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  • 1
    In: Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 41, No. 16_suppl ( 2023-06-01), p. 4069-4069
    Abstract: 4069 Background: Esophageal and gastric cancer (EC and GC) are two common cancer types that severely impact patients’ health. The 5-year survival rate for EC and GC is as low as 19% and 31%, respectively. However, early detection will significantly increase the survival rate: stage-1 EC has a 5-year survival rate of 51%, while for stage-1 GC it’s 69%. Invasive screening methods, such as endoscopy and biopsy, caused low compliance. Computational tomography and carcinoembryonic antigen were limited by low sensitivity. To address this problem, we developed GaEsSeer, a non-invasive targeted-sequencing-based assay that utilizes multiple methylation and fragmentomics features of cell-free DNA (cfDNA) to accurately detect EC and GC signals in blood. Methods: cfDNA was tested using the GaEsSeer panel, which was developed using in-house genome-wide sequencing data on EC and GC samples, and public datasets from databases and literature. Methylation features, which was quantified as methylation haplotypes or methylation encoding score, and fragmentomics features including copy number and end motif ratio were taken for modeling. Separate sub-models were trained utilizing each type of feature, which were eventually combined via logistic regression to establish the final predicting model. Results: A total of 1770 participants were recruited from multiple centers. This included 787 healthy individuals, 448 cancers (209 EC, 239 GC; stage I:156, -II:120, -III:78, and -IV:58), 174 benign esophageal diseases, and 361 benign gastric diseases. For cancer detection, the methylation-only model had an AUC of 0.909 and 0.897 in training (618 total) and test sets (617 total), respectively; while the AUC of the fragmentomics-based model was 0.885 and 0.911, respectively. The combinatorial model further improved performances, which achieves an AUC of 0.940 and 0.931 in the training and test cohorts, respectively. While the specificity remained at 96.7%, GaEsSeer detected 81.1% EC and 70.3% GC cases in the test cohort. It had a sensitivity of 74.2% and 48.9% for stage-I EC and GC, respectively. GaEsSeer also has high specificities of 87.9% and 89.8% for benign esophageal and gastric diseases, respectively. Additionally, the performance of GaEsSeer was compared with known serum cancer markers such as CEA, CA19-9, and CA72-4; and the results show that it had significantly higher sensitivity than any of these serum markers (54.8% vs 6.4% when against CEA; 53.5% vs 7.1% when against CA19-9; 50% and 16.7% when against CA72-4). Conclusions: In this pilot study, we developed the blood-based GaEsSeer assay and a model for EC and GC detection with high accuracy by stacking multiple methylation- and fragmentomics-based submodules together. Further optimization and validation of GaEsSeer using larger prospective cohorts are needed to validate its potentials for clinical application.
    Type of Medium: Online Resource
    ISSN: 0732-183X , 1527-7755
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Clinical Oncology (ASCO)
    Publication Date: 2023
    detail.hit.zdb_id: 2005181-5
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  • 2
    In: Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 41, No. 16_suppl ( 2023-06-01), p. 4128-4128
    Abstract: 4128 Background: Hepatocellular carcinoma (HCC) is one of the most common cancers in China, and one of the leading causes of cancer-related deaths in the country. With a 5-year survival rate of only 15-20%, early detection is crucial to improve the treatment and survival of HCC patients. Currently, alpha-fetoprotein (AFP) is commonly used as a serum marker for HCC, but it is not a sufficiently specific and can cause false positive readings due to elevated levels caused by other liver conditions. An alternative method is to use circulating free DNA (cfDNA) released by tumor cells as cancer-screening targets, which has been shown to be a more sensitive and specific biomarkers for HCC detection. This study aims to develop a non-invasive screening assay based on cfDNA features to improve the detection of early-stage HCC. Methods: Candidate methylation markers for HCC detection were collected and evaluated using GEO, TCGA and in-house datasets, 1601 of which were incorporated into a targeted sequencing panel named HcSeer. Multiple types of cfDNA features were constructed from the sequencing data, which included methylation-related features such as methylation haplotype blocks (MHBs) and methylated haplotype fraction (MHF), and fragmentomics features such as end motif and CNV. For model building, Cancer and healthy plasma samples were randomly divided into a training and a testing set at a 2:1 ratio. A two-step deep neural network model was built to classify HCC using selected features of both types. Results: We previously enrolled a total of 401 plasma samples (200 healthy, 201 HCC) for model construction and the performance of the HcSeer model have been documented. An independent validation cohort of 421 plasma samples (280 healthy, 141 HCC) was currently collected from different centers. In this independent validation, the HcSeer model achieved an AUC of 0.98 with a sensitivity of 96.5% at a specificity of 96.4%. Importantly, HcSeer maintained a high sensitivity for HCC across all stages: 94.3%, 96%, 100% and 100% for stage I – IV cases, respectively. When compared to AFP, HcSeer achieved a significantly higher sensitivity of 94% than AFP’s 55% in 137 HCC cases having AFP level tested. When AFP level was combined with the HcSeer model, the sensitivity for HCC further increased to 96%. Conclusions: This study demonstrated that the DNA methylation and fragmentomics patterns of cfDNA can accurately distinguish HCC and healthy plasma samples, particularly in the early stages of HCC. The combination of the HcSeer and AFP further improved the accuracy of the prediction. Although this study was limited in sample size, it clearly showed the potential of the HcSeer assay for accurate HCC detection in blood.
