Methylation of Cancer Stem Cell-associated Wnt target genes predicts poor prognosis in colorectal cancer patients
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ABSTRACT: This SuperSeries is composed of the following subset Series: GSE33112: Gene expression in colon cancer stem cells (CSC) cultures identified by Wnt signaling levels GSE33113: AMC colon cancer AJCCII Refer to individual Series
Project description:Primary colon CSC cultures were transduced with a Wnt responsive construct (TOP-GFP). 10% highest and lowest TOP-GFP cell fractions were FACS sorted and arrayed. Primary colon CSC cultures with a responsive construct (TOP-GFP): high and low TOP-GFP cell fractions. 12 samples.
Project description:Profiling project of CRC patient material collected in the Academic Medical Center (AMC) in Amsterdam, The Netherlands. We focused on a set of 90 AJCC stage II patients that underwent intentionally curative surgery in the years 1997-2006 (AMC-AJCCII-90). Extensive medical records are kept from these patients and long-term clinical follow-up is available for the large majority. Both paraffin-embedded as well as fresh frozen tissue is available from all these patients for analysis. 90 AJCC stage II CRC patients were included in the story
Project description:Profiling project of a panel of tubular adenoma and serrated adenoma patient material collected in the Academic Medical Center (AMC) in Amsterdam, The Netherlands. The aim of the study was to compare the expression profiles of different types of colon cancer precursor lesions (tubular versus serrated adenomas) and determine their correspondence with a set of colon cancer patient-derived profiles that have distinct clinical outcomes. 6 serrated adenomas and 7 tubular adenomas are profiled in this study.
Project description:The transcription factor OTX2 has been implicated as an oncogene in medulloblastoma, which is the most common malignant brain tumor in children. It is highly expressed in most medulloblastomas and amplified in a subset of them. The role of OTX2 in medulloblastoma and its downstream targets are unclear. Therefore, we generated D425 medulloblastoma cells in which we can silence endogenous OTX2 by inducible shRNA. Silencing of OTX2 strongly inhibited cell proliferation and resulted in a neuronal-like differentiation. Expression profiling of time courses after silencing showed a progressive change in gene expression for many cellular processes. Down regulated genes were highly enriched for cell cycle and visual perception genes, while up regulated genes were enriched for genes involved in development and differentiation. This shift in expression profiles is reminiscent to changes described to occur during normal cerebellum development. OTX2 is expressed in proliferating granular progenitor cells, but the expression diminishes when these cells exit the cell cycle and start differentiating. ChIP-on-chip analyses of OTX2 in D425 cells showed that cell cycle and perception genes were direct OTX2 targets, while regulation of most differentiation genes appears to be indirect. These analyses provide the first insight in the molecular network of OTX2, demonstrating that OTX2 is essential in medulloblastoma and directly drives proliferation by regulating the expression of cell cycle genes. Since many of these genes also correlate in expression with OTX2 in primary tumors, they might be potential targets for therapy in medulloblastoma patients. Keywords: OTX2, medulloblastoma, mRNA profiling *** This Series represents the gene expression component of the study. Three independent time course experiments of OTX2 silencing, and 1 control experiment in D425 medulloblastoma cells.
Project description:IMR32 was transduced with control or shMYCN virus (duplo). For each experiment 3 time points were analyzed and 2 no virus controls. IMR32 was transduced with control or shMYCN virus (duplo). For each experiment 3 time points were analyzed and 2 no virus controls.
