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Cheng JC, Swarup N, Morselli M, Huang WL, Aziz M, Caggiano C, Kordi M, Patel A, Chia D, Kim Y, Li F, Wei F, Zaitlen N, Krysan K, Dubinett S, Pellegrini M, Wong DW. Single-stranded pre-methylated 5mC adapters uncover the methylation profile of plasma ultrashort Single-stranded cell-free DNA. Nucleic Acids Res 2024; 52:e50. [PMID: 38797520 PMCID: PMC11194076 DOI: 10.1093/nar/gkae276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 03/21/2024] [Accepted: 04/15/2024] [Indexed: 05/29/2024] Open
Abstract
Whole-genome bisulfite sequencing (BS-Seq) measures cytosine methylation changes at single-base resolution and can be used to profile cell-free DNA (cfDNA). In plasma, ultrashort single-stranded cfDNA (uscfDNA, ∼50 nt) has been identified together with 167 bp double-stranded mononucleosomal cell-free DNA (mncfDNA). However, the methylation profile of uscfDNA has not been described. Conventional BS-Seq workflows may not be helpful because bisulfite conversion degrades larger DNA into smaller fragments, leading to erroneous categorization as uscfDNA. We describe the '5mCAdpBS-Seq' workflow in which pre-methylated 5mC (5-methylcytosine) single-stranded adapters are ligated to heat-denatured cfDNA before bisulfite conversion. This method retains only DNA fragments that are unaltered by bisulfite treatment, resulting in less biased uscfDNA methylation analysis. Using 5mCAdpBS-Seq, uscfDNA had lower levels of DNA methylation (∼15%) compared to mncfDNA and was enriched in promoters and CpG islands. Hypomethylated uscfDNA fragments were enriched in upstream transcription start sites (TSSs), and the intensity of enrichment was correlated with expressed genes of hemopoietic cells. Using tissue-of-origin deconvolution, we inferred that uscfDNA is derived primarily from eosinophils, neutrophils, and monocytes. As proof-of-principle, we show that characteristics of the methylation profile of uscfDNA can distinguish non-small cell lung carcinoma from non-cancer samples. The 5mCAdpBS-Seq workflow is recommended for any cfDNA methylation-based investigations.
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Affiliation(s)
- Jordan C Cheng
- School of Dentistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Neeti Swarup
- School of Dentistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Marco Morselli
- Department of Molecular, Cell, and Developmental Biology, Life Sciences Division, University of California, Los Angeles, Los Angeles, CA 90095, USA
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Wei-Lun Huang
- Center of Applied Nanomedicine, National Cheng Kung University, Tainan, Taiwan
| | - Mohammad Aziz
- School of Dentistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Christa Caggiano
- Department of Computational Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Misagh Kordi
- School of Dentistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Abhijit A Patel
- Department of Therapeutic Radiology, Yale University, New Haven, CT, USA
| | - David Chia
- Department of Pathology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Yong Kim
- School of Dentistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Feng Li
- School of Dentistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Fang Wei
- School of Dentistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Noah Zaitlen
- Department of Computational Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Kostyantyn Krysan
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Steve Dubinett
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Matteo Pellegrini
- Department of Molecular, Cell, and Developmental Biology, Life Sciences Division, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - David T W Wong
- School of Dentistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
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Linscott JA, Miyagi H, Murthy PB, Yao S, Grass GD, Vosoughi A, Xu H, Wang X, Yu X, Yu A, Zemp L, Gilbert SM, Poch MA, Sexton WJ, Spiess PE, Li R. From Detection to Cure - Emerging Roles for Urinary Tumor DNA (utDNA) in Bladder Cancer. Curr Oncol Rep 2024:10.1007/s11912-024-01555-0. [PMID: 38837106 DOI: 10.1007/s11912-024-01555-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2024] [Indexed: 06/06/2024]
Abstract
PURPOSE OF REVIEW This review sought to define the emerging roles of urinary tumor DNA (utDNA) for diagnosis, monitoring, and treatment of bladder cancer. Building from early landmark studies the focus is on recent studies, highlighting how utDNA could aid personalized care. RECENT FINDINGS Recent research underscores the potential for utDNA to be the premiere biomarker in bladder cancer due to the constant interface between urine and tumor. Many studies find utDNA to be more informative than other biomarkers in bladder cancer, especially in early stages of disease. Points of emphasis include superior sensitivity over traditional urine cytology, broad genomic and epigenetic insights, and the potential for non-invasive, real-time analysis of tumor biology. utDNA shows promise for improving all phases of bladder cancer care, paving the way for personalized treatment strategies. Building from current research, future comprehensive clinical trials will validate utDNA's clinical utility, potentially revolutionizing bladder cancer management.
