scholarly journals Genome-wide cell-free DNA termini in patients with cancer.

2021 ◽  
Author(s):  
Norbert Moldovan ◽  
Ymke van der Pol ◽  
Tom van den Ende ◽  
Dries Boers ◽  
Sandra Verkuijlen ◽  
...  
Keyword(s):  
Residual Disease ◽  
Fragmentation Pattern ◽  
Healthy Controls ◽  
Cell Free Dna ◽  
Free Dna ◽  
Genome Wide ◽  
A Genome ◽  
Pattern Length ◽  
Cancer Types ◽  
End Sequences

The structure, fragmentation pattern, length and terminal sequence of cell-free DNA (cfDNA) is under the influence of nucleases present in the blood. We hypothesized that differences in the diversity of bases at the end of cfDNA fragments can be leveraged on a genome-wide scale to enhance the sensitivity for detecting the presence of tumor signals in plasma. We surveyed the cfDNA termini in 572 plasma samples from 319 patients with 18 different cancer types using low-coverage whole genome sequencing. The fragment-end sequence and diversity were altered in all cancer types in comparison to 76 healthy controls. We converted the fragment end sequences into a quantitative metric and observed that this correlates with circulating tumor DNA tumor fraction (R = 0.58, p < 0.001, Spearman). Using these metrics, we were able to classify cancer samples from control at a low tumor content (AUROC of 91% at 1% tumor fraction) and shallow sequencing coverage (mean AUROC = 0.99 at >1M fragments). Combining fragment-end sequences and diversity using machine learning, we classified cancer from healthy controls (mean AUROC = 0.99, SD = 0.01). Using unsupervised clustering we showed that early-stage lung cancer (n = 13) can be classified from control or later stages based on fragment-end sequences. We observed that fragment-end sequences can be used for prognostication (hazard ratio: 0.49) and residual disease detection in resectable esophageal adenocarcinoma patients, moving fragmentomics toward a greater clinical implementation.

scholarly journals Cell-Free-DNA-Based Copy Number Index Score in Epithelial Ovarian Cancer—Impact for Diagnosis and Treatment Monitoring

Cancers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 168
Author(s):  
Elena Ioana Braicu ◽  
Andreas du Bois ◽  
Jalid Sehouli ◽  
Julia Beck ◽  
Sonia Prader ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Epithelial Ovarian Cancer ◽  
Copy Number ◽  
High Grade ◽  
Copy Number State ◽  
Cell Free Dna ◽  
Blood Samples ◽  
Free Dna ◽  
Genome Wide ◽  
A Genome

Background: Chromosomal instability, a hallmark of cancer, results in changes in the copy number state. These deviant copy number states can be detected in the cell-free DNA (cfDNA) and provide a quantitative measure of the ctDNA levels by converting cfDNA next-generation sequencing results into a genome-wide copy number instability score (CNI-Score). Our aim was to determine the role of the CNI-Score in detecting epithelial ovarian cancer (EOC) and its role as a marker to monitor the response to treatment. Methods: Blood samples were prospectively collected from 109 patients with high-grade EOC. cfDNA was extracted and analyzed using a clinical-grade assay designed to calculate a genome-wide CNI-Score from low-coverage sequencing data. Stored data from 241 apparently healthy controls were used as a reference set. Results: Comparison of the CNI-Scores of primary EOC patients versus controls yielded sensitivities of 91% at a specificity of 95% to detect OC, respectively. Significantly elevated CNI-Scores were detected in primary (median: 87, IQR: 351) and recurrent (median: 346, IQR: 1891) blood samples. Substantially reduced CNI-Scores were detected after primary debulking surgery. Using a cut-off of 24, a diagnostic sensitivity of 87% for primary and recurrent EOC was determined at a specificity of 95%. CNI-Scores above this threshold were detected in 21/23 primary tumor (91%), 36/42 of platinum-eligible recurrent (85.7%), and 19/22 of non-platinum-eligible recurrent (86.3%) samples, respectively. Conclusion: ctDNA-quantification based on genomic instability determined by the CNI-Score was a biomarker with high diagnostic accuracy in high-grade EOC. The applied assay might be a promising tool for diagnostics and therapy monitoring, as it requires no a priori information about the tumor.

