70b362d0-a776-479a-a477-3efb7fc9a54f - samples
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ABSTRACT:
PROVIDER: EGAD00001009283 | EGA |
REPOSITORIES: EGA
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Project description:Approximately 5% of all breast cancers can be attributed to an inherited mutation in one of two cancer susceptibility genes, BRCA1 and BRCA2. We searched for genes that have the potential to distinguish healthy BRCA1 and BRCA2 mutation carriers from non-carriers based on differences in expression profiling. Using expression microarrays we compared gene expression of irradiated lymphocytes from BRCA1 and BRCA2 mutation carriers versus control non-carriers. We identified 137 probe sets in BRCA1 carriers and 1345 in BRCA2 carriers with differential gene expression. Gene Ontology analysis revealed that most of these genes relate to regulation pathways of DNA repair processes, cell cycle regulation and apoptosis. Real-time PCR was performed on the 36 genes which were most prominently differentially expressed in the microarray assay; 21 genes were shown to be significantly differentially expressed in BRCA1 or BRCA2 mutation carriers as compared to controls (p<0.05). Based on a validation study with 40 mutation carriers and 17 non-carriers, a multiplex model that included six or more coincidental genes of 18 selected genes was constructed in order to predict the risk of carrying a mutation. The results using this model showed sensitivity 95% and specificity 88%. In summary, our study provides insight into the biological effect of heterozygous mutations in BRCA1 and BRCA2 genes in response to ionizing irradiation induced DNA damage. We also suggest a set of 18 genes that can be used as a prediction and screening tool for BRCA1 or BRCA2 mutational carriers by using easily obtained lymphocytes. Using expression microarrays we compared gene expression of irradiated lymphocytes from BRCA1 and BRCA2 mutation carriers versus control non-carriers
2013-01-10 | GSE39976 | GEO
Project description:Approximately 5% of all breast cancers can be attributed to an inherited mutation in one of two cancer susceptibility genes, BRCA1 and BRCA2. We searched for genes that have the potential to distinguish healthy BRCA1 and BRCA2 mutation carriers from non-carriers based on differences in expression profiling. Using expression microarrays we compared gene expression of irradiated lymphocytes from BRCA1 and BRCA2 mutation carriers versus control non-carriers. We identified 137 probe sets in BRCA1 carriers and 1345 in BRCA2 carriers with differential gene expression. Gene Ontology analysis revealed that most of these genes relate to regulation pathways of DNA repair processes, cell cycle regulation and apoptosis. Real-time PCR was performed on the 36 genes which were most prominently differentially expressed in the microarray assay; 21 genes were shown to be significantly differentially expressed in BRCA1 or BRCA2 mutation carriers as compared to controls (p<0.05). Based on a validation study with 40 mutation carriers and 17 non-carriers, a multiplex model that included six or more coincidental genes of 18 selected genes was constructed in order to predict the risk of carrying a mutation. The results using this model showed sensitivity 95% and specificity 88%. In summary, our study provides insight into the biological effect of heterozygous mutations in BRCA1 and BRCA2 genes in response to ionizing irradiation induced DNA damage. We also suggest a set of 18 genes that can be used as a prediction and screening tool for BRCA1 or BRCA2 mutational carriers by using easily obtained lymphocytes. Using expression microarrays we compared gene expression of irradiated lymphocytes from BRCA1 and BRCA2 mutation carriers versus control non-carriers Fresh blood samples were obtained from 9 BRCA1 and 8 BRCA2 mutation carriers and 9 mutation-negative women. Lymphocytes were collected from fresh blood samples, and RNA was extracted one hour after γ-irradiation
2013-01-10 | E-GEOD-39976 | biostudies-arrayexpress
Project description:Female BRCA1 mutation carriers have a nearly 80% probability of developing breast cancer during their life-time. We hypothesized that the breast epithelium at risk in BRCA1 mutation carriers harbors mammary epithelial cells (MECs) with altered proliferation and differentiation properties. Microarray studies revealed that PMEC colonies from BRCA1 mutation carriers anticipate expression profiles found in BRCA1-related tumors, and that the EGFR pathway is upregulated in BRCA1 mutation carriers compared ton non BRCA1 mutation carriers. Keywords: Class comparison and pathway analysis 10 colonies were collected and RNA was isolated using the Absolutely RNA Nanoprep kit, Stratagene. The arrays included duplicates from four normal controls and from two BRCA1 mutation carriers and single arrays from another two BRCA1 mutation carriers.
2008-11-19 | E-GEOD-13671 | biostudies-arrayexpress
Project description:This study aimed to estimate the influence of POLD1 L474P on somatic and germline mutagenesis.