    Type of Medium: Online Resource
    ISSN: 0732-183X , 1527-7755
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Clinical Oncology (ASCO)
    Publication Date: 2023
    detail.hit.zdb_id: 2005181-5
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  • 3
    In: Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 41, No. 16_suppl ( 2023-06-01), p. 4169-4169
    Abstract: 4169 Background: Five major gastrointestinal (GI) cancers - colorectal (CRC), gastric (GC), liver (LC), esophageal (EC), and pancreatic cancer (PC) - are responsible for hundreds of thousands of mortalities annually worldwide. Unfortunately, there is a lack of cost-effective, blood-based screening method for their early detection. To address this issue, we aimed to develop GutSeer, a noninvasive, targeted methylation sequencing-based test by leveraging methylation and fragmentomic signatures carried by cell-free DNA (cfDNA). Methods: The panel of GutSeer consists of 1656 target regions which were either differentially methylated between healthy and cancer samples, or distinctively methylated in a specific GI cancer. Cancer and healthy participants were recruited and randomly divided into a training and a validation cohort. Their plasma DNA samples were analyzed to generate DNA methylation and fragmentomic features. These multi-dimensional features were integrated to build ensemble stacked machine learning models to differentiate cancer against healthy, and to determine the tissue-of-origin (TOO) of the cancer. Results: A total of 1844 cases (787 healthy, 342 LC, 239 GC, 209 EC, 180 CRC, and 87 PC cases) were recruited for this study. A cancer- vs-healthy model achieved an AUC of 0.94 and 0.95 (sensitivity of 77.7% and 77.1% under the specificity around 96%) using either methylation or fragmentomic features only, respectively. Combining both methylation and fragmentomic features further improved performances, achieving an AUC of 0.96 (sensitivity = 86.2% at a specificity of 96.7%). For individual type of cancer, GutSeer has a sensitivity of 93.3% for CRC, 81.1% for EC, 70.3% for GC, 96.5% for LC, and 86.4% for PC. An independent test using 629 benign cases as controls achieved a specificity of 87.1%. A separate TOO model was built using all features and achieved an overall accuracy of 82% for all cancer cases (66.7% for CRC, 87.0% for GC and EC combined, 89.0% for LC, and 63.2% for PC). Same as the cancer detection model, using multi-dimensional features in TOO prediction yielded higher accuracy than when models using only methylation or fragmentomics features (accuracy = 75.6% or 75.4%, respectively). When compared with whole-genome sequencing (WGS) based approaches, GutSeer showed a comparable performance in cancer detection but a higher accuracy in TOO identification, further confirming its effectiveness for detection of GI cancers. Conclusions: GutSeer, a non-invasive test integrating multi-dimensional features, was demonstrated to detect and localize the 5 main types of GI cancer with high accuracy. Our results further showed that a reasonably sized panel can perform comparably or even better than WGS-based methods in cancer detection and TOO localization, indicating GutSeer may be a low-cost solution for blood-based early screening for GI cancers.
