Alternative processing of pre-mRNA transcripts is a major source of protein diversity in eukaryotes and has been implicated in several disease processes including cancer. In this study we have performed a genome wide analysis of alternative splicing events with the GeneChip Human Exon 1.0 ST Array from Affymetrix in lung adenocarcinoma. We found that ~13.3% of the 17800 core Refseq genes appear to have alternative transcripts that are differentially expressed in lung adenocarcinoma versus normal. According to their known functions the largest subset of these genes (30.8%) is believed to be cancer related. Detailed analysis was performed for several genes using PCR, quantitative RT-PCR and DNA sequencing. We found overexpression of ERG variant 2 but not variant 1 in lung tumors and overexpression of CEACAM1 variant 1 but not variant 2 in lung tumors but not in breast or colon tumors. We also identified a novel, overexpressed variant of CDH3 and verified the overexpression of a novel variant of P16. These findings demonstrate how analysis of alternative pre-mRNA processing can shed additional light on differences between tumors and normal tissues as well as between different tumor types. Such studies may lead to the development of additional tools for tumor diagnosis, prognosis and therapy.
Whole genome exon arrays identify differential expression of alternatively spliced, cancer-related genes in lung cancer.
Sex, Age, Race, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The microRNA miR-34 modulates ageing and neurodegeneration in Drosophila.
Specimen part, Time
View Samplesgene expression profiles in fly brains between wildtype and miR-34 null flies
The microRNA miR-34 modulates ageing and neurodegeneration in Drosophila.
Specimen part, Time
View Samplesgene expression profiles in fly brains with age
The microRNA miR-34 modulates ageing and neurodegeneration in Drosophila.
Specimen part, Time
View SamplesThe incidence of esophageal adenocarcinoma (EAC) has risen 600% over the last 30 years. With an extremely poor five-year survival rate of only 15%, identification of new therapeutic targets for EAC is of great importance. Here, we analyze the mutation spectra from the whole exome sequencing of 149 EAC tumors/normal pairs, 15 of which have also been subjected to whole genome sequencing. We identify a novel mutational signature in EACs defined by a high prevalence of A to C transversions at Ap*A dinucleotides. Statistical analysis of the exome data identified 26 genes that are mutated at a significant frequency. Of these 26 genes, only four (TP53, CDKN2A, SMAD4, and PIK3CA) have been previously implicated in EAC. The novel significantly mutated genes include several chromatin modifying factors and candidate contributors to EAC: SPG20, TLR4, ELMO1, and DOCK2. Notably, functional analyses of EAC-derived mutations in ELMO1 increase cellular invasion. Therefore, we suggest a new hypothesis about the potential activation of the RAC1 pathway to be a contributor to EAC tumorigenesis.
Exome and whole-genome sequencing of esophageal adenocarcinoma identifies recurrent driver events and mutational complexity.
Sex, Age, Specimen part, Disease stage, Race
View SamplesThe conserved multi-subunit Ccr4-Not complex regulates gene expression in diverse ways. In this work, we characterize the suppression of temperature sensitivity associated with a mutation in the gene encoding the scaffold subunit of the Ccr4-Not complex, NOT1, by the deletion of SPT3.
A SAGA-independent function of SPT3 mediates transcriptional deregulation in a mutant of the Ccr4-not complex in Saccharomyces cerevisiae.
No sample metadata fields
View SamplesApproximately 75% of the human genome is transcribed, the majority of which does not encode protein. However, most noncoding RNA (ncRNA) is rapidly degraded after transcription, and relatively few have established functions, questioning the significance of this observation. Here we show that esBAF, a SWI/SNF family nucleosome remodeling factor, suppresses transcription of ncRNAs from approximately 57,000 nucleosome-depleted regions (NDRs) throughout the genome of mouse embryonic stem cells (ESCs). We show that esBAF functions both to keep NDRs nucleosome-free and to promote elevated nucleosome occupancy adjacent to NDRs. Reduction of adjacent nucleosome occupancy upon esBAF depletion is strongly correlated with ncRNA expression, suggesting that flanking nucleosomes form a barrier to pervasive transcription. Upon forcing nucleosome occupancy near an NDR using a nucleosome-positioning sequence, we find that esBAF is no longer required to silence transcription. These data reveal a novel role for esBAF in suppressing pervasive transcription from open chromatin regions in ESCs. Overall design: Examine nucleosome occupancy (MNase-Seq) and transcript production (CapSeq and RNA-Seq) in EGFP KD and Smarca4 KD ESCs
Suppression of pervasive noncoding transcription in embryonic stem cells by esBAF.
