An enhanced next-generation sequencing liquid biopsy assay for simultaneous detection of somatic variants, microsatellite instability and viral DNA.

2018 ◽  
Vol 36 (15_suppl) ◽  
pp. e24107-e24107
Author(s):  
Yukti Choudhury ◽  
Hao Chen ◽  
Farah Fadhlullah ◽  
Daniel Kian Hin Tan ◽  
Kim Tien Ng ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Microsatellite Instability ◽  
Liquid Biopsy ◽  
Simultaneous Detection ◽  
Next Generation ◽  
Viral Dna ◽  
Generation Sequencing

A Novel Method for Microsatellite Instability Detection by Liquid Biopsy Based on Next- Generation Sequencing

2020 ◽  
Vol 15 ◽  
Author(s):  
Zheng Jiang ◽  
Hui Liu ◽  
Siwen Zhang ◽  
Jia Liu ◽  
Weitao Wang ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Microsatellite Instability ◽  
Liquid Biopsy ◽  
Tumor Tissue ◽  
High Sensitivity ◽  
Next Generation ◽  
Tissue Samples ◽  
Next Generation Sequencing Technology ◽  
Medication Selection ◽  
Generation Sequencing

Background: Microsatellite instability (MSI) is a prognostic biomarker used to guide medication selection in multiple cancers, such as colorectal cancer. Traditional PCR with capillary electrophoresis and next-generation sequencing using paired tumor tissue and leukocyte samples are the main approaches for MSI detection due to their high sensitivity and specificity. Currently, patient tissue samples are obtained through puncture or surgery, which causes injury and risk of concurrent disease, further illustrating the need for MSI detection by liquid biopsy. Methods: We propose an analytic method using paired plasma/leukocyte samples and MSI detection using next-generation sequencing technology. Based on the theoretical progress of oncogenesis, we hypothesized that the microsatellite site length in plasma equals the combination of the distribution of tumor tissue and leukocytes. Thus, we defined a window-judgement method to identify whether biomarkers were stable. Results: Compared to traditional PCR as the standard, we evaluated three methods in 20 samples (MSI-H:3/MSS:17): peak shifting method using tissue vs. leukocytes, peak shifting method using plasma vs. leukocytes, and our method using plasma vs. leukocytes. Compared to traditional PCR, we observed a sensitivity of 100%, 0%, and 100%, and a specificity of 100.00%, 94.12%, and 88.24%, respectively. Conclusion: Our method has the advantage of possibly detecting MSI in a liquid biopsy and provides a novel direction for future studies to increase the specificity of the method.

scholarly journals Detection of activating mutations in liquid biopsy of Egyptian breast cancer patients using targeted next-generation sequencing: a pilot study

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Neemat Kassem ◽  
Hebatallah Kassem ◽  
Loay Kassem ◽  
Mohamed Hassan
Keyword(s):  
Breast Cancer ◽  
Next Generation Sequencing ◽  
Microsatellite Instability ◽  
Cancer Patients ◽  
Liquid Biopsy ◽  
Missense Mutations ◽  
Next Generation ◽  
Breast Cancer Patients ◽  
Activating Mutations ◽  
Generation Sequencing

Abstract Background Breast cancer (BC) is the 2nd most prevalent malignancy worldwide and is the most prevalent cancer among Egyptian women. The number of newly described cancer-associated genes has grown exponentially since the emergence of next-generation sequencing (NGS) technology. We aim to identify activating mutations in liquid biopsy of Egyptian breast cancer patients using targeted NGS technology. We also demonstrate the microsatellite instability (MSI) status using BAT25, BAT26, and NR27 markers which are tested on the Bioanalyzer 2100 system. Results Twenty-one variants were detected in 15 genes: 7 Substitution-Missense, 12 Substitution-coding silent, and 2 Substitution-intronic. Regarding ClinVar database, out of 21 variants there were 14 benign variants, 3 variants with conflicting interpretations of pathogenicity, 3 variants not reported, and 1 drug response variant. TP53 p.(Pro72Arg) missense mutations were found in 75% of patients. PIK3CA p.(Ile391Met), KDR p.(Gln472His) missense mutations were detected in 25% of patients each. Two patients revealed APC gene missense mutation with p.(Ile1307Lys) and p.(Glu1317Gln) variants. Only one patient showed ATM p.(Phe858Leu) gene mutation and one showed FGFR3 p.(Ala719Thr) variant. Regarding microsatellite instability (MSI) status, 2/8 (25%) patients were MSS, 3/8 (37.5%) patients were MSI-L, and 3/8 (37.5%) patients were MSI-HI. Conclusion It is essential to use and validate minimally invasive liquid biopsy for activating mutations detection by next-generation sequencing especially in patients with inoperable disease or bone metastasis. This work should be extended with larger patient series with comparison of genetic mutations in liquid-based versus tissue-based biopsy and longer follow up period.