Project description:Neuroblastoma tumors frequently show loss of heterozygosity of chromosome 11q with a shortest region of overlap in the 11q23 region. These deletions are thought to cause inactivation of tumor suppressor genes leading to haploinsufficiency. Alternatively, micro-deletions could lead to gene fusion products that are tumor-driving. To identify such events we analyzed a series of neuroblastomas by comparative genomic hybridization (CGH) and single nucleotide polymorphism (SNP) arrays and integrated these data with Affymetrix mRNA profiling data with the bioinformatic tool R2 (http://r2.amc.nl). We identified three neuroblastoma samples with small interstitial deletions at 11q23, upstream of the forkhead-box transcription factor FOXR1. Genes at the proximal side of the deletion were fused to FOXR1, resulting in fusion transcripts of MLL-FOXR1 and PAFAH1B2-FOXR1. FOXR1 expression has only been detected in early embryogenesis. Affymetrix microarray analysis showed high FOXR1 mRNA expression exclusively in the neuroblastomas with micro-deletions and rare cases of other tumor types, including osteosarcoma cell line HOS. RNAi silencing of FOXR1 strongly inhibited proliferation of HOS cells and triggered apoptosis. Expression profiling of these cells and reporter assays suggested that FOXR1 is a negative regulator of forkhead-box factor mediated transcription. The neural crest stem cell line JoMa1 proliferates in culture conditional to activity of a MYC-ER transgene. Over-expression of the wild-type FOXR1 could functionally replace MYC and drive proliferation of JoMa1. We conclude that FOXR1 is recurrently activated in neuroblastoma by intrachromosomal deletion/fusion events, resulting in over-expression of fusion transcripts. Forkhead-box transcription factors have not been previously implicated in neuroblastoma pathogenesis. Furthermore, this is the first identification of intrachromosomal fusion genes in neuroblastoma. Time series Affymetrix U133p2 profiling of Osteosarcoma HOS cells transduced with FOXR1 targeted shRNAs or control shRNA
Project description:Microglia, the resident immune cells of the central nervous system (CNS), have two distinct phenotypes in the developing brain: amoeboid form, known to be amoeboid microglial cells (AMC) and ramified form, known to be ramified microglial cells (RMC) alongside several intermediate forms. The AMC are characterized by being proliferative, phagocytic and migratory whereas the RMC are quiescent and exhibit a slow turnover rate. The AMC transform into RMC with advancing age, and this transformation is indicative of the gradual shift in the microglial functions. Both AMC and RMC respond to CNS inflammation, and they become hypertrophic when they are activated by trauma, infection or neurodegenerative stimuli. The molecular mechanisms and functional significance of morphological transformation of microglia during normal development and in disease conditions is not clear. It is hypothesized that AMC and RMC are functionally regulated by a specific set of genes encoding various signaling molecules and transcription factors. To address this, we carried out cDNA microarray analysis using lectin-labeled AMC and RMC isolated from frozen tissue sections of the corpus callosum of 5-day and 4-week old rat brain respectively, by laser capture microdissection (LCM). The global gene expression profiles of both microglial phenotypes were compared and the differentially expressed genes in AMC and RMC were clustered based on their functional annotations. This genome wide comparative analysis helps in identifying genes that are specific to AMC and RMC. The novel and specific molecules identified in both microglial phenotypes can be targeted for therapeutic purposes in developing and adult brain diseases. We used microarrays to identify the genes specific to amoeboid and ramified microglia. RNA was isolated from the laser-captured amoeboid and ramified microglia from the corpus callosum of 5-day and 4-week old rat brain. The RNA was hybridised onto Affymetrix Rat 230 2.0 array.
Project description:Profiling project of a panel of tubular adenoma and serrated adenoma patient material collected in the Academic Medical Center (AMC) in Amsterdam, The Netherlands. The aim of the study was to compare the expression profiles of different types of colon cancer precursor lesions (tubular versus serrated adenomas) and determine their correspondence with a set of colon cancer patient-derived profiles that have distinct clinical outcomes.
Project description:The antenno-maxilary complex (AMC) forms the chemosensory system of the Drosophila larva and is involved in gustatory and olfactory perception. We have previously shown that a mutant allele of the homeodomain transcription factor Prospero (prosVoila1, V1), presents several developmental defects including abnormal growth and altered taste responses. In addition, many neural tracts connecting the AMC to the central nervous system (CNS) were affected. Our earlier reports on larval AMC did not argue in favour of a role of pros in cell fate decision, but strongly suggested that pros could be involved in the control of other aspect of neuronal development. In order to identify these functions, we used microarray analysis of larval AMC and CNS tissue isolated from the wild type, and three other previously characterised prospero alleles, including the V1 mutant, considered as a null allele for the AMC. A total of 17 samples were first analysed with hierarchical clustering. To determine those genes affected by loss of pros function, we calculated a discriminating score reflecting the differential expression between V1 mutant and other pros alleles. We identified a total of 64 genes in the AMC. Additional manual annotation using all the computed information on the attributed role of these genes in the Drosophila larvae nervous system, enabled us to identify a first functional category of potential Prospero target genes known to be involved in neurite outgrowth, synaptic transmission and more specifically in neuronal connectivity remodelling. The second category of genes found to be differentially expressed between the null mutant AMC and the other alleles concerned the development of the sensory organs and more particularly the larval olfactory system. Surprisingly, a third category emerged from our analyses and suggests an association of pros with the genes that regulate autophagy, growth and insulin pathways. Interestingly, EGFR and Notch pathways were represented in all of these three functional categories. We now propose that Pros could perform all of these different functions through the modulation of these two antagonistic and synergic pathways. The current data contribute to the clarification of the Prospero function in the larval AMC and show that pros regulates different function in larvae as compared to those controlled by this gene in embryos. In the future, the possible mechanism by which Pros could achieve its function in the AMC and the possible involvement of EGFR and Notch pathway will be explored in detail Gene expression was measured in two different tissues (Brain and AMC) of prospero mutants flies (V1, V13, V14, V24). 3 biological replicates were performed for V1, V13 and V24 AMC and V14 Brain; 2 biological replicates for V14 AMC and V13 Brain.