Comparative microRNA profiling of sporadic and BRCA1 associated basal-like breast cancers
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Max Yan
PROVIDER: E-GEOD-61438 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Analysis of miRNA expression in grade 3 luminal, sporadic and BRCA1 associated basal-like breast cancers
2014-09-16 | GSE61438 | GEO
Project description:Breast tumors from BRCA1 germ line mutation carriers typically exhibit features of the basal-like molecular subtype. However, the specific genes recurrently mutated as a consequence of BRCA1 dysfunction have not been fully elucidated. In this study, we utilized gene expression profiling to molecularly subtype 577 breast tumors, including 73 breast tumors from BRCA1/2 mutation carriers. Focusing on the RB1 locus, we analyzed 33 BRCA1-mutated, 36 BRCA2-mutated and 48 non-BRCA1/2-mutated breast tumors using a custom-designed high-density oligomicroarray covering the RB1 gene. We found a strong association between the basal-like subtype and BRCA1-mutated breast tumors and the luminal B subtype and BRCA2-mutated breast tumors. RB1 was identified as a major target for genomic disruption in tumors arising in BRCA1 mutation carriers and in sporadic tumors with BRCA1 promoter-methylation, but rarely in other breast cancers. Homozygous deletions, intragenic breaks, or microdeletions were found in 33% of BRCA1-mutant tumors, 36% of BRCA1 promoter-methylated basal-like tumors, 13% of non-BRCA1 deficient basal-like tumors, and 3% of BRCA2-mutated tumors. In addition, RB1 was frequently inactivated by gross gene disruption in BRCA1-related hereditary breast cancer and BRCA1-methylated sporadic basal-like breast cancer, but rarely in BRCA2-hereditary breast cancer and non-BRCA1-deficient sporadic breast cancers. Together, our findings demonstrate the existence of genetic heterogeneity within the basal-like breast cancer subtype that is based upon BRCA1-status. Gene expression profiling of breast tumors. Dual color common reference gene expression study using 55K oligonucleotide microarrays.
2012-06-26 | E-GEOD-25307 | biostudies-arrayexpress
Project description:Breast tumors from BRCA1 germ line mutation carriers typically exhibit features of the basal-like molecular subtype. However, the specific genes recurrently mutated as a consequence of BRCA1 dysfunction have not been fully elucidated. In this study, we utilized gene expression profiling to molecularly subtype 577 breast tumors, including 73 breast tumors from BRCA1/2 mutation carriers. Focusing on the RB1 locus, we analyzed 33 BRCA1-mutated, 36 BRCA2-mutated and 48 non-BRCA1/2-mutated breast tumors using a custom-designed high-density oligomicroarray covering the RB1 gene. We found a strong association between the basal-like subtype and BRCA1-mutated breast tumors and the luminal B subtype and BRCA2-mutated breast tumors. RB1 was identified as a major target for genomic disruption in tumors arising in BRCA1 mutation carriers and in sporadic tumors with BRCA1 promoter-methylation, but rarely in other breast cancers. Homozygous deletions, intragenic breaks, or microdeletions were found in 33% of BRCA1-mutant tumors, 36% of BRCA1 promoter-methylated basal-like tumors, 13% of non-BRCA1 deficient basal-like tumors, and 3% of BRCA2-mutated tumors. In addition, RB1 was frequently inactivated by gross gene disruption in BRCA1-related hereditary breast cancer and BRCA1-methylated sporadic basal-like breast cancer, but rarely in BRCA2-hereditary breast cancer and non-BRCA1-deficient sporadic breast cancers. Together, our findings demonstrate the existence of genetic heterogeneity within the basal-like breast cancer subtype that is based upon BRCA1-status.
2012-06-27 | GSE25307 | GEO
Project description:It is now well understood that epigenetic alterations occur frequently in sporadic breast carcinogenesis, but little is known about the epigenetic alterations associated with familial breast tumors. We performed genome-wide DNA methylation profiling on familial breast cancers (n=33) to identify patterns of methylation specific to the different mutation groups (BRCA1, BRCA2 and BRCAx) or intrinsic subtypes of breast cancer (basal, luminal A, luminal B, HER2 and normal-like). We used methylated DNA immunoprecipitation (meDIP) on Affymetrix human promoter chips to interrogate methylation profiles across 25,500 distinct transcripts.
2010-03-12 | GSE17125 | GEO
Project description:It is now well understood that epigenetic alterations occur frequently in sporadic breast carcinogenesis, but little is known about the epigenetic alterations associated with familial breast tumors. We performed genome-wide DNA methylation profiling on familial breast cancers (n=33) to identify patterns of methylation specific to the different mutation groups (BRCA1, BRCA2 and BRCAx) or intrinsic subtypes of breast cancer (basal, luminal A, luminal B, HER2 and normal-like). We used methylated DNA immunoprecipitation (meDIP) on Affymetrix human promoter chips to interrogate methylation profiles across 25,500 distinct transcripts.
2010-03-12 | GSE17125 | GEO
Project description:In order to identify new targets for basal-like breast cancers, we performed RNA-Seq of 10 breast cancer cell lines. Basal-like cell lines (MDAMB231, MDAMB436, HCC1937, SUM149, SUM1315 and MCF10A) were compared to luminal cell lines (MCF7 and T47D). Moreover we could also study BRCA1 influence on transcriptome of basal-like breast cancer. 4 of our cell lines are indeed BRCA1 mutated (MDAMB436, HCC1937, SUM149 and SUM1315) and we also developed 2 cell lines that come from the BRCA1 mutated SUM1315 cell line stably transfected with empty LXSN plasmid (SUM1315-LXSN) or with a BRCA1 coding plasmid (SUM1315-BRCA1).
