Ena-DATASET-THE UNIVERSITY OF HONG KONG DEPARTMENT OF PATHOLOGY AND PFIZER INC.-18-12-2019-11:12:21:554-1297 - samples
Ontology highlight
ABSTRACT:
PROVIDER: EGAD00001005753 | EGA |
REPOSITORIES: EGA
Publications
Organoid cultures of early-onset colorectal cancers reveal distinct and rare genetic profiles.
Yan Helen H N HHN Siu Hoi Cheong HC Ho Siu Lun SL Yue Sarah S K SSK Gao Yang Y Tsui Wai Yin WY Chan Dessy D Chan April S AS Wong Jason W H JWH Man Alice H Y AHY Lee Bernard C H BCH Chan Annie S Y ASY Chan Anthony K W AKW Hui Ho Sang HS Cheung Arthur K L AKL Law Wai Lun WL Lo Oswens S H OSH Yuen Siu Tsan ST Clevers Hans H Leung Suet Yi SY
Gut 20200326 12
<h4>Objective</h4>Sporadic early-onset colorectal cancer (EOCRC) has bad prognosis, yet is poorly represented by cell line models. We examine the key mutational and transcriptomic alterations in an organoid biobank enriched in EOCRCs.<h4>Design</h4>We established paired cancer (n=32) and normal organoids (n=18) from 20 patients enriched in microsatellite-stable EOCRC. Exome and transcriptome analysis was performed.<h4>Results</h4>We observed a striking diversity of molecular phenotypes, includin ...[more]
Similar Datasets
Project description:High-throughput sequencing (HTS) has become a powerful tool for the detection of and sequence characterization of microRNAs (miRNA) and other small RNAs (sRNA). Unfortunately, the use of HTS data to determine the relative quantity of different miRNAs in a sample has been shown to be inconsistent with quantitative PCR and Northern Blot results. Several recent studies have concluded that the major contributor to this inconsistency is bias introduced during the construction of sRNA libraries for HTS and that the bias is primarily derived from the adaptor ligation steps; specifically where single stranded adaptors are sequentially ligated to the 3' and 5'-end of sRNAs using T4 RNA ligases. In this study we investigated the effects of ligation bias by using a pool of randomized ligation substrates, defined mixtures of miRNA sequences and several combinations of adaptors in HTS library construction. We show that like the 3' adaptor ligation step, the 5' adaptor ligation is also biased, not because of primary sequence, but instead due to secondary structures of the two ligation substrates. We find that multiple secondary structural factors influence final representation in HTS results. Our results provide insight about the nature of ligation bias and allowed us to design adaptors that reduce ligation bias and produce HTS results that more accurately reflect the actual concentrations of miRNAs in the defined starting material. 28 samples were sequenced and the libraries were made using various synthetic oligo mixtures and adaptor combinations
2015-05-15 | E-GEOD-67053 | biostudies-arrayexpress
Project description:Five hundred nanograms of genomic DNA was fragmented by Covaris S2, the fragmented DNAs were performed end-repair, A-tailing at the 3 prime end, adaptors ligation with an IDT dual-indexed UMI adaptor system at the terminal ends. The adapter ligated library with size range 300-750bp were selected by dual-SPRI method. Twenty percent of the size selected PCR-free libraries were enriched by 5 PCR cycles prior to library size assessment by Bioanalyzer Fragment Analyzer. The PCR-free libraries were quantified by qPCR.The PCR-free libraries were denatured and diluted to optimal concentration. Illumina NovaSeq 6000 was used for Pair-End 151bp sequencing.
| EGAD00001005759 | EGA
Project description:High-throughput sequencing (HTS) has become a powerful tool for the detection of and sequence characterization of microRNAs (miRNA) and other small RNAs (sRNA). Unfortunately, the use of HTS data to determine the relative quantity of different miRNAs in a sample has been shown to be inconsistent with quantitative PCR and Northern Blot results. Several recent studies have concluded that the major contributor to this inconsistency is bias introduced during the construction of sRNA libraries for HTS and that the bias is primarily derived from the adaptor ligation steps; specifically where single stranded adaptors are sequentially ligated to the 3' and 5'-end of sRNAs using T4 RNA ligases. In this study we investigated the effects of ligation bias by using a pool of randomized ligation substrates, defined mixtures of miRNA sequences and several combinations of adaptors in HTS library construction. We show that like the 3' adaptor ligation step, the 5' adaptor ligation is also biased, not because of primary sequence, but instead due to secondary structures of the two ligation substrates. We find that multiple secondary structural factors influence final representation in HTS results. Our results provide insight about the nature of ligation bias and allowed us to design adaptors that reduce ligation bias and produce HTS results that more accurately reflect the actual concentrations of miRNAs in the defined starting material.
