This SuperSeries is composed of the SubSeries listed below.
Wnt signaling potentiates nevogenesis.
Specimen part, Cell line
View SamplesMelanocytes within benign human nevi are the paradigm for tumor suppressive senescent cells in a pre-malignant neoplasm. These cells typically contain mutations in either the BRAF or N-RAS oncogene and express markers of senescence, including p16. However, a nevus can contain 10s to 100s of thousands of clonal melanocytes and approximately 20-30% of melanoma are thought to arise in association with a pre-existing nevus. Neither observation is indicative of fail-safe senescence-associated proliferation arrest and tumor suppression. We set out to better understand the status of nevus melanocytes. Proliferation-promoting Wnt target genes, such as cyclin D1 and c-myc, were repressed in oncogene-induced senescent melanocytes in vitro, and repression of Wnt signaling in these cells induced a senescent-like state. In contrast, cyclin D1 and c-myc were expressed in many melanocytes of human benign nevi. Specifically, activated Wnt signalling in nevi correlated inversely with nevus maturation, an established dermatopathological correlate of clinical benignancy. Single cell analyses of lone epidermal melanocytes and nevus melanocytes showed that expression of proliferation-promoting Wnt targets correlates with prior proliferative expansion of p16-expressing nevus melanocytes. In a mouse model, activation of Wnt signaling delayed, but did not bypass, senescence of oncogene-expressing melanocytes, leading to massive accumulation of proliferation-arrested, p16-positive non-malignant melanocytes. We conclude that clonal hyperproliferation of oncogene-expressing melanocytes to form a nevus is facilitated by transient delay of senescence due to activated Wnt signaling. The observation that activation of Wnt signaling correlates inversely with nevus maturation, an indicator of clinical benignancy, supports the notion that persistent destabilization of senescence by Wnt signaling contributes to the malignant potential of nevi.
Wnt signaling potentiates nevogenesis.
Specimen part
View SamplesOIS is characterized by a stable proliferation arrest and secretion of pro-inflammatory cytokines and chemokines, the senescence-associated secretory phenotype (SASP). Proliferation arrest and the SASP collaborate to enact tumor suppression, the former by blocking cell proliferation and the latter by recruiting immune cells to clear damaged cells. However, the interactions of OIS cells with the immune system are still poorly defined. Here we show that engagement of OIS in primary human melanocytes, specifically by melanoma driver mutations NRASQ61K and BRAFV600E, causes expression of the MHC class II antigen presentation apparatus, via secreted IL1ß signaling and expression of CIITA, a master regulator of MHC class II gene transcription. Overall design: We quantify transcription via high throughput RNA sequencing in nevus melanocytes in cross FVB/NJ mice with Cre inducible NRAS61K with an MHCII cross
Oncogene-Expressing Senescent Melanocytes Up-Regulate MHC Class II, a Candidate Melanoma Suppressor Function.
Cell line, Subject
View SamplesThe goal of the study was to evaluate the influence of mutations in MLK4 on the protein function and the process of tumorigenesis in colorectal cancers. Biochemical data imply that a majority of MLK4 mutations in colon cancer are loss-of-function, including, E314K and Y330H mutations.
Recurrent MLK4 Loss-of-Function Mutations Suppress JNK Signaling to Promote Colon Tumorigenesis.
Specimen part, Cell line
View SamplesOncogene-induced senescence (OIS) is a tumor suppression mechanism that blocks cell proliferation in response to oncogenic signalling. OIS is frequently accompanied by multinucleation; however, the origin of this is unknown. Here we show that multinucleate OIS cells originated mostly from failed mitosis. Prior to senescence, mutant RasV12 activation in primary human fibroblasts compromised mitosis, associated with abnormal expression of mitotic genes that enter M-phase. Simultaneously, RasV12 activation enhanced survival of damaged mitoses, culminating in extended mitotic arrest and aberrant exit from mitosis via mitotic slippage. ERK-dependent transcriptional up-regulation of Mcl1 was responsible for enhanced slippage of cells with mitotic defects and subsequent cell survival. Importantly, mitotic slippage and oncogene signalling synergistically induced senescence and key senescence regulators p21 and p16. We propose that activated Ras induces transcriptional changes that predispose cells undergoing OIS to mitotic stress and multinucleation. Overall design: We used RNA-seq of IMR90 cells with inducible expression of oncogenic RasV12 that were synchronised in mitosis, to characterise the nature of mitotic defects that lead to multinucleation of oncogene-induced senescent cells
Mitotic Stress Is an Integral Part of the Oncogene-Induced Senescence Program that Promotes Multinucleation and Cell Cycle Arrest.
