Gene expression and alternative splicing in human gastric cancer
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE13195 | GEO | 2009/09/24
SECONDARY ACCESSION(S): PRJNA109489
REPOSITORIES: GEO
Similar Datasets
Project description:Alternative splicing is a molecular process that contributes greatly to the diversification of proteome and to gene functions. Understanding the mechanisms of stage-specific alternative splicing can provide a better understanding of the development of eukaryotes and the functions of different genes. Schistosoma japonicum is an infectious blood-dwelling trematode with a complex lifecycle that causes the tropical disease schistosomiasis. In this study, we analyzed the transcriptome of Schistosoma japonicum to discover alternative splicing events in this parasite, by applying RNA-seq to cDNA library of adults and schistosomula. Results were validated by RT-PCR and sequencing. We found 11,623 alternative splicing events among 7,099 protein encoding genes and average proportion of alternative splicing events per gene was 42.14%. We showed that exon skip is the most common type of alternative splicing events as found in high eukaryotes, whereas intron retention is the least common alternative splicing type. BioProject accession number is PRJNA290970, and the SRA Study accession number is SRP061588. Mixed sample of cDNA libaraies of Schistosomula and adult were sequenced using Illumina HiSeq2000.
2015-09-06 | E-GEOD-71722 | biostudies-arrayexpress
Project description:We used a high read depth (>75 million reads per sample) RNA sequencing to determine how the expression and splicing of genes change with advancing age.
2022-12-31 | GSE156655 | GEO
Project description:MSI (Microsatellite Instability) colorectal cancer (CRC) show improved survival, are less prone to metastasis and show poor response to chemotherapy (compared to MSS tumors). The underlying reasons for these characteristics are still not understood and no specific therapeutic approach for MSI colon tumours (15% of CRC overall) has yet been developed.
The MSI process is oncogenic when it affects DNA repeat sequences that have a functional role, e.g. Small Coding Repeats (SCR). MSI also frequently affects Long Non-Coding Repeats (LNCR) in tumour DNA. In contrast to SCR, only a few LNCR are endowed with biological activity. Consequently, this area has received very little attention. Our group recently identified HSP110 mutant chaperone protein in MSI CRC that was generated by somatic deletion of a LNCR. Of interest, HSP110 mutant (due to exon skipping) have anti-oncogenic properties and the survival of MSI CRC patients receiving chemotherapy is positively associated with HSP110 mutations in tumour DNA.
The aim of the current project is to identify additional clinically relevant MSI-associated splicing aberrations due to mutations in LNCR located in splice acceptor sites. The four main steps are as follows:
1. To identify exon/intron sites affected by aberrant splicing events due to MSI in CRC . All RNASeq data will be exploited to identify recurrent splicing aberrations (mostly exon skipping) that occur specifically in MSI colon tumours;
2. To investigate for possible functional links between MSI and any detected aberrant splicing events . All specific aberrant splicing events detected by RNAseq in MSI CRC samples will be first confirmed (quantitative RT-PCR) in order to eliminate false positive cases. For validated exon candidates, the allelic profiles of adjacent intronic LNCR will be analysed (PCR and fluorescence genotyping) in CRC cell lines and primary tumours (MSI and MSS), as well as in matching normal mucosa samples in order to assess their polymorphic status;
3. To identify splicing events and LNCR mutations with clinical relevance in MSI CRC patients . All LNCR with a confirmed role in gene splicing in MSI CRC will be analysed. The clinical relevance of candidate genes will be assessed using multivariate survival regression models for Relapse- Free Survival, with interaction terms (response to chemotherapy);
4. To initiate functional studies on a limited number of clinically relevant, cancer-related genes whose splicing is perturbed in MSI cancer cells, and to develop biological tools to simplify screening in future clinical assays Similar to HSP110, we will focus on 4 or 5 mutant proteins that are promising drug therapeutic targets. Functional assays will be developed to further elucidate their role in the pathophysiology of MSI tumours. We also aim to develop biological tools for these candidate genes, such as the detection of wild-type or mutant proteins by immunohistochemistry.
