Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 20 de 228
1.
Genome Res ; 34(2): 189-200, 2024 Mar 20.
Article En | MEDLINE | ID: mdl-38408788

Recent studies have revealed an unexplored population of long cell-free DNA (cfDNA) molecules in human plasma using long-read sequencing technologies. However, the biological properties of long cfDNA molecules (>500 bp) remain largely unknown. To this end, we have investigated the origins of long cfDNA molecules from different genomic elements. Analysis of plasma cfDNA using long-read sequencing reveals an uneven distribution of long molecules from across the genome. Long cfDNA molecules show overrepresentation in euchromatic regions of the genome, in sharp contrast to short DNA molecules. We observe a stronger relationship between the abundance of long molecules and mRNA gene expression levels, compared with short molecules (Pearson's r = 0.71 vs. -0.14). Moreover, long and short molecules show distinct fragmentation patterns surrounding CpG sites. Leveraging the cleavage preferences surrounding CpG sites, the combined cleavage ratios of long and short molecules can differentiate patients with hepatocellular carcinoma (HCC) from non-HCC subjects (AUC = 0.87). We also investigated knockout mice in which selected nuclease genes had been inactivated in comparison with wild-type mice. The proportion of long molecules originating from transcription start sites are lower in Dffb-deficient mice but higher in Dnase1l3-deficient mice compared with that of wild-type mice. This work thus provides new insights into the biological properties and potential clinical applications of long cfDNA molecules.


Carcinoma, Hepatocellular , Cell-Free Nucleic Acids , Liver Neoplasms , Humans , Animals , Mice , Cell-Free Nucleic Acids/genetics , Carcinoma, Hepatocellular/genetics , Liver Neoplasms/genetics , DNA/genetics , Genomics , Mice, Knockout , Endodeoxyribonucleases/genetics
2.
J Natl Cancer Inst ; 116(5): 665-672, 2024 May 08.
Article En | MEDLINE | ID: mdl-38171488

BACKGROUND: Although contrast-enhanced magnetic resonance imaging (MRI) detects early-stage nasopharyngeal carcinoma (NPC) not detected by endoscopic-guided biopsy (EGB), a short contrast-free screening MRI would be desirable for NPC screening programs. This study evaluated a screening MRI in a plasma Epstein-Barr virus (EBV)-DNA NPC screening program. METHODS: EBV-DNA-screen-positive patients underwent endoscopy, and endoscopy-positive patients underwent EGB. EGB was negative if the biopsy was negative or was not performed. Patients also underwent a screening MRI. Diagnostic performance was based on histologic confirmation of NPC in the initial study or during a follow-up period of at least 2 years. RESULTS: The study prospectively recruited 354 patients for MRI and endoscopy; 40/354 (11.3%) endoscopy-positive patients underwent EGB. Eighteen had NPC (5.1%), and 336 without NPC (94.9%) were followed up for a median of 44.8 months. MRI detected additional NPCs in 3/18 (16.7%) endoscopy-negative and 2/18 (11.1%) EGB-negative patients (stage I/II, n = 4; stage III, n = 1). None of the 24 EGB-negative patients who were MRI-negative had NPC. MRI missed NPC in 2/18 (11.1%), one of which was also endoscopy-negative. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MRI, endoscopy, and EGB were 88.9%, 91.1%, 34.8%, 99.4%, and 91.0%; 77.8%, 92.3%, 35.0%, 98.7%, and 91.5%; and 66.7%, 92.3%, 31.6%, 98.1%, and 91.0%, respectively. CONCLUSION: A quick contrast-free screening MRI complements endoscopy in NPC screening programs. In EBV-screen-positive patients, MRI enables early detection of NPC that is endoscopically occult or negative on EGB and increases confidence that NPC has not been missed.


