scholarly journals Forensic Epigenetic Analysis: The Path Ahead

2019 ◽  
Vol 28 (4) ◽  
pp. 301-308 ◽  
Author(s):  
Sabeeha ◽  
Seyed E. Hasnain 

Unlike DNA fingerprinting, which scores for differences in the genome that are phenotype neutral, epigenetic variations are gaining importance in forensic investigations. Methylation of DNA has a broad range of effects on the lifestyle, health status, and physical appearance of individuals. DNA methylation profiling of forensic samples is useful in determination of the cell or tissue type of the DNA source and also for estimation of age. The quality and quantity of the biosample available from the crime scene limits the possible number of DNA methylation tests and the selection of the technology that can be used. Several techniques have been used for DNA methylation analysis for epigenetic investigations of forensic biological samples. However, novel techniques are needed for multiplex analysis of epigenetic markers as the techniques that are currently available require a large amount of high-quality DNA and are also limited in their multiplexing capacities that are often insufficient to fully resolve a forensic query of interest.

2017 ◽  
Vol 9 (10) ◽  
pp. 1537-1549 ◽  
Author(s):  
Takaaki Kurinomaru ◽  
Ryoji Kurita

The determination of epigenetic modification, especially that of 5-methylcytosine in the CpG sequence in mammals, has attracted attention because it should prove valuable in a wide range of research fields including diagnosis, drug discovery and therapy. In this review, we introduce the recent development of bisulfite-free DNA methylation analysis, which we classify into two categories, namely labelling-based and labelling-free assays.


2021 ◽  
Author(s):  
Christian Koelsche ◽  
Jamal K. Benhamida ◽  
Felix K. F. Kommoss ◽  
Damian Stichel ◽  
David T. W. Jones ◽  
...  

AbstractUndifferentiated mesenchymal tumors arising from the inner lining (intima) of large arteries are classified as intimal sarcomas (ISA) with MDM2 amplification as their molecular hallmark. Interestingly, undifferentiated pleomorphic sarcomas (UPS) of the heart have recently been suggested to represent the cardiac analog of ISA due to morphological overlap and high prevalence of MDM2 amplifications in both neoplasms. However, little is known about ISAs and cardiac UPS without MDM2 amplifications and molecular data supporting their common classification is sparse. Here, we report a series of 35 cases comprising 25 ISAs of the pulmonary artery, one ISA of the renal artery and 9 UPS of the left atrium. Tumors were analyzed utilizing the Illumina Infinium MethylationEPIC BeadChip array, enabling copy number profile generation and unsupervised DNA methylation analysis. DNA methylation patterns were investigated using t-distributed stochastic neighbor embedding (t-SNE) analysis. Histologically, all ISAs and UPS of the left atrium resembled extra-cardiac UPS. All cases exhibited highly complex karyotypes with overlapping patterns between ISA and UPS. 29/35 cases showed mutually exclusive amplifications in the cell-cycle associated oncogenes MDM2 (25/35), MDM4 (2/35), and CDK6 (2/35). We further observed recurrent co-amplifications in PDGFRA (21/35), CDK4 (15/35), TERT (11/35), HDAC9 (9/35), and CCND1 (4/35). Sporadic co-amplifications occurred in MYC, MYCN, and MET (each 1/35). The tumor suppressor CDKN2A/B was frequently deleted (10/35). Interestingly, DNA methylation profiling (t-SNE) revealed an overlap of ISA and cardiac UPS. This “ISA” methylation signature was distinct from potential histologic and molecular mimics. In conclusion, our data reveal MDM4 and CDK6 amplifications in ISAs and UPS of the left atrium, lacking MDM2 amplification. We further report novel co-amplifications of various oncogenes, which may have therapeutic implications. Finally, the genetic and epigenetic concordance of ISAs and UPS of the left atrium further supports a shared pathogenesis and common classification.


2021 ◽  
Vol 16 (3) ◽  
pp. S490
Author(s):  
D.M. Aguilar-Beltrán ◽  
A.G. Alcázar-Ramos ◽  
A.L. Vega-Rodríguez ◽  
D.G. García-Gutiérrez ◽  
A.D. Bertadillo-Jilote ◽  
...  

2021 ◽  
Vol 22 (8) ◽  
pp. 4247
Author(s):  
Andrea Martisova ◽  
Jitka Holcakova ◽  
Nasim Izadi ◽  
Ravery Sebuyoya ◽  
Roman Hrstka ◽  
...  

DNA methylation, i.e., addition of methyl group to 5′-carbon of cytosine residues in CpG dinucleotides, is an important epigenetic modification regulating gene expression, and thus implied in many cellular processes. Deregulation of DNA methylation is strongly associated with onset of various diseases, including cancer. Here, we review how DNA methylation affects carcinogenesis process and give examples of solid tumors where aberrant DNA methylation is often present. We explain principles of methods developed for DNA methylation analysis at both single gene and whole genome level, based on (i) sodium bisulfite conversion, (ii) methylation-sensitive restriction enzymes, and (iii) interactions of 5-methylcytosine (5mC) with methyl-binding proteins or antibodies against 5mC. In addition to standard methods, we describe recent advances in next generation sequencing technologies applied to DNA methylation analysis, as well as in development of biosensors that represent their cheaper and faster alternatives. Most importantly, we highlight not only advantages, but also disadvantages and challenges of each method.


GigaScience ◽  
2020 ◽  
Vol 9 (5) ◽  
Author(s):  
Katarzyna Murat ◽  
Björn Grüning ◽  
Paulina Wiktoria Poterlowicz ◽  
Gillian Westgate ◽  
Desmond J Tobin ◽  
...  

Abstract Background Infinium Human Methylation BeadChip is an array platform for complex evaluation of DNA methylation at an individual CpG locus in the human genome based on Illumina’s bead technology and is one of the most common techniques used in epigenome-wide association studies. Finding associations between epigenetic variation and phenotype is a significant challenge in biomedical research. The newest version, HumanMethylationEPIC, quantifies the DNA methylation level of 850,000 CpG sites, while the previous versions, HumanMethylation450 and HumanMethylation27, measured >450,000 and 27,000 loci, respectively. Although a number of bioinformatics tools have been developed to analyse this assay, they require some programming skills and experience in order to be usable. Results We have developed a pipeline for the Galaxy platform for those without experience aimed at DNA methylation analysis using the Infinium Human Methylation BeadChip. Our tool is integrated into Galaxy (http://galaxyproject.org), a web-based platform. This allows users to analyse data from the Infinium Human Methylation BeadChip in the easiest possible way. Conclusions The pipeline provides a group of integrated analytical methods wrapped into an easy-to-use interface. Our tool is available from the Galaxy ToolShed, GitHub repository, and also as a Docker image. The aim of this project is to make Infinium Human Methylation BeadChip analysis more flexible and accessible to everyone.


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