Post-hybridization washing is an essential part of microarray experiments. Both, the quality of the experimental washing protocol and the adequate consideration of washing in intensity calibration ultimately affect the quality of the expression estimates extracted from the microarray intensities. We conducted experiments on GeneChip microarrays with altered protocols for washing, scanning and staining to study the probe-level intensity changes as a function of washing cycles. Particularly, three Affymetrix GeneChip HGU133plus2 arrays were hybridized and equilibrated for 16 hours in the hybridization oven. For one of the three arrays washing and staining was performed according to the manufacturers instructions. For another array the first scan was done immediately after low stringent wash and staining without intermitting stringent washing. Then, the array was stringently washed and scanned in alternating order three more times where each washing step consists of a definite number of washing cycles. The third array was low stringently washed followed by two stringent washing cycles and staining before the first scan. Subsequently it was analogously processed as array A. All three chips are repeatedly processed in a second series of alternating wash/scan-cycles which was performed using the same protocol for each chip as in the first series as described above. As in the first series the arrays were also stained a second time to compensate for any loss of bleached fluorescent dye. Analysis of the washing kinetics shows that the signal-to-noise ratio doubles roughly every ten stringent washing cycles. Washing can be characterized by time-dependent rate constants which reflect the heterogeneous character of target binding to microarray probes. We propose an empirical washing function which estimates the survival of probe bound targets. The washing function allows calibrating probe intensities for the effect of washing. On a relative scale, proper calibration for washing markedly increases expression measures especially in the limit of small and large values.
Washing scaling of GeneChip microarray expression.
Cell line
View SamplesThe fallopian tube epithelium is one of the potential sources of high-grade serous ovarian cancer (HGSC). The use of estrogen only hormone replacement therapy increases ovarian cancer risk. Despite estrogen’s influence in OVCA, selective estrogen receptor modulators (SERMs) typically demonstrate only a 20% response rate. This low response could be due to a variety of factors including the loss of estrogen receptor signaling or the role of estrogen receptor signaling in different potential cell types of origin. The response of fallopian tube epithelium to SERMs is not known, and would be useful when determining therapeutic options for tumors that arise from this cell type, such as high-grade serous cancer. Using normal murine derived oviductal epithelial cells (mouse equivalent to the fallopian tube) estrogen receptor expression was confirmed and interaction with its ligand, estradiol, triggered mRNA and protein induction of progesterone receptor (PR). The SERMs 4-hydroxytamoxifen, raloxifene and desmethylarzoxifene, functioned as estrogen receptor antagonists in the oviductal cells. Cellular proliferation and migration assays suggested that estradiol does not significantly impact cellular migration and increased proliferation in CD1, but not in FVB derived cell lines. Further, using RNAseq, the oviduct specific transcriptional genes targets of estrogen and 4-hydroxytamoxifen signaling were determined and validated. The RNA-seq revealed enrichment in proliferation, anti-apoptosis, calcium signaling and steroid signaling processes. Finally, the ER and PR receptor status of a panel of HGSC cell lines was investigated highlighting the need for better models of estrogen responsive HGSC cell lines. Overall design: Murine oviductal epithelial cells from the FVB background were hormone starved for 48 hours (with a media change after 24 hours), then treated in triplicate with solvent control (DMSO) (0.1%), 1 nM 17-betaestradiol or 100 nM 4-hydroxytamoxifen for 24 hours. Following treatment, RNA was was isolated, libraries were prepped and sequenced using the Illumina HiSeq 2500 platform.
Genome-wide transcriptional regulation of estrogen receptor targets in fallopian tube cells and the role of selective estrogen receptor modulators.
No sample metadata fields
View SamplesIn skeletal muscle, the pattern of electrical activity regulates the expression of proteins involved in synaptic transmission, contraction and metabolism. Disruptions in electrical activity, resulting from prolonged bed-rest, cast-immobilization or trauma, inevitably lead to muscle atrophy. The mechanisms that regulate muscle atrophy are poorly understood, but it seems likely that changes in gene expression play a key role in initiating and maintaining a muscle atrophy program. Previously, we found that Runx1, a transcription factor previously termed AML1, was substantially induced in muscle following denervation. More recently, we sought to determine whether this increase in Runx1 expression may be causally related to the morphological changes in skeletal muscle that accompany muscle disuse, notably muscle atrophy. We found that Runx1 is indeed required to sustain muscle and to minimize atrophy following denervation. Experiments described here are designed to identify the genes that are regulated by Runx1 in skeletal muscle with the particular goal of identifying genes that regulate muscle atrophy.