Early Detection of Cancer , Epstein-Barr Virus Infections , Herpesvirus 4, Human , Magnetic Resonance Imaging , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms , Humans , Nasopharyngeal Neoplasms/virology , Nasopharyngeal Neoplasms/diagnostic imaging , Nasopharyngeal Neoplasms/diagnosis , Nasopharyngeal Neoplasms/pathology , Male , Middle Aged , Female , Magnetic Resonance Imaging/methods , Early Detection of Cancer/methods , Adult , Herpesvirus 4, Human/isolation & purification , Nasopharyngeal Carcinoma/virology , Nasopharyngeal Carcinoma/diagnostic imaging , Nasopharyngeal Carcinoma/diagnosis , Nasopharyngeal Carcinoma/pathology , Prospective Studies , Aged , Epstein-Barr Virus Infections/complications , Epstein-Barr Virus Infections/diagnosis , DNA, Viral/blood , Carcinoma/diagnostic imaging , Carcinoma/virology , Carcinoma/diagnosis , Carcinoma/pathology , Sensitivity and Specificity , Endoscopy/methods , Neoplasm Staging , Mass Screening/methods , Contrast Media/administration & dosage
6.
J Clin Oncol ; 41(26): 4257-4266, 2023 09 10.
Article En | MEDLINE | ID: mdl-37478397

PURPOSE: Two Epstein-Barr virus (EBV)-based testing approaches have shown promise for early detection of nasopharyngeal carcinoma (NPC). Neither has been independently validated nor their performance compared. We compared their diagnostic performance in an independent population. METHODS: We tested blood samples from 819 incident Taiwanese NPC cases (213 early-stage, American Joint Committee on Cancer version 7 stages I and II) diagnosed from 2010 to 2014 and from 1,768 controls from the same region, frequency matched to cases on age and sex. We compared an EBV antibody score using immunoglobulin A antibodies measured by enzyme-linked immunosorbent assay (EBV antibody score) and plasma EBV DNA load measured by real-time PCR followed by next-generation sequencing (NGS) among EBV DNA-positive individuals (EBV DNA algorithm). RESULTS: EBV antibodies and DNA load were measured for 2,522 (802 cases; 1,720 controls) and 2,542 (797 cases; 1,745 controls) individuals, respectively. Of the 898 individuals positive for plasma EBV DNA and therefore eligible for NGS, we selected 442 (49%) for NGS testing. The EBV antibody score had a sensitivity of 88.4% (95% CI, 86.1 to 90.6) and a specificity of 94.9% (95% CI, 93.8 to 96.0) for NPC. The EBV DNA algorithm yielded significantly higher sensitivity (93.2%; 95% CI, 91.3 to 94.9; P = 1.33 × 10-4) and specificity (98.1%; 95% CI, 97.3 to 98.8; P = 3.53 × 10-7). For early-stage NPC, the sensitivities were 87.1% (95% CI, 82.7 to 92.4) for the EBV antibody score and 87.0% (95% CI, 81.9 to 91.5) for the EBV DNA algorithm (P = .514). For regions with a NPC incidence of 20-100/100,000 person-years (eg, residents in southern China and Hong Kong), these two approaches yielded similar numbers needed to screen (EBV antibody score: 5,656-1,131; EBV DNA algorithm: 5,365-1,073); positive predictive values ranged from 0.4% to 1.7% and 1.0% to 4.7%, respectively. CONCLUSION: We demonstrated high sensitivity and specificity of EBV antibody and plasma EBV DNA for NPC detection, with slightly inferior performance of the EBV antibody score. Cost-effectiveness studies are needed to guide screening implementation.


