MiRNA profiling of pre- and postoperative breast tumors
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Riis ML
PROVIDER: S-ECPF-MTAB-469 | biostudies-other | 2012
REPOSITORIES: biostudies-other
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Project description:Gene expression studies on breast cancer have generally been performed on tissue obtained at the time of surgery. Overexpression of several genes may be a result of surgical trauma or preoperative manipulation, and may not reflect any biological impact of the disease. This study compares the expression profiles in preoperative tissue while tumor is still in its normal milieu to postoperative tissue from the same tumor obtained during surgery.
2011-03-01 | E-MTAB-469 | biostudies-arrayexpress
Project description:Gene expression studies on breast cancer have generally been performed on tissue obtained at the time of surgery. Overexpression of several genes may be a result of surgical trauma or preoperative manipulation, and may not reflect any biological impact of the disease. This study compares the expression profiles in preoperative tissue while tumor is still in its normal milieu to postoperative tissue from the same tumor obtained during surgery.
| S-ECPF-MTAB-470 | biostudies-other
Project description:Gene expression studies on breast cancer have generally been performed on tissue obtained at the time of surgery. Overexpression of several genes may be a result of surgical trauma or preoperative manipulation, and may not reflect any biological impact of the disease. This study compares the expression profiles in preoperative tissue while tumor is still in its normal milieu to postoperative tissue from the same tumor obtained during surgery.
2011-03-01 | E-MTAB-470 | biostudies-arrayexpress
Project description:The objective of the study was to characterize hereditary breast tumors based on their miRNA expression profiles. To this end, we performed global miRNA expression analysis of more than 800 human miRNA genes in a large series of 80 FFPE breast tissue samples. The series included 66 hereditary breast primary tumors from 13 BRCA1 mutation carriers, 10 BRCA2 mutation carriers and 43 non-BRCA12 tumors denominated hereafter as BRCAX tumors. In addition we have analyzed 10 sporadic breast carcinomas and 4 normal breast tissues obtained after breast reduction surgery from healthy donors with no family history of breast cancer. To avoid contamination with normal breast tissue, tumoral area on FFPE blocks was marked by a pathologist and macrodissected for subsequent total RNA extraction. Microarray expression profiling was performed using miRCURY LNATM microRNA Array v.11 (Exiqon A/S, Denmark), in a single color experiments in a pairwise comparison experimantal design.
| S-ECPF-GEOD-44899 | biostudies-other
Project description:Hereditary breast cancer constitutes only 5-10% of all breast cancer cases and is characterized by strong family history of breast and/or other associated cancer types. Only ~ 25% of hereditary breast cancer cases carry a mutation in BRCA1 or BRCA2 gene, while mutations in other rare high and moderate-risk genes and common low penetrance variants may account for additional 20% of the cases. Thus the majority of cases are still unaccounted for and designated as BRCAX tumors. MicroRNAs are small non-coding RNAs that play important roles as regulators of gene expression and are deregulated in cancer. To characterize hereditary breast tumors based on their miRNA expression profiles we performed global microarray miRNA expression profiling on a retrospective cohort of 80 FFPE breast tissues, including 66 hereditary breast tumors (13 BRCA1, 10 BRCA2 and 43 BRCAX), 10 sporadic breast carcinomas and 4 normal breast tissues, using Exiqon miRCURY LNA™ microRNA Array v.11.0. Here we describe in detail the miRNA microarray expression data and tumor samples used for the study of BRCAX tumor heterogeneity (Tanic et al., 2013) and biomarkers associated with positive BRCA1/2 mutation status (Tanic et al., 2014). Additionally, we provide the R code for data preprocessing and quality control.
| S-EPMC4535901 | biostudies-literature
Project description:Gene and miRNA profiles from a unique Chinese/Caucasian trans-ethnic collection of breast cancer from Shanghai (China) and Milan (Italy) were compared using an unsupervised approach that identified similar clusters of correlated features in Chinese and Caucasian datasets. Partition of gene expression data using previously published gene signatures, such as the PAM50 intrinsic gene list and the extracellular matrix (ECM) genes, revealed Chinese and Caucasian subgroups with equivalent gene and miRNA expression profiles. A significant reduction of Luminal-A tumors was observed in the Chinese series. Tissue samples from 78 Chinese (Han Chinese) and 97 Italian (South Europe Caucasian) consecutive primary breast tumors were subjected to gene and miRNA profiling. Tissue specimens, initially collected respectively in the Chinese and Italian hospitals, were all stored, randomly processed and analyzed in identical experimental conditions in the Italian center to minimize pre-analytical, instrumental and computational variability, enabling direct comparison of gene and miRNA profiles from the two groups.
