Comparison of the RNA expression profile between P-cadherin over-expressing BLM melanoma cells and empty-vector control cells
ABSTRACT: Van Marck et al. (Cancer Research, 2005) published that overexpression of P-cadherin in a melanoma cell line promoted homo- and heterotypic cell-cell adhesion, induced an epitheloïd morphology, and impaired cancer cell invasion. Therefore, we wanted to compare the RNA expression profile between the empty vector control cells and the P-cadherin overexpression variant. This experiment could provide us with effector molecules of P-cadherin that mediate its anti-invasive function. 2 samples were analyzed, each with 2 replicates
Project description:Enterotoxigenic Escherichia coli (ETEC) strains that produce both heat-stable (ST) and heat-labile (LT) enterotoxins cause severe post-weaning diarrhea in piglets. However, the relative importance of the individual enterotoxins to the pathogenesis of ETEC infection is poorly understood. In this study, we investigated the effect on virulence of an F4+ ETEC strain when removing some or all of its enterotoxins. Several isogenic mutant strains were constructed that lack the expression of LT in combination with one or both types of ST enterotoxins (STa and/or STb). Host early immune responses induced by these mutant strains 4h after infection were compared to the wild type strain GIS26 (O149:F4ac+, LT+ STa+ STb+). At the same time, the immune response of this wild type ETEC strain was compared to the mock-infected control, demonstrating the expression of porcine inflammatory response genes. For these purposes, the small intestinal segment perfusion (SISP) technique and microarray analysis were used and results were validated by qRT-PCR. We also measured net fluid absorption of pig small intestinal mucosa 4h after infection with wild type ETEC, the mutant strains and PBS (mock-infected). These data indicate an important role for STb in inducing small intestinal secretion early after infection. The microarray analysis of the different mutant strains also revealed an important role for STb in ETEC-induced immune response by the significant differential regulation of immune mediators like matrix metalloproteinase 3, interleukin 1 and interleukin 17. We conclude that STb can play a prominent role in ETEC-induced secretion and early immune response. In three pigs, 6 different treatments were performed. These treatments consisted of 4 mutant enterotoxigenic Escherichia coli GIS26 strains, GIS26 wild type strain, or PBS control. Per pig, the small intestine was divided into 6 loops with an interloop in between to avoid cross-contamination. In conclusion, every pig received each of the 6 treatments ad random.
Project description:Objective : To study molecular changes in the articular cartilage and subchondral bone of the tibial plateau from mice deficient in frizzled related protein (Frzb) compared to wild-type mice by transcriptome analysis. Methods : Gene-expression analysis of the articular cartilage and subchondral bone of 3 wild-type and 3 Frzb-/- mice was performed by microarray. Pathway analysis of differentially expressed genes between 3 wild-type and 2 Frzb-/- samples was explored with PANTHER, DAVID and GSEA bioinformatics tools. Activation of the WNT pathway was analyzed using western blot. The effects of Frzb gain and loss of function on chondrogenesis and cell proliferation was examined using ATDC5 micromasses and mouse ribcage chondrocytes. Results : Extracellular matrix-associated integrin and cadherin pathways, as well as WNT pathway genes were upregulated in Frzb-/- samples. Several WNT receptors, target genes, and other antagonists were upregulated, but no difference in active β-catenin was found. Analysis of ATDC5 cell micromasses overexpressing FRZB indicated an upregulation of aggrecan and Col2a1, and downregulation of molecules related to damage and repair in cartilage, Col3a1 and Col5a1. Silencing of Frzb resulted in downregulation of aggrecan and Col2a1. Pathways associated with cell cycle were downregulated. Ribcage chondrocytes derived from Frzb-/- mice showed decreased proliferation compared to wild-type cells. Conclusions : Our analysis provides evidence for tight regulation of WNT signaling, shifts in extracellular matrix components and effects on cell proliferation and differentiation in the articular cartilage - subchondral bone unit in Frzb-/- mice. These data further support an important role for FRZB in joint homeostasis and highlight the complex biology of WNT signaling in the joint. Gene-expression analysis of the articular cartilage and subchondral bone of 3 wild-type and 3 Frzb-/- mice was performed by microarray. Pathway analysis of differentially expressed genes between 3 wild-type and 2 Frzb-/- samples was explored with PANTHER, DAVID and GSEA bioinformatics tools.