    Type of Medium: Online Resource
    ISSN: 0732-183X , 1527-7755
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Clinical Oncology (ASCO)
    Publication Date: 2023
    detail.hit.zdb_id: 2005181-5
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  • 4
    Online Resource
    Online Resource
    American Society of Clinical Oncology (ASCO) ; 2023
    In:  Journal of Clinical Oncology Vol. 41, No. 16_suppl ( 2023-06-01), p. e16338-e16338
    In: Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 41, No. 16_suppl ( 2023-06-01), p. e16338-e16338
    Abstract: e16338 Background: Many cancers are symptoms free in early clinical stages, resulting in nearly half of cancer patients diagnosed in advanced-stages when therapeutic options are limited. Early cancer detection is key to improve clinical outcomes. We developed PanSeer7, a multi-cancer detection assay based on targeted bisulfite sequencing of circulating cell-free DNA (cfDNA) and evaluated its technical performances of reproducibility and sensitivity. Methods: The panel of PanSeer7 consists of 2447 markers which were either differentially methylated between healthy and cancer samples, or distinctively methylated in a specific cancer. We assessed PanSeer7’s reproducibility by using it to sequence technical replicates of cfDNA samples. For its limit of detection (LOD), we prepared samples mimicking cancer plasma DNA by diluting fragmented cancer cell line DNA, which represent 7 common cancer types, into GM12878 control at ratios of 1/10,000 to 1/100. We further tested PanSeer7’s ability to identify tissue of origin (TOO) by analyzing DNA samples from formalin-fixed paraffin-embedded (FFPE) tissues and healthy plasma. Results: We analyzed PanSeer7’s reproducibility by sequencing 40 replicates of synthetic healthy cfDNA samples on four independent batches and with different inputs (from 2ng to 20ng). Results show that at a minimum of 10ng input, PanSeer7 produced highly consistent methylation levels among replicates. As to cancer signal detection, we found that PanSeer7’s technical LOD was 1/10,000 for lung cancer cell line H1650, liver cancer line HepG2, gastric cancer line HGC27, esophageal cancer line KYSE150 and colorectal cancer line SW480; it was slightly lower as 5/10,000 for pancreatic cancer line PANC1 and breast cancer line MDA-MB-231. To evaluate PanSeer7’s accuracy of TOO identification, we sequenced 38 healthy plasma and 121 FFPE tissues (17 of liver cancer, 13 of pancreatic cancer, 21 of gastric cancer, 18 of esophageal cancer, 16 of colorectal cancer, 14 of lung cancer, and 22 of breast cancer). Clustering analysis showed that they were segregated according to their TOO based on methylation levels. We also generated 3500 sets of simulated data by mixing the reads of cancer tissue into those of healthy plasma at ratios of 1/10,000 to 1/100, and trained TOO-predicting models with train data sets. At a ratio of 5/10,000, the model predicted TOO of test data sets with an accuracy of over 95%. Conclusions: PanSeer7 required as low as 10ng input DNA for high reproducibility. Its technical LOD in detecting cancer signal was no lower than 5/10,000 for all 7 cancer cell lines tested, and has an in silico TOO detection LOD of 5/10,000. Thus, PanSeer7 had excellent performances in both cancer signal detection and TOO identification, showing promise to be clinically applied for non-invasive multi-cancer detection after future optimization and validation.
    Type of Medium: Online Resource
    ISSN: 0732-183X , 1527-7755
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Clinical Oncology (ASCO)
    Publication Date: 2023
    detail.hit.zdb_id: 2005181-5
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  • 5
    Online Resource
    Online Resource
    Wiley ; 2013
    In:  Journal of Systematics and Evolution Vol. 51, No. 3 ( 2013-05), p. 365-369
    In: Journal of Systematics and Evolution, Wiley, Vol. 51, No. 3 ( 2013-05), p. 365-369
    Abstract: Recently, several statistical methods have been independently proposed for estimating the degree ( n ) of gene pleiotropy (i.e. the capacity of a gene to affect many phenotypes) without knowing measurable phenotypic traits. However, the theoretical limitation of these approaches has not been well demonstrated. In this short note, we show that our previous method based on the phylogeny of protein sequences is, in fact, an effective estimate of a parameter that can be written symbolically as K = min( n , r ), where r is the rank of mutations at an amino acid site. Hence, understanding of r is crucial for appropriate interpretation of the estimated K , denoted by K e (the effective gene pleiotropy). Indeed, when protein sequence alignment is used to estimate effective gene pleiotropy ( K e ) by this method, K e can be interpreted as an effective estimate of n when n ≤ 20, as long as the phylogeny is sufficiently large. If n 〉 20, K e → 20, although the true n could be much higher.