2015-05-15 | GSE67053 | GEO
Project description:Background: Next-generation sequencing (NGS) is fundamental to the current biological and biomedical research. Construction of sequencing library is a key step of NGS. Therefore, various library construction methods have been explored. However, the current methods are still limited by some shortcomings. Results: This study developed a new NGS library construction method, Single strand Adaptor Library Preparation (SALP), by using a novel single strand adaptor (SSA). SSA is a double-stranded oligonucleotide with a 3ʹ overhang of 3 random nucleotides, which can be efficiently ligated to the 3′ end of single strand DNA by T4 DNA ligase. SALP can be started with any denatured DNA fragments such as those sheared by Tn5 tagmentation, enzyme digestion and sonication. When started with Tn5-tagmented chromatin, SALP can overcome a key limitation of ATAC-seq and become a high-throughput NGS library construction method, SALP-seq, which can be used to comparatively characterize the chromatin openness state of multiple cells unbiasly. In this way, this study successfully characterized the comparative chromatin openness states of four different cell lines, including GM12878, HepG2, HeLa and 293T, with SALP-seq. Similarly, this study also successfully characterized the chromatin openness states of HepG2 cells with SALP-seq by using 105 to 500 cells. Conclusions: This study developed a new NGS library construction method, SALP, by using a novel kind of single strand adaptor (SSA), which should has wide applications in the future due to its unique performance.
2018-01-31 | GSE104162 | GEO
Project description:Purpose: The goal of this study is to analyze microRNA affected by wuho and mei-p26 mutations in Drosophila ovary Ovarian microRNA prolife of 7 day old control flies and flies bearing wuho and mei-p26 mutations, in duplicate.Sample libraries were prepared using the QIAseq miRNA Library Kit (QIAGEN) according to the manufacturer's protocols. Adaptors are ligated sequentially to the 3' and 5' ends of miRNAs. Subsequently, universal cDNA synthesis with UMI assignment, cDNA cleanup, library amplification and library cleanup are performed. Libraries were sequenced on an Illumina instrument (75-cycle single-end read, 75SE). Sequencing data was processed using the Illumina software BCL2FASTQ v2.20.
2020-01-03 | GSE142830 | GEO
Project description:Total RNA was isolated from different tissues (leaf, stem and flesh, rind and placenta of the fruits) using TRIzol reagent and small RNA libraries were generated from four cucurbit species: bottle gourd (Lagenaria siceraria (accession Grif 1617 collection from India)), Cucurbita moschata (accession Grif 14244 Early Butternut) Cucurbita pepo (accession NSL98075 Table King), and watermelon (Citrullus lanatus var. lanatus) (PI 438676 Charleston Grey) by pooling equimolar amounts of total RNA from the aforesaid tissues. Construction of small RNA libraries from size fractionated RNA was carried out as described previously. In brief, small RNA fractions of 18–28 nt were isolated from 15% denaturing polyacrylamide gels and sequentially ligated to 5′ and 3′ RNA adapters. Small RNAs ligated with adapters were converted to DNA by RT-PCR following Solexa protocol. The final PCR product was gel purified and sequenced by Genome Analyser II (Illumina).