scholarly journals An improved experimental pipeline for preparing circular ssDNA viruses for next-generation sequencing

2020 ◽  
Author(s):  
Catherine D. Aimone ◽  
J. Steen Hoyer ◽  
Anna E. Dye ◽  
David O. Deppong ◽  
Siobain Duffy ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Rolling Circle Amplification ◽  
Next Generation ◽  
Viral Dna ◽  
Single Stranded Dna ◽  
Dna Viruses ◽  
Short Read ◽  
Rolling Circle ◽  
Optimized Protocol ◽  
Generation Sequencing

AbstractWe present an optimized protocol for enhanced amplification and enrichment of viral DNA for Next Generation Sequencing of begomovirus genomes. The rapid ability of these viruses to evolve threatens many crops and underscores the importance of using next generation sequencing efficiently to detect and understand the diversity of these viruses. We combined enhanced rolling circle amplification (RCA) with EquiPhi29 polymerase and size selection to generate a cost-effective, short-read sequencing method. This optimized protocol produced short-read sequencing with at least 50% of the reads mapping to the viral reference genome. We provide other insights into common misconceptions about RCA and lessons we have learned from sequencing single-stranded DNA viruses. Our protocol can be used to examine viral DNA as it moves through the entire pathosystem from host to vector, providing valuable information for viral DNA population studies, and would likely work well with other CRESS DNA viruses.HighlightsProtocol for short-read, high throughput sequencing of single-stranded DNA viruses using random primersComparison of the sequencing of total DNA versus size-selected DNAComparison of phi29 and Equiphi29 DNA polymerases for rolling circle amplification of viral single-stranded DNA genomes

Microsatellite instability detection using a large next-generation sequencing cancer panel across diverse tumour types

2019 ◽  
Vol 73 (2) ◽  
pp. 83-89 ◽  
Author(s):  
Jiuhong Pang ◽  
Tatyana Gindin ◽  
Mahesh Mansukhani ◽  
Helen Fernandes ◽  
Susan Hsiao
Keyword(s):  
Next Generation Sequencing ◽  
Microsatellite Instability ◽  
Microsatellite Loci ◽  
Clinical Samples ◽  
Next Generation ◽  
Diverse Range ◽  
Tree Classifier ◽  
Generation Sequencing ◽  
Cancer Panel ◽  
Clinical Cases

AimMicrosatellite instability (MSI), a hallmark of DNA mismatch repair deficiency, is a key molecular biomarker with multiple clinical implications including the selection of patients for immunotherapy, identifying patients who may have Lynch syndrome and predicting prognosis in patients with colorectal tumours. Next-generation sequencing (NGS) provides the opportunity to interrogate large numbers of microsatellite loci concurrently with genomic variants. We sought to develop a method to detect MSI that would not require paired normal tissue and would leverage the sequence data obtained from a broad range of tumours tested using our 467-gene NGS Columbia Combined Cancer Panel (CCCP).MethodsAltered mononucleotide and dinucleotide microsatellite loci across the CCCP region of interest were evaluated in clinical samples encompassing a diverse range of tumour types. The number of altered loci was used to develop a decision tree classifier model trained on the retrospectively collected cohort of 107 clinical cases sequenced by the CCCP assay.ResultsThe classifier was able to correctly classify all cases and was then used to analyse a test set of clinical cases (n=112) and was able to correctly predict their MSI status with 100% sensitivity and specificity. Analysis of recurrently altered loci identified alterations in genes involved in DNA repair, signalling and transcriptional regulation pathways, many of which have been implicated in MSI tumours.ConclusionThis study highlights the utility of this approach, which should be applicable to laboratories performing similar testing.

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