SNParray_CASCADE
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ABSTRACT:
PROVIDER: EGAD00010002398 | EGA |
REPOSITORIES: EGA
Similar Datasets
Project description:Tumor and matched normal DNA profiling by SNP array
| EGAD00010002359 | EGA
Project description:With the whole genome SNP array information obtained from tumor and matched normal control, we could evaluate the acquired copy number variations (CNVs) and uniparental disomies (UPDs) . Seven MDS patients in a whole genome sequencing project were included in this experiment.
2014-05-22 | GSE57229 | GEO
Project description:With the whole genome SNP array information obtained from tumor and matched normal control, we could evaluate the acquired copy number alterations (CNAs) and uniparental disomies (UPDs) . Here we identified somatic mutations by whole-exome sequencing in 25 NKTCL patients and extended validation through targeted sequencing in an additional 80 cases.
2015-05-29 | GSE69382 | GEO
Project description:Affymetrix SNP array data of mixtures of tumor and normal DNA
| PRJNA150371 | ENA
Project description:In the study of tumor genetics, formalin-fixed paraffin-embedded (FFPE) tumors are the most readily available tissue samples. While DNA derived from FFPE tissue has been validated for array comparative genomic hybridization (aCGH) application, the suitability of such fragmented DNA for single-nucleotide polymorphism (SNP) array analysis has not been well examined. Furthermore, whole-genome amplification (WGA) has been used in the study of small precursor lesions to produce sufficient amount of DNA for aCGH analysis. It is unclear whether the same approach can be extended to SNP analysis. In this study, we examined the utility and limitations of genotyping platform performed on whole-genome amplified DNA from FFPE tumor samples for both copy number and SNP analyses. We analyzed the results obtained using DNA derived from matched FFPE and frozen tissue samples on Affymetrix 250K Nsp SNP array. Two widely used WGA methods, Qiagen (isothermal protocol) and Sigma (thermocycling protocol), were used to determine how WGA methods affect the results. We found that the use of DNA derived from FFPE tumors (without or with WGA) for high-resolution SNP array application can produce a significant amount of false positive and false negative findings. While some of these misinterpretations appear to cluster in genomic regions with high or low GC contents, the majority appears to occur randomly. Only large-scale chromosome LOH (>10Mb) can be reliably detected from FFPE tumor DNA samples (without or with WGA) but not smaller LOH or copy number alterations. Our findings here indicate a need for caution in SNP array data interpretation when using FFPE tumor-derived DNA, particularly with WGA.
2011-08-15 | GSE27399 | GEO
Project description:Single nucleotide polymorphism (SNP) microarrays are commonly applied to tumors to identify genomic regions with copy number alterations (CNA) or loss of heterozygosity (LOH). However, in typical tumor specimens collected in clinical studies, up to 60% of the DNA derives from stromal cells with a normal genome, resulting in attenuated sensitivity to true somatic aberrations in the tumor. Here we describe SNPfilter, a model-based method to decompose SNP array data from heterogeneous tumor specimens into their corresponding normal and tumor profiles. Unlike existing methods, SNPfilter does not require paired normal control data. We assessed the performance of this method using SNP array data representing cancer cell lines with aberrant genomes, B-cell lymphoblastoid cell lines with normal genomes, and defined mixtures of the two. In the pure tumor samples, SNPfilter identified CNA and LOH regions with accuracy similar to existing methods. In the mixture samples containing 40–80% tumor genomic DNA, SNPfilter yielded prediction sensitivity superior to existing methods. Thus, SNPfilter provides a powerful tool for discovery of clinically relevant somatic aberrations in tumor genomes.
2011-12-30 | GSE34754 | GEO
Project description:Affymetrix 10K SNP mapping arrays were used to profile 14 basal cell carcinomas (BCCs) with matched blood DNA samples. Loss of heterozygosity (LOH) and copy number abnormality (CNA) profiles were derived from each tumour-blood pair. Keywords: Genomic DNA on Affymetrix 10K SNP array
2005-07-21 | GSE2959 | GEO
Project description:High-throughput analyses of concordant gene methylation and expression events were carried out for 91 human prostate specimens, including prostate cancer (T), matched normal adjacent to tumor (AT), and organ donor (OD). Methylated DNA in genomic DNA was immunoprecipitated with anti-methylcytidine antibodies and detected by Affymetrix human whole genome SNP 6.0 chips. Methylated genomic DNA was purified by 5-hmc antibodies and Affymetrix SNP arrays were performed according to the manufacturer's manual.
2013-08-01 | GSE45000 | GEO
Project description:In the United States, African-American (AA) women are more likely to develop early-onset breast cancer and have historically poorer outcomes due to this disease compared to European-American (EA) women. Here, we analyzed genomic profiles of breast tumors from young women (<50 years old), matched by tumor subtype, histological grade, and ethnicity (African-American, AA, compared to European-American, EA). DNA copy number alterations (CNAs) were analyzed on the Affymetrix Human SNP Array v 6.0 platform. The study provides insight into the genetic component of ethnicity-related breast cancer health disparities. DNA copy number alterations (CNAs) and genotypes were analyzed using the Affymetrix SNP 6.0 platform. Breast tumor samples from young women (< 50 years old) were matched as follows: a matched pair consists of one AA and one EA sample, matched for tumor grade and tumor subtype (based on immunohistochemical analysis of ER, PR, and HER2 status). DNA from forty-four samples (22 AA, 22 EA) was analyzed on the Affymetrix SNP 6.0 array according to manufacturer’s directions.
2013-01-29 | E-GEOD-26232 | biostudies-arrayexpress
Project description:DNA copy number changes with or without accompanying copy neutral changes such as unparental disomy (UPD) is a feature of the cancer genome that is linked to cancer development. However, technical problems with archived formalin-fixed, paraffin-embedded (FFPE) tissue samples have limited their general use in genomic profiling studies done using high-density single nucleotide polymorphism (SNP) microarray. To overcome the current problems with the use of this material in the detection of DNA copy number and copy neutral changes, we have devised two new protocols for extracting DNA from FFPE tissue. Genotyping efficiency and accuracy were improved using our novel protocols. After censoring the larger fragments, we obtained call rates for FFPE DNA equivalent to those for FF tissue DNA, with concordance rates between FFPE and FF tumor exceeding 99%. Identical DNA copy number changes were obtained for FFPE and FF; and between two new extraction protocols in tumor samples by using Affymetrix® high-density oligo-based SNP microarray platform. We observed UPD and recurrent gains and losses in tumor samples. Interestingly, we also identified UPD in the 5q and 13q regions in matching normal blood, FF adjacent breast tissue and tumor tissue in two samples. In conclusion, our new two DNA extraction protocols should substantially improve the ability to use archived material to help elucidate the complexity of early-stage breast cancer genomes. Keywords: SNP based array
2008-09-18 | GSE9154 | GEO