Project description:Comparison of t(11;18)-positive MALT lymphoma to t(11;18)-negative MALT lymphoma, with a special focus on the NF-KB pathway and it's targets 8 t(11;18)-negative and 6 t(11;18)-positive cases of MALT lymphoma, as well as six spleen control samples (1 mix of spleens and 5 singular spleen samples)
Project description:Lymph node involvement is the most important prognostic factor in breast cancer, but little is known about the underlying molecular changes. First, to identify a molecular signature associated with nodal metastasis, gene expression analysis was performed on a homogeneous group of 96 primary breast tumors, balanced for lymph node involvement. Each tumor was diagnosed as a poorly differentiated, estrogen positive, her2-neu negative invasive ductal cancer. (Affymetrix Human U133 Plus 2.0 microarray chips). A model, including 241 genes was built and validated on an internal and external dataset performed with Affymetrix technology. All samples used for validation had the same characteristics as the initial tumors. The area under the ROC curve (AUC) for the internal dataset was 0.646 and 0.651 for the external datasets. Thus, the molecular profile of a breast tumor reveals information about lymph node involvement, even in a homogeneous group of tumors. However, an AUC of 0.65 indicates only a weak correlation. Our model includes multiple kinases, apoptosis related and zinc ion binding genes. Pathway analysis using the Molecular Signatures Database revealed relevant gene sets (BAF57, Van 't Veer). Next, miRNA profiling was performed on 82/96 tumors using Human MiRNA microarray chips (Illumina). Eight miRNAs were significantly differentially expressed according to lymph node status at a significance level of 0.05, without correcting for multiple testing. The analysis of the inverse correlation between a miRNA and its computationally predicted targets point to general deregulation of the miRNA machinery potentially responsible for lymph node invasion. In conclusion, our results provide evidence that lymph node involvement in breast cancer is not a random process. Gene expression profiling: A training set of 96 patients and an independent internal dataset of 20 patients balanced for lymph node involvement was selected from the multidisciplinary breast centre database miRNA profiling not provided in this Series.
Project description:The sfr6-1 mutant of Arabidopsis has been shown to be defective in freezing tolerance and fails to express a number of cold-regulated genes to normal wild type levels. The aim of this experiment was to test whether two other mutant alleles, sfr6-2 and sfr6-3 showed similar defects in cold-inducible gene expression. Two experiments were performed. In each, one sfr6 mutant was cold-treated alongside its corresponding wild type.
Project description:Cidofovir is an acyclic nucleoside phosphonate with strong antiviral activity against a broad spectrum of DNA viruses. Although it has previously been shown that cidofovir exerts an antiproliferative effect on HPV positive cells by the induction of apoptosis, the exact mechanism of action remains to be unraveled. In order to study the activity of cidofovir against HPV, gene expression profiling was performed in cidofovir-treated and cidofovir-resistant HeLa, HaCaT, and PHK cells by means of microarrays (HG-U133 Plus 2, Affymetrix). Controls (untreated HeLa, HaCaT, and PHK wild-type cells): 72h of growth. Cidofovir treated (50 µg/ml) HeLa, HaCaT, and PHK cells: 72h of growth. Cidofovir resistant cells (HeLa #52 and HaCaT #51): 72h of growth. All samples were performed in triplicates.
Project description:The goal of this study is to identify co-expressed genes downstream of Atonal and Senseless. These gene lists are used as candidate target genes (technically: as foreground sets) in computational predictions of cis-regulatory elements using the cisTargetX method (http://med.kuleuven.be/cme-mg/lng/cisTargetX). Together, the gene expression results and cis-regulatory predictions, yield a gene regulatory network underlying the early events in retinal differentiation. Predicted cis-regulatory interactions have been validated extensively in vivo using enhancer reporter assays and genetic perturbations. Six samples were analyzed for Atonal gain-of-function (GOF) in the eye-antennal imaginal discs of third instar larvae of Drosophila melanogaster, namely three biological repeats for two different Gal4 drivers (Gal4/7 and AtoGal), crossed with UASato. Three samples were analyzed for Atonal loss-of-function (LOF) in the eye-antennal imaginal discs, namely three biological repeats of ato-/- larvae. Three samples were analyzed for Senseless GOF, namely three biological repeats of atoGal4 crossed with UASsens. Finally, eight control samples were analyzed, namely two biological repeats of four different lines (atoGal4, Gal4/7, UASato, and cantonS wild type).
Project description:The purpose of this study was to determine the gene expression patterns of the colon of GPR41 KO and GPR43 KO mice in response to ETOH treatment The mice were treated with rectal injection of ETOH. 24 hours later, the colon tissues were harvested and total RNA was isolated for array experiments.
Project description:Objectives: The aim of this study was to identify the dysregulated genes involved in tumorigenesis, invasion, and metastasis of endometrial endometrioid adenocarcinoma (EEC). Materials and methods: Surgical specimens of endometrial tissues were obtained from 20 patients with normal endometrium (NEM), 20 patients with atypical endometrial hyperplasia (AEH), and 169 patients with EEC. The expression profiles of NEM, AEH, and EEC were compared by using GeneChip Array. The expression of dysregulated genes was first validated by semi-quantitative reverse transcriptase PCR (SQ RT-PCR). The gene expression levels were determined by real time reverse transcriptase PCR (RTQ RT-PCR) in 85 EEC patients as the training test and 84 EEC patients as the testing test. The protein expressions were then examined by immunohistochemical (IHC) staining. The correlations between the expression of dysregualted genes and clinico-pathologic parameters such as tumorigenesis, invasion, and metastasis of EEC were finally evaluated. Results: Seven dysregulated genes were identified by SQ RT-PCR after microarray analysis. Conclusions: uPA is a dysregulated gene in the tumorigenesis of endometrial carcinomas. The gene expression between tissues from NEM, AEH, and EEC were analyzed by microarray. The samples were grouped according to clinical stages but selected at random from our list of banked, frozen tissues. Ten NEM, 10 AEH, and 20 EEC of early and advanced stages were used for microarray experiments (Group 1: early-staged (stages I and II) EEC (n=10), Group 2: advanced-staged EEC (stages III and IV) (n=10)). Samples were pooled in equimolar amounts (10 samples / pool) for microarray analysis.