Project description:5-methylcytosine (5-mC) can be oxidized to 5-hydroxymethylcytosine (5-hmC). Genome-wide profiling of 5-hmC thus far indicated 5-hmC may not only be an intermediate form of DNA demethylation but could also constitute an epigenetic mark per se. We describe a cost-effective and selective method to detect both the hydroxymethylation and methylation status of cytosines in more than 1.8 million MspI sites in the human genome. This method involves the selective glucosylation of 5-hmC residues, short-sequence tag generation and high-throughput sequencing. We tested this method by screening H9 human embryonic stem cells and their differentiated embroid body cells, and found that differential hydroxymethylation preferentially occur in bivalent genes during cellular differentiation. Especially, our results support hydroxymethylation can regulate key transcription regulators with bivalent marks through demethylation and affect cellular decision on choosing active or inactive state of these genes upon cellular differentiation. We developed a cost-effective and selective method to detect both the hydroxymethylation and methylation status of cytosines in more than 1.8 million MspI sites in the human genome. In order to validate the results generated by this method, we applied MeDIP-seq and hMeDIP-seq to screen H9 human embryonic stem cells in comparison with the newly developed method.
Project description:We developed a genome-wide DNA methylation profiling technology that determines methylation patterns using small amounts of starting material. This process involves a novel amplification step for DNA subjected to bisulfite-mediated cytosine conversion and generates highly reproducible datasets with low technical variation. The technology, named BiMP (for Bisulfite Methylation Profiling), is more cost-effective than mC immunoprecipitation techniques (mCIP) and can be applied to as little as 100 ng of Arabidopsis DNA. It is anticipated that this technology can be applied to mammalian genomes and may allow methylation profiling of a small number of physiologically uniform cells. Keywords: bisulfite DNA methylation profiling, Arabidopsis, methylation polymorphisms, met1-3,
Project description:Here, we report an enrichment-based ultra-low input cfDNA methylation profiling method using methyl-CpG binding proteins capture, termed cfMBD-seq. We optimized the conditions of cfMBD capture by adjusting the amount of MethylCap protein along with using methylated filler DNA. Our data showed that cfMBD-seq performs equally to the standard MBD-seq (>1000 ng input) even when using 1 ng DNA as the input. cfMBD-seq demonstrated equivalent sequencing data quality as well as similar methylation profile when compared to cfMeDIP-seq. We showed that cfMBD-seq outperforms cfMeDIP-seq in the enrichment of CpG islands. This new bisulfite-free ultra-low input methylation profiling technology has a great potential in non-invasive and cost-effective cancer detection and classification.
Project description:Alterations in chromatin accessibility independent of DNA methylation can affect cancer-related gene expression, but are often overlooked in conventional epigenomic profiling approaches. In this study, we describe a cost-effective and computationally simple assay called AcceSssIble to simultaneously interrogate DNA methylation and chromatin accessibility alterations in primary human clear cell renal cell carcinomas (ccRCC). Our study revealed significant perturbations to the ccRCC epigenome, and identified gene expression changes that were specifically attributed to the chromatin accessibility status whether or not DNA methylation was involved. Compared to commonly mutated genes in ccRCC, such as the von Hippel-Lindau (VHL) tumor suppressor, the genes identified by AcceSssIble comprised distinct pathways and more frequently underwent epigenetic changes, suggesting that genetic and epigenetic alterations could be independent events in ccRCC. Specifically, we found unique DNA methylation-independent promoter accessibility alterations in pathways mimicking VHL deficiency. Overall, this study provides a novel approach for identifying new epigenetic-based therapeutic targets, previously undetectable by DNA methylation studies alone, that may complement current genetic-based treatment strategies. Examination of 3 different histone modifications in 2 patient tumor and adjacent normal samples.