    Type of Medium: Online Resource
    ISSN: 1674-4918 , 1759-6831
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2013
    detail.hit.zdb_id: 2516638-4
    SSG: 6,25
    SSG: 12
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  • 6
    In: Evolutionary Bioinformatics, SAGE Publications, Vol. 12 ( 2016-01), p. EBO.S40703-
    Type of Medium: Online Resource
    ISSN: 1176-9343 , 1176-9343
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2016
    detail.hit.zdb_id: 2227610-5
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  • 7
    Online Resource
    Online Resource
    Wiley ; 2017
    In:  Journal of Systematics and Evolution Vol. 55, No. 3 ( 2017-05), p. 231-234
    In: Journal of Systematics and Evolution, Wiley, Vol. 55, No. 3 ( 2017-05), p. 231-234
    Abstract: In spite of high‐throughput phosphoproteomics for protein kinase–phosphorylation site interactions, the evolutionary mechanism for the origin of protein phosphorylation remains a mystery. Pearlman and his colleagues proposed that some phosphorylation sites may have evolved from acidic amino acids, because those negatively charged amino acids (Asp/Glu) can mimic the phosphorylated state of a protein. Moreover, phosphorylation has the potential to conditionally restore the salt bridge that was originally constitutively formed by Asp/Glu. Although this insightful mimic hypothesis has been supported by several examples, we point out that the replacements from Asp/Glu to serine/threonine require at least two non‐synonymous nucleotide substitutions, casting some doubt about whether it is the major mechanism for the origin of phosphorylation. As the intermediate amino acid types, such as Ala/Asn/Gly, are not observed frequently, we have to invoke the hypothesis of double‐mutation driven by natural selection; that is, the very strong positive selection for the second mutation has overcome the deleterious effect caused by the first mutation. Furthermore, we propose an alternative evolutionary scenario that phosphorylation was primarily evolved to introduce negative charges to the protein surface, thus reducing spurious protein–protein interactions in vivo by electrostatic repulsion. The specific protein–protein interaction could be regulated when corresponding signals change surface charges by means of dephosphorylation and other recognition mechanisms. Probably this is a more universal mechanism that provided the first step toward the emergence of more accurate cell signaling and regulation. Further study is needed to distinguish between these hypotheses.
    Type of Medium: Online Resource
    ISSN: 1674-4918 , 1759-6831
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2017
    detail.hit.zdb_id: 2516638-4
    SSG: 6,25
    SSG: 12
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  • 8
    Online Resource
    Online Resource
    Informa UK Limited ; 2006
    In:  Food and Agricultural Immunology Vol. 17, No. 3-4 ( 2006-09), p. 173-181
    In: Food and Agricultural Immunology, Informa UK Limited, Vol. 17, No. 3-4 ( 2006-09), p. 173-181
    Type of Medium: Online Resource
    ISSN: 0954-0105 , 1465-3443
    Language: English
    Publisher: Informa UK Limited
    Publication Date: 2006
    detail.hit.zdb_id: 1477529-3
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  • 9
    Online Resource
    Online Resource
    American Chemical Society (ACS) ; 2006
    In:  Journal of Agricultural and Food Chemistry Vol. 54, No. 14 ( 2006-07-01), p. 4948-4953
    In: Journal of Agricultural and Food Chemistry, American Chemical Society (ACS), Vol. 54, No. 14 ( 2006-07-01), p. 4948-4953
    Type of Medium: Online Resource
    ISSN: 0021-8561 , 1520-5118
    Language: English
    Publisher: American Chemical Society (ACS)
    Publication Date: 2006
    detail.hit.zdb_id: 1483109-0
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  • 10
    Online Resource
    Online Resource
    Springer Science and Business Media LLC ; 2016
    In:  Scientific Reports Vol. 6, No. 1 ( 2016-02-17)
    In: Scientific Reports, Springer Science and Business Media LLC, Vol. 6, No. 1 ( 2016-02-17)
    Abstract: Resource allocation takes place in various types of real-world complex systems such as urban traffic, social services institutions, economical and ecosystems. Mathematically, the dynamical process of resource allocation can be modeled as minority games . Spontaneous evolution of the resource allocation dynamics, however, often leads to a harmful herding behavior accompanied by strong fluctuations in which a large majority of agents crowd temporarily for a few resources, leaving many others unused. Developing effective control methods to suppress and eliminate herding is an important but open problem. Here we develop a pinning control method, that the fluctuations of the system consist of intrinsic and systematic components allows us to design a control scheme with separated control variables. A striking finding is the universal existence of an optimal pinning fraction to minimize the variance of the system, regardless of the pinning patterns and the network topology. We carry out a generally applicable theory to explain the emergence of optimal pinning and to predict the dependence of the optimal pinning fraction on the network topology. Our work represents a general framework to deal with the broader problem of controlling collective dynamics in complex systems with potential applications in social, economical and political systems.
    Type of Medium: Online Resource
    ISSN: 2045-2322
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2016
    detail.hit.zdb_id: 2615211-3
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