Project description:Illumina Infinium DNA Methylation (5mC) profiling arrays are a popular technology to measure genome-scale distribution of 5mC at low cost and high throughput, especially in cancer and other complex diseases. Following the success of the HumanMethylation450 array (450k), Illumina released the MethylationEPIC array (850k) featuring increased coverage of enhancers in addition to regulatory regions primarily covered by the 450k (i.e. promoters, gene bodies). Despite its widespread use, the analysis of 850k data remains suboptimal as it mostly still relies on Illumina’s default annotation, which underestimates enhancers and long noncoding RNAs (lncRNAs). We thus developed an approach, based on ENCODE and LNCipedia databases, that greatly improves Illumina’s default annotation of enhancers and long noncoding transcripts. Comparisons between the re-annotated 850k and its precursor, the 450k, or RRBS, another high-throughput 5mC profiling technology, revealed that the 850k covers at least three times more enhancers and lncRNAs than the other two technologies. We further investigated the reproducibility of the three technologies and applied various normalisation methods to 850k data, showing that most of them reduce variability to a level below that of RRBS. When analyzed with our new annotation and normalization pipeline, profiling for 5mC changes in breast cancer biopsies with the 850k highlighted aberrant enhancers methylation as the predominant feature, confirming previous reports. In conclusion, our study provides an updated analysis pipeline for 850k data based on a refined probe annotation and normalization that allows for the improved analysis of methylation at enhancers and long noncoding transcripts.
Project description:Illumina Infinium DNA Methylation (5mC) profiling arrays are a popular technology to measure genome-scale distribution of 5mC at low cost and high throughput, especially in cancer and other complex diseases. Following the success of the HumanMethylation450 array (450k), Illumina released the MethylationEPIC array (850k) featuring increased coverage of enhancers in addition to regulatory regions primarily covered by the 450k (i.e. promoters, gene bodies). Despite its widespread use, the analysis of 850k data remains suboptimal as it mostly still relies on Illumina’s default annotation, which underestimates enhancers and long noncoding RNAs (lncRNAs). We thus developed an approach, based on ENCODE and LNCipedia databases, that greatly improves Illumina’s default annotation of enhancers and long noncoding transcripts. Comparisons between the re-annotated 850k and its precursor, the 450k, or RRBS, another high-throughput 5mC profiling technology, revealed that the 850k covers at least three times more enhancers and lncRNAs than the other two technologies. We further investigated the reproducibility of the three technologies and applied various normalisation methods to 850k data, showing that most of them reduce variability to a level below that of RRBS. When analyzed with our new annotation and normalization pipeline, profiling for 5mC changes in breast cancer biopsies with the 850k highlighted aberrant enhancers methylation as the predominant feature, confirming previous reports. In conclusion, our study provides an updated analysis pipeline for 850k data based on a refined probe annotation and normalization that allows for the improved analysis of methylation at enhancers and long noncoding transcripts.
Project description:Genome wide DNA methylation in blood, subcutaneous and omental visceral adipose tissue from two-step surgical approach (N=9) was analysed in patients with severe obesity using Illumina 850K EPIC technology before and after metabolic surgery (Leipzig Obesity BioBank (LOBB) cohort). Additionally, a validation blood cohort of patients with obesity undergoing metabolic surgery was analyzed for results validation.
Project description:Illumina Infinium MethylationEPIC BeadChip (850k) array analysis of DNA methylation of 12 different growing teratoma tissues. Samples were subgrouped based on growth speed into GTSslow to GTSrapid (see corresponding publication).
Project description:Illumina Infinium MethylationEPIC BeadChip (850k) array analysis of DNA methylation of germ cell tumor related somati-type malignancies (STM), i. e. adenocarcinomas and rhabdomyosarcomas. As controls, yolk-sac tumors and teratoma without STM population were included.