Loss of Pten in the KrasG12D;Amhr2-Cre mutant mice leads to the transformation of ovarian surface epithelial (OSE) cells and rapid development of low-grade, invasive serous adenocarcinomas. Tumors occur with 100% penetrance and express elevated expression of wild type tumor repressor protein 53 (TRP53). To test the functions of TRP53 in the Pten;Kras (Trp53+) mice, we disrupted the Trp53 gene yielding Pten;Kras(Trp53-) mice. By comparing morphology and gene expression profiles in the Trp53+ and Trp53- OSE cells, we document that wild-type TRP53 acts as a major promoter of OSE cell survival and differentiation: cells lacking Trp53 are transformed yet are less adherent, migratory and invasive and exhibit a gene expression profile more like normal OSE cells. These results provide a new paradigm: wild type TRP53 does not preferentially induce apoptotic or senescent related genes in the Pten;Kras(Trp53+) cancer cells but rather increases genes regulating DNA repair, cell cycle progression and proliferation and decreases putative tumor suppressor genes. However, if TRP53 activity is forced higher by exposure to nutlin-3a (an MDM2 antagonist), TRP53 suppresses DNA repair genes and induces the expression of genes that control cell cycle arrest and apoptosis. Thus, in the Pten;Kras(Trp53+) mutant mouse OSE cells and likely in human TP53+ low grade ovarian cancer cells, wild type TRP53 controls global molecular changes that are dependent on its activation status. These results suggest that activation of TP53 may provide a promising new therapy for managing type I ovarian cancer and other cancers in humans where wild-type TP53 is expressed.
Wild-type tumor repressor protein 53 (Trp53) promotes ovarian cancer cell survival.
Age, Specimen part
View SamplesThe impact of specific p53 mutations on ovarian tumor development and response to therapeutic treatment remain limited. Here, using transgenic mouse models of epithelial ovarian cancer (EOC), we demonstrated that the Trp53R172H mutation promotes EOC progression compared to wild-type p53, but with different consequences between heterozygous and homozygous mutation status. EOC expressing heterozygous Trp53R172H mutation has enhanced responsiveness to steroid hormones and at late stage developed mucinous cystadenocarcinoma. These findings open new realms for exploring the interaction between p53 and steroid receptor, and the allelic status of p53 in EOC development and treatment.
Mutant p53 Promotes Epithelial Ovarian Cancer by Regulating Tumor Differentiation, Metastasis, and Responsiveness to Steroid Hormones.
Age, Specimen part
View SamplesThe functional status of the tumor repressor protein (TP53 or TRP53) is a defining feature of ovarian cancer. Mutant or null alleles of TP53 are expressed in greater than 90% of all high-grade serous adenocarcinomas. Wild type TP53 is elevated in low-grade serous adenocarcinomas in women and in our Pten/Kras/Amhr2-Cre mutant mouse model. Disruption of the Trp53 gene in this mouse model did not lead to high-grade ovarian cancer but did increase expression of estrogen receptor alpha (ERalpha; ESR1) and markedly enhanced the responsiveness of these cells to estrogen. Specifically, when Trp53 positive and Trp53 null mutant mice were treated with estradiol or vehicle, only the Trp53 null and Esr1 positive tumors respond vigorously to estradiol in vivo and exhibit features characteristic of high-grade type ovarian cancer: invasive growth into the ovarian stroma, rampant metastases to the peritoneal cavity and signs of genomic instability. Estrogen promoted and progesterone suppressed the growth of Trp53 null ovarian tumors and tumor cells injected intraperitoneally (IP), subcutaneously (SC) or when grown in matrigel. Exposure of the Trp53 depleted cells to estrogen also has a profound impact on the tumor microenvironment and immune-related events. These results led to the new paradigm that TRP53 status is related to the susceptibility of transformed ovarian surface epithelial (OSE) cells to estradiol-induced metastases and genomic instability. This novel finding is relevant not only for women during their reproductive years but also for women on hormone (estradiol) replacement therapies.
Tumor repressor protein 53 and steroid hormones provide a new paradigm for ovarian cancer metastases.
Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
FUS Regulates Activity of MicroRNA-Mediated Gene Silencing.
Cell line
View SamplesIndividuals with the ALS-linked (amyotrophic lateral sclerosis) truncation mutation (R495X) in FUS (fused in sarcoma) are known to have a more aggressive form of the disease than those with point mutations. The underlying cause for this difference is unclear. We report that FUS is a component of miRISC (miRNA-induced silencing complex) and that overexpression of its truncation mutant R495X negatively impacts miRNA mediated RNA silencing.
FUS Regulates Activity of MicroRNA-Mediated Gene Silencing.
