Identification of cell-free DNA in gastric cancer patient
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE108602 | GEO | 2018/03/31
REPOSITORIES: GEO
Similar Datasets
Project description:Identification of cell-free DNA in gastric cancer patient
| PRJNA427805 | ENA
Project description:Copy number alteration (CNA) is a good signpost to identify cancer related genes. CNAs were analyzed using the Agilent 400K array comparative genomic hybridization (aCGH) in fresh-frozen tumor and matched normal tissues from 30 gastric cancer patients.
2015-05-28 | GSE69266 | GEO
Project description:Copy number alteration (CNA) is a good signpost to identify cancer related genes. CNAs were analyzed using the Agilent 244K array comparative genomic hybridization (aCGH) in fresh-frozen tumor and matched normal tissues from 10 gastric cancer patients.
2015-05-29 | GSE69318 | GEO
Project description:Regions of recurrent genomic amplification and deletion are frequently observed in primary gastric cancers (GC). However, identifying specific oncogenes and tumor suppressor genes within these regions can be challenging, as they often cover tens to hundreds of genes. Here, we combined high-resolution array-based comparative genomic hybridization (aCGH) with gene expression profiling to target genes lying within focal high-level amplifications in GC cell lines, and identified RAB23 as an amplified and overexpressed Chr 6p11p12 gene in Hs746T cells. High RAB23 protein expression was also observed in some lines lacking RAB23 amplification, suggesting additional mechanisms besides gene amplification for up-regulating RAB23. siRNA silencing of RAB23 reduced the invasive potential of both amplified and nonamplified GC cell lines. RAB23 gene amplifications were observed in 13% of primary gastric carcinomas. In two independent patient cohorts, RAB23 transcript and protein expression was significantly associated with diffuse-type gastric cancer (dGC) compared to intestinal-type gastric cancer (iGC), providing further evidence that dGC and iGC likely represent two molecularly distinct tumor types. Our study demonstrates that investigating focal chromosomal amplifications by combining highresolution aCGH with expression profiling is a powerful general strategy for identifying novel cancer genes in recurrent regions of chromosomal aberration. Keywords: gastric cancer cell lines, comparative genomic hybridization, gene expression profiling
2008-12-29 | GSE10611 | GEO
Project description:Copy number alteration (CNA) is a good signpost to identify cancer related genes. CNAs were analyzed using the Agilent 400K array comparative genomic hybridization (aCGH) in fresh-frozen tumor and matched normal tissues from 30 gastric cancer patients. Whole genomic CNAs in 30 human gastric cancers were analyzed using the Agilent aCGH-400K arrays. Matched normal tissues were used as the reference.
2015-05-28 | E-GEOD-69266 | biostudies-arrayexpress
Project description:Regions of recurrent genomic amplification and deletion are frequently observed in primary gastric cancers (GC). However, identifying specific oncogenes and tumor suppressor genes within these regions can be challenging, as they often cover tens to hundreds of genes. Here, we combined high-resolution array-based comparative genomic hybridization (aCGH) with gene expression profiling to target genes lying within focal high-level amplifications in GC cell lines, and identified RAB23 as an amplified and overexpressed Chr 6p11p12 gene in Hs746T cells. High RAB23 protein expression was also observed in some lines lacking RAB23 amplification, suggesting additional mechanisms besides gene amplification for up-regulating RAB23. siRNA silencing of RAB23 reduced the invasive potential of both amplified and nonamplified GC cell lines. RAB23 gene amplifications were observed in 13% of primary gastric carcinomas. In two independent patient cohorts, RAB23 transcript and protein expression was significantly associated with diffuse-type gastric cancer (dGC) compared to intestinal-type gastric cancer (iGC), providing further evidence that dGC and iGC likely represent two molecularly distinct tumor types. Our study demonstrates that investigating focal chromosomal amplifications by combining highresolution aCGH with expression profiling is a powerful general strategy for identifying novel cancer genes in recurrent regions of chromosomal aberration. Keywords: gastric cancer cell lines, comparative genomic hybridization, gene expression profiling Affy 100K SNP profiling and 32K BAC Array profiling for 7 Gastric Cancer Cell Lines
2010-05-14 | E-GEOD-10611 | biostudies-arrayexpress
