Project description:Profiling the methylation landscape of undifferentiated sarcomas. Comparisons to be made with publically available methylation datasets of other sarcomas.
Project description:Banking of high-quality placental tissue specimens will enable biomarker discovery and molecular studies on diseases involving placental dysfunction. Systematic studies aimed at developing feasible standardized methodology for placental collection for genomic analyses are lacking. To determine the acceptable timeframe for placental collection, we collected multiple samples from first and third trimester placentas at serial time points 0-120 minutes after delivery, simultaneously comparing the traditional snap-freeze technique to collection in commercial solutions designed to preserve RNA (RNAlaterTM, Ambion), and DNA (DNAgard®, Biomatrica). The performance of RNAlater for preserving DNA was also tested. Nucleic acid quality was assessed by determining the RNA integrity number (RIN) and genome-wide expression and DNA methylation microarray profiling. We found that samples collected in RNAlater had higher and more consistent RINs compared to snap frozen tissue, with similar RINs obtained for tissue collected in RNAlater as large (1 cm3) and small (~0.1 cm3) tissue pieces. RNAlater appeared to better stabilize the time zero gene expression pattern compared to snap freezing for first trimester placenta. Microarray DNA methylation analysis showed that overall the DNA methylation profiles remained quite stable over a two hour time period after removal of the placenta from the uterus, with the DNAgard condition being superior to both snap freezing and RNAlater. The collection of placental samples in RNAlater and DNAgard is simple, and eliminates the need for liquid nitrogen or a freezer on-site. Moreover, the quality of the nucleic acids and the resulting data from samples collected in these preservation solutions is actually higher than that from samples collected using the traditional snap-freeze method. Thus, this new approach to placental sample collection is both easier to implement in busy clinical environments and yields higher quality data. 48 samples In this study, our objective was to identify the optimal timing and mode of collection for nucleic acids of sufficient quality to perform genome-wide RNA gene expression and DNA methylation studies for downstream molecular and functional enrichment analysis. To do this, we evaluated three different placenta collection methods: snap freezing in liquid nitrogen, RNAlaterTM, and DNAgard, over a two-hour window upon removal from the uterus, to determine: 1) the optimal collection method(s) for evaluation of mRNA expression and DNA methylation; and 2) the time period after delivery during which such optimal samples should be collected.
Project description:Human pluripotent stem cells hold great potential for regenerative medicine, but existing cell types have imitations. Human embryonic stem cells derived from fertilized embryos (IVF-ESCs) are considered the “gold standard”, but are allogeneic to potential recipients. Autologous induced pluripotent stem cells (iPSCs) can be produced from somatic cells by forced expression of pluripotency-associated factors, but are prone to genetic and epigenetic aberrations. To determine whether accumulation of such aberrations is intrinsic to somatic cell reprogramming, or secondary to the reprogramming method, we employed an alternative approach by somatic cell nuclear transfer (SCNT). SCNT-based reprogramming to NT-ESCs is mediated by factors present in oocyte’s cytoplasm, thus mimicking early embryogenesis. We generated genetically matched pluripotent stem cells and conducted genome-wide genetic, epigenetic and transcriptional analyses. We discovered that unlike iPSCs, NT-ESCs have a low burden of de novo copy number variations (CNVs), reflecting superior maintenance of genetic stability. Moreover, DNA methylation and transcriptome profiles of NT-ESCs corresponded closely to those of IVF-ESCs. In contrast, iPSCs harbored methylation abnormalities including residual CpG methylation typical of parental fibroblasts, suggesting incomplete reprogramming. We conclude that human somatic cells can be faithfully reprogrammed to pluripotency by SCNT with the potential to satisfy the clinical requirements for cell replacement therapies. Bisulphite converted DNAs of two IVF-ESCs, two sendai produced iPSC lines, two retro-virus produced iPSC lines, four NT-ESCs, and the parental fibroblast were hybridized to the Illumina Infinium HumanMethylation 450K Beadchip
Project description:The principal aim of this work was to investigate the methylation profiles of specific ocular tissues, and compare this profile to matched peripheral blood. Matched human blood and eye tissue were obtained post-mortem (n=8) and DNA methylation profiling performed on blood, neurosensory retina, retinal pigment epithelium (RPE)/choroid and optic nerve tissue using the Illumina Infinium HumanMethylation450 platform.
