The cyclin-dependent kinase inhibitor p21WAF1/Cip1 is the prototype downstream effector of the tumor suppressor protein p53. Yet, evidence from human cancer and mice models, imply that p21WAF1/Cip1, under certain conditions, can exercise oncogenic activity. The mechanism behind this behavior is still obscure. Within this context we unexpectedly noticed, predominantly in p53 mutant human cancers, that a subset of highly atypical cancerous cells expressing strongly p21WAF1/Cip1 demonstrated also signs of proliferation. This finding suggests either tolerance to high p21WAF1/Cip1 levels or that p21WAF1/Cip1 per se guided a selective process that led to more aggressive off-springs. To address the latter scenario we employed p21WAF1/Cip1-inducible p53-null cellular models and monitored them over a prolonged time period, using high-throughput screening means. After an initial phase characterized by stalled growth, mainly due to senescence, a subpopulation of p21WAF1/Cip1 cells emerged, demonstrating increased genomic instability, aggressiveness and chemo-resistance. At the mechanistic level unremitted p21WAF1/Cip1 production saturates the CRL4CDT2 and SCFSkp2 ubiquitin ligase complexes reducing the turn-over of the replication licensing machinery. Deregulation of replication licensing triggered replication stress fuelling genomic instability. Conceptually, the above notion should be considered when anti-tumor strategies are designed, since p21WAF1/Cip1 responds also to p53-independent signals, including various chemotherapeutic compounds.
Chronic p53-independent p21 expression causes genomic instability by deregulating replication licensing.
Specimen part, Cell line
View SamplesMouse sinoatrial node transcriptome
RNA sequencing of mouse sinoatrial node reveals an upstream regulatory role for Islet-1 in cardiac pacemaker cells.
No sample metadata fields
View SamplesRelatively brief bouts of exercise alter gene expression in peripheral blood mononuclear cells (PBMCs), but whether or not exercise changes gene expression in circulating neutrophils (whose numbers, like PBMCs, increase) is not known. We hypothesized that exercise would activate neutrophil genes involved in apoptosis, inflammation, and cell growth and repair, since these functions in leukocytes are known to be influenced by exercise. Blood was sampled before and immediately after 30-min of constant, heavy (about 80% peak O2 uptake) cycle-ergometer exercise in 12 healthy men (19-29 yr old) of average fitness. Neutrophils were isolated using density gradients; RNA was hybridized to Affymetrix U133+2 Genechip arrays. Using FDR<0.05 with 95% confidence a total of 526 genes were differentially expressed between before and after exercise. 316 genes had higher expression after exercise. The Jak/STAT pathway, known to inhibit apoptosis, was significantly activated (EASE score, p<0.005), but 14 genes were altered in a way likely to accelerate apoptosis as well. Similarly, both proinflammatory (e.g., IL32, TNFSF8 and CCR5) and anti-inflammatory (e.g., ANXA1) were affected. Growth and repair genes like AREG and FGF2 receptor genes (involved in angiogenesis) were also activated. Finally, a number of neutrophil genes known to be involved in pathological conditions like asthma and arthritis were altered by exercise, suggesting novel links between physical activity and disease or its prevention. In summary, brief heavy exercise leads to a previously unknown substantial and significant alteration in neutrophil gene expression.
Effects of 30 min of aerobic exercise on gene expression in human neutrophils.
No sample metadata fields
View SamplesStem cells (SC) exhibit a unique capacity for self-renewal in an undifferentiated state. It is unclear whether the self-renewal of pluripotent embryonic SC (ESC) and of tissue-specific adult SC such as hematopoietic SC (HSC) is controlled by common mechanisms. The deletion of transcription factor Zfx impaired the self-renewal but not the differentiation capacity of murine ESC; conversely, Zfx overexpression facilitated ESC self-renewal by opposing differentiation. Furthermore, Zfx deletion abolished the maintenance of adult bone marrow HSC, but did not affect erythromyeloid progenitors or fetal HSC. In both ESC and HSC, Zfx activated a common set of direct target genes. In addition, the loss of Zfx resulted in the induction of immediate-early and/or stress-inducible genes in both SC types but not in their differentiated progeny. These studies identify the first shared transcriptional regulator of ESC and HSC, suggesting a common molecular basis of self-renewal in embryonic and adult SC.
Zfx controls the self-renewal of embryonic and hematopoietic stem cells.
