scholarly journals The effect of pre-analytical and physiological variables on cell-free DNA fragmentation.

2021 ◽  
Author(s):  
Ymke van der Pol ◽  
Norbert Moldovan ◽  
Sandra Verkuijlen ◽  
Jip Ramaker ◽  
Dries Boers ◽  
...  

Assays that account for the biological properties and fragmentation of cell-free DNA (cfDNA) can improve the performance of liquid biopsy. However, pre-analytic and physiological differences between individuals on fragmentomic analysis are poorly defined. We analyzed the impact of collection tube, plasma processing time and physiology on the size distribution of cfDNA, their genome-wide representation and sequence diversity at the cfDNA fragment-ends using shallow Whole Genome Sequencing. We observed that using different stabilizing collection tubes, or processing times does not affect the cfDNA fragment sizes, but can impact the genome-wide fragmentation patterns and fragment-end sequences of cfDNA. In addition, beyond differences depending on the gender, the physiological conditions tested between 63 individuals (age, body mass index, use of medication and chronic conditions) minimally influenced the outcome of fragmentomic methods. Our results highlight that fragmentomic approaches have potential for implementation in the clinic, pending clear traceability of analytical and physiological factors.

2020 ◽  
Author(s):  
Haizi Zheng ◽  
Michelle S Zhu ◽  
Yaping Liu

AbstractSummaryCirculating cell-free DNA (cfDNA) is a promising biomarker for the diagnosis and prognosis of many diseases, including cancer. The genome-wide non-random fragmentation patterns of cfDNA are associated with the nucleosomal protection, epigenetic environment, and gene expression in the cell types that contributed to cfDNA. However, current progress on the development of computational methods and understanding of molecular mechanisms behind cfDNA fragmentation patterns is significantly limited by the controlled-access of cfDNA whole-genome sequencing (WGS) dataset. Here, we present FinaleDB (FragmentatIoN AnaLysis of cEll-free DNA DataBase), a comprehensive database to host thousands of uniformly processed and curated de-identified cfDNA WGS datasets across different pathological conditions. Furthermore, FinaleDB comes with a fragmentation genome browser, from which users can seamlessly integrate thousands of other omics data in different cell types to experience a comprehensive view of both gene-regulatory landscape and cfDNA fragmentation patterns.Availability and implementationFinaleDB service: http://finaledb.research.cchmc.org/ FinaleDB source code: https://github.com/epifluidlab/finaledb_portal and https://github.com/epifluidlab/[email protected]


Author(s):  
Haizi Zheng ◽  
Michelle S Zhu ◽  
Yaping Liu

Abstract Summary Circulating cell-free DNA (cfDNA) is a promising biomarker for the diagnosis and prognosis of many diseases, including cancer. The genome-wide non-random fragmentation patterns of cfDNA are associated with the nucleosomal protection, epigenetic environment, and gene expression in the cell types that contributed to cfDNA. However, current progress on the development of computational methods and understanding of molecular mechanisms behind cfDNA fragmentation patterns is significantly limited by the controlled-access of cfDNA whole-genome sequencing (WGS) dataset. Here, we present FinaleDB (FragmentatIoN AnaLysis of cEll-free DNA DataBase), a comprehensive database to host thousands of uniformly processed and curated de-identified cfDNA WGS datasets across different pathological conditions. Furthermore, FinaleDB comes with a fragmentation genome browser, from which users can seamlessly integrate thousands of other omics data in different cell types to experience a comprehensive view of both gene-regulatory landscape and cfDNA fragmentation patterns. Availability and implementation FinaleDB service: http://finaledb.research.cchmc.org/. FinaleDB source code: https://github.com/epifluidlab/finaledb_portal, https://github.com/epifluidlab/finaledb_workflow Supplementary information Supplementary data are available at Bioinformatics online.


2019 ◽  
Author(s):  
Havell Markus ◽  
Jun Zhao ◽  
Tania Contente-Cuomo ◽  
Elizabeth Raupach ◽  
Ahuva Odenheimer-Bergman ◽  
...  