Epstein-Barr Virus Infections , Nasopharyngeal Neoplasms , Humans , Nasopharyngeal Carcinoma/diagnosis , Herpesvirus 4, Human/genetics , Nasopharyngeal Neoplasms/diagnosis , Feasibility Studies , DNA, Viral/genetics , Antibodies, Viral
7.
Proc Natl Acad Sci U S A ; 120(17): e2220982120, 2023 04 25.
Article En | MEDLINE | ID: mdl-37075072

Cell-free DNA (cfDNA) fragmentation is nonrandom, at least partially mediated by various DNA nucleases, forming characteristic cfDNA end motifs. However, there is a paucity of tools for deciphering the relative contributions of cfDNA cleavage patterns related to underlying fragmentation factors. In this study, through non-negative matrix factorization algorithm, we used 256 5' 4-mer end motifs to identify distinct types of cfDNA cleavage patterns, referred to as "founder" end-motif profiles (F-profiles). F-profiles were associated with different DNA nucleases based on whether such patterns were disrupted in nuclease-knockout mouse models. Contributions of individual F-profiles in a cfDNA sample could be determined by deconvolutional analysis. We analyzed 93 murine cfDNA samples of different nuclease-deficient mice and identified six types of F-profiles. F-profiles I, II, and III were linked to deoxyribonuclease 1 like 3 (DNASE1L3), deoxyribonuclease 1 (DNASE1), and DNA fragmentation factor subunit beta (DFFB), respectively. We revealed that 42.9% of plasma cfDNA molecules were attributed to DNASE1L3-mediated fragmentation, whereas 43.4% of urinary cfDNA molecules involved DNASE1-mediated fragmentation. We further demonstrated that the relative contributions of F-profiles were useful to inform pathological states, such as autoimmune disorders and cancer. Among the six F-profiles, the use of F-profile I could inform the human patients with systemic lupus erythematosus. F-profile VI could be used to detect individuals with hepatocellular carcinoma, with an area under the receiver operating characteristic curve of 0.97. F-profile VI was more prominent in patients with nasopharyngeal carcinoma undergoing chemoradiotherapy. We proposed that this profile might be related to oxidative stress.


Cell-Free Nucleic Acids , Humans , Mice , Animals , Cell-Free Nucleic Acids/genetics , Deoxyribonucleases/genetics , Mice, Knockout , Endonucleases/genetics , DNA Fragmentation , Endodeoxyribonucleases/genetics
8.
J Natl Cancer Inst ; 115(4): 355-364, 2023 04 11.
Article En | MEDLINE | ID: mdl-36723440

A meeting of experts was held in November 2021 to review and discuss available data on performance of Epstein-Barr virus (EBV)-based approaches to screen for early stage nasopharyngeal carcinoma (NPC) and methods for the investigation and management of screen-positive individuals. Serum EBV antibody and plasma EBV DNA testing methods were considered. Both approaches were found to have favorable performance characteristics and to be cost-effective in high-risk populations. In addition to endoscopy, use of magnetic resonance imaging (MRI) to investigate screen-positive individuals was found to increase the sensitivity of NPC detection with minimal impact on cost-effectiveness of the screening program.


Carcinoma , Epstein-Barr Virus Infections , Nasopharyngeal Neoplasms , Humans , Nasopharyngeal Carcinoma/diagnosis , Nasopharyngeal Neoplasms/diagnosis , Herpesvirus 4, Human/genetics , Epstein-Barr Virus Infections/complications , Epstein-Barr Virus Infections/diagnosis , Early Detection of Cancer/methods , DNA, Viral/genetics
9.
Clin Chem ; 69(2): 189-201, 2023 02 01.
Article En | MEDLINE | ID: mdl-36576350