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Affiliation(s)
- Joshua A Linscott
- Department of Genitourinary Oncology, Moffitt Cancer Center and Research Institute, Tampa, FL, USA.
| | - Hiroko Miyagi
- Department of Genitourinary Oncology, Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Prithvi B Murthy
- Department of Genitourinary Oncology, Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Sijie Yao
- Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - G Daniel Grass
- Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Aram Vosoughi
- Department of Pathology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Hongzhi Xu
- Department of Pathology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Xuefeng Wang
- Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Xiaoqing Yu
- Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Alice Yu
- Department of Genitourinary Oncology, Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Logan Zemp
- Department of Genitourinary Oncology, Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Scott M Gilbert
- Department of Genitourinary Oncology, Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Michael A Poch
- Department of Genitourinary Oncology, Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Wade J Sexton
- Department of Genitourinary Oncology, Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Philippe E Spiess
- Department of Genitourinary Oncology, Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Roger Li
- Department of Genitourinary Oncology, Moffitt Cancer Center and Research Institute, Tampa, FL, USA
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Wever BMM, Schaafsma M, Bleeker MCG, van den Burgt Y, van den Helder R, Lok CAR, Dijk F, van der Pol Y, Mouliere F, Moldovan N, van Trommel NE, Steenbergen RDM. Molecular analysis for ovarian cancer detection in patient-friendly samples. COMMUNICATIONS MEDICINE 2024; 4:88. [PMID: 38755429 PMCID: PMC11099128 DOI: 10.1038/s43856-024-00517-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 05/03/2024] [Indexed: 05/18/2024] Open
Abstract
BACKGROUND High ovarian cancer mortality rates motivate the development of effective and patient-friendly diagnostics. Here, we explored the potential of molecular testing in patient-friendly samples for ovarian cancer detection. METHODS Home-collected urine, cervicovaginal self-samples, and clinician-taken cervical scrapes were prospectively collected from 54 patients diagnosed with a highly suspicious ovarian mass (benign n = 25, malignant n = 29). All samples were tested for nine methylation markers, using quantitative methylation-specific PCRs that were verified on ovarian tissue samples, and compared to non-paired patient-friendly samples of 110 age-matched healthy controls. Copy number analysis was performed on a subset of urine samples of ovarian cancer patients by shallow whole-genome sequencing. RESULTS Three methylation markers are significantly elevated in full void urine of ovarian cancer patients as compared to healthy controls (C2CD4D, P = 0.008; CDO1, P = 0.022; MAL, P = 0.008), of which two are also discriminatory in cervical scrapes (C2CD4D, P = 0.001; CDO1, P = 0.004). When comparing benign and malignant ovarian masses, GHSR shows significantly elevated methylation levels in the urine sediment of ovarian cancer patients (P = 0.024). Other methylation markers demonstrate comparably high methylation levels in benign and malignant ovarian masses. Cervicovaginal self-samples show no elevated methylation levels in patients with ovarian masses as compared to healthy controls. Copy number changes are identified in 4 out of 23 urine samples of ovarian cancer patients. CONCLUSIONS Our study reveals increased methylation levels of ovarian cancer-associated genes and copy number aberrations in the urine of ovarian cancer patients. Our findings support continued research into urine biomarkers for ovarian cancer detection and highlight the importance of including benign ovarian masses in future studies to develop a clinically useful test.