scholarly journals Nuclease deficiencies alter plasma cell-free DNA methylation profiles

2021 ◽  
pp. gr.275426.121
Author(s):  
Diana Siao Cheng Han ◽  
Meng Ni ◽  
Rebecca Wing Yan Chan ◽  
Danny Ka Lok Wong ◽  
Linda T Hiraki ◽  
...  
Keyword(s):  
Fragment Size ◽  
Cpg Islands ◽  
Periodic Pattern ◽  
Open Chromatin ◽  
Cell Free Dna ◽  
Free Dna ◽  
Genome Wide ◽  
A Genome ◽  
Wide Scale ◽  
Deficient Mice

The effects of DNASE1L3 or DNASE1 deficiency on cell-free DNA (cfDNA) methylation was explored in plasma of mice deficient in these nucleases and in DNASE1L3-deficient humans. Compared to wild-type cfDNA, cfDNA in Dnase1l3-deficient mice was significantly hypomethylated, while cfDNA in Dnase1-deficient mice was hypermethylated. The cfDNA hypomethylation in Dnase1l3-deficient mice was due to increased fragmentation and representation from open chromatin regions (OCRs) and CpG islands (CGIs). These findings were absent in Dnase1-deficient mice, demonstrating the preference of DNASE1 to cleave in hypomethylated OCRs and CGIs. We also observed a substantial decrease of fragment ends and coverage at methylated CpGs in the absence of DNASE1L3, thereby demonstrating that DNASE1L3 prefers to cleave at methylated CpGs. Furthermore, we found that methylation levels of cfDNA varied by fragment size in a periodic pattern, with cfDNA of specific sizes being more hypomethylated and enriched for OCRs and CGIs. These findings were confirmed in DNASE1L3-deficient human cfDNA. Thus, we have found that nuclease-mediated cfDNA fragmentation markedly affected cfDNA methylation level on a genome-wide scale. This work provides a foundational understanding of the relationship between methylation, nuclease biology and cfDNA fragmentation.

scholarly journals A Genome-Wide Association Study Identifies UGT1A1 as a Regulator of Serum Cell-Free DNA in Young Adults: The Cardiovascular Risk in Young Finns Study

PLoS ONE ◽  
2012 ◽  
Vol 7 (4) ◽  
pp. e35426 ◽  
Author(s):  
Juulia Jylhävä ◽  
Leo-Pekka Lyytikäinen ◽  
Mika Kähönen ◽  
Nina Hutri-Kähönen ◽  
Johannes Kettunen ◽  
...  
Keyword(s):  
Young Adults ◽  
Cardiovascular Risk ◽  
Association Study ◽  
Genome Wide Association Study ◽  
Genome Wide Association ◽  
Cell Free Dna ◽  
Free Dna ◽  
Genome Wide ◽  
A Genome ◽  
Young Finns Study

scholarly journals 5-Hydroxymethylcytosine Signatures in Circulating Cell-Free DNA as Diagnostic Biomarkers for Late-Onset Alzheimer’s Disease

2021 ◽  
pp. 1-13
Author(s):  
Lei Chen ◽  
Qianqian Shen ◽  
Shunliang Xu ◽  
Hongzhuan Yu ◽  
Shengjie Pei ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Late Onset ◽  
Critical Role ◽  
Cell Free Dna ◽  
Free Dna ◽  
Genome Wide ◽  
A Genome ◽  
Normal Controls ◽  
Circulating Cell Free Dna

