Whole-exome sequencing in radically resected gastric cancer (GC): Analysis of patients (pts) with poor prognostic factors from the Italian Trial of Adjuvant Chemotherapy Adenocarcinoma (ITACA-S) trial.

2017 ◽  
Vol 35 (4_suppl) ◽  
pp. 64-64
Author(s):  
Maria Di Bartolomeo ◽  
Devecchi Andrea ◽  
Silvana Canevari ◽  
Alessandro Pellegrinelli ◽  
Filippo Pietrantonio ◽  
...  

64 Background: At present, the clinical management of resected GC is only based on risk stratification according to the AJCC staging. This project evaluates molecular factors on formalin-fixed, paraffin-embedded (FFEP) specimens of the primary tumor radically resected in an omogeneous group patients considered at poor prognosis according by nodal involvement (pN3a/b AJCC 7th edition) and included in the ITACA-S trial. Methods: Matched pairs of tumor-normal GC FFPE specimens collected from 15 patients were subjected to whole-exome sequencing using TruSeq Exome technology and NextSeq500 (Illumina). Somatic mutations (single-nucleotide variants) were identified, filtered and then searched for recurrently mutated genes and pathways. Patients with recurrence (cases) were compared to an equally-sized sample of patients without recurrence (controls) with the same follow up time (60 months). Results: Clinical characteristics of 15 pts: median age 61 (41-71) yrs. Nodal involvement: pN3a( 5); pN3b (10). Histotype: Intestinal (4); diffuse (8); mixed (3). Primary site: gastroesophageal junction (1); gastric (14). Patients with GC relapse (8) and without relapse (7). Whole exome sequencing revealed the presence of an average of 553 somatic mutations (range: 197 - 1318) following removal of not exonic/silent variants and of variants with an alternative allele depth < 5. Among a list of 48 genes, reported as mutated in some GC studies, we found that CDH1, GNAS and DCC were mutated in 57% of patients, whereas CTNNB1, LRP1B, LRRK2, NOTCH1, and TRRAP were mutated in 42%. Furthermore RHOA, KRAS, FGFR2, PDGFRA and PRKDC showed mutation in 28% of cases. We are currently evaluating the presence of mutual exclusive relationships mechanisms, functions and molecular pathways in “cases” versus “controls”. Conclusions: Our findings confirm a relevant role of disregulation of cell adhesion pathway involving CDH1 and DCC in GC. However, a validation analysis with an independent and bigger cohort of GC patients is ongoing, in order to find outcome-related mutational patterns that could be relevant for the selection of treatment in GC.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alana R. Rodney ◽  
Reuben M. Buckley ◽  
Robert S. Fulton ◽  
Catrina Fronick ◽  
Todd Richmond ◽  
...  

AbstractOver 94 million domestic cats are susceptible to cancers and other common and rare diseases. Whole exome sequencing (WES) is a proven strategy to study these disease-causing variants. Presented is a 35.7 Mb exome capture design based on the annotated Felis_catus_9.0 genome assembly, covering 201,683 regions of the cat genome. Whole exome sequencing was conducted on 41 cats with known and unknown genetic diseases and traits, of which ten cats had matching whole genome sequence (WGS) data available, used to validate WES performance. At 80 × mean exome depth of coverage, 96.4% of on-target base coverage had a sequencing depth > 20-fold, while over 98% of single nucleotide variants (SNVs) identified by WGS were also identified by WES. Platform-specific SNVs were restricted to sex chromosomes and a small number of olfactory receptor genes. Within the 41 cats, we identified 31 previously known causal variants and discovered new gene candidate variants, including novel missense variance for polycystic kidney disease and atrichia in the Peterbald cat. These results show the utility of WES to identify novel gene candidate alleles for diseases and traits for the first time in a feline model.


Author(s):  
Yuanqing Yan ◽  
Rebecca Martinez ◽  
Maria N. Rasheed ◽  
Joshua Cahal ◽  
Zhen Xu ◽  
...  