| S-ECPF-GEOD-59594 | biostudies-other
Project description:BACKGROUND:MicroRNAs (miRNAs) are small non-coding RNAs involved in post-transcriptional gene expression regulation and have been described as key regulators of carcinogenesis. Aberrant miRNA expression has been frequently reported in sporadic breast cancers, but few studies have focused on profiling hereditary breast cancers. In this study, we aimed to identify specific miRNA signatures in hereditary breast tumors and to compare with sporadic breast cancer and normal breast tissues. METHODS:Global miRNA expression profiling using NanoString technology was performed on 43 hereditary breast tumors (15 BRCA1, 14 BRCA2, and 14 BRCAX), 23 sporadic breast tumors and 8 normal breast tissues. These normal breast tissues derived from BRCA1- and BRCA2- mutation carriers (n =?5) and non-mutation carriers (n =?3). Subsequently, we performed receiver operating characteristic (ROC) curve analyses to evaluate the diagnostic performance of differentially expressed miRNAs. Putative target genes of each miRNAs considered as potential biomarkers were identified using miRDIP platform and used for pathway enrichment analysis. RESULTS:miRNA expression analyses identified several profiles that were specific to hereditary breast cancers. A total of 25 miRNAs were found to be differentially expressed (fold change: >?2.0 and p <?0.05) and considered as potential biomarkers (area under the curve >?0.75) in hereditary breast tumors compared to normal breast tissues, with an expressive upregulation among BRCAX cases. Furthermore, bioinformatic analysis revealed that these miRNAs shared target genes involved in ErbB, FoxO, and PI3K-Akt signaling pathways. CONCLUSIONS:Our results showed that miRNA expression profiling can differentiate hereditary from sporadic breast tumors and normal breast tissues. These miRNAs were remarkably deregulated in BRCAX hereditary breast cancers. Therefore, miRNA signatures can be used as potential novel diagnostic biomarkers for the prediction of BRCA1/2- germline mutations and may be useful for future clinical management.
| S-EPMC7036228 | biostudies-literature
Project description:Chemotherapy resistance frequently drives tumor progression. However, the underlying molecular mechanisms are poorly characterized. Epithelial-to-mesenchymal transition (EMT) has been shown to correlate with therapy resistance, but the functional link and signaling pathways remain to be elucidated. We report here that miR-30c, a human breast tumor prognostic marker, plays a pivotal role in chemo-resistance by a direct targeting of the actintransporter TWF1, which promotes EMT. An IL-6 family member, IL-11 was identified as a secondary target of TWF1 in the miR-30c signaling pathway. Expression of miR-30c inversely correlated with IL-11 expression in clinical tumors and IL-11 correlated with relapse-free survival in breast cancer patients. Identification of a novel miRNA-mediated pathway that regulates chemo-resistance in breast cancer will facilitate the development of new management strategies. For the primary breast tumor and normal breast samples, both mRNAs (Agilent array data deposited in GSE22049) and miRNAs (Exiqon array data deposited here) profiles have been examined. Patient information include age, tumor subtype and outcome etc. When clustering samples and genes 152 of 757 miRNA passed the filtering criteria on variation across samples; standard deviation > 0.50. Hence, the upper 152 miRNAs in the expression matrix were used in the two-way hierarchical clustering of genes. The matrix numbers are all log2(Hy3/Hy5) ratios, meaning sample/pool. The percentages above the matrix indicates the present call in each sample/slide. When calling of a particular miRNA failed on an array this is indicated as a blank in the row containing this miRNA and in the column corresponding to this array. The criteria for deciding that the calling of a miRNA had failed on a particular array, was that 2 or more of the 4 replicated measures of this miRNA were flagged 1 or 2 (i.e. the signal is below background) by the image analysis software. Further in the expression matrix all capture probes with Hy3 and Hy5 signals lower than 1.5x of the median signal intensity of the given slide is indicated as a blank.
| S-ECPF-GEOD-39543 | biostudies-other
Project description:We performed global microRNA expression profiling of a cohort of primary melanoma patient samples linked to a well-annotated clinical database. The goal of this study was to identify microRNA that are associated to or correlated with various clinical parameters and patient outcomes. Candidate microRNA were identified for building prognostic models and functional testing. 92 primary melanoma (well-annotated with long clinical follow-up) and 9 congenital nevi samples were analyzed to Exiqon miRCURY two color arrays. The reference sample used was an equal combination of all samples analyzed. By this design, ratio data of test sample/reference is mean-centered data.
| S-ECPF-GEOD-62370 | biostudies-other
Project description:We performed global microRNA expression profiling of a cohort of primary melanoma patient samples linked to a well-annotated clinical database. The goal of this study was to identify microRNA that are associated to or correlated with various clinical parameters and patient outcomes. Candidate microRNA were identified for building prognostic models and functional testing. 119 primary melanoma samples were analyzed in two color arrays. The reference sample used was an equal combination of all samples analyzed. By this design, ratio data of test sample/reference is mean-centered data.
| S-ECPF-GEOD-62371 | biostudies-other