BACKGROUND: Nuclear-derived cell-free DNA (cfDNA) molecules in blood plasma are nonrandomly fragmented, bearing a wealth of information related to tissues of origin. DNASE1L3 (deoxyribonuclease 1 like 3) is an important player in shaping the fragmentation of nuclear-derived cfDNA molecules, preferentially generating molecules with 5 CC dinucleotide termini (i.e., 5 CC-end motif). However, the fragment end properties of microbial cfDNA and its clinical implication remain to be explored. METHODS: We performed end motif analysis on microbial cfDNA fragments in plasma samples from patients with sepsis. A sequence context-based normalization method was used to minimize the potential biases for end motif analysis. RESULTS: The end motif profiles of microbial cfDNA appeared to resemble that of nuclear cfDNA (Spearman correlation coefficient: 0.82, P value 0.001). The CC-end motif was the most preferred end motif in microbial cfDNA, suggesting that DNASE1L3 might also play a role in the fragmentation of microbe-derived cfDNA in plasma. Of note, differential end motifs were present between microbial cfDNA originating from infection-causing pathogens (enriched at the CC-end) and contaminating microbial DNA potentially derived from reagents or the environment (nearly random). The use of fragment end signatures allowed differentiation between confirmed pathogens and contaminating microbes, with an area under the receiver operating characteristic curve of 0.99. The performance appeared to be superior to conventional analysis based on microbial cfDNA abundance alone. CONCLUSIONS: The use of fragmentomic features could facilitate the differentiation of underlying contaminating microbes from true pathogens in sepsis. This work demonstrates the potential usefulness of microbial cfDNA fragmentomics in metagenomics analysis.


Cell-Free Nucleic Acids , Sepsis , Humans , DNA/genetics , Sepsis/diagnosis , DNA Fragmentation
10.
NEJM Evid ; 2(7): EVIDoa2200309, 2023 Jul.
Article En | MEDLINE | ID: mdl-38320164

EBV DNA Rescreening StudyPatients who had participated in a previous plasma Epstein-Barr virus (EBV) DNA screening study were rescreened. Of the 17,838 rescreened patients, 423 had persistently detectable plasma EBV DNA; 24 of these patients developed nasopharyngeal carcinoma. Sixty-seven percent of them received a diagnosis of early-stage disease and had increased progression-free survival compared with historical controls.


Epstein-Barr Virus Infections , Nasopharyngeal Neoplasms , Humans , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms/diagnosis , Herpesvirus 4, Human/genetics , Prognosis , DNA, Viral
11.
Proc Natl Acad Sci U S A ; 119(44): e2209852119, 2022 11.
Article En | MEDLINE | ID: mdl-36288287

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.


Cell-Free Nucleic Acids , Liver Neoplasms , Pregnancy , Female , Humans , Cell-Free Nucleic Acids/genetics , Biomarkers, Tumor/genetics , DNA Methylation , Liver Neoplasms/genetics , Epigenesis, Genetic , DNA/genetics , Cytosine , Guanine , Nucleotides , Phosphates
12.
Front Oncol ; 12: 970242, 2022.
Article En | MEDLINE | ID: mdl-36248993

Advances in Next Generation Sequencing (NGS) technologies have enabled the accurate detection and quantification of circulating tumor-derived (ct)DNA in most gastrointestinal (GI) cancers. The prognostic and predictive utility of ctDNA in patiets with different stages of colorectal (CRC), gastro-esophageal (GEC) and pancreaticobiliary cancers (PBC) are currently under active investigation. The most mature clinical data to date are derived from studies in the prognostic utility of personalized ctDNA-based NGS assays in the detection of minimal residual disease (MRD) and early recurrence after surgery in CRC and other GI cancers. These findings are being validated in several prospective studies which are designed to test if ctDNA could outperform conventional approaches in guiding adjuvant chemotherapy, and in post-operative surveillance in some GI cancers. Several adaptive studies using ctDNA as a screening platform are also being used to identify patients with actionable genomic alterations for clinical trials of targeted therapies. In the palliative setting, ctDNA monitoring during treatment has shown promise in the detection and tracking of clonal variants associated with acquired resistance to targeted therapies and immune-checkpoint inhibitors (ICI). Moreover, ctDNA may help to guide the therapeutic re-challenge of targeted therapies in patients who have prior exposure to such treatment. This review will examine the most updated research findings on ctDNA as a biomarker in CRC, GEC and PBCs. It aims to provide insights into how the unique strengths of this biomarker could be optimally leveraged in improving the management of these GI cancers.