No sample metadata fields
View SamplesExtracellular RNAs (exRNAs) in blood and other biofluids have attracted great interest as potential biomarkers in liquid biopsy applications, as well as for their potential biological functions. Whereas it is well-established that extracellular microRNAs are present in human blood circulation, the degree to which messenger RNAs (mRNA) and long noncoding RNAs (lncRNA) are represented in plasma is less clear. Here we report that mRNA and lncRNA species are present as small fragments in plasma that are not detected by standard small RNA-seq methods, because they lack 5'-phosphorylation or carry 3'-phosphorylation. We developed a modified sequencing protocol (termed "phospho-sRNA-seq") that incorporates upfront RNA treatment with T4 polynucleotide kinase (which also has 3' phosphatase activity) and compared it to a standard small RNA-seq protocol, using as input both a pool of synthetic RNAs with diverse 5' and 3' end chemistries, as well exRNA isolated from human blood plasma. Using a custom, high-stringency pipeline for data analysis we identified mRNA and lncRNA transcriptome fingerprints in plasma, including multiple tissue-specific gene sets. In a longitudinal study of hematopoietic stem cell transplant (HSCT) patients, we found different sets corresponding to bone marrow- and liver- enriched genes, which tracked with bone marrow recovery or liver injury, providing proof-of-concept validation of this method as a biomarker approach. By accessing a previously unexplored realm of mRNA and lncRNA fragments in blood plasma, phospho-sRNA-seq opens up a new space for plasma transcriptome-based biomarker development in diverse clinical settings. Overall design: ExRNA-seq libraries were prepared from platelet-poor plasma obtained from serial blood draws collected from two individuals undergoing bone marrow transplantation. A total of 11 samples were collected from each individual, starting prior to chemotherapy/ratiation treatment (approximately 7 days pre-HSCT) the day of transplant, and then weekly up to approximately Day 63.
Phospho-RNA-seq: a modified small RNA-seq method that reveals circulating mRNA and lncRNA fragments as potential biomarkers in human plasma.
No sample metadata fields
View SamplesRheumatoid arthritis (RA) is an inflammatory joint disorder that results in progressive joint damage when insufficiently treated. In order to prevent joint destruction and functional disability in RA, early diagnosis and initiation of appropriate treatment with Disease-Modifying Antirheumatic Drugs (DMARDs) is needed. However, in daily clinical practice, patients may initially display symptoms of arthritis that do not fulfil the classification criteria for a definite diagnosis of RA, or any other joint disease, a situation called Undifferentiated Arthritis (UA). Out of the patients with UA, 30 to 50% usually develop RA, and early identification of these remains a challenge.
Identification of distinct gene expression profiles in the synovium of patients with systemic lupus erythematosus.
Sex, Age, Specimen part, Disease, Treatment
View SamplesTo investigate differential gene expression, we analyzed the entire transcriptomes of tumor and matched normal brain tissues obtained from a patient who had glioblastoma multiforme. We extracted and sequenced the mRNA using Illumina GA2 platform. The raw data was analyzed using our recently developed program called RNASEQR, as well as ERANGE, MapSplice, SpliceMap, and TopHat. Overall design: Tumor and matched control brain tissues were obtained from a Han-Chinese patient.
RNASEQR--a streamlined and accurate RNA-seq sequence analysis program.
Specimen part, Subject
View SamplesMutations in GRIN2B are associated with intellectual disability in humans. We generated iPSC derived mature cortical neurons with mutations in GRIN2B and compared them to isogenic control cells. We found that both loss of function (LOF) and reduced dosage (RD) mutations in GRIN2B lead to reduced expression of NMDAR genes and increased expression of marker of immaturity, including KI67 and MET. Overall design: Examination of transcriptome in iPSC-derved mature neurons with and without the presence of mutations in GRIN2B
Disruption of GRIN2B Impairs Differentiation in Human Neurons.
Subject
View SamplesThe type III RNase Dicer is responsible for the maturation and function of microRNA (miRNA) molecules in the cell. It is now well documented that Dicer and the fine-tuning of the miRNA gene network are important for neuronal integrity. However, the underlying mechanisms involved in neuronal death, particularly in the adult brain, remain poorly defined. Here, we show that absence of Dicer in the adult forebrain is accompanied by a mixed neurodegenerative phenotype. While neuronal loss is observed in the hippocampus, cellular shrinkage is predominant in the cortex. Interestingly, neuronal degeneration coincides with the hyperphosphorylation of endogenous tau at several epitopes previously associated with neurofibrillary pathology. Transcriptome analysis of enzymes involved in tau phosphorylation identified ERK1 as one of the candidate kinases responsible for this event in vivo. We further demonstrate that miRNAs belonging to the miR-15 family are potent regulators of ERK1 expression in mouse neuronal cells and co-expressed with ERK1/2 in vivo. Last, we show that miR-15a is specifically downregulated in Alzheimers disease brain. In sum, these results support the hypothesis that changes in the miRNA network may contribute to a neurodegenerative phenotype by affecting tau phosphorylation.
Genetic ablation of Dicer in adult forebrain neurons results in abnormal tau hyperphosphorylation and neurodegeneration.
Specimen part
View SamplesThese studies address temporal changes in gene expression during spontaneous sleep and extended wakefulness in the mouse cerebral cortex, a neuronal target for processes that control sleep; and the hypothalamus, an important site of sleep regulatory processes. We determined these changes by comparing expression in sleeping animals sacrificed at different times during the lights on period, to that in animals sleep deprived and sacrificed at the same diurnal time.
Macromolecule biosynthesis: a key function of sleep.
Sex, Age, Specimen part
View Samples