed in a substantial proportion of HCC contributing to tumor progression and resistance to chemotherapy, suggesting that WT1 may be an important target for HCC treatment.
Wilms' tumor 1 gene expression in hepatocellular carcinoma promotes cell dedifferentiation and resistance to chemotherapy.
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View SamplesLymphatic endothelial cells were grown under normoxia, hypoxia (1% 0xygen) and conditioned medio from NSLCN growth under normoxia or hypoxia. Gene expression was measured and comparition between samples performed
Hypoxia alters the adhesive properties of lymphatic endothelial cells. A transcriptional and functional study.
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View SamplesHepatocellular carcinoma (HCC) represents a major health problem as it afflicts an increasing number of patients worldwide. Albeit most of the risk factors for HCC are known, this is a deadly syndrome with a life expectancy at the time of diagnosis of less than 1 year. Definition of the molecular principles governing the neoplastic transformation of the liver is an urgent need to facilitate the clinical management of patients, based on innovative methods to detect the disease in its early stages and on more efficient therapies. In the present study we have combined the analysis of a murine model and human samples of HCC to identify genes differentially expressed early in the process of hepatocarcinogenesis, using a microarray based approach. Expression of 190 genes was impaired in murine HCC from which 65 were further validated by low-density array RT PCR. The expression of the best 45 genes was then investigated in human samples resulting in 18 genes which expression was significantly modified in HCC. Among them, JUN, methionine adenosyltransferase 1A and 2A, phosphoglucomutase 1, and acyl CoA dehydrogenase short branched chain indicate defective cell proliferation as well as one carbon pathway, glucose and fatty acid metabolism, both in HCC and cirrhotic liver, a well known preneoplastic condition. These alterations were further confirmed in public transcriptomic datasets from other authors. In addition, vasodilator stimulated phosphoprotein, an actin-associated protein involved in cytoskeleton remodelling, was also found to be increased in the liver and serum of cirrhotic and HCC patients. In addition to revealing the impairment of central metabolic pathways for liver homeostasis, further studies may probe the potential value of the reported genes for the early detection of HCC.
A signature of six genes highlights defects on cell growth and specific metabolic pathways in murine and human hepatocellular carcinoma.
Specimen part
View SamplesDUSP1 is involved in different cellular pathways including cancer cell proliferation, angiogenesis, invasion and resistance to chemotherapy. To gain insight into the cellular signaling pathways involving DUSP1 actions and the response to Cisplatin (CDDP) in non small cell lung cancer (NSCLC), we have used a double strategy that combines microarray and SiRNA technology. This strategy provided a differential expression profile of genes involved in CDDP response in NSCLC cell line regulated by DUSP1 using H460 and H460cri and a time course to CDDP.
No associated publication
Cell line, Time
View SamplesDUSP1 is involved in different cellular pathways including cancer cell proliferation, angiogenesis, invasion and resistance to chemotherapy. To understand more about the cellular responses regulated by DUSP1 in NSCLC cells, we interfered DUSP1 expression in the NSCLC cell line H460 and studied the changes in gene expression differentially regulated by this phosphatase.
DUSP1/MKP1 promotes angiogenesis, invasion and metastasis in non-small-cell lung cancer.
Specimen part, Cell line
View SamplesThe aim of this study was to analyze gene response to a 10-week dietary intervention for weight loss in peripheral blood mononuclear cells of overweight/obese male children.
Peripheral blood mononuclear cell gene expression profile in obese boys who followed a moderate energy-restricted diet: differences between high and low responders at baseline and after the intervention.
Sex, Age, Specimen part, Treatment
View SamplesBackground: Resveratrol has been demonstrated to exert pleiotropic health beneficial effects. Among the various mechanisms of action antioxidant, anti-inflammatory, cardio- and cancer-protective outcomes have been reported. Particularly, an important function of this natural compound against atherosclerosis has been postulated and the action of resveratrol on lipids and lipoprotein levels seems to be of relevance in this pathology, but also for other metabolic diseases. Accordingly, taking into consideration the straight contact of resveratrol with the intestine, this study aimed to gain insights into the protective effects of trans-resveratrol on enterocyte physiology and metabolism in proinflammatory conditions. For this purpose, a DNA microarray analysis was conducted in Caco-2 cells where global gene expression profile at intestinal level was screened. Cells were pretreated with 50 of trans-resveratrol and, subsequently, lipopolysaccharide (LPS) was added for 48 h. Results: The microarray analysis revealed 121 genes differentially expressed between resveratrol-treated and non-treated cells (B> 0). Four genes, inhibitor of DNA binding 1(ID1), histidine-rich glycoprotein (HRG), NADPH oxidase (NOX1) and sprouty homolog 1 (SPRY), were upregulated by LPS treatment, but significantly downregulated with trans-resveratrol pretreatment (padj< 0.05). Moreover, genes implicated in pathways related to lipid metabolism, such as synthesis of lipids (z-score= -1.195) and concentration of cholesterol (z-score= -0.109), were markedly downregulated by trans-resveratrol. Other genes implicated in lipid metabolism, but also in cell death and survival function, such as transcription factors Krppel-like factor 5 (KLF5) and amphiregulin (AREG), were also significantly inhibited by trans-resveratrol pretreatment. RT-qPCR-data confirmed the microarray results. Special mention deserves acyl-CoA synthetase long-chain family member 3 (ACSL3) and endothelial lipase (LIPG), which were downregulated by the stilbene and have been previously associated with fatty acid synthesis and obesity in other tissues. Conclusions: This study envisages that trans-resveratrol might exert important anti-lipogenic effect at intestinal level under proinflammatory conditions, which have not been previously described.