AbstractCell-free DNA (cfDNA) in urine is a promising analyte for noninvasive diagnostics. However, urine cfDNA is highly fragmented and whether characteristics of these fragments reflect underlying genomic architecture is unknown. Here, we perform comprehensive characterization of fragmentation patterns in urine cfDNA. We show modal size and genome-wide distribution of urine cfDNA fragments are consistent with transient protection from degradation by stable intermediates of nucleosome disassembly. Genome-wide nucleosome occupancy and fragment sizes in urine cfDNA are informative of cell of origin and renal epithelial cells are amongst the highest contributors in urine. Compared to a nucleosome occupancy map based on control urine samples, we observe a higher fraction of fragments with aberrant ends in cancer patients, distinguishing cancer samples with an area under the curve of 0.89. Our results demonstrate sub-nucleosomal organization in urine cfDNA and are proof-of-principle that genome-wide fragmentation analysis of urine cfDNA can enable cancer diagnostics.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 3018-3018
Author(s):  
Alessandro Leal ◽  
Stephen Cristiano ◽  
Jillian Phallen ◽  
Jacob Fiksel ◽  
Vilmos Adleff ◽  
...  

3018 Background: Analyses of cell-free DNA (cfDNA) in the blood provide a noninvasive diagnostic avenue for patients with cancer. However, cfDNA analyses have largely focused on targeted sequencing of specific genes, and the characteristics of the origins and molecular features of cfDNA are poorly understood. We developed an ultrasensitive approach that allows simultaneous examination of a large number of abnormalities in cfDNA through genome-wide analysis of fragmentation patterns. Methods: We used a machine learning model to examined cfDNA fragmentation profiles of 236 patients with largely localized breast, colorectal, lung, ovarian, pancreatic, gastric, or bile duct cancer and 245 healthy individuals. Estimation of performance was determined by ten-fold cross validation repeated ten times. Results: cfDNA profiles of healthy individuals reflected nucleosomal patterns of white blood cells, while patients with cancer had altered fragmentation patterns. The degree of abnormality in fragmentation profiles during therapy closely matched levels of mutant allele fractions in cfDNA as determined using ultra-deep targeted sequencing. The sensitivity of detection ranged from 57% to > 99% among the seven cancer types at 98% specificity, with an overall AUC of 0.94. Fragmentation profiles could be used to identify the tissue of origin of the cancers to a limited number of sites in 75% of cases. Combining our approach with mutation-based cfDNA analyses detected 91% of cancer patients. Conclusions: This effort is the first study to demonstrate genome-wide cell-free DNA fragmentation abnormalities in patients with cancer. Results of these analyses highlight important properties of cfDNA and provide a facile approach for screening, early detection, and monitoring of human cancer.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Wardah Mahmood ◽  
Lars Erichsen ◽  
Pauline Ott ◽  
Wolfgang A. Schulz ◽  
Johannes C. Fischer ◽  
...  

AbstractLINE-1 hypomethylation of cell-free DNA has been described as an epigenetic biomarker of human aging. However, in the past, insufficient differentiation between cellular and cell-free DNA may have confounded analyses of genome-wide methylation levels in aging cells. Here we present a new methodological strategy to properly and unambiguously extract DNA methylation patterns of repetitive, as well as single genetic loci from pure cell-free DNA from peripheral blood. Since this nucleic acid fraction originates mainly in apoptotic, senescent and cancerous cells, this approach allows efficient analysis of aged and cancerous cell-specific DNA methylation patterns for diagnostic and prognostic purposes. Using this methodology, we observe a significant age-associated erosion of LINE-1 methylation in cfDNA suggesting that the threshold of hypomethylation sufficient for relevant LINE-1 activation and consequential harmful retrotransposition might be reached at higher age. We speculate that this process might contribute to making aging the main risk factor for many cancers.


Diagnostics ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 650
Author(s):  
Selena Y. Lin ◽  
Yue Luo ◽  
Matthew M. Marshall ◽  
Barbara J. Johnson ◽  
Sung R. Park ◽  
...  

