The premature aging disorder Werner Syndrome (WS) is characterized by early onset of aging phenotypes resembling natural aging. In most WS patients there are mutations in the DNA helicase WRN, an enzyme important in maintaining genome stability and telomere replication. Interestingly, its clinical manifestations reflect a severe degree of deterioration for connective tissue, whereas the central nervous system is less affected. We suggest that the varied vulnerability to aging is regulated by an unknown mechanism that protects specific lineages of stem cells from premature senescence. To address this problem, we reprogrammed patient skin fibroblasts to induced pluripotent stem cells (iPSC). The expression profile for the differentiated normal and WS fibroblasts and undifferentiated iPSC were compared. A distinct expression profile was found between normal and WS fibroblasts, however, few changes of gene expression were found in iPSC. Our findings suggest an erasure of aging phenotype associated with WS in reprogrammed iPSC.
Telomerase protects werner syndrome lineage-specific stem cells from premature aging.
Sex, Age, Specimen part
View SamplesAberrant methylation has been postulated to play an important role in tumorigenesis. We report the use of methylated DNA immunoprecipitation (MeDIP) and whole-genome tiling arrays to investigate methylation changes in testicular germ cell tumor (TGCT) cells. Coupled to expression profiling changes, we found that only 22-26% of differentially methylated genes were also expressed differentially. This phenomenon was independent of the presence of CpG islands in the promoter. Differential methylation and expression of some of these genes were confirmed in testicular tumor tissue. A substantial number of differentially methylated regions in the human genome were not linked to annotated gene loci. Subsequent analysis indicated several microRNAs and small nucleolar RNAs were regulated by these differentially methylated regions. Our results demonstrate the power of the combination of MeDIP-chip analysis and expression profiling for discovery in cancer cells of epigenetically regulated genes and non-coding RNAs in cancer cells.
Genome-wide DNA methylation profiling reveals novel epigenetically regulated genes and non-coding RNAs in human testicular cancer.
Sex, Age, Specimen part, Cell line
View SamplesThe objective of this study was to understand the genetic mechanisms of Vitamin-A-Deficiency (VAD)-induced arrest of spermatogonial stem-cell differentiation. Vitamin A and its derivatives (the retinoids) participate in many physiological processes including vision, cellular differentiation and reproduction. VAD affects spermatogenesis, the subject of our present study. Spermatogenesis is a highly regulated process of differentiation and complex morphologic alterations that, in the postnatal testis, leads to the formation of sperm in the seminiferous epithelium. VAD causes early cessation of spermatogenesis, characterized by degeneration of meiotic germ cells, leading to seminiferous tubules containing mostly type A spermatogonia and Sertoli cells. In this study, we investigated the molecular basis of VAD on spermatogenesis in mice. We used adult Balb/C mice fed with a Control or VAD diet for an extended period of time (8-28 weeks) and selected two time points (18 and 25 weeks) for microarray analysis.
Long-term vitamin A deficiency induces alteration of adult mouse spermatogenesis and spermatogonial differentiation: direct effect on spermatogonial gene expression and indirect effects via somatic cells.
Specimen part, Treatment
View SamplesBackground: Elevated plasma cholesterol promotes the formation of atherosclerotic lesions in which monocyte-derived lipid-laden macrophages are frequently found. To analyze, if circulating monocytes already show increased lipid content and differences in lipoprotein metabolism, we compared monocytes from patients with Familial Hypercholesterolemia (FH) with those from healthy individuals.
Monocytes of patients with familial hypercholesterolemia show alterations in cholesterol metabolism.
Specimen part, Disease, Disease stage
View SamplesTranscriptional profiles of HCMV or Mock infected neonatal and adult were anayzed
IL-12 and type I IFN response of neonatal myeloid DC to human CMV infection.
Specimen part, Time
View SamplesIn response to acute loss of the Ulp2 SUMO-specific protease, yeast become disomic for chromosome I (ChrI) and ChrXII. Here we report that ChrI disomy, which creates an adaptive advantage in part by increasing the dosage of the Ccr4 deadenylase, was eliminated by extended passaging. Loss of aneuploidy is often accompanied by mutations in essential SUMO-ligating enzymes, which reduced polySUMO-conjugate accumulation. The mRNA levels for almost all ribosomal proteins increases transiently upon initial loss of Ulp2, but elevated Ccr4 levels limit excess ribosome formation. Notably, extended passaging leads to increased levels of many small nucleolar RNAs (snoRNAs) involved in ribosome biogenesis, and higher dosage of three linked ChrXII snoRNA genes suppressed ChrXII disomy in ulp2? cells. Our data reveal that aneuploidy allows rapid adaptation to Ulp2 loss, but long-term adaptation restores euploidy. Cellular evolution restores homeostasis through countervailing mutations in SUMO-modification pathways and regulatory shifts in ribosome biogenesis. Overall design: In these comparisons, the ulp2? cells either carried a WT ULP2 plasmid or empty vector and were passaged for 50 or 500 generations. mRNA profiles of them were generated by sequencing, in triplicate, using Illumina HiSeq 2500 .