Runx1 prevents wasting, myofibrillar disorganization, and autophagy of skeletal muscle.
No sample metadata fields
View SamplesHigh grade serous ovarian cancer (HGSOC) can originate from fallopian tube epithelium (FTE) and ovarian surface epithelium (OSE). We report the application of unique spontaneous model that mimics cellular aging for understanding the origin and progression of HGSOC from oviductal epithelium. Oviductal epithelium is equivalent to human FTE. Serial passaging of the outbred mouse CD1 oviductal cells (MOE low) to MOE high produced transformed cells that lead to benign tumors. To understand the altered molecular signaling pathways in MOEhigh cells versus MOElow cells, we performed RNA sequencing. Total RNA was extracted from MOELOW (passages 8, 9, & 10) and MOEHIGH (passages 90, 103, & 113) cells. Each total RNA sample had ribosomal RNA removed using TruSeq Stranded Total RNA with Ribo-Zero (Illumina, San Diego, CA). Strand-specific libraries were constructed and quantitated using Qubit, and cDNAs verified by qPCR. qRT–PCR validation was performed using SYBR Green assays. Samples were barcoded and sequenced using Illumina HiSeq2500 sequencing. The reads were aligned to the Mus musculus genome (mm10) using TopHat, version and were used to determine the expression of known mmu10 gene annotations from the University of California-Santa Cruz website using Cuffdiff version. By merging the individual transcript from Cuffdiff into a single gene annotation file, we determined the differential expression analysis. By applying a false discovery rate (FDR)-adjusted p-value, where significance was set to p = 0.05, statistically significant differential expression was determined. Furthermore, pathway analysis was performed on transcript lists from both cell lines using GeneCoDis to identify the KEGG and Panther pathways that are significantly different between MOELOW and MOEHIGH cell lines. We find that the splicesome, RNA transport, the cell cycle, and DNA replication were the most highly upregulated pathway whereas the repressed pathways included processing in the endoplasmic reticulum, focal adhesion, and the lysosome. RNA sequencing revealed that p53 in MOELOW and MOEHIGH cells was not mutated; however, MOEHIGH cells had a significant upregulation of a splice variant of p53. The splice variant behaved like wild-type on few targets and missense on some transcriptional targets by qRT-PCR. This study provides a framework for the application of comprehensive chromatin profiling towards characterization of diverse mammalian cell populations. This model provides a framework to uncover a step-wise progression of tumor formation from an oviductal origin to be compared to human disease. Overall design: Examination of altered molecular signaling pathways in 2 cell types.
Spontaneous Transformation of Murine Oviductal Epithelial Cells: A Model System to Investigate the Onset of Fallopian-Derived Tumors.
No sample metadata fields
View SamplesThese experiments are designed to discover genes that are expressed selectively by synaptic nuclei in skeletal muscle with the particular goal of identifying genes that regulate motor axon growth and differentiation.
CD24 is expressed by myofiber synaptic nuclei and regulates synaptic transmission.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Parkinson's disease induced pluripotent stem cells with triplication of the α-synuclein locus.
Specimen part
View SamplesA major barrier to research on Parkinsons disease (PD) is inaccessibility of diseased tissue for study. One solution is to derive induced pluripotent stem cells (iPSCs) from patients with PD and differentiate them into neurons affected by disease. We created an iPSC model of PD caused by triplication of SNCA encoding -synuclein. -Synuclein dysfunction is common to all forms of PD, and SNCA triplication leads to fully penetrant familial PD with accelerated pathogenesis. After differentiation of iPSCs into neurons enriched for midbrain dopaminergic subtypes, those from the patient contain double -synuclein protein compared to those from an unaffected relative, precisely recapitulating the cause of PD in these individuals. A measurable biomarker makes this model ideal for drug screening for compounds that reduce levels of -synuclein, and for mechanistic experiments to study PD pathogenesis.