13.
PLoS Genet ; 18(7): e1010262, 2022 07.
Article En | MEDLINE | ID: mdl-35793278

Urinary cell-free DNA (ucfDNA) is a potential biomarker for bladder cancer detection. However, the biological characteristics of ucfDNA are not well understood. We explored the roles of deoxyribonuclease 1 (DNASE1) and deoxyribonuclease 1-like 3 (DNASE1L3) in the fragmentation of ucfDNA using mouse models. The deletion of Dnase1 in mice (Dnase1-/-) caused aberrations in ucfDNA fragmentation, including a 24-fold increase in DNA concentration, and a 3-fold enrichment of long DNA molecules, with a relative decrease of fragments with thymine ends and reduction of jaggedness (i.e., the presence of single-stranded protruding ends). In contrast, such changes were not observed in mice with Dnase1l3 deletion (Dnase1l3-/-). These results suggested that DNASE1 was an important nuclease contributing to the ucfDNA fragmentation. Western blot analysis revealed that the concentration of DNASE1 protein was higher in urine than DNASE1L3. The native-polyacrylamide gel electrophoresis zymogram showed that DNASE1 activity in urine was higher than that in plasma. Furthermore, the proportion of ucfDNA fragment ends within DNase I hypersensitive sites (DHSs) was significantly increased in Dnase1-deficient mice. In humans, patients with bladder cancer had lower proportions of ucfDNA fragment ends within the DHSs when compared with participants without bladder cancer. The area under the curve (AUC) for differentiating patients with and without bladder cancer was 0.83, suggesting the analysis of ucfDNA fragmentation in the DHSs may have potential for bladder cancer detection. This work revealed the intrinsic links between the nucleases in urine and ucfDNA fragmentomics.


Cell-Free Nucleic Acids , Urinary Bladder Neoplasms , Animals , Cell-Free Nucleic Acids/genetics , DNA/genetics , Deoxyribonuclease I/genetics , Deoxyribonuclease I/metabolism , Endodeoxyribonucleases/genetics , Endonucleases , Humans , Mice , Mice, Knockout , Urinary Bladder Neoplasms/genetics
14.
East Asian Arch Psychiatry ; 32(2): 43-44, 2022 Jun.
Article En | MEDLINE | ID: mdl-35732480

We report a case of refractory psychosis after carbon monoxide poisoning in a 65-year-old woman who attempted suicide by charcoal burning in 2018. On discharge from hospital, she was bedbound, tube-fed, and had limited verbal output. In early 2019, she was able to resume oral feeding and her physical condition improved. However, she started to have paranoid ideas and auditory hallucinations. She was diagnosed as having organic brain syndrome and was prescribed with quetiapine 300 mg every night. Because of the poor clinical response, quetiapine was switched to olanzapine 20 mg every night and augmented with amisulpride and valproate sodium. However, she remained distressed, psychotic, and suicidal. She was then prescribed with clozapine 300 mg every night. Her symptoms improved despite residual auditory hallucinations remained, but she was less distressed about them.


Carbon Monoxide Poisoning , Psychotic Disorders , Aged , Carbon Monoxide Poisoning/complications , Female , Hallucinations/etiology , Humans , Olanzapine , Psychotic Disorders/drug therapy , Psychotic Disorders/etiology , Quetiapine Fumarate
15.
Ann Oncol ; 33(8): 794-803, 2022 08.
Article En | MEDLINE | ID: mdl-35491007