Project description:Elevated level of circulating cell-free DNA (cfDNA) has been associated with poor prognosis and relapse in patients with diffuse large B-cell lymphoma (DLBCL), but the tumor-specific molecular alterations in cfDNA with prognostic significance remain unclear. We investigated the association between 5-hydroxymethylcytosines (5hmC), a mark of active demethylation and gene activation, in cfDNA from blood plasma and prognosis in DLBCL. We used the 5hmC-Seal, a highly sensitive chemical labeling technique, to profile genome-wide 5hmC in plasma cfDNA samples from 48 newly diagnosed patients with DLBCL at the University of Chicago between 2010 and 2012. Patients were followed through December 31, 2017. We found a distinct genomic distribution of 5hmC in cfDNA marking tissue-specific enhancers, consistent with their potential roles in gene regulation. The 5hmC profiles in cfDNA differed by cell-of-origin, and were associated with clinical prognostic features including Ann Arbor stage, serum lactate dehydrogenase (LDH) level, and the International Prognostic Index (IPI). We developed a 29 gene-based weighted prognostic score (wp-score) for predicting event-free survival (EFS) and overall survival (OS), by applying the elastic net regularization on the Cox proportional hazard model. The wp-scores showed significantly improved prognostic accuracy and/or sensitivity/specificity than the established prognostic factors. In multivariate Cox models, patients with high wp-scores were associated with worse event-free survival (Hazard Ratio [HR] = 9.17, 95% confidence interval [CI] = 2.01- 41.89, p = 0.004), compared with those in the low risk group. Our findings suggest that the 5hmC signatures in cfDNA at the time of diagnosis are associated with clinical outcomes in DLBCL and may provide a novel non-invasive prognostic approach for DLBCL.
2019-11-15 | GSE126676 | GEO
Project description:DNA modifications such as 5-methylcytosines (5mC) and 5-hydroxymethylcytosines (5hmC) are epigenetic marks known to affect global gene expression in mammals. Given their prevalence in the human genome, close correlation with gene expression, and high chemical stability, these DNA epigenetic marks could serve as ideal biomarkers for cancer diagnosis. Taking advantage of a highly sensitive and selective chemical labeling technology, we report here genome-wide 5hmC profiling in circulating cell-free DNA (cfDNA) and paired tumor/adjacent tissues collected from a cohort of 90 healthy individuals and 260 patients recently diagnosed with colorectal, gastric, pancreatic, liver, or thyroid cancer. 5hmC was mainly distributed in transcriptionally active regions coincident with open chromatin and permissive histone modifications. Robust cancer-specific epigenetic signatures in cfDNA were identified in different cancers. 5hmC-based biomarkers demonstrated highly accurate predictive value for patients with colorectal and gastric cancers versus healthy controls, superior to conventional biomarkers, and comparable to epigenetic biomarkers from tissue biopsies. This new strategy could lead to the development of an effective blood-based, minimally-invasive cancer diagnosis and prognosis approach.
2017-09-05 | GSE89570 | GEO
Project description:We explored the differential methylation patterns found in cfDNA between healthy controls (individuals with no colorectal findings, NCF) and patients with advanced neoplasia (advanced adenomas and colorectal cancer, AA andCRC) using pooled samples, to determine if pooled serum cfDNA samples can be used to search for non-invasive methylation biomarkers, as an affordable and efficient alternative to tissue biopsy. cfDNA was extracted from serum samples and methylation measurements were assessed with the Infinium MethylationEPIC BeadChip. Data was mainly preprocessed and analyzed with R/Bioconductor packages.
2018-04-17 | GSE110185 | GEO
Project description:As a non-invasive blood testing, the detection of cell-free DNA (cfDNA) methylation in plasma is raising increasing interest due to its diagnostic and biology applications. Although extensively used in cfDNA methylation analysis, bisulfite sequencing is less cost-effective. Through enriching methylated cfDNA fragments with MeDIP followed by deep sequencing, we aimed to characterize cfDNA methylome in cancer patients. In this study, we investigated the cfDNA methylation patterns in lung cancer patients by MeDIP-seq. MEDIPS package was used for the identification of differentially methylated regions (DMRs) between patients and normal ones. Overall, we identified 330 differentially methylated regions (DMRs) in gene promoter regions, 33 hypermethylation and 297 hypomethylation respectively, by comparing lung cancer patients and healthy individuals as controls. The 33 hypermethylation regions represent 32 genes. Some of the genes had been previously reported to be associated with lung cancers, such as GAS7, AQP10, HLF, CHRNA9 and HOPX. Taken together, our study provided an alternative method of cfDNA methylation analysis in lung cancer patients with potential clinical applications.
2019-03-31 | E-MTAB-7163 | biostudies-arrayexpress