2012-08-03 | GSE38176 | GEO
Project description:This data was generated by ENCODE. If you have questions about the data, contact the submitting laboratory directly (). If you have questions about the Genome Browser track associated with this data, contact ENCODE (mailto:genome@soe.ucsc.edu). This track was produced as part of the ENCODE project. It reports the percentage of DNA molecules that exhibit cytosine methylation. In general, DNA methylation within a gene's promoter is associated with gene silencing, and DNA methylation within the exons and introns of a gene is associated with gene expression. Proper regulation of DNA methylation is essential during development and aberrant DNA methylation is a hallmark of cancer. DNA methylation status was assayed with Whole Genome Bisulfite Sequencing (WGBS). Genomic DNA was sheared by sonication, end-repaired and then ligated to methylated sequencing adapters. The library fragments were treated with sodium bisulfite and amplified by PCR to convert every unmethylated cytosine to a thymine while leaving methylated cytosines intact. The sequenced fragments were aligned to a bisulfite-converted reference genome. For each assayed cytosine, the number of sequencing reads covering that C and the percentage of those reads that were methylated were reported. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf DNA methylation at cytosines across the genome was assayed with Whole Genome Bisulfite Sequencing (WGBS). WGBS was performed on cell lines grown by ENCODE production groups. WGBS was carried out by the Myers production group at the HudsonAlpha Institute for Biotechnology. Isolation of Genomic DNA: Genomic DNA was isolated from each cell line using the QIAGEN DNeasy Blood & Tissue Kit according to the instructions provided by the manufacturer. DNA concentrations for each genomic DNA preparation were determined using fluorescent DNA-binding dye and a fluorometer (Invitrogen Quant-iT dsDNA High Sensitivity Kit and Qubit Fluorometer). Typically, 2 µg of genomic DNA is used to make WGBS libraries. WGBS Library Construction and Sequencing: WGBS library construction started with sonication of genomic DNA on a Covaris S2 instrument. Sheared ends were then repaired and blunted with DNA polymerase I, T4 DNA polymerase and T4 polynucleotide kinase in the presence of dATP, dGTP and dTTP. After end repair, Klenow exo- DNA Polymerase was used to add an adenosine as a 3' overhang. Next, a methylated version of the Illumina paired-end adapters was ligated onto the DNA. Adapter-ligated 400 bp genomic DNA fragments were selected using a 2% agarose SizeSelect E-gel. The selected adapter-ligated fragments were treated with sodium bisulfite using the Zymo Research EZ DNA Methylation Gold Kit, which converts unmethylated cytosines to uracils and leaves methylated cytosines unchanged. Bisulfite-treated DNA was amplified in a final PCR reaction which was optimized to uniformly amplify diverse fragment sizes and sequence contexts in the same reaction. During this final PCR reaction, uracils were copied as thymines, resulting in a thymine in the PCR products wherever an unmethylated cytosine existed in the genomic DNA. These libraries were then sequenced with an Illumina HiSeq 2000 according to the manufacturer's recommendations as paired-end 50 bp reads. Libraries were sequenced to a depth of 600 million aligned reads. Data Analysis: To analyze the sequence data, Bismark (Krueger and Andrews, 2011) was used to align sequences reads. Generally, each read went through a conversion of Cs to Ts and was then aligned to fully converted plus and minus strands of the hg19 build of the human genome. A few custom refinements were made to the Bismark program. Since these libraries were made in a directional orientation with the first read always being C-poor, we skipped unnecessary alignments to impossible orientations. We also implemented a more stringent uniqueness filter, only allowing reads that have one acceptable alignment (based on default Bowtie parameters) across both strands. Once reads were aligned, the percent methylation was calculated for each cytosine using the original sequence reads. The percent methylation and number of reads is reported for each CpG in the wgEncodeHaibMethylWgbsXXXXCpg.bigBed file and for each non CpG cytosine in the wgEncodeHaibMethylWgbsXXXXNoncpg.bigBed file.
2012-09-12 | E-GEOD-40832 | biostudies-arrayexpress
Project description:We infected ZNF417 ZNF587 dKO 293T or control 293T with NL4.3 virus for 48 hours. Then genomic DNA was purified from cell lysis with by phenol chloroform. DNA was sheared into 300 bp-500 bp random fragments using Covaris Adaptive Focused Acoustics (Covaris, Woburn, MA). Sheared DNA was ligated with a linker and PCR with primers targeting HIV LTR and linker. PCR products were performed second PCR with Illumina adaptor primers. Libraries were so constructed and sequenced on Novaseq 6000.
2021-12-31 | GSE174239 | GEO
Project description:Construction of Reusable Plasmid Libraries for Strain Construction
| PRJNA189258 | ENA