Background: We hypothesize that important genomic differences between breast cancer subtypes occur early in carcinogenesis. Therefore, gene expression might distinguish histologically normal breast epithelium (NlEpi) from breasts containing estrogen receptor positive (ER+) compared with estrogen receptor negative (ER-) cancers.
Gene expression profiles of estrogen receptor-positive and estrogen receptor-negative breast cancers are detectable in histologically normal breast epithelium.
Specimen part, Disease, Disease stage
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Expression of microRNA and their gene targets are dysregulated in preinvasive breast cancer.
Sex, Age, Specimen part, Disease
View SamplesIntroduction: microRNAs (miRNAs) are short non-coding RNAs that negatively regulate gene expression and may play a causal role in invasive breast cancer. Since many genetic aberrations of invasive disease are detectable in earlier stages, we hypothesized that miRNA expression dysregulation and the predicted changes in gene expression would also be found in early breast neoplasias. Methods: Expression profiling of 365 miRNAs by RT-qPCR was combined with laser-capture microdissection to obtain an epithelial specific miRNA expression signature of normal breast epithelium (n=9) and of paired samples of histologically normal epithelium (HN) and ductal carcinoma in situ (DCIS) (n=16). To determine how miRNAs may control the expression of co-dysregulated mRNAs we also performed gene expression microarray analysis in the same paired HN and DCIS samples and integrated this with miRNA-target prediction. We further validated several target pairs by modulating the expression levels of miRNAs in MCF7 cells and measured the expression of target mRNAs and proteins. Results: Thirty-five miRNAs were aberrantly expressed between RM, HN and DCIS. Twenty-nine miRNAs and 420 mRNAs were aberrantly expressed between HN and DCIS. Combining these two datasets with miRNA-target prediction we identified two established target pairs (miR-195:CCND1 and miR-21:NFIB) and tested several novel miRNA:mRNA target pairs. Over-expression of the putative tumor-suppressor miR-125b, under-expressed in DCIS, repressed the expression of MEMO1, which is required for ErbB2-driven cell motility (also a target of miR-125b); and NRIP1/RIP140, which modulates the transcriptional activity of the estrogen receptor. Knockdown of the putative oncogenic miRNAs miR-182 and miR-183, both highly over-expressed in DCIS, increased the expression of CBX7 (which regulates E-cadherin expression), DOK4, NMT2, and EGR1. Augmentation of CBX7 by knockdown of miR-182 expression, in turn, positively regulated the expression of E-cadherin, a key protein involved in maintaining normal epithelial cell morphology which is commonly lost during neoplastic progression. Conclusions: These data provide the first miRNA expression profile of normal breast epithelium and of pre-invasive breast carcinoma. Further, we demonstrate that altered miRNA expression can modulate gene expression changes that characterize these early cancers. We conclude that miRNA dysregulation likely plays a substantial role in early breast cancer development.
Expression of microRNA and their gene targets are dysregulated in preinvasive breast cancer.
Sex, Age, Specimen part, Disease
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Surgery-Induced Weight Loss Is Associated With the Downregulation of Genes Targeted by MicroRNAs in Adipose Tissue.
Sex, Specimen part, Subject
View SamplesMolecular mechanisms associated with pathophysiological variations in adipose tissue (AT) are not fully recognized. The main aim of this study was to identify novel candidate genes and miRNAs that may contribute to the pathophysiology of hyperplastic AT. Therefore, wide gene and microRNA (miRNA) expression patterns were assessed in subcutaneous AT of 16 morbidly obese women before and after surgery-induced weight loss. Validation of microarray data was performed by quantitative real-time PCR both longitudinally (n=25 paired samples) and cross-sectionally (25 obese vs. 26 age-matched lean women). Analyses in macrophages and differentiated human adipocytes were also performed to try to comprehend the associations found in AT. 5,018 different probe sets identified significant variations in gene expression after treatment (adjusted p-value<0.05). A set of 16 miRNAs also showed significant modifications. Functional analysis revealed changes in genes and miRNAs associated with cell cycle, development and proliferation, lipid metabolism, and the inflammatory response. Canonical affected pathways included TREM1, PI3K, and EIF2 signaling, hepatic stellate cell activation, and mitochondrial function. Increased expression of SLC27A2, ELOVL6, FASN, GYS2, LGALS12, PKP2, ACLY, and miR-575, as well as decreased FOS, EGFL6, PRG4, AQP9, DUSP1, RGS1, EGR1, SPP1, LYZ, miR-130b, miR-221, and miR-155, were further validated. The clustering of similar expression patterns for gene products with related functions revealed molecular footprints, some of them described for the first time, which elucidate changes in biological processes after the surgery-induced weight loss.