BACKGROUND: Quantitative measurement of plasma Epstein-Barr virus (EBV) DNA by real-time PCR at the end of primary treatment is a robust prognostic marker for nasopharyngeal carcinoma (NPC) patients. However, up to 40% of patients who would later develop disease recurrence had undetectable post-treatment plasma EBV DNA. Targeted sequencing for the entire EBV genome potentially allows a more comprehensive and unbiased detection of plasma EBV DNA and enables the use of other parameters such as fragment size as biomarkers. Hence, we explored if plasma EBV DNA sequencing might allow more accurate prognostication of NPC patients. PATIENTS AND METHODS: Plasma samples collected from 769 patients with stage IIB-IVB NPC at 6-8 weeks after radiotherapy were analysed using targeted sequencing for EBV DNA. RESULTS: The sensitivities of the PCR-based analysis, at a cut-off of any detectable levels of plasma EBV DNA, for prediction of local and distant recurrences were 42.3% and 85.3%, respectively. The sequencing-based analysis (involving quantitation and size profiling) achieved better performance for both local and distant recurrences than PCR. Using a cut-off of the proportion of plasma EBV DNA deduced by sequencing at 0.01%, the sensitivities of the sequencing-based analysis for local and distant recurrences were 88.5% and 97.1%, with the resultant negative predictive values of 99.1% and 99.4%, respectively. Among patients with undetectable EBV DNA on quantitative PCR, sequencing could further define a subgroup that enjoyed superior survival outcomes based on the proportion of plasma EBV DNA, with a 5-year progression-free survival (PFS) approaching 90%. On multivariate analysis, sequencing-based quantitative level of plasma EBV DNA was the independent prognostic factor with the highest hazard ratio for prediction of overall survival and PFS. CONCLUSION: NPC prognostication using post-treatment plasma EBV DNA could be enhanced through sequencing.


Epstein-Barr Virus Infections , Nasopharyngeal Neoplasms , DNA, Viral/genetics , Herpesvirus 4, Human/genetics , Humans , Nasopharyngeal Carcinoma/pathology , Nasopharyngeal Carcinoma/therapy , Nasopharyngeal Neoplasms/genetics , Nasopharyngeal Neoplasms/pathology , Nasopharyngeal Neoplasms/therapy , Neoplasm Recurrence, Local/genetics , Prognosis , Real-Time Polymerase Chain Reaction , Risk Assessment
16.
Clin Chem ; 68(9): 1151-1163, 2022 09 01.
Article En | MEDLINE | ID: mdl-35587130

BACKGROUND: Analysis of circulating tumor DNA has become increasingly important as a tool for cancer care. However, the focus of previous studies has been on short fragments of DNA. Also, bisulfite sequencing, a conventional approach for methylation analysis, causes DNA degradation, which is not ideal for the assessment of long DNA properties and methylation patterns. This study attempted to overcome such obstacles by single-molecule sequencing. METHODS: Single-molecule real-time (SMRT) sequencing was used to sequence plasma DNA. We performed fragment size and direct methylation analysis for each molecule. A methylation score concerning single-molecule methylation patterns was used for cancer detection. RESULTS: A substantial proportion of plasma DNA was longer than 1 kb with a median of 16% in hepatocellular carcinoma (HCC) patients, hepatitis B virus carriers, and healthy individuals. The longest plasma DNA molecule in the HCC patients was 39.8 kb. Tumoral cell-free DNA (cfDNA) was generally shorter than nontumoral cfDNA. The longest tumoral cfDNA was 13.6 kb. Tumoral cfDNA had lower methylation levels compared with nontumoral cfDNA (median: 59.3% vs 76.9%). We developed and analyzed a metric reflecting single-molecule methylation patterns associated with cancer, named the HCC methylation score. HCC patients displayed significantly higher HCC methylation scores than those without HCC. Interestingly, compared to using short cfDNA (area under the receiver operating characteristic [ROC] curve, AUC: 0.75), the use of long cfDNA molecules greatly enhanced the discriminatory power (AUC: 0.91). CONCLUSIONS: A previously unidentified long cfDNA population was revealed in cancer patients. The presence and direct methylation analysis of these molecules open new possibilities for cancer liquid biopsy.