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Affiliation(s)
- Birgit M M Wever
- Amsterdam UMC, location Vrije Universiteit Amsterdam, Department of Pathology, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
| | - Mirte Schaafsma
- Amsterdam UMC, location Vrije Universiteit Amsterdam, Department of Pathology, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
- Antoni van Leeuwenhoek/Netherlands Cancer Institute, Department of Gynecologic Oncology, Center of Gynecologic Oncology Amsterdam, Amsterdam, The Netherlands
| | - Maaike C G Bleeker
- Amsterdam UMC, location Vrije Universiteit Amsterdam, Department of Pathology, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
| | - Yara van den Burgt
- Amsterdam UMC, location Vrije Universiteit Amsterdam, Department of Pathology, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
| | - Rianne van den Helder
- Amsterdam UMC, location Vrije Universiteit Amsterdam, Department of Pathology, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
- Antoni van Leeuwenhoek/Netherlands Cancer Institute, Department of Gynecologic Oncology, Center of Gynecologic Oncology Amsterdam, Amsterdam, The Netherlands
| | - Christianne A R Lok
- Antoni van Leeuwenhoek/Netherlands Cancer Institute, Department of Gynecologic Oncology, Center of Gynecologic Oncology Amsterdam, Amsterdam, The Netherlands
| | - Frederike Dijk
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
- Amsterdam UMC, location University of Amsterdam, Department of Pathology, Amsterdam, The Netherlands
| | - Ymke van der Pol
- Amsterdam UMC, location Vrije Universiteit Amsterdam, Department of Pathology, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
| | - Florent Mouliere
- Amsterdam UMC, location Vrije Universiteit Amsterdam, Department of Pathology, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
| | - Norbert Moldovan
- Amsterdam UMC, location Vrije Universiteit Amsterdam, Department of Pathology, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands
| | - Nienke E van Trommel
- Antoni van Leeuwenhoek/Netherlands Cancer Institute, Department of Gynecologic Oncology, Center of Gynecologic Oncology Amsterdam, Amsterdam, The Netherlands
| | - Renske D M Steenbergen
- Amsterdam UMC, location Vrije Universiteit Amsterdam, Department of Pathology, Amsterdam, The Netherlands.
- Cancer Center Amsterdam, Imaging and Biomarkers, Amsterdam, The Netherlands.
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Eletr LF, Ibnouf SH, Salih TA, Ibrahim HI, Mustafa MI, Alhashmi NA, Alfaki M. Comprehensive Analysis Reveals Deoxyribonuclease 1 as a Potential Prognostic and Diagnostic Biomarker in Human Cancers. Cureus 2024; 16:e56171. [PMID: 38618458 PMCID: PMC11015913 DOI: 10.7759/cureus.56171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/14/2024] [Indexed: 04/16/2024] Open
Abstract
BACKGROUND Deoxyribonuclease 1 (DNASE1) is an important gene associated with several cancers, including liver, bladder, and gastric cancer. It has been linked to autoimmune illnesses, including systemic lupus erythematosus, which may lead to cancer formation. However, the role of DNASE1 in cancer has not been studied. MATERIALS AND METHODS We performed a pan-cancer analysis using bioinformatics tools, including Tumor Immune Estimation Resource (TIMER), Gene Expression Profiling Interactive Analysis (GEPIA), and University of Alabama at Birmingham Cancer Data Analysis Portal (UALCAN) databases, Kaplan-Meier plotter, and cBioPortal, to investigate the expression of DNASE1 across various cancers as well as its association with immune infiltration and genetic alterations. Public datasets were used to validate DNASE1 expression in kidney renal clear cell carcinoma (KIRC) and kidney papillary renal cell carcinoma (KIRP) samples. RESULTS DNASE1 was found to be highly expressed in many cancers, such as bladder urothelial carcinoma (BLCA), breast invasive carcinoma (BRCA), head and neck squamous cell carcinoma (HNSC), and was lowly expressed in other cancers, including KIRC, KIRP, and thyroid carcinoma (THCA). Additionally, TIMER results showed an association of DNASE1 with immune cell infiltration in KIRC and KIRP. Survival analysis indicated that high DNASE1 expression was associated with poor prognosis in KIRC. We also discovered that altered DNASE1 expression was related to poor prognosis in The Cancer Genome Atlas (TCGA) tumors. CONCLUSION DNASE1 could potentially be used as a prognostic and diagnostic biomarker for KIRC and as a diagnostic biomarker for KIRP.