Surgery-Induced Weight Loss Is Associated With the Downregulation of Genes Targeted by MicroRNAs in Adipose Tissue.
Sex, Specimen part, Subject
View SamplesThe Oscillation Zone (OZ) of unsynchronized roots was disected and divided into an upper (OZ2) and lower (OZ1) half .
Oscillating gene expression determines competence for periodic Arabidopsis root branching.
Age, Specimen part
View SamplesNormal-appearing epithelium of cancer patients can harbor occult genetic abnormalities. Data comprehensively comparing gene expression between histologically normal breast epithelium of breast cancer patients and cancer-free controls are limited. The present study compares global gene expression between these groups. We performed microarrays using RNA from microdissected histologically normal terminal ductal-lobular units (TDLU) from 2 groups: (i) cancer normal (CN) (TDLUs adjacent to untreated ER1 breast cancers (n = 14)) and (ii) reduction mammoplasty (RM) (TDLUs of age-matched women without breast disease (n = 15)). Cyber-T identi?ed differentially expressed genes. Quantitative RT-PCR (qRT-PCR), immunohistochemistry (IHC), and comparison to independent microarray data including 6 carcinomas in situ (CIS), validated the results. Gene ontology (GO), UniProt and published literature evaluated gene function. About 127 probesets, corresponding to 105 genes, were differentially expressed between CN and RM (p < 0.0009, corresponding to FDR <0.10). 104/127 (82%) probesets were also differentially expressed between CIS and RM, nearly always (102/104 (98%)) in the same direction as in CN vs. RM. Two-thirds of the 105 genes were implicated previously in carcinogenesis. Overrepresented functional groups included transcription, G-protein coupled and chemokine receptor activity, the MAPK cascade and immediate early genes. Most genes in these categories were under-expressed in CN vs. RM. We conclude that global gene expression abnormalities exist in normal epithelium of breast cancer patients and are also present in early cancers. Thus, cancer-related pathways may be perturbed in normal epithelium. These abnormalities could be markers of disease risk, occult disease, or the tissues response to an existing tumor.
Gene expression abnormalities in histologically normal breast epithelium of breast cancer patients.
Specimen part, Disease, Disease stage, Subject
View SamplesGene expression in histologically normal epithelium from breast cancer patients and cancer-free prophylactic mastectomy patients share a similar profile
Gene expression in histologically normal epithelium from breast cancer patients and from cancer-free prophylactic mastectomy patients shares a similar profile.
Specimen part, Disease, Disease stage
View SamplesFoxO6 is expressed in the brain, craniofacial region and somite, but the precise role of FoxO6 in craniofacial development remain unknown. We found that FoxO6 is expressed specifically in craniofacial tissues and FoxO6-/- mice undergo expansion of the face, frontal cortex, olfactory component and skull.
FoxO6 regulates Hippo signaling and growth of the craniofacial complex.
Specimen part
View SamplesThe underlying mechanisms which are responsible and govern early haematopoietic differentiation during development are poorly understood. Gene expression comparison between pluripotent human embryonic stem cells and earliest haematopoietic progenitors may reveal novel transcripts and pathways and provide crucial insight into early haematopoietic lineage specification and development.
Large-scale transcriptional profiling and functional assays reveal important roles for Rho-GTPase signalling and SCL during haematopoietic differentiation of human embryonic stem cells.
Specimen part, Cell line
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