We studied the mutation rate and spectra in germline and soma in an extended family harboring the
POLD1 c.1421T>C p.(Leu474Pro) pathogenic variant. The study includes WGS data for DNA
extracted from blood, fibroblasts or buccal swabs from the 16 family members, from DNA obtained
single-cell derived colonies obtained from immortalized fibroblasts for 8 of 16 family members and from the same single-cell derived immortalized fibroblasts after approximately 40 passages for 6 out of 8 family members. Additionaly, study includes WXS sequencing for 1 tumor FFPE sample and adjacent normal tissue from the individual from one family member.
| EGAS00001006434 | EGA
Project description:Female BRCA1 mutation carriers have a nearly 80% probability of developing breast cancer during their life-time. We hypothesized that the breast epithelium at risk in BRCA1 mutation carriers harbors mammary epithelial cells (MECs) with altered proliferation and differentiation properties. Microarray studies revealed that PMEC colonies from BRCA1 mutation carriers anticipate expression profiles found in BRCA1-related tumors, and that the EGFR pathway is upregulated in BRCA1 mutation carriers compared ton non BRCA1 mutation carriers. Keywords: Class comparison and pathway analysis
2008-11-20 | GSE13671 | GEO
Project description:Genome wide DNA methylation profiling of non-tumoral and infiltrating ductal breast cancer (tumoral) samples. The HumanMethylation450 BeadChip was used to obtain DNA methylation profiles across approximately 450,000 CpG in non-tumoral and tumoral samples. Non-tumoral samples included six frozen non-neoplastic breast tissues from reduction mammoplasties and tumoral samples included eight frozen tumors from each BC subtype, i.e. luminal A (LA), luminal B (LB), luminal-HER2 (LH), HER2 (H) and triple-negative (TN) (Total: 40 tumors).
2020-02-17 | GSE141338 | GEO
Project description:Induced pluripotent stem cells (iPSCs) are usually clonally derived. The selection of fully reprogrammed cells generally involves picking of individual colonies with morphology similar to embryonic stem cells (ESCs). However, successfully reprogrammed cells are highly proliferative and escape from cellular senescence - it is therefore conceivable that they outgrow non-pluripotent and partially reprogrammed cells during culture expansion without the need of clonal selection. In this study, we have reprogrammed human dermal fibroblasts (HDFs) with episomal plasmid vectors. Colony frequency and size was higher when using murine embryonic fibroblasts (MEFs) as stromal support instead of HDFs or human mesenchymal stromal cells (MSCs). We have then compared iPSCs which were either clonally derived by manual selection of a single colony, or derived from bulk-cultures of all initial colonies. After few passages their morphology, expression of pluripotency markers, and gene expression profiles did not reveal any significant differences. Furthermore, clonally-derived and bulk-cultured iPSCs had indistinguishable in vitro differentiation potential towards the three germ layers. Therefore, manual selection of individual colonies does not appear to be necessary for the generation of iPSCs – this is of relevance for standardization and automation of cell culture procedures
2013-06-03 | GSE42807 | GEO
Project description:Induced pluripotent stem cells (iPSCs) are usually clonally derived. The selection of fully reprogrammed cells generally involves picking of individual colonies with morphology similar to embryonic stem cells (ESCs). However, successfully reprogrammed cells are highly proliferative and escape from cellular senescence - it is therefore conceivable that they outgrow non-pluripotent and partially reprogrammed cells during culture expansion without the need of clonal selection. In this study, we have reprogrammed human dermal fibroblasts (HDFs) with episomal plasmid vectors. Colony frequency and size was higher when using murine embryonic fibroblasts (MEFs) as stromal support instead of HDFs or human mesenchymal stromal cells (MSCs). We have then compared iPSCs which were either clonally derived by manual selection of a single colony, or derived from bulk-cultures of all initial colonies. After few passages their morphology, expression of pluripotency markers, and gene expression profiles did not reveal any significant differences. Furthermore, clonally-derived and bulk-cultured iPSCs had indistinguishable in vitro differentiation potential towards the three germ layers. Therefore, manual selection of individual colonies does not appear to be necessary for the generation of iPSCs M-bM-^@M-^S this is of relevance for standardization and automation of cell culture procedures Gene expression profiles of induced fibroblasts (M-bM-^@M-^\iFM-bM-^@M-^]) from three different donors which were either clonally derived (M-bM-^@M-^\CM-bM-^@M-^]) or bulk-cultured (M-bM-^@M-^\BM-bM-^@M-^]) were compared
2013-06-03 | E-GEOD-42807 | biostudies-arrayexpress