Parkinson's disease induced pluripotent stem cells with triplication of the α-synuclein locus.
Specimen part
View SamplesA major barrier to research on Parkinsons disease (PD) is inaccessibility of diseased tissue for study. One solution is to derive induced pluripotent stem cells (iPSCs) from patients with PD and differentiate them into neurons affected by disease. We created an iPSC model of PD caused by triplication of SNCA encoding -synuclein. -Synuclein dysfunction is common to all forms of PD, and SNCA triplication leads to fully penetrant familial PD with accelerated pathogenesis. After differentiation of iPSCs into neurons enriched for midbrain dopaminergic subtypes, those from the patient contain double -synuclein protein compared to those from an unaffected relative, precisely recapitulating the cause of PD in these individuals. A measurable biomarker makes this model ideal for drug screening for compounds that reduce levels of -synuclein, and for mechanistic experiments to study PD pathogenesis.
Parkinson's disease induced pluripotent stem cells with triplication of the α-synuclein locus.
Specimen part, Cell line
View SamplesOvarian cancer is the fifth leading cause of cancer death among US women. Evidence supports the hypothesis that high-grade serous ovarian cancers (HGSC) may originate in the distal end of the fallopian tube. Although a heterogeneous disease, 96% of HGSC contain mutations in p53. In addition, the p53 signature, or overexpression of p53 protein (usually associated with mutation), is a potential precursor lesion of fallopian tube derived HGSC suggesting an essential role for p53 mutation in early serous tumorigenesis. To further clarify p53-mutation dependent effects on cells, murine oviductal epithelial cells (MOE) were stably transfected with a construct encoding for the R273H DNA binding domain mutation in p53, the most common mutation in HGSC. Mutation in p53 was not sufficient to transform MOE cells, but did significantly increase cell migration. A similar p53 mutation in murine ovarian surface epithelium (MOSE), another potential progenitor cell for serous cancer, was not sufficient to transform the cells nor change migration suggesting tissue specific effects of p53 mutation. Microarray data confirmed expression changes in pro-migratory genes in p53R273H MOE compared to parental cells, which could be reversed by suppressing Slug expression. Combining p53R273H with KRASG12V activation caused transformation of MOE into high-grade sarcomatoid carcinoma when xenografted into nude mice. Elucidating the specific role of p53R273H in the fallopian tube will improve understanding of changes at the earliest stage of transformation and could help develop chemopreventative strategies to prevent the accumulation of additional mutations and reverse progression of the p53 signature thereby, improving survival rates.
Mutant p53 expression in fallopian tube epithelium drives cell migration.
Specimen part
View SamplesOn the basis of the cell-surface molecule expression, CD16+ monocytes are likely comprised of distinct subpopulations of monocytes rather than a continuum of CD14+ monocytes with differing levels of cell activation. To better study this, we used gene array analysis that compared overall gene expression profiles of CD16+ subpopulations (CD14+CD16+ and CD16+) with that of CD14+CD16-. Gene expression in three FACS-sorted monocyte subsets was assessed by Affymetrix rhesus macaque oligonucleotide gene arrays that contain 52,024 probe sets covering 47,000 monkey genes. There were 29,361 probe sets that expressed in at least one subpopulation (raw array signal intensity > 32). Raw data were processed using robust multi-array average. To identify the most strongly, differentially expressed genes in each subpopulation, we only selected transcripts with consistently greater than four-fold difference (P < .05). In comparison to CD14+CD16- monocyte subset, a large number of genes (9098/29361, 30.9%) were differentially expressed in both CD14+CD16+ and CD16+ subsets: 1999 genes down-regulated; and 7099 genes up-regulated. Altogether, we observed large-scale gene expression differences between the CD14+CD16- subset and the two CD16+ subsets (CD14+CD16+ and CD16+), demonstrating transcriptional heterogeneity. The differential gene expression between CD16- and CD16+ monocytes underscore the fundamental differences between these cells.
Monocyte heterogeneity underlying phenotypic changes in monocytes according to SIV disease stage.
Specimen part
View Samples