2017-02-14 | E-MTAB-5465 | biostudies-arrayexpress
Project description:In order to identify new targets for basal-like breast cancers, we performed Methyl-Seq of 10 breast cancer cell lines. Basal-like cell lines (MDAMB231, MDAMB436, HCC1937, SUM149, SUM1315 and MCF10A) were compared to luminal cell lines (MCF7 and T47D). Moreover we could also study BRCA1 influence on methylome of basal-like breast cancer. 4 of our cell lines are indeed BRCA1 mutated (MDAMB436, HCC1937, SUM149 and SUM1315) and we also developed 2 cell lines that come from the BRCA1 mutated SUM1315 cell line stably transfected with empty LXSN plasmid (SUM1315-LXSN) or with a BRCA1 coding plasmid (SUM1315-BRCA1).
2017-02-14 | E-MTAB-5468 | biostudies-arrayexpress
Project description:Pathogenic germline mutations in BRCA1 or BRCA2 are detected in less than one third of families with a strong history of breast cancer. It is therefore expected that mutations still remain undetected by currently used screening methods. In addition, a growing number of BRCA1/2 sequence variants of unclear pathogen significance are found in the families, constituting an increasing clinical challenge. New methods are therefore needed to improve the detection rate and aid the interpretation of the clinically uncertain variants. In this study we analyzed a series of 33 BRCA1, 22 BRCA2, and 128 sporadic tumors by RNA profiling to investigate the classification potential of RNA profiles to predict BRCA1/2 mutation status. We found that breast tumors from BRCA1 and BRCA2 mutation carriers display characteristic RNA expression patterns, allowing them to be distinguished from sporadic tumors. The majority of BRCA1 tumors were basal-like while BRCA2 tumors were mainly luminal B. Using RNA profiles, we were able to distinguish BRCA1 tumors from sporadic tumors among basal-like tumors with 83% accuracy and BRCA2 from sporadic tumors among luminal B tumors with 89% accuracy. Furthermore, subtype-specific BRCA1/2 gene signatures were successfully validated in two independent data sets with high accuracies. Although additional validation studies are required, indication of BRCA1/2 involvement (“BRCAness”) by RNA profiling could potentially be valuable as a tool for distinguishing pathogenic mutations from benign variants, for identification of undetected mutation carriers, and for selecting patients sensitive to new therapeutics such as PARP inhibitors. Gene expression profiling of 183 breast tumor samples. Breast tumors from hereditary breast cancer patients carrying a pathogenic BRCA1 (n=33) or BRCA2 (n=22) germ-line mutation were included in the study. Serving as a representative control group, primary breast tumor samples (n=128) were randomly selected. The study was conducted using Agilent-029949 Custom SurePrint G3 Human GE 8x60K Microarray platform. For cross-platform validation, a subset of the tumor samples (92 of the 183 samples) were analyzed by our in-house spotted microarray platform.
2013-06-28 | E-GEOD-40115 | biostudies-arrayexpress
Project description:We have analyzed, using DNA microarrays, putative differences in gene-expression level between hereditary BRCA1 mutation-linked and sporadic breast cancer. Our results show that a previously reported marked difference between BRCA1-mutation linked and sporadic breast cancer was probably due to uneven stratification of samples with different ER status and basal-like versus luminal-like subtype. We observed that apparent difference between BRCA1-linked and other types of breast cancer found in univariate analysis was diminished when data were corrected for ER status and molecular subtype in multivariate analyses. In fact, the difference in gene expression pattern of BRCA1-mutated and sporadic cancer is very discrete. These conclusions were supported by the results of Q-PCR validation. We also found that BRCA1 gene inactivation due to promoter hypermethylation had similar effect on general gene expression profile as mutation-induced protein truncation. This suggests that in the molecular studies of hereditary breast cancer, BRCA1 gene methylation should be recognized and considered together with gene mutation.
2013-09-05 | GSE50567 | GEO
Project description:BRCA1 germline mutation carriers are predisposed to breast cancers. Epigenomic regulations have been known to strongly interact with genetic variations and potentially mediate biochemical cascades involved in tumorigenesis. Due to the cell-type specificity of epigenomic features, profiling of individual cell types is critical for understanding the molecular events in various cellular compartments within complex breast tissue. Here we report cell-type specific profiling of genome-wide histone modifications, including H3K27ac and H3K4me3 in basal, luminal progenitor, mature luminal, and stromal cells, extracted from pre-cancer BRCA1 mutation carriers and non-carriers, using a low-input technology. We discover that basal and stromal cells present the most substantial epigenomic differences between mutation carriers and non-carriers while luminal progenitor and mature luminal cells are relatively unchanged with the mutation. Furthermore, the epigenomic changes in basal cells due to BRCA1 mutation appear to facilitate their transformation into luminal progenitor cells. Our findings shed light on the pre-cancer epigenomic dynamics due to BRCA1 mutation and how they may contribute to eventual development of basal-like breast cancer.
2020-08-25 | GSE148995 | GEO