Although it is well established that the ovarian reserve diminishes with increasing age, and that a womans age is correlated to lower oocyte quality, the interplay of a diminished reserve and age on oocyte developmental competence is not clear. After maturation, oocytes are mostly transcriptionally quiescent, and developmental competence prior to embryonic genome activation (EGA) relies on maternal RNA and proteins. Age and ovarian reserve both affects oocyte developmental competence, however, their relative importance in this process are difficult to tease out, as ageing is accompanied by a decrease in ovarian reserve. Oocytes store large quantities of RNA, including several noncoding transcripts (ncRNAs) involved in early development transcription and translation modulation. Despite the central role of ncRNAs in maternal to zygote transition, no characterization of the ncRNA transcriptome in human oocytes has been reported. This study aims at identifying how the human oocyte transcriptome changes across reproductive ages and ovarian reserve levels, with the goal of identifying candidate markers of developmental competence, and to assess the independent relevance of age and ovarian reserve in the changes of the transcriptome
The transcriptome of human oocytes is related to age and ovarian reserve.
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Position-dependent alternative splicing activity revealed by global profiling of alternative splicing events regulated by PTB.
Cell line
View SamplesDifferentiating erythroid cells execute a unique gene expression program that insures synthesis of the appropriate proteome at each stage of maturation. Standard expression microarrays provide important insight into erythroid gene expression, but cannot detect qualitative changes in transcript structure, mediated by RNA processing, that alter structure and function of encoded proteins. We analyzed stage-specific changes in the late erythroid transcriptome via use of high resolution microarrays that detect altered expression of individual exons. Ten differentiation-associated changes in erythroblast splicing patterns were identified, including the previously known activation of protein 4.1R exon 16 splicing. Six new alternative splicing switches involving enhanced inclusion of internal cassette exons were discovered, as well as three changes in use of alternative first exons. All of these erythroid stage-specific splicing events represent activated inclusion of authentic annotated exons, suggesting they represent an active regulatory process rather than a general loss of splicing fidelity. The observation that three of the regulated transcripts encode RNA binding proteins (SNRP70, HNRPLL, MBNL2) may indicate significant changes in the RNA processing machinery of late erythroblasts. Together these results support the existence of a regulated alternative pre-mRNA splicing program that is critical for late erythroid differentiation.
Alternative pre-mRNA splicing switches modulate gene expression in late erythropoiesis.
No sample metadata fields
View SamplesTo gain global insights into the role of the well-known repressive splicing regulator PTB we analyzed the consequences of PTB knockdown in HeLa cells using high-density oliogonucleotide splice-sensitive microarrays. The major class of identified PTB-regulated splicing event was PTB-repressed cassette exons, but there was also a substantial number of PTB-activated splicing events. PTB repressed and activated exons showed a distinct arrangement of motifs with pyrimidine-rich motif enrichment within and upstream of repressed exons, but downstream of activated exons. The N-terminal half of PTB was sufficient to activate splicing when recruited downstream of a PTB-activated exon. Moreover, insertion of an upstream pyrimidine tract was sufficient to convert a PTBactivated to a PTB-repressed exon. Our results demonstrate that PTB, an archetypal splicing repressor, has variable splicing activity that predictably depends upon its binding location with respect to target exons.
Position-dependent alternative splicing activity revealed by global profiling of alternative splicing events regulated by PTB.
Cell line
View SamplesOxidative stress is a common phenomenon and is linked to a wide range of diseases and pathological processes. Tissue-specific variation in redox signaling and cellular responses to oxidative stress may be associated with vulnerability to toxic agents and carcinogenic exposures. In order to provide a basis for tissue-specific difference, we examined the tissue-specific transcriptional features of 101 oxidative stress-associated genes in 10 different tissues and organs of healthy mice under physiological conditions.
Tissue-Specific Profiling of Oxidative Stress-Associated Transcriptome in a Healthy Mouse Model.
Sex
View SamplesBACKGROUND: In patients with suspicious pulmonary lesions, bronchoscopy is frequently non-diagnostic. This often results in additional invasive testing, including surgical biopsy, although many patients have benign disease. We sought to validate an airway gene-expression classifier for lung cancer in patients undergoing diagnostic bronchoscopy. METHODS: Two multicenter prospective studies (AEGIS 1 and 2) enrolled 1357 current or former smokers undergoing bronchoscopy for suspected lung cancer. Bronchial epithelial cells were collected from normal appearing mucosa in the mainstem bronchus during bronchoscopy. Patients without a definitive diagnosis from bronchoscopy were followed for 12 months. A gene-expression classifier was used to assess the risk of lung cancer, and its performance was evaluated. RESULTS: A total of 298 patients from AEGIS 1 and 341 from AEGIS 2 met criteria for analysis. Bronchoscopy was non-diagnostic for cancer in 272 of 639 patients (43%; 95%CI, 39-46%). The gene expression classifier correctly identified 431 of 487 patients with cancer (89% sensitivity; 95%CI, 85-91%), and 72 of 152 patients without cancer (47% specificity; 95%CI, 40-55%). The combination of the classifier and bronchoscopy had a sensitivity of 97% (95%CI, 95-98%), which was independent of size, location, stage, and histological subtype of lung cancer. In patients with an intermediate pre-test risk (10-60%) of lung cancer, the NPV of the classifier was 91% (95%CI 75-98%). CONCLUSIONS: In patients with an intermediate risk of lung cancer and a non-diagnostic bronchoscopy, a gene-expression classification of low-risk warrants consideration of a more conservative diagnostic approach that could reduce unnecessary invasive testing in patients with benign disease.
A Bronchial Genomic Classifier for the Diagnostic Evaluation of Lung Cancer.
Sex, Specimen part
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Gene expression profiling reveals epithelial mesenchymal transition (EMT) genes can selectively differentiate eribulin sensitive breast cancer cells.
Specimen part, Cell line
View SamplesThe systematic characterization of somatic mutations in cancer genomes is essential for understanding the disease and for developing targeted therapeutics. Here we report the identification of 2,576 somatic mutations across approximately 1,800 megabases of DNA representing 1,507 coding genes from 441 tumours comprising breast, lung, ovarian and prostate cancer types and subtypes. Additionally, 373 tumors were assayed for copy number alterations via Agilent 244A CGH arrays and 153 breast, lung, and colon samples were assayed for mRNA abundance with Affymetrix HuEx1 Exon Arrays.
Diverse somatic mutation patterns and pathway alterations in human cancers.
Specimen part
View SamplesGastric cancer, a leading cause of cancer related deaths, is a heterogeneous disease, with little consensus on molecular subclasses and their clinical relevance. We describe four molecular subtypes linked with distinct patterns of molecular alterations, disease progression and prognosis viz. a) Microsatellite Instable: hypermutated intestinal subtype tumors occurring in antrum, best overall prognosis, lower frequency of recurrence (22%), with liver metastasis in 23% of recurred cases b) Mesenchymal-like: diffuse tumors with worst prognosis, a tendency to occur at an earlier age and highest recurrence (63%) with peritoneal seeding in 64% of recurred cases, low frequency of molecular alterations c) TP53-inactive with TP53 loss, presence of focal amplifications and chromosomal instability d) TP53-active marked by EBV infection and PIK3CA mutations. The key molecular mechanisms and associated survival patterns are validated in multiple independent cohorts, to provide a consistent and unified framework for further preclinical and clinical research.
Molecular analysis of gastric cancer identifies subtypes associated with distinct clinical outcomes.
Specimen part, Subject
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No associated publication
Specimen part, Subject
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