Carcinoma, Hepatocellular , Cell-Free Nucleic Acids , Liver Neoplasms , Biomarkers, Tumor , Carcinoma, Hepatocellular/diagnosis , Carcinoma, Hepatocellular/genetics , Cell-Free Nucleic Acids/genetics , DNA , DNA Methylation , Humans , Liver Neoplasms/diagnosis , Liver Neoplasms/genetics
17.
J Gastroenterol Hepatol ; 37(7): 1197-1206, 2022 Jul.
Article En | MEDLINE | ID: mdl-35570200

Systemic treatment for hepatocellular carcinoma (HCC) has been advancing rapidly over the last decade. More novel agents, including both targeted agents and immune checkpoint inhibitors, are available for physicians to use sequentially or concurrently for patients with advanced HCC. Despite more options, only a proportion of patients benefit from each regimen. Therefore, clinicians are facing challenges on how to choose the right regimen for the right patient with HCC, which raises the importance of personalized treatment approach. To advance personalized treatment for HCC, one approach relies on the acquisition of biomarker data from clinical trials to evaluate clinical parameters or genotypes in association with outcomes of selected drugs. This approach has led to finding of high baseline alpha-fetoprotein levels in association with benefits of ramucirumab. Cumulative findings from multiple clinical trials and translational studies also suggest that selected etiology and/or genotype of HCC could predict resistance to immune checkpoint inhibitors. The second approach is to decipher the tumor heterogeneity of HCC with an aim to identify clinically relevant patterns to guide clinical decisions. Tumor heterogeneity could exist within a single tumor (intra-tumoral heterogeneity), among different tumors in the same patient (inter-tumoral heterogeneity) or between primary and recurrent tumors (temporal tumor heterogeneity). The analyses of tumor heterogeneity have also been powered by coverage of tumor immune environment and incorporation of circulating tumor nucleic acid technology. Emerging publications have been reported above tumor heterogeneity exist in HCC, which is potentially clinically impactful.


Carcinoma, Hepatocellular , Liver Neoplasms , Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/genetics , Humans , Immune Checkpoint Inhibitors , Liver Neoplasms/drug therapy , Liver Neoplasms/genetics , Neoplasm Recurrence, Local/pathology , Precision Medicine
18.
NPJ Genom Med ; 7(1): 14, 2022 Feb 23.
Article En | MEDLINE | ID: mdl-35197474

Single-stranded ends of double-stranded DNA (jagged ends) are more abundant in urinary DNA than in plasma DNA. However, the lengths of jagged ends in urinary DNA remained undetermined, as a previous method used for urinary DNA jagged end sequencing analysis (Jag-seq) relied on unmethylation at CpG sites, limiting the resolution. Here, we performed high-resolution Jag-seq analysis using methylation at non-CpG cytosine sites, allowing determination of exact length of jagged ends. The urinary DNA bore longer jagged ends (~26-nt) than plasma DNA (~17-nt). The jagged end length distribution displayed 10-nt periodicities in urinary DNA, which were much less observable in plasma DNA. Amplitude of the 10-nt periodicities increased in patients with renal cell carcinoma. Heparin treatment of urine diminished the 10-nt periodicities. The urinary DNA jagged ends often extended into nucleosomal cores, suggesting potential interactions with histones. This study has thus advanced our knowledge of jagged ends in urine DNA.