No sample metadata fields
View SamplesGlucocorticoids are a well recognized and common cause of muscle atrophy. Glucocorticoid-induced atrophy can be prevented by testosterone, but the molecular mechanisms underlying such protection have not been described. Thus, the global effects of testosterone on dexamethasone-induced changes in gene expression were evaluated in rat gastrocnemius muscle using Affymetrix 230_2 DNA microarrays. Gene expression was analyzed after 7 days administration of dexamethasone, dexamethasone plus testosterone, or vehicle. Effects of these agents on weights of gastrocnemius muscles from these animals has been reported (1. Zhao W, Pan J, Zhao Z, Wu Y, Bauman WA, and Cardozo CP. Testosterone protects against dexamethasone-induced muscle atrophy, protein degradation and MAFbx upregulation. J Steroid Biochem Mol Biol 110: 125-129, 2008.) Dexamethasone changed expression of 876 probe sets by at least 2-fold, of which 474 probe sets were changed by at least two fold in the opposite direction in the dexamethasone plus testosterone group (genes in opposition). Major biological themes represented by genes in opposition included IGF-1 signaling, protein synthesis, myogenesis and muscle development, and ubiquitin conjugases and ligases. Testosterone blocked increased expression of DDIT4 and eIF4EBP1, FOXO1 and of the p85 regulatory subunit of the IGF-1 receptor, while preventing decreased expression of IRS-1. Testosterone blocked decreased expression of LXR and suppressed upregulation of C/EBP beta and delta. Testosterone prevented increase expression of Cdkn1A (p21) and decrease expression of cyclins B and D, as well as many other changes that would be expected to reduce cell cycle progression. Testosterone prevented increased expression of muscle development factors Csrp3 and Mbn1 and blocked reduced expression of Wnt4. These data suggest that testosterone blocks multiple changes in gene expression that, collectively, would otherwise downregulate molecular signals that promote protein synthesis and muscle hypertrophy and that stimulate muscle protein catabolism.
REDD1 is a major target of testosterone action in preventing dexamethasone-induced muscle loss.
No sample metadata fields
View SamplesHuman aging is associated with loss of function and regenerative capacity. Human bone marrow derived mesenchymal stromal cells (hMSCs) are involved in tissue regeneration, evidenced by their capacity to differentiate into several lineages and therefore are considered the gold standard for cell-based regeneration therapy. Tissue maintenance and regeneration is dependent on stem cells and declines with age and aging is thought to influence therapeutic efficacy, therefore, more insight in the process of aging of hMSCs is of high interest. We, therefore, hypothesized that hMSCs might reflect signs of aging. In order to find markers for donor age, early passage hMSCs were isolated from bone marrow of 61 donors, with ages varying from 17-84, and clinical parameters, in vitro characteristics and microarray analysis were assessed. Although clinical parameters and in vitro performance did not yield reliable markers for aging since large donor variations were present, genome-wide microarray analysis resulted in a considerable list of genes correlating with human age. By comparing the transcriptional profile of aging in human with the one from rat, we discovered follistatin as a common marker for aging in both species. The gene signature presented here could be a useful tool for drug testing to rejuvenate hMSCs or for the selection of more potent, hMSCs for cell-based therapy.
A mesenchymal stromal cell gene signature for donor age.
Sex, Age
View SamplesWe evaluated transcriptional profiles in peripheral blood mononuclear cells (PBMCs) from 54 pregnant women in Kenya, 19 of whom delivered preterm.
Influenza-Induced Interferon Lambda Response Is Associated With Longer Time to Delivery Among Pregnant Kenyan Women.
Specimen part, Treatment
View SamplesDystonia is characterized by involuntary muscle contractions. Its many forms are genetically, phenotypically and etiologically diverse and it is unknown whether their pathogenesis converges on shared pathways. Mutations in THAP1, a zinc-finger transcription factor, cause DYT6, but its neuronal targets and functions are unknown. We used RNA-Seq to assay the in vivo effect of a heterozygote Thap1C54Y or ?Exon2 allele on the gene transcription signatures in neonatal mouse striatum and cerebellum. Enriched pathways and gene ontology terms include eIF2a Signaling, Mitochondrial Dysfunction, Neuron Projection Development, Axonal Guidance Signaling, and Synaptic Long Term Depression pathways, which are dysregulated in a genotype and tissue-dependent manner. Electrophysiological and neurite outgrowth assays confirmed the functional significance of those findings. Notably, several of these pathways were recently implicated in other forms of inherited dystonia, including DYT1. We conclude that dysfunction of these pathways may represent a point of convergence on the pathogenesis of unrelated forms of inherited dystonia. Overall design: We used RNA-Seq to assay the in vivo effect of a heterozygote Thap1C54Y or deltaExon2 allele on the gene transcription signatures in neonatal mouse striatum and cerebellum
Mutations in THAP1/DYT6 reveal that diverse dystonia genes disrupt similar neuronal pathways and functions.
Specimen part, Cell line, Subject
View SamplesWe sorted for GFP+ cells using the enhancer trap J0571 with the UAS promoter driving the expression of different BIRD genes. Different genetic backgrounds are use and listed below.
Transcriptional control of tissue formation throughout root development.
Specimen part
View Samples