Project description:Genome wide DNA methylation profiling study of PBMC from 71 unique primary patient blood samples. The Illumina Human Methylation 450k array was used. 29 challenge proven food allergy, 29 sensitized but oral tolerant, 13 non food allergics Mixture of food allergy phenotypes (egg allergic (15), peanut allergic (14)), food sensitization phenotypes (egg sensitized (14), peanut sensitized (15)). 4 samples had technical replicate hybridzations. Bisulphite converted DNA from the 75 samples were hybridised to the Illumina Infinium 450k Human Methylation Beadchip v1.2. Technical replicates were combined during processing, resulting in normalized Beta values for 71 unique primary patient blood samples.
Project description:Using the Infinium HM450 platform, we have performed a longitudinal study of DNA methylation at birth and age 18 months in DNA from buccal swabs from 10 monozygotic (MZ) and 5 dizygotic (DZ) twin pairs from the Peri/postnatal Epigenetic Twins Study (PETS) cohort. Beta methylation measurements from bisulphite-converted DNA and raw intensity values from 53 samples. Samples were collected at birth ('_B') or 18 months ('_18m'). Data were preprocessed using the Minfi package in R by the 'illumina' method and normalized to control probes. Subset quantile normalization was performed on type 1 and type 2 probes. Probes failing P detection cutoff of <0.01 were removed. Probes on the X and Y chromosomes have been removed from the processed data. Outlier samples were removed. Between-array quantile normalization was performed to arrive at the final data set of 330168 probes and 53 samples.
Project description:Melanoma remains the most lethal skin cancer, mainly because of high resistance to therapy. Side population (SP) cells are found in many types of cancer and are usually enriched in therapy-resistant as well as tumorigenic cells. Here, we identified a Hoechst dye-effluxing SP in a large series of human melanoma samples representing different progression phases. The SP size did not change with disease stage but was correlated with the prognostic “Breslow’s depth” in the primary (cutaneous) tumors. When injected into immunodeficient mice, the SP generated larger tumors than the bulk “main population” (MP) melanoma cells in two consecutive generations, and showed tumorigenic capacity at lower cell numbers than the MP. In addition, the SP reconstituted the heterogeneous composition of the human A375 melanoma cell line, and its clonogenic activity was 2.5-fold higher than that of the MP. Gene-expression analysis revealed upregulated expression in the melanoma SP (versus the MP) of genes associated with chemoresistance and anti-apoptosis. Consistent with these molecular characteristics, the SP increased in proportion when A375 cells were exposed to the melanoma standard chemotherapeutic agent dacarbazine, and to the aggravating condition of hypoxia. In addition, the SP showed enhanced expression of genes related to cell invasion and migration, as well as to putative (melanoma) cancer stem cells (CSC) including ABCB1 and JARID1B. ABCB1 immunoreactivity was detected in a number of tumor cells in human melanomas, and in particular in clusters at the invasive front of the primary tumors. Together, our findings support that the human melanoma SP is enriched in tumorigenic and chemoresistant capacity, considered key characteristics of CSC. The melanoma SP may therefore represent an interesting therapeutic target. Four primary melanomas (subtype SSMM) were dissociated into single cells. From each of these single cell suspensions, side population (SP) and bulk \main population\ (MP) cells were isolated based on their Hoechst-effluxing capability using fluorescence-activated cell sorting. Gene expression of SP cells is analyzed relative to the gene expression of the corresponding MP cells.
Project description:The Amish and Hutterites are U.S. farming populations with remarkably similar lifestyles. However, the Amish follow traditional farming practices, while the Hutterites employ modern farming techniques, and also show striking differences in asthma prevalence. Little is known about immune responses underlying these differences. To address this, we obtained genome-wide gene expression data in peripheral blood leukocytes from Amish and Hutterite schoolchildren. The study includes data from whole blood samples from age- and sex-matched Amish and Hutterite schoolchildren. Written consent was obtained from the parents and written assent was obtained from the children. One mL of whole blood was drawn into a TruCulture tube containing media alone, and incubated upright on a dry heat block at 37°C for 30 hours. Cells were isolated and total RNA was extracted using Qiagen AllPrep DNA/RNA Mini Kits. RNA concentration was assayed with a Nanodrop ND-100 Sepectrophotometer; RNA quality was assessed with an Agilent 2100 Bioanalyzer. Samples underwent cDNA synthesis and were then hybridized on the Illumina HumanHT-12 v4 Expression BeadChip arrays at the Functional Genomics Core at the University of Chicago.