19.
Clin Cancer Res ; 27(10): 2827-2836, 2021 05 15.
Article En | MEDLINE | ID: mdl-33692028

PURPOSE: To study the dynamic changes in plasma Epstein-Barr virus (pEBV) DNA after radiotherapy in nasopharyngeal cancer (NPC). EXPERIMENTAL DESIGN: We conducted a randomized controlled trial of adjuvant chemotherapy versus observation in patients with NPC who had detectable pEBV DNA at 6 weeks post-radiotherapy. Randomized patients had a second pEBV DNA checked at 6 months post-randomization. The primary endpoint was progression-free survival (PFS). RESULTS: We prospectively enrolled 789 patients. Baseline post-radiotherapy pEBV DNA was undetectable in 573 (72.6%) patients, and detectable in 216 (27.4%) patients, of whom 104 (13.2%) patients were eligible for randomization to adjuvant chemotherapy (n = 52) versus observation (n = 52). The first post-radiotherapy pEBV DNA had a sensitivity of 0.48, specificity of 0.81, area under receiver-operator characteristics curve (AUC) of 0.65, false positive (FP) rate of 13.8%, and false negative (FN) rate of 14.4% for disease progression. The second post-radiotherapy pEBV DNA had improved sensitivity of 0.81, specificity of 0.75, AUC of 0.78, FP rate of 14.3%, and FN rate of 8.1%. Patients with complete clearance of post-radiotherapy pEBV DNA (51%) had survival superior to that of patients without post-radiotherapy pEBV DNA clearance (5-year PFS, 85.5% vs. 23.3%; HR, 9.6; P < 0.0001), comparable with patients with initially undetectable post-radiotherapy pEBV DNA (5-year PFS, 77.1%), irrespective of adjuvant chemotherapy or observation. CONCLUSIONS: Patients with NPC with detectable post-radiotherapy pEBV DNA who experienced subsequent pEBV DNA clearance had superior survival comparable with patients with initially undetectable post-radiotherapy pEBV DNA. Post-radiotherapy pEBV DNA clearance may serve as an early surrogate endpoint for long-term survival in NPC.


DNA, Viral , Epstein-Barr Virus Infections/complications , Epstein-Barr Virus Infections/virology , Herpesvirus 4, Human/genetics , Nasopharyngeal Neoplasms/diagnosis , Nasopharyngeal Neoplasms/etiology , Viral Load , Biomarkers, Tumor , Chemotherapy, Adjuvant/adverse effects , Chemotherapy, Adjuvant/methods , Combined Modality Therapy/adverse effects , Combined Modality Therapy/methods , DNA, Viral/blood , Disease Management , Disease Progression , Disease Susceptibility , Humans , Nasopharyngeal Neoplasms/mortality , Nasopharyngeal Neoplasms/therapy , Positron Emission Tomography Computed Tomography , Prognosis , Survival Analysis , Viral Load/methods
20.
Clin Chem ; 67(4): 621-630, 2021 03 31.
Article En | MEDLINE | ID: mdl-33604652

BACKGROUND: Double-stranded DNA in plasma is known to carry single-stranded ends, called jagged ends. Plasma DNA jagged ends are biomarkers for pathophysiologic states such as pregnancy and cancer. It remains unknown whether urinary cell-free DNA (cfDNA) molecules have jagged ends. METHODS: Jagged ends of cfDNA were detected by incorporating unmethylated cytosines during a DNA end-repair process, followed by bisulfite sequencing. Incorporation of unmethylated cytosines during the repair of the jagged ends lowered the apparent methylation levels measured by bisulfite sequencing and were used to calculate a jagged end index. This approach is called jagged end analysis by sequencing. RESULTS: The jagged end index of urinary cfDNA was higher than that of plasma DNA. The jagged end index profile of plasma DNA displayed several strongly oscillating major peaks at intervals of approximately 165 bp (i.e., nucleosome size) and weakly oscillating minor peaks with periodicities of approximately 10 bp. In contrast, the urinary DNA jagged end index profile showed weakly oscillating major peaks but strongly oscillating minor peaks. The jagged end index was generally higher in nucleosomal linker DNA regions. Patients with bladder cancer (n = 46) had lower jagged end indexed of urinary DNA than participants without bladder cancer (n = 39). The area under the curve for differentiating between patients with and without bladder cancer was 0.83. CONCLUSIONS: Jagged ends represent a property of urinary cfDNA. The generation of jagged ends might be related to nucleosomal structures, with enrichment in linker DNA regions. Jagged ends of urinary DNA could potentially serve as a new biomarker for bladder cancer detection.


Cell-Free Nucleic Acids , Urinary Bladder Neoplasms , Biomarkers, Tumor/genetics , Cell-Free Nucleic Acids/genetics , DNA/genetics , DNA Methylation , Feasibility Studies , Female , Humans , Nucleosomes , Pregnancy , Sequence Analysis, DNA , Urinary Bladder Neoplasms/diagnosis , Urinary Bladder Neoplasms/genetics
...