No associated publication
Cell line, Treatment
View SamplesThe EVI1 gene codes for a transcription factor with important roles in development and leukemogenesis. Overexpression of EVI1 in acute myeloid leukemia (AML) is one of the worst prognostic factors in patients with and without 3q26 rearrangements. Evi1 acts in several pathways through the interaction with proteins with important functions in hematopoiesis; however, the role of Evi1 as a transcription factor is not well known, and only some Evi1 target genes have been identified in mice. Our aim was to investigate the pathways and direct target genes of EVI1. Differential expression profiles after EVI1 knockdown allowed us to identify 125 genes involved in cell growth, differentiation and signal transduction that could be related to EVI1. Moreover, we looked for potential EVI1 binding sites within the region 1000 bp upstream of the transcription start sites of all human genes. We selected a total of 70 genes from the bioinformatics search, genes related to EVI1 by literature, and genes differentially expressed in the expression array. ChIP in the TF1 and HEL cell lines with two EVI1 antibodies demonstrated that EVI1 binds to the proximal promoter regions of 18 of these genes, most of them involved in important differentiation and proliferation pathways, confirming the important role of EVI1. Interestingly, EVI1 binds to the proximal region of its promoter, suggesting that it could be regulating its own transcription. Further functional studies are in progress. These data provide a starting point for further studies aimed at uncovering the mechanism for EVI1-induced transformation leukemias.
No associated publication
Sex, Age, Disease, Cell line, Race
View SamplesBioactive compounds, including some fatty acids (FAs), can induce beneficial effects on body fat-content and metabolism. In this work, we have used C. elegans as a model to examine the effects of several FAs on body fat accumulation. Both omega-3 and omega-6 fatty acids induced a reduction of fat content in C. elegans, with linoleic, gamma-linolenic and dihomo-gamma-linolenic acids being the most effective ones. These three FAs are sequential metabolites in PUFA synthesis pathway and the effects seem to be primarily due to dihomo-gamma-linolenic acid, being independent of transformation into omega-3 or arachidonic acid. Gene expression analyses show that peroxisomal beta oxidation is the main mechanism involved in this fat-loss. All these results point out the importance of further analysis of the activity of these omega-6 FAs, due to their potential application in obesity and related diseases.
No associated publication
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View SamplesEndothelial cells (EC) lining arteries and veins have distinct molecular and functional signatures. The (epi)genetic regulatory mechanisms underlying this heterogeneity in human EC are incompletely understood. Using genome-wide microarray screening we established a specific fingerprint of freshly isolated arterial (HUAEC) and venous EC (HUVEC) from human umbilical cord comprising 64 arterial and 12 venous genes, representing distinct functions and pathways. Among the arterial genes were 8 transcription factors, including HEY2, a downstream target of Notch signaling and the current golden standard pathway for arterial EC specification. Short-term culture of HUAEC or HUVEC abrogated differential gene expression resulting in a default state. Erasure of arterial gene expression was at least in part due to loss of canonical Notch activity and HEY2 expression. Notably, nCounter analysis revealed that restoring HEY2 expression or Delta-like 4 (Dll4)-induced Notch signaling in cultured HUVEC or HUAEC only partially reinstated the arterial EC gene signature while combined overexpression of the 8 transcription factors restored this fingerprint much more robustly. Each transcription factor had a different impact on gene regulation, with some stimulating only few and others boosting a large proportion of arterial genes. Interestingly, although there was some overlap and cross-regulation, the transcription factors largely complemented each other in regulating the arterial EC gene profile. Thus, our study showed that Notch signaling determines only part of the arterial EC signature and identified additional novel and complementary transcriptional players in the complex regulation of human arteriovenous EC identity
Unraveling a novel transcription factor code determining the human arterial-specific endothelial cell signature.
Specimen part
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