Background: 5-Hydroxymethylcytosine (5hmC) is an epigenetic DNA modification that is highly abundant in central nervous system. It has been reported that DNA 5hmC dysregulation play a critical role in Alzheimer’s disease (AD) pathology. Changes in 5hmC signatures can be detected in circulating cell-free DNA (cfDNA), which has shown potential as a non-invasive liquid biopsy material. Objective: However, the genome-wide profiling of 5hmC in cfDNA and its potential for the diagnosis of AD has not been reported to date. Methods: We carried out a case-control study and used a genome-wide chemical capture followed by high-throughput sequencing to detect the genome-wide profiles of 5hmC in human cfDNA and identified differentially hydroxymethylated regions (DhMRs) in late-onset AD patients and the control. Results: We discovered significant differences of 5hmC enrichment in gene bodies which were linked to multiple AD pathogenesis-associated signaling pathways in AD patients compared with cognitively normal controls, indicating they can be well distinguished from normal controls by DhMRs in cfDNA. Specially, we identified 7 distinct genes (RABEP1, CPNE4, DNAJC15, REEP3, ROR1, CAMK1D, and RBFOX1) with predicting diagnostic potential based on their significant correlations with MMSE and MoCA scores of subjects. Conclusion: The present results suggest that 5hmC markers derived from plasma cfDNA can served as an effective, minimally invasive biomarkers for clinical auxiliary diagnosis of late-onset AD.

Changes in DNA hydroxymethylation for the detection of multiple cancers in plasma cell-free DNA.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 3058-3058
Author(s):  
Anna Bergamaschi ◽  
Francois Collins ◽  
Chris Ellison ◽  
Yuhong Ning ◽  
Gulfem Guler ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Tumor Tissue ◽  
Early Stage ◽  
Genomic Feature ◽  
Cell Free Dna ◽  
Early Stage Disease ◽  
Free Dna ◽  
Genome Wide ◽  
Cancer Types

3058 Background: Methylation and hydroxymethylation of cytosines enable the epigenomic regulation of gene suppression and activation. 5-hydroxymethyl-cytosine (5hmC) is globally decreased in tumor tissue. However, genome-wide analysis using precise 5hmC labelling techniques reveals more nuanced changes upon tumorigenesis and raises the possibility that this loss could be exploited for developing a cancer biomarker. This suggests that 5hmC profiles might enable discrete classification of not only tumor tissue but also of tumor cell-free DNA (cfDNA). We sought to identify genome-wide 5hmC changes in plasma based cfDNA from cancer patients representing multiple disease types, stages and clinical characteristics in comparison with non-cancer patients. Methods: cfDNA was isolated from plasma, enriched for the 5hmC fraction using chemical labelling, sequenced, and aligned to the genome to determine 5hmC counts per genomic feature. Regularized regression models were constructed to classify cancer samples (age matched or corrected for smoking status) on non-overlapping training (80% of all samples) and test sample sets (20% of all samples). Results: 226 non-cancer patients and 278 cancers across four cancer types (breast, colorectal, lung-squamous and pancreas) were included in this study, where more than 60% of cancer samples were early stage disease (I or II). Upon comparison with non-cancer samples, 5hmC peaks have reduced enrichment in exons in breast, colorectal and lung cancer but not in pancreatic cancer. Further, 5hmC peaks in pancreas show different patterns of enrichment in 3’UTR, translational termination sites, promoters and LTR. Overall 5hmC signal density was reduced in late stage cancers across all four diseases. The ability to classify non-cancer versus cancer patients was evaluated via cross-validation of out of fold prediction in the training set with AUC > 0.84 for all four cancer types. Further, test set sensitivity across all four cancer types was found to be > 66% with 98% specificity. Conclusions: These findings suggest that 5hmC changes in plasma cfDNA enable classification of early stages of breast, colorectal, lung-squamous and pancreas cancer and are promising biomarkers for disease detection.

scholarly journals Genome-Wide Analysis of Cell-Free DNA Methylation Profiling with MeDIP-Seq Identified Potential Biomarkers for Colorectal Cancer