This study assessed three commercially available cell-free DNA (cfDNA) extraction kits and the impact of a PEG-based DNA cleanup procedure (DNApure) on cfDNA quality and yield. Six normal donor urine and plasma samples and specimens from four pregnant (PG) women carrying male fetuses underwent extractions with the JBS cfDNA extraction kit (kit J), MagMAX Cell-Free DNA Extraction kit (kit M), and QIAamp Circulating Nucleic Acid Kit (kit Q). Recovery of a PCR product spike-in, endogenous TP53, and Y-chromosome DNA was used to assess kit performance. Nucleosomal-sized DNA profiles varied among the kits, with prominent multi-nucleosomal-sized peaks present in urine and plasma DNA isolated by kits J and M only. Kit J recovered significantly more spike-in DNA than did kits M or Q (p < 0.001) from urine, and similar amounts from plasma (p = 0.12). Applying DNApure to kit M- and Q-isolated DNA significantly improved the amplification efficiency of spike-in DNA from urine (p < 0.001) and plasma (p ≤ 0.013). Furthermore, kit J isolated significantly more Y-chromosome DNA from PG urine compared to kit Q (p = 0.05). We demonstrate that DNApure can provide an efficient means of improving the yield and purity of cfDNA and minimize the effects of pre-analytical biospecimen variability on liquid biopsy assay performance.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Brian C.-H. Chiu ◽  
Chang Chen ◽  
Qiancheng You ◽  
Rudyard Chiu ◽  
Girish Venkataraman ◽  
...  

AbstractThe 5-methylcytosines (5mC) have been implicated in the pathogenesis of diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). However, the role of 5-hydroxymethylcytosines (5hmC) that are generated from 5mC through active demethylation, in lymphomagenesis is unknown. We profiled genome-wide 5hmC in circulating cell-free DNA (cfDNA) from 73 newly diagnosed patients with DLBCL and FL. We identified 294 differentially modified genes between DLBCL and FL. The differential 5hmC in the DLBCL/FL-differentiating genes co-localized with enhancer marks H3K4me1 and H3K27ac. A four-gene panel (CNN2, HMG20B, ACRBP, IZUMO1) robustly represented the overall 5hmC modification pattern that distinguished FL from DLBCL with an area under curve of 88.5% in the testing set. The median 5hmC modification levels in signature genes showed potential for separating patients for risk of all-cause mortality. This study provides evidence that genome-wide 5hmC profiles in cfDNA differ between DLBCL and FL and could be exploited as a non-invasive approach.


2021 ◽  
Vol 224 (2) ◽  
pp. S156
Author(s):  
Jill Rafalko ◽  
Samantha Caldwell ◽  
Eyad Almasri ◽  
Erica Soster ◽  
Kimberly Fanelli ◽  
...  
Keyword(s):  
Free Dna ◽  

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 3058-3058
Author(s):  
Jacob Carey ◽  
Bryan Chesnick ◽  
Denise Butler ◽  
Michael Rongione ◽  
Giovanni Parmigiani ◽  
...  

3058 Background: Circulating cell-free DNA (cfDNA) is largely nucleosomal in origin with typical fragment lengths of 167 base-pairs reflecting the length of DNA wrapped around-the histone and H1 linker. Given the nucleosomal origin of cfDNA, we have previously used low coverage whole genome sequencing to evaluate DNA fragmentation profiles to sensitively and specifically detect tumor-derived DNA with altered fragment lengths or coverage. Methods: Here we evaluate the use of Bayesian finite mixtures to model the fragment length distribution and demonstrate how the parameters from these models can be useful to distinguish between individuals with and without cancer. We examined the number of cfDNA fragments by size ranging from 100-220bp and approximated the mixture component location, scale, and weight using Markov Chain Monte Carlo. The performance of the method was determined using a ten-fold, ten repeat cross-validation of Gradient Boosted Machine model using 1) our previously described genome-wide fragmentation profile approach, 2) the parameters from the mixture model and 3) a combination of approaches 1) and 2) as features. Results: In this study of 215 cancer patients and 208 cancer-free individuals, we observed cross-validated AUCs of 1) 0.94, 2) 0.95, and 3) 0.97 among the three approaches. Conclusions: Our findings indicate that parsimonious mixture models may improve detection of cancer in conjunction with fragmentation profile analyses across the genome.


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