Project description:We developed a novel approach, J-binding protein 1 sequencing (JBP1-seq), that combines the benefits of an improved recombinant JBP1 protein, Nextera-based library construction, and nextgeneration sequencing (NGS) for genome-wide profiling of 5-hydroxymethylcytosine (5hmC). Compared with the original JBP1, this new recombinant JBP1 was biotinylatedin vivo and conjugated to magnetic beads via biotin-streptavidin interactions. These modifications allowed a more efficient and consistent pull-down of β-glucosyl-5-hydroxymethylcytosine (β-glu-5hmC), and sequence-ready libraries can be generated within 4.5 hours from DNA inputs as low as 50 ng. 5hmC enrichment of human brain DNA using the new JBP1 resulted in over 25,000 peaks called, which is significantly higher than the 4,003 peaks enriched using the old JBP1. Comparison of the technical duplicates and validations with other platforms indicated the results are reproducible and reliable. Thus, JBP1-seq provides a fast, efficient, cost-effective method for accurate 5hmC genome-wide profiling. An improvement of JBP1-Seq
Project description:Methylated DNA enrichment is a key step in a microarray based genome-wide methylation profiling study, and even for future high-throughput sequencing based methylome analysis. In order to evaluate the sensitivity and accuracy of methylated DNA enrichment, we investigated and optimized a number of important parameters to improve the performance of several enrichment assays, including differential methylation hybridization (DMH), microarray-based methylation assessment of single samples (MMASS), and methylated DNA immunoprecipitation (MeDIP). With advantages and disadvantages unique to each approach, we found that assays based on methylation-sensitive enzyme digestion and those based on immunoprecipitation detected different methylated DNA fragments, indicating that they are complementary in their relative ability to detect methylation differences. Our study provides the first comprehensive evaluation for widely used methodologies for methylated DNA enrichment, and could be helpful for developing a cost effective approach for DNA methylation profiling.
Project description:DNA methylation is a mechanism for long-term transcriptional regulation and is required for normal cellular differentiation. Failure to properly establish or maintain DNA methylation patterns leads to cell dysfunction and diseases such as cancer. Identifying DNA methylation signatures in complex tissues can be challenging due to inaccurate cell enrichment methods and low DNA yields. We have developed a technique called Laser Capture Microdissection-Reduced Representation Bisulfite Sequencing (LCM-RRBS) for the multiplexed interrogation of the DNA methylation status of CpG Islands and promoters. LCM-RRBS accurately and reproducibly profiles genome-wide methylation of DNA extracted from microdissected fresh frozen or formalin-fixed paraffin-embedded tissue samples. To demonstrate the utility of LCM-RRBS, we characterized changes in DNA methylation associated with gonadectomy-induced adrenocortical neoplasia in the mouse. Compared to adjacent normal tissue, the adrenocortical tumors showed reproducible gains and losses of DNA methylation at genes involved in cell differentiation and organ development. LCM-RRBS is a rapid, cost-effective, and sensitive technique for analyzing DNA methylation in heterogeneous tissues and will facilitate the investigation of DNA methylation in cancer and organ development. Laser capture microdissection-reduced representation bisulfite sequencing and reduced representation bisulfite sequencing on human blood leukocyte, human endometrial tumor, mouse liver tissue, and mouse normal and neoplastic adrenal tissue
Project description:Background: Researching the murine epigenome in disease models has been hampered by the lack of an appropriate and cost-effective DNA methylation array. Until recently, investigators have been limited to the relatively expensive and analysis intensive bisulphite sequencing methods. Here, we performed a comprehensive, comparative analysis between the new Mouse Methylation BeadChip (MMB) and reduced representation bisulphite sequencing (RRBS) in two murine models of colorectal carcinogenesis, providing insight into the utility to each platforms in a real world environment. Results: We captured 1.47x106 CpGs by RRBS and 2.64x105 CpGs by MMB, mapping to 13,778 and 13,365 CpG islands, respectively. RRBS captured significantly more CpGs per island (median 41 for RRBS versus 2 for MMB). We found that 64.4% of intra-island CpG methylation variability can be captured by measuring approximately one quarter of CpG island (CGI) CpGs. MMB was more precise in measuring DNA methylation, especially at sites that had low RRBS coverage. This impacted differential methylation analysis, with more statistically significantly differentially methylated CpG sites identified by MMB in all experimental conditions, however the difference was minute when appropriate thresholding for the magnitude of methylation change (0.2 beta value difference) was applied, providing confidence that both techniques can identify similar differential DNA methylation. Gene ontology enrichment analysis of differentially hypermethylated gene promoters identified similar biological processes and pathways by both RRBS and MMB across two murine model systems. Conclusion: MMB is an effective tool for profiling the murine methylome that performs comparably to RRBS, identifying similar differentially methylated pathways. Although MMB captures a similar proportion of CpG islands, it does so with fewer CpGs per island. We show that subsampling informative CpGs from CpG islands is an appropriate strategy to capture whole island variation. Choice of technology is experiment dependent and will be predicated on the underlying biology being probed.