Author(s):  
Juan Chen ◽  
Yan Li ◽  
Jianlei Wu ◽  
Yakun Liu ◽  
Shan Kang

Abstract Background Malignant ovarian germ cell tumors (MOGCTs) are rare and heterogeneous ovary tumors. We aimed to identify potential germline mutations and somatic mutations in MOGCTs by whole-exome sequencing. Methods The peripheral blood and tumor samples from these patients were used to identify germline mutations and somatic mutations, respectively. For those genes corresponding to copy number alterations (CNA) deletion and duplication region, functional annotation of was performed. Immunohistochemistry was performed to evaluate the expression of mutated genes corresponding to CNA deletion region. Results In peripheral blood, copy number loss and gain were mostly found in yolk sac tumors (YST). Moreover, POU5F1 was the most significant mutated gene with mutation frequency &gt; 10% in both CNA deletion and duplication region. In addition, strong cytoplasm staining of POU5F1 (corresponding to CNA deletion region) was found in 2 YST and nuclear staining in 2 dysgerminomas (DG) tumor samples. Genes corresponding to CNA deletion region were significantly enriched in the signaling pathway of regulating pluripotency of stem cells. In addition, genes corresponding to CNA duplication region were significantly enriched in the signaling pathways of RIG-I-like receptor, Toll-like receptor, NF-kappa B and Jak–STAT. KRT4, RPL14, PCSK6, PABPC3 and SARM1 mutations were detected in both peripheral blood and tumor samples. Conclusions Identification of potential germline mutations and somatic mutations in MOGCTs may provide a new field in understanding the genetic feature of the rare biological tumor type in the ovary.


2019 ◽  
Vol 10 ◽  
Author(s):  
Alejandro Mendoza-Alvarez ◽  
Beatriz Guillen-Guio ◽  
Adrian Baez-Ortega ◽  
Carolina Hernandez-Perez ◽  
Sita Lakhwani-Lakhwani ◽  
...  

BMC Cancer ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Keiichi Akizuki ◽  
Masaaki Sekine ◽  
Yasunori Kogure ◽  
Takuro Kameda ◽  
Kotaro Shide ◽  
...  

Abstract Background The occurrence of a mediastinal germ cell tumor (GCT) and hematological malignancy in the same patient is very rare. Due to its rarity, there have been only two reports of the concurrent cases undergoing detailed genetic analysis with whole-exome sequencing (WES), and the possible clonal relationship between the both tumors remained not fully elucidated. Methods We performed whole-exome sequencing analysis of mediastinal GCT and acute myeloid leukemia (AML) samples obtained from one young Japanese male adult patient with concurrent both tumors, and investigated the possible clonal relationship between them. Results Sixteen somatic mutations were detected in the mediastinal GCT sample and 18 somatic mutations in the AML sample. Mutations in nine genes, including TP53 and PTEN both known as tumor suppressor genes, were shared in both tumors. Conclusions All in our case and in the previous two cases with concurrent mediastinal GCT and AML undergoing with whole-exome sequencing analysis, TP53 and PTEN mutations were commonly shared in both tumors. These data not only suggest that these tumors share a common founding clone, but also indicate that associated mediastinal GCT and AML harboring TP53 and PTEN mutations represent a unique biological entity.


2021 ◽  
Vol 12 ◽  
Author(s):  
Feifan Xiao ◽  
Yulan Lu ◽  
Bingbing Wu ◽  
Bo Liu ◽  
Gang Li ◽  
...  

Next-generation sequencing (NGS) has been used to detect severe combined immunodeficiency (SCID) in patients, and some patients with DNA cross-link repair 1C (DCLRE1C) variants have been identified. Moreover, some compound variants, such as copy number variants (CNV) and single nucleotide variants (SNV), have been reported. The purpose of this study was to expand the genetic data related to patients with SCID carrying the compound DCLRE1C variant. Whole-exome sequencing (WES) was performed for genetic analysis, and variants were verified by performing Sanger sequencing or quantitative PCR. Moreover, we searched PubMed and summarized the data of the reported variants. Four SCID patients with DCLRE1C variants were identified in this study. WES revealed a homozygous deletion in the DCLRE1C gene from exons 1–5 in patient 1, exons 1–3 deletion and a novel rare variant (c.92T&gt;C, p.L31P) in patient 2, exons 1–3 deletion and a novel rare variant (c.328C&gt;G, p.L110V) in patient 3, and exons 1–4 deletion and a novel frameshift variant (c.449dup, p.His151Alafs*20) in patient 4. Based on literature review, exons 1–3 was recognized as a hotspot region for deletion variation. Moreover, we found that compound variations (CNV + SNV) accounted for approximately 7% variations in all variants. When patients are screened for T-cell receptor excision circles (TRECs), NGS can be used to expand genetic testing. Deletion of the DCLRE1C gene should not be ignored when a variant has been found in patients with SCID.