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Affiliation(s)
- Loai F Eletr
- Computing and Bioinformatics, Faculty of Science, Port Said University, Port Said, EGY
| | | | | | - Hadba I Ibrahim
- Zoology, Faculty of Science, University of Khartoum, Khartoum, SDN
| | - Mustafa I Mustafa
- Internal Medicine, Sudan Medical Specialization Board, Khartoum, SDN
- Clinical Immunology, Sudan Medical Specialization Board, Khartoum, SDN
- Neurology, King Abdulaziz Medical City Jeddah, Jeddah, SAU
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5
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Kim J, Hong SP, Lee S, Lee W, Lee D, Kim R, Park YJ, Moon S, Park K, Cha B, Kim JI. Multidimensional fragmentomic profiling of cell-free DNA released from patient-derived organoids. Hum Genomics 2023; 17:96. [PMID: 37898819 PMCID: PMC10613368 DOI: 10.1186/s40246-023-00533-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 09/11/2023] [Indexed: 10/30/2023] Open
Abstract
BACKGROUND Fragmentomics, the investigation of fragmentation patterns of cell-free DNA (cfDNA), has emerged as a promising strategy for the early detection of multiple cancers in the field of liquid biopsy. However, the clinical application of this approach has been hindered by a limited understanding of cfDNA biology. Furthermore, the prevalence of hematopoietic cell-derived cfDNA in plasma complicates the in vivo investigation of tissue-specific cfDNA other than that of hematopoietic origin. While conventional two-dimensional cell lines have contributed to research on cfDNA biology, their limited representation of in vivo tissue contexts underscores the need for more robust models. In this study, we propose three-dimensional organoids as a novel in vitro model for studying cfDNA biology, focusing on multifaceted fragmentomic analyses. RESULTS We established nine patient-derived organoid lines from normal lung airway, normal gastric, and gastric cancer tissues. We then extracted cfDNA from the culture medium of these organoids in both proliferative and apoptotic states. Using whole-genome sequencing data from cfDNA, we analyzed various fragmentomic features, including fragment size, footprints, end motifs, and repeat types at the end. The distribution of cfDNA fragment sizes in organoids, especially in apoptosis samples, was similar to that found in plasma, implying occupancy by mononucleosomes. The footprints determined by sequencing depth exhibited distinct patterns depending on fragment sizes, reflecting occupancy by a variety of DNA-binding proteins. Notably, we discovered that short fragments (< 118 bp) were exclusively enriched in the proliferative state and exhibited distinct fragmentomic profiles, characterized by 3 bp palindromic end motifs and specific repeats. CONCLUSIONS In conclusion, our results highlight the utility of in vitro organoid models as a valuable tool for studying cfDNA biology and its associated fragmentation patterns. This, in turn, will pave the way for further enhancements in noninvasive cancer detection methodologies based on fragmentomics.
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Affiliation(s)
- Jaeryuk Kim
- Genomic Medicine Institute, Medical Research Center, Seoul National University, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, Republic of Korea
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Seung-Pyo Hong
- Genomic Medicine Institute, Medical Research Center, Seoul National University, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, Republic of Korea
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Seyoon Lee
- Genomic Medicine Institute, Medical Research Center, Seoul National University, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, Republic of Korea
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Woochan Lee
- Genomic Medicine Institute, Medical Research Center, Seoul National University, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, Republic of Korea
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Dakyung Lee
- Genomic Medicine Institute, Medical Research Center, Seoul National University, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, Republic of Korea
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Rokhyun Kim
- Genomic Medicine Institute, Medical Research Center, Seoul National University, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, Republic of Korea
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Young Jun Park
- Genomic Medicine Institute, Medical Research Center, Seoul National University, Seoul, Republic of Korea
- Department of Translational Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Sungji Moon
- Genomic Medicine Institute, Medical Research Center, Seoul National University, Seoul, Republic of Korea
- Interdisciplinary Program in Cancer Biology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Kyunghyuk Park
- Genomic Medicine Institute, Medical Research Center, Seoul National University, Seoul, Republic of Korea
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Bukyoung Cha
- Genomic Medicine Institute, Medical Research Center, Seoul National University, Seoul, Republic of Korea
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jong-Il Kim
- Genomic Medicine Institute, Medical Research Center, Seoul National University, Seoul, Republic of Korea.
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, Republic of Korea.
- Department of Translational Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
- Interdisciplinary Program in Cancer Biology, Seoul National University College of Medicine, Seoul, Republic of Korea.
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Republic of Korea.
- Cancer Research Institute, Seoul National University, Seoul, Republic of Korea.