Cell line
View SamplesRelatively little is known about how the identity of early neuronal stem cells changes before and after neural tube closure (neurulation). We performed RNA sequencing on microdissected forebrain precursors and revealed sharp reductions in expresion of protein biosynthetic machinery after neurulation. These reductions were paralleled by down-regulation of Myc, which regulated forebrain precursor ribosome ribosome biogenesis. To study consequences of Myc dysregulation, we overexpressed Myc in Nestin+ neural progenitors, sorted these progenitors for RNA sequencing, and identified 135 genes that are differentially expressed between Myc-overexpressed embryos and their wildtype littermates. Overall design: The first RNA sequencing dataset contains micordissected neuroepithelium from E8.5 and E10.5 mouse embryos, two biological replicates for each age. The second RNA sequencing dataset contain FACS isolated Pax6+ neural progenitors form the cortex of E13.5 MYC-overexpressed embryos and their wildtype littermates, three biological replicates for each genotype.
Downregulation of ribosome biogenesis during early forebrain development.
Specimen part, Cell line, Subject
View SamplesPurpose: Investigate cellular heterogeneity in a fresh human ovarian cancer tissue sample Methods: Enzymatic digestion of fresh tissue sample collected from the operating room to produce single cell suspension. Cells were labelled with fluorescent antibodies to CD3, CD14, CD19, CD20, CD56 and FACS sorted to remove immune cells. The negative population was used for sequencing. Single cells were processed using the Fluidigm C1 Chip to generate barcoded cDNA for each cell. Amplifed cDNA was sequenced using an Illumina HiSeq 2500 machine. Results: Single cell RNA sequence data was obtained for 92 cells and a "bulk" sample of 1000 cells. 26 cells were removed from analysis due to quality control standards. The remaining 66 cells and the bulk sample were analyzed. Conclusion: Single cell RNA sequence analysis reveals heterogeneity in gene expression in cells harvested from a high grade ovarian serous cancer Overall design: A single cell suspension generated from a fresh high grade serous ovarian cancer sample was run through two Fluidigm C1 chips to isolate single cells and produce barcoded cDNA. Sequencing was performed in a single lane of an Illumina HiSeq 2500 machine. 92 single cells were sequenced and 1 bulk sample was sequenced, for a total of 93 samples.
Single cell sequencing reveals heterogeneity within ovarian cancer epithelium and cancer associated stromal cells.
Subject
View SamplesNeuronal differentiation of PC12 cells in response to NGF is a prototypical model in which signal duration determines a biological response. Sustained ERK activity induced by NGF, as compared to transient activity induced by EGF, is critical to the differentiation of these cells. To characterize the transcriptional program activated preferentially by NGF, we compared global gene expression profiles between cells treated with NGF and EGF for 2-4 hrs, when sustained ERK signaling in response to NGF is most distinct from the transient signal elicited by EGF. This analysis identified 69 genes that were preferentially upregulated in response to NGF.
Global expression analysis identified a preferentially nerve growth factor-induced transcriptional program regulated by sustained mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) and AP-1 protein activation during PC12 cell differentiation.
Specimen part, Cell line, Time
View SamplesWe propose the hypothesis that loss of estrogen receptor function which leads to endocrine resistance in breast cancer, also results in de-differentiation from an epithelial to a mesenchymal phenotype that is responsible for increased aggressiveness and metastatic propensity. siRNA mediated silencing of the estrogen receptor in MCF7 breast cancer cells resulted in estrogen/tamoxifen resistant cells (pII) with altered morphology, increased motility with rearrangement and switch from an actin to a vimentin based cytoskeleton, and ability to invade simulated components of the extracellular matrix. Phenotypic profiling using an Affymetrix Human Genome U133 plus 2.0 GeneChip indicated fold changes 3 in approximately 2500 identifiable unique sequences, with about 1270 of these being up-regulated in pII cells. Changes were associated with genes whose products are involved in cell motility, loss of cellular adhesion and interaction with the extracellular matrix. Selective analysis of the data also showed a shift from luminal to basal cell markers and increased expression of a wide spectrum of genes normally associated with mesenchymal characteristics, with consequent loss of epithelial specific markers. Over-expression of several peptide growth factors and their receptors are indicative of an increased contribution to the higher proliferative rates of pII cells as well as aiding their potential for metastatic activity. Signalling molecules that have been identified as key transcriptional drivers of epithelial to mesenchymal transition were also found to be elevated in pII cells. We suggest that these data support our hypothesis that induced loss of estrogen receptor in previously antiestrogen sensitive cells is a trigger for the concomitant loss of endocrine dependence and onset of a series of possibly parallel events that changes the cell from an epithelial to a mesenchymal type. Inhibition of this transition through targeting of specific mediators may be a useful supplementary strategy to circumvent the effects of loss of endocrine sensitivity.
Estrogen receptor silencing induces epithelial to mesenchymal transition in human breast cancer cells.
Cell line
View SamplesObjective: To quantify changes in adipogenic gene expression in the presence of ritonavir (RTV) or tenofovir (TDF), and determine whether conjugated linoleic acid (CLA) isomers (cis9,trans11 or trans10,cis12) can mitigate detrimental effects of antiretoviral drugs.
Microarray Analysis Reveals Altered Lipid and Glucose Metabolism Genes in Differentiated, Ritonavir-Treated 3T3-L1 Adipocytes.
Specimen part, Cell line, Treatment
View Samples