Distinct adaptive mechanisms drive recovery from aneuploidy caused by loss of the Ulp2 SUMO protease.
Subject
View SamplesWe have performed bioinformatic approaches to identify the level of enrichment between gene expression profiles characterizing MSI tumors and gene changes induced in vitro by the PARP-1 inhibitor Phenanthridinone and others using the Connectivity Map tool. In a first step, we have anyzed the expression of 300 colorectal cancers from the MECC study and generated a gene expression signature by microsatellite status. The criteria followed for selection of probe sets and detailed lists to be submitted subsequently to the Connectivity Map have been published previously by us in Clinical Cancer Research in 2009. In a second step, once we observed that deficiency in MRE11 exist among MSI tumors, our interest was focused on assessing if the homologous recombination pathway showed evidence of deregulation in MSI tumors. Therefore, we examined the expression levels of those genes integrated in the KEGG pathway hsa03440 using the previously generated gene expression data set.
MRE11 deficiency increases sensitivity to poly(ADP-ribose) polymerase inhibition in microsatellite unstable colorectal cancers.
Sex, Age
View SamplesGoal of this experiment is the identify differentially expressed genes in GBM zenografts that have been exposed to Cilengitide for 1 or 8 hours. A control with no cilengitide is also included. None of the tumors recieved radiation.
Radiation sensitization of glioblastoma by cilengitide has unanticipated schedule-dependency.
No sample metadata fields
View SamplesBackground: Kaposis sarcoma associated herpes virus (KSHV) is associated with tumors of endothelial and lymphoid origin. During latent infection, KSHV expresses miR-K12-11, an ortholog of the human tumor gene hsa-miR-155. Both gene products are microRNAs (miRNAs), which are important post-transcriptional regulators that contribute to tissue specific gene expression. Advances in target identification technologies and molecular interaction databases have allowed a systems biology approach to unravel the gene regulatory networks (GRNs) triggered by miR-K12-11 in endothelial and lymphoid cells. Understanding the tissue specific function of miR-K12-11 will help to elucidate underlying mechanisms of KSHV pathogenesis. Results: Ectopic expression of miR-K12-11 differentially affected gene expression in BJAB cells of lymphoid origin and TIVE cells of endothelial origin. Direct miRNA targeting accounted for a small fraction of the observed transcriptome changes: only 29 common genes were identified as putative direct targets of miR-K12-11 in both cell types. However, a number of commonly affected biological pathways, such as carbohydrate metabolism and interferon response related signaling, were revealed by gene ontology analysis. Integration of transcriptome profiling, bioinformatic algorithms, and databases of protein-protein interactome from the ENCODE project identified different nodes of GRNs utilized by miR-K12-11 in a tissue-specific fashion. These effector genes, including cancer associated transcription factors (TFs) and signaling proteins, amplified the regulatory potential of a single miRNA, from a small set of putative direct targets to a larger set of genes. Conclusions: This is the first comparative analysis of miRNA-K12-11s effects in endothelial and B cells, from tissues infected with KSHV in vivo. MiR-K12-11 was able to broadly modulate gene expression in both cell types. Using a systems biology approach, we inferred that miR-K12-11 establishes its GRN by both repressing master TFs and influencing signaling pathways, to counter the host anti-viral response and to promote proliferation and survival of infected cells. The targeted GRNs are more reproducible and informative than target gene identification, and our approach can be applied to other regulatory factors of interest.
A systems biology approach identified different regulatory networks targeted by KSHV miR-K12-11 in B cells and endothelial cells.
Specimen part, Cell line
View SamplesGene expression profiling of three PEL cell lines compare to three Burkitt's lymphoma lines to figure out the changed genes under KSHV latent infection.
The latency-associated nuclear antigen of Kaposi's sarcoma-associated herpesvirus modulates cellular gene expression and protects lymphoid cells from p16 INK4A-induced cell cycle arrest.
No sample metadata fields
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