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Janovičová Ľ, Kmeťová K, Tóthová Ľ, Vlková B, Celec P. DNA in fresh urine supernatant is not affected by additional centrifugation and is protected against deoxyribonuclease. Mol Cell Probes 2023; 68:101900. [PMID: 36764623 DOI: 10.1016/j.mcp.2023.101900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 01/20/2023] [Accepted: 02/07/2023] [Indexed: 02/12/2023]
Abstract
Urinary DNA is widely studied as a non-invasive marker for monitoring of kidneys after transplantation or the progression of urinary tract tumors. The quantity of urinary DNA especially of mitochondrial origin has been reported to mirror kidney damage in various renal diseases and their models. Processing of samples might affect urinary DNA concentrations but the details are not clear. Samples of urine were collected from fifteen healthy volunteers. DNA was extracted from the whole urine, but also from the supernatant after centrifugation at 1600 g and 16000 g. In addition, we have analyzed the DNA in the microparticles in the pellet after the last spin. DNA was measured using fluorometry and real time PCR targeting nuclear and mitochondrial sequences. Addition of deoxyribonuclease to aliquots of samples enabled the characterization of DNA protection. Centrifugation at 1600 g decreased the concentration of extracted DNA by 66% at least in samples with higher DNA in whole urine. Interestingly, the additional spin at 16000 g did not result in a significant decrease in DNA concentration in the supernatant despite detectable microparticle-associated DNA. Deoxyribonuclease decreases total and nuclear DNA by 26% and 31% in whole urine. The majority of urinary mitochondrial DNA seems to be protected against deoxyribonuclease. Our results indicate high variability in urinary DNA even in healthy probands. Extracellular urinary DNA is partially bound to cell debris or microparticles, but a considerable part is still in the supernatant and is protected against cleavage. Further research should identify the nature of the protection, especially for mitochondrial DNA. Better understanding of the biology of urinary DNA should help its clinical interpretation.
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Affiliation(s)
- Ľubica Janovičová
- Institute of Molecular Biomedicine, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Katarína Kmeťová
- Institute of Molecular Biomedicine, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Ľubomíra Tóthová
- Institute of Molecular Biomedicine, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Barbora Vlková
- Institute of Molecular Biomedicine, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Peter Celec
- Institute of Molecular Biomedicine, Faculty of Medicine, Comenius University, Bratislava, Slovakia; Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia.
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Abstract
Cell-free DNA (cfDNA) is nonrandomly fragmented and contains a wealth of molecular information useful for noninvasive prenatal testing and cancer detection. cfDNA fragmentomics contains information beyond genetics, such as gene expression inference. However, the feasibility of using cfDNA fragmentomics for deducing cfDNA methylomics remains unexplored. This study demonstrated the possibility of using cfDNA fragmentation patterns to deduce the methylation patterns of cfDNA molecules, breaking free from the limitation of bisulfite sequencing. By using cfDNA cleavage profiles surrounding a cytosine-phosphate-guanine (CpG) site, we determined the methylation status ranging from a particular region down to a single CpG assisted by a deep learning algorithm. Both genetic and epigenetic information of cfDNA can therefore be obtained in a single nondestructive assay. Cell-free DNA (cfDNA) fragmentation patterns contain important molecular information linked to tissues of origin. We explored the possibility of using fragmentation patterns to predict cytosine-phosphate-guanine (CpG) methylation of cfDNA, obviating the use of bisulfite treatment and associated risks of DNA degradation. This study investigated the cfDNA cleavage profile surrounding a CpG (i.e., within an 11-nucleotide [nt] window) to analyze cfDNA methylation. The cfDNA cleavage proportion across positions within the window appeared nonrandom and exhibited correlation with methylation status. The mean cleavage proportion was ∼twofold higher at the cytosine of methylated CpGs than unmethylated ones in healthy controls. In contrast, the mean cleavage proportion rapidly decreased at the 1-nt position immediately preceding methylated CpGs. Such differential cleavages resulted in a characteristic change in relative presentations of CGN and NCG motifs at 5′ ends, where N represented any nucleotide. CGN/NCG motif ratios were correlated with methylation levels at tissue-specific methylated CpGs (e.g., placenta or liver) (Pearson’s absolute r > 0.86). cfDNA cleavage profiles were thus informative for cfDNA methylation and tissue-of-origin analyses. Using CG-containing end motifs, we achieved an area under a receiver operating characteristic curve (AUC) of 0.98 in differentiating patients with and without hepatocellular carcinoma and enhanced the positive predictive value of nasopharyngeal carcinoma screening (from 19.6 to 26.8%). Furthermore, we elucidated the feasibility of using cfDNA cleavage patterns to deduce CpG methylation at single CpG resolution using a deep learning algorithm and achieved an AUC of 0.93. FRAGmentomics-based Methylation Analysis (FRAGMA) presents many possibilities for noninvasive prenatal, cancer, and organ transplantation assessment.
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