2020 ◽  
Vol Volume 13 ◽  
pp. 6485-6496 ◽  
Author(s):  
Ao-Xiang Guo ◽  
Fan Xiao ◽  
Wei-Hua Shao ◽  
Yan Zhan ◽  
Le Zhang ◽  
...  

2016 ◽  
Vol 15 ◽  
pp. CIN.S36612 ◽  
Author(s):  
Lun-Ching Chang ◽  
Biswajit Das ◽  
Chih-Jian Lih ◽  
Han Si ◽  
Corinne E. Camalier ◽  
...  

With rapid advances in DNA sequencing technologies, whole exome sequencing (WES) has become a popular approach for detecting somatic mutations in oncology studies. The initial intent of WES was to characterize single nucleotide variants, but it was observed that the number of sequencing reads that mapped to a genomic region correlated with the DNA copy number variants (CNVs). We propose a method RefCNV that uses a reference set to estimate the distribution of the coverage for each exon. The construction of the reference set includes an evaluation of the sources of variability in the coverage distribution. We observed that the processing steps had an impact on the coverage distribution. For each exon, we compared the observed coverage with the expected normal coverage. Thresholds for determining CNVs were selected to control the false-positive error rate. RefCNV prediction correlated significantly ( r = 0.96–0.86) with CNV measured by digital polymerase chain reaction for MET (7q31), EGFR (7p12), or ERBB2 (17q12) in 13 tumor cell lines. The genome-wide CNV analysis showed a good overall correlation (Spearman's coefficient = 0.82) between RefCNV estimation and publicly available CNV data in Cancer Cell Line Encyclopedia. RefCNV also showed better performance than three other CNV estimation methods in genome-wide CNV analysis.


2016 ◽  
Author(s):  
Shintaro Iwata ◽  
Yasutoshi Tatsumi ◽  
Tsukasa Yonemoto ◽  
Hiroto Kamoda ◽  
Takeshi Ishii ◽  
...  

Author(s):  
Andrew V Uzilov ◽  
Patricia Taik ◽  
Khadeen C Cheesman ◽  
Pedram Javanmard ◽  
Kai Ying ◽  
...  

Abstract Context Pituitary corticotroph adenomas are rare tumors that can be associated with excess adrenocorticotropin (ACTH) and adrenal cortisol production, resulting in the clinically debilitating endocrine condition Cushing disease. A subset of corticotroph tumors behave aggressively, and genomic drivers behind the development of these tumors are largely unknown. Objective To investigate genomic drivers of corticotroph tumors at risk for aggressive behavior. Design Whole-exome sequencing of patient-matched corticotroph tumor and normal deoxyribonucleic acid (DNA) from a patient cohort enriched for tumors at risk for aggressive behavior. Setting Tertiary care center Patients Twenty-seven corticotroph tumors from 22 patients were analyzed. Twelve tumors were macroadenomas, of which 6 were silent ACTH tumors, 2 were Crooke’s cell tumors, and 1 was a corticotroph carcinoma. Intervention Whole-exome sequencing. Main outcome measure Somatic mutation genomic biomarkers. Results We found recurrent somatic mutations in USP8 and TP53 genes, both with higher allelic fractions than other somatic mutations. These mutations were mutually exclusive, with TP53 mutations occurring only in USP8 wildtype (WT) tumors, indicating they may be independent driver genes. USP8-WT tumors were characterized by extensive somatic copy number variation compared with USP8-mutated tumors. Independent of molecular driver status, we found an association between invasiveness, macroadenomas, and aneuploidy. Conclusions Our data suggest that corticotroph tumors may be categorized into a USP8-mutated, genome-stable subtype versus a USP8-WT, genome-disrupted subtype, the latter of which has a TP53-mutated subtype with high level of chromosome instability. These findings could help identify high risk corticotroph tumors, namely those with widespread CNV, that may need closer monitoring and more aggressive treatment.


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