| 2266966 | ecrin-mdr-crc
Project description:We used Affymetrix GeneChipM-BM-. Human Exon 1.0 ST Arrays to identify alternative splicing events in 15 samples of PDAC compared to 6 non-tumor samples. Several commercial and open source software approaches for the analysis of differential splicing were tested and a subset of overlapping results was validated using RT-PCR and sequencing. Splicing variants could be validated in several genes closely related to cancer. Pathway analysis of genes predicted to be alternatively spliced revealed an enrichment of genes in categories closely related to cell-cell interactions and kinase activity. 15 samples of pancreatic ductal adenocarcinoma and 6 non tumor pancreatic samples were analyzed for alternative splicing events
2013-08-01 | E-GEOD-23397 | biostudies-arrayexpress
Project description:6 pairs of OLK tissues and normal oral mucusal (NOM) tissues were obtained to detect circRNAs expression.The profile data showed that 366 circRNAs were significantly dysregulated in the OLK tissues, including 65 upregulated and 301 downregulated circRNA transcripts.There are 28 circRNAs were discovered firstly. 7 out of 10 selected circRNAs were further validated using Qrt-PCR
2020-12-16 | GSE131568 | GEO
Project description:Objective: To identify genes involved in idiopathic absence epilepsies by analysing gene expression using a monozygotic (MZ) twin design. Methods: Genome-wide gene expression in lymphoblastoid cell lines was determined using microarrays derived from five discordant and four concordant MZ twin pairs with idiopathic absence epilepsies and five unaffected MZ twin pairs. Gene expression was analysed using three strategies: discordant MZ twins were compared as matched pairs, MZ twins concordant for epilepsy were compared to control MZ twins, and a singleton design of affected versus unaffected MZ twin individuals was used irrespective of twin pairing. An overlapping gene list was generated from these analyses. Dysregulation of genes recognised from the microarray experiment were validated using quantitative real time PCR (qRT-PCR) in the twin sample and in an independent sample of 18 sporadic absence cases and 24 healthy controls. Results: Sixty-five probe sets were identified from the microarray analysis strategies. Sixteen genes were chosen for validation and nine of these genes confirmed by qRT-PCR in the twin sample. Differential expression of the immediate early gene EGR1 and RCN2, coding for the calcium-binding protein Reticulocalbin 2, was re-confirmed by qRT-PCR in the independent sample. Interpretation: Using a unique sample of discordant MZ twins, our study identified genes with altered expression, which suggest novel mechanisms in idiopathic absence epilepsy. Dysregulation of EGR1 and RCN2 might represent common transcriptional alterations in idiopathic absence epilepsy. Keywords: Childhood Absence Epilepsy, Juvenile Absence Epilepsy, Idiopathic Generalised Epilepsy, gene expression, twin study, monozygotic twins
2008-02-28 | GSE7486 | GEO
Project description:We used Affymetrix GeneChip® Human Exon 1.0 ST Arrays to identify alternative splicing events in 15 samples of PDAC compared to 6 non-tumor samples. Several commercial and open source software approaches for the analysis of differential splicing were tested and a subset of overlapping results was validated using RT-PCR and sequencing. Splicing variants could be validated in several genes closely related to cancer. Pathway analysis of genes predicted to be alternatively spliced revealed an enrichment of genes in categories closely related to cell-cell interactions and kinase activity.
2013-08-01 | GSE23397 | GEO
Project description:Purpose: The goals of this study are to compare the transcriptome profiling and alternative splicing (AS) profiling between Col-0 wild type and SFPS knockout mutant (sfps-2) through RNA-seq to determine the molecular mechanisms of how splicing factor SFPS regulates photomorphogenesis in Arabidopsis. Results: Using an optimized data analysis workflow, we mapped about 100 million sequence reads per sample to the Arabidopsis genome (TAIR10) and identified 1495 differentially expressed genes between Col-0 and mutant dark samples; 1361 differentially expressed genes between Col-0 and mutant red light treated samples; 4291 differentially expressed genes between Col-0 dark and red light treated samples; and 4479 differentially expressed genes between mutant dark and red light treated samples. Except for gene expression, we also discovered 788 differentially spliced bins between Col-0 and mutant dark samples; 827 differentially spliced bins between Col-0 and mutant red light treated samples; 610 differentially spliced bins between Col-0 dark and red light treated samples; and 405 differentially spliced bins between mutant dark and red light treated samples. Altered splicing of 9 genes was confirmed with qRT-PCR, demonstrating the high degree of sensitivity of the RNA-seq method. Conclusions: Our study represents the first detailed analysis of SFPS mutant transcriptomes, with biologic replicates, generated by RNA-seq technology. Our results show that SFPS regulates photomorphogenesis in Arabidopisis through regulating the splicing activity of light signaling genes, which helps us.
2017-08-10 | GSE85883 | GEO
Project description:Misregulated alternative splicing appears to be a major factor in the pathogenesis of myotonic dystrophy. The present study was done to further explore alternative splicing in this condition by doing exon-level analysis of mRNA from skeletal muscle of 8 subjects with type 1 myotonic dystrophy, 7 subjects with type 2 myotonic dystrophy, 8 disease controls (subjects with facioscapulohumeral muscular dystrophy), and 8 healthy controls . The ratios of signals from the various exons of a gene provided an index of altered exon inclusion/exclusion that was independent of the overall expression of that gene. There were numerous transcripts for which there was evidence of abnormal alternative splicing in subjects with myotonic dystrophy. For many of these transcripts, the abnormal splicing was confirmed by an independent RT-PCR approach. 31 subjects, one sample per subject, four groups: healthy subjects (n = 8), facioscapulohumeral dystrophy (n = 8), type 1 myotonic dystrophy (n = 8), type 2 myotonic dystrophy (n = 7)
2013-06-15 | E-GEOD-47968 | biostudies-arrayexpress
Project description:We performed an RNA-Seq experiment for three sample groups on base, middle, and apex regions of chick cochlea to identify genes and splicing events whose regulation mechanisms are associated with tonotopy.
2021-08-31 | GSE176521 | GEO