2021 ◽  
Author(s):  
Xin Zhang ◽  
Tao Li ◽  
Qiang Niu ◽  
Chang Jiang Qin ◽  
Ming Zhang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Dna Methylation ◽  
Cancer Patients ◽  
Cell Free Dna ◽  
Free Dna ◽  
Genome Wide ◽  
A Genome ◽  
Colorectal Cancer Patients ◽  
Methylation Profiling ◽  
Potential Biomarkers

Abstract Background: To verify the feasibility of genome-wide plasma cell-free DNA(cfDNA) methylation profiling for early diagnosis of colorectal cancer.Methods: We performed a genome-wide cfDNA methylation profiling study of colorectal cancer patients by methylated DNA immunoprecipitation coupled with high throughput sequencing (MeDIP-seq).Results: Compared with the control group, 939 differentially methylated regions (DMRs) located in promoter regions were found in colorectal cancer patients, 16 of these DMRs were hypermethylated and the remaining 923 were hypomethylated. In addition, these hypermethylated genes, mainly including PRDM14, RALYL, ELMOD1, and TMEM132E, were validated and confirmed in colorectal cancer by using publicly available DNA methylation data.Conclusions: Our study indicates that MeDIP-seq can be used as an optimal approach for analyzing cfDNA methylomes, and the differentially methylated genes obtained by MeDIP-seq can be used as potential biomarkers for clinical application in patients with colorectal cancer.

scholarly journals Circulating Cell-Free DNA in Liquid Biopsies as Potential Biomarker for Bladder Cancer: A Review

Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1448
Author(s):  
Raquel Herranz ◽  
Julia Oto ◽  
Emma Plana ◽  
Álvaro Fernández-Pardo ◽  
Fernando Cana ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Cancer Progression ◽  
Specific Treatment ◽  
Predictive Biomarkers ◽  
Liquid Biopsies ◽  
Cell Free Dna ◽  
Specific Patient ◽  
Free Dna ◽  
Potential Biomarker ◽  
Cancer Types

Bladder cancer (BC) is among the most frequent cancer types in the world and is the most lethal urological malignancy. Presently, diagnostic and follow-up methods for BC are expensive and invasive. Thus, the identification of novel predictive biomarkers for diagnosis, progression, and prognosis of BC is of paramount importance. To date, several studies have evidenced that cell-free DNA (cfDNA) found in liquid biopsies such as blood and urine may play a role in the particular scenario of urologic tumors, and its analysis may improve BC diagnosis report about cancer progression or even evaluate the effectiveness of a specific treatment or anticipate whether a treatment would be useful for a specific patient depending on the tumor characteristics. In the present review, we have summarized the up-to-date studies evaluating the value of cfDNA as potential diagnostic, prognostic, or monitoring biomarker for BC in several biofluids.

scholarly journals Aging-associated distinctive DNA methylation changes of LINE-1 retrotransposons in pure cell-free DNA from human blood

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Wardah Mahmood ◽  
Lars Erichsen ◽  
Pauline Ott ◽  
Wolfgang A. Schulz ◽  
Johannes C. Fischer ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Cell Free Dna ◽  
The Past ◽  
Free Dna ◽  
Genome Wide ◽  
Cancerous Cell ◽  
Pure Cell ◽  
Epigenetic Biomarker ◽  
Methylation Patterns ◽  
Cancerous Cells

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.

scholarly journals Alterations of 5-hydroxymethylation in circulating cell-free DNA reflect molecular distinctions of subtypes of non-Hodgkin lymphoma

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Brian C.-H. Chiu ◽  
Chang Chen ◽  
Qiancheng You ◽  
Rudyard Chiu ◽  
Girish Venkataraman ◽  
...  
Keyword(s):  
B Cell Lymphoma ◽  
Cell Free Dna ◽  
Invasive Approach ◽  
Non Invasive ◽  
Signature Genes ◽  
Non Hodgkin Lymphoma ◽  
Free Dna ◽  
Genome Wide ◽  
Circulating Cell Free Dna

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.

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