No sample metadata fields
View SamplesIn the central nervous system (CNS), the microRNAs (miRNAs), small endogenous RNAs exerting a negative post-transcriptional regulation on mRNAs, are involved in major functions, such as neurogenesis, and synaptic plasticity. Moreover, they are essential to define the specific transcriptome of the tissues and cell types. However, few studies were performed to determine the miRNome of the different structures of the rat CNS, even through rat is a major model in neuroscience. We determined the miRNome profile of the hippocampus, the cortex, the striatum, the spinal cord and the olfactory bulb, by small RNA-Seq. We found a total of 365 known miRNAs' and 90 novel miRNAs expressed in the CNS of the rat. Novel miRNAs seemed to be important in defining structure-specific miRNomes. Differential analysis showed that several miRNAs were specifically enriched/depleted in these CNS structures. Then, we correlated miRNAs' expression with the expression of their mRNA targets by mRNA-Seq. This analysis suggests that the transcriptomic identity of each structure is regulated by specific miRNAs. Altogether, these results suggest the critical role played by these enriched/depleted miRNAs in the functional identities of CNS structures. Overall design: miRNA and mRNA profile of 5 structures of the central nervous system of rat, for each structurewe analyzed three biological replicates
Small RNA-Seq reveals novel miRNAs shaping the transcriptomic identity of rat brain structures.
Specimen part, Cell line, Subject
View SamplesYin Yang 1 (YY1) is a multifunctional zinc-finger-containing transcription factor that plays crucial roles in numerous biological processes by selectively activating or repressing transcription, depending upon promoter contextual differences and specific protein interactions. In mice, Yy1 null mutants die early in gestation while Yy1 hypomorphs die at birth from lung defects. We studied how the epithelial-specific inactivation of Yy1 impacts on lung development. The Yy1 mutation in lung epithelium resulted in neonatal death due to respiratory failure. It impaired tracheal cartilage formation, altered cell differentiation, abrogated lung branching, and caused airway dilation similar to those seen in human congenital cystic lung diseases. The cystic lung phenotype in Yy1 mutants can be explained by the reduced expression of Shh in lung endoderm, a transcriptional target of YY1, and the subsequent derepression of mesenchymal Fgf10 expression. Accordingly, SHH supplementation partially rescued the lung phenotype in vitro. Analysis of human lung tissues revealed decreased YY1 expression in children with pleuropulmonary blastoma (PPB), a rare pediatric lung tumor arising during fetal development and associated with DICER1 mutations. No evidence for a potential genetic interplay between murine Dicer and Yy1 genes during lung morphogenesis was observed. However, the cystic lung phenotype resulting from the epithelial inactivation of Dicer function mimics the Yy1 lung malformations with similar changes in Shh and Fgf10 expression. Together, our data demonstrate the critical requirement for YY1 in lung morphogenesis and identify Yy1 mutant mice as a potential model for studying the genetic basis of PPB.
Epithelial inactivation of Yy1 abrogates lung branching morphogenesis.
Specimen part
View SamplesWe used microarrays to analyze gene expression changes in liver after treatment of rats with two compounds from drug development (R1, R2) to identify potential effects related to hepatotoxicity.
Gene expression-based in vivo and in vitro prediction of liver toxicity allows compound selection at an early stage of drug development.
Sex, Specimen part, Treatment
View Samples