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GSE38893
Homo sapiens
16 Downloadable Samples
Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Regulatory factors controlling stem cell identity and self-renewal are often active in aggressive cancers and are thought to promote their growth and progression. TCF3 (also known as TCF7L1) is a member of the TCF/LEF transcription factor family that is central in regulating epidermal and embryonic stem (ES) cell identity. We found that TCF3 is highly expressed in poorly differentiated human breast cancers, preferentially of the basal-like subtype. This suggested that TCF3 is involved in the regulation of breast cancer cell differentiation state and tumorigenicity. Silencing of TCF3 dramatically decreased the ability of breast cancer cells to initiate tumor formation, and led to decreased tumor growth rates. In culture, TCF3 promotes the sphere formation capacity of breast cancer cells and their self-renewal. We found that in contrast to ES cells, where it represses Wnt-pathway target genes, TCF3 promotes the expression of a subset of Wnt-responsive genes in breast cancer cells, while repressing another distinct target subset. In the normal mouse mammary gland Tcf3 is highly expressed in terminal end buds, structures that lead duct development. Primary mammary cells are dependent on Tcf3 for mammosphere formation, and its overexpression in the developing gland disrupts ductal growth. Our results identify TCF3 as a central regulator of tumor growth and initiation, and a novel link between stem cells and cancer.
Publication Title
Control of breast cancer growth and initiation by the stem cell-associated transcription factor TCF3.
Sample Metadata Fields
Cell line, Treatment
View Samples- Hordeum vulgare
- 35 Downloadable Samples
- Affymetrix Barley Genome Array (barley1)
Description
Drought tolerance is a key trait for increasing and stabilizing barley productivity in dry areas worldwide. Identification of the genes responsible for drought tolerance in barley (Hordeum vulgare L.) will facilitate understanding of the molecular mechanisms of drought tolerance, and also genetic improvement of barley through marker-assisted selection or gene transformation. To monitor the changes in gene expression at transcription levels in barley leaves during the reproductive stage under drought conditions, the 22K Affymetrix Barley 1 microarray was used to screen two drought-tolerant barley genotypes, Martin and Hordeum spontaneum 41-1 (HS41-1), and one drought-sensitive genotype Moroc9-75. Seventeen genes were expressed exclusively in the two drought-tolerant genotypes under drought stress, and their encoded proteins may play significant roles in enhancing drought tolerance through controlling stomatal closure via carbon metabolism (NADP malic enzyme (NADP-ME) and pyruvate dehydrogenase (PDH), synthesizing the osmoprotectant glycine-betaine (C-4 sterol methyl oxidase (CSMO), generating protectants against reactive-oxygen-species scavenging (aldehyde dehydrogenase (ALDH), ascorbate-dependant oxidoreductase (ADOR), and stabilizing membranes and proteins (heat-shock protein 17.8 (HSP17.8) and dehydrin 3 (DHN3). Moreover, 17 genes were abundantly expressed in Martin and HS41-1 compared with Moroc9-75 under both drought and control conditions. These genes were likely constitutively expressed in drought-tolerant genotypes. Among them, 7 known annotated genes might enhance drought tolerance through signaling (such as calcium-dependent protein kinase (CDPK) and membrane steroid binding protein (MSBP), anti-senescence (G2 pea dark accumulated protein GDA2) and detoxification (glutathione S-transferase (GST) pathways. In addition, 18 genes, including those encoding l-pyrroline-5-carboxylate synthetase (P5CS), protein phosphatase 2C-like protein (PP2C) and several chaperones, were differentially expressed in all genotypes under drought; thus, they were more likely general drought-responsive genes in barley. These results could provide new insights into further understanding of drought-tolerance mechanisms in barley.
Publication Title
Differentially expressed genes between drought-tolerant and drought-sensitive barley genotypes in response to drought stress during the reproductive stage.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Homo sapiens
- 34 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
Several reports have focused on the identification of biological elements involved in the development of abnormal systemic biochemical alterations in chronic kidney disease, but this abundant literature results most of the time fragmented. To better define the cellular machinery associated to this condition, we employed an innovative high-throughput approach based on a whole transcriptomic analysis and classical biomolecular methodologies. The genomic screening of peripheral blood mononuclear cells revealed that 44 genes were up-regulated in both chronic kidney disease patients in conservative treatment (CKD, n=9) and hemodialysis (HD, n=17) compared to healthy subjects (NORM) (p<0.001, FDR=1%). Functional analysis demonstrated that 11/44 genes were involved in the oxidative phosphorylation system (OXPHOS). Western blotting for COXI and COXIV, key constituents of the complex IV of OXPHOS, performed on an independent testing-group (12 NORM, 10 CKD and 14 HD) confirmed the elevated synthesis of these subunits in CKD/HD patients. However, complex IV activity was significantly reduced in CKD/HD patients compared to NORM (p<0.01). Finally, CKD/HD patients presented higher reactive oxygen species and 8-hydroxydeoxyguanosine levels compared to NORM. Taken together these results suggest, for the first time, that CKD/HD patients may have an impaired mitochondrial respiratory system and this condition may be both the consequence and the cause of an enhanced oxidative stress.
Publication Title
Mitochondrial dysregulation and oxidative stress in patients with chronic kidney disease.
Sample Metadata Fields
Disease, Treatment, Subject
View Samples- Homo sapiens
- 16 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
The mechanisms regulating breast cancer differentiation state are poorly understood. Of particular interest are molecular regulators controlling the highly aggressive and poorly differentiated traits of basal-like breast carcinomas. Here we show that the Polycomb factor EZH2 maintains the differentiation state of basal-like breast cancer cells, and promotes the expression of progenitor-associated and basal-lineage genes. Specifically, EZH2 regulates the composition of basal-like breast cancer cell populations by promoting a bi-lineage differentiation state, in which cells co-express basal- and luminal-lineage markers. We show that human basal-like breast cancers contain a subpopulation of bi-lineage cells, and that EZH2-deficient cells give rise to tumors with a decreased proportion of such cells. Bi-lineage cells express genes that are active in normal luminal progenitors, and possess increased colony formation capacity, consistent with a primitive differentiation state. We found that GATA3, a driver of luminal differentiation, performs a function opposite to EZH2, acting to suppress bi-lineage identity and luminal progenitor gene expression. GATA3 levels increase upon EZH2 silencing, leading to the observed decrease in bi-lineage cell numbers. Our findings reveal a novel role for EZH2 in controlling basal-like breast cancer differentiation state and intra-tumoral cell composition.
Publication Title
EZH2 promotes a bi-lineage identity in basal-like breast cancer cells.
Sample Metadata Fields
Specimen part, Cell line, Treatment
View Samples- Homo sapiens
- 20 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Mammary epithelial cells MCF10A and HER2 overexpressing MCF10A cells were grown on matrigel in the absence or presence of epidermal growth factor. Cells were lysed and RNA was collected at 1.5,3,5,7,9 days.
Publication Title
Modeling ductal carcinoma in situ: a HER2-Notch3 collaboration enables luminal filling.
Sample Metadata Fields
Cell line, Treatment
View Samples- Homo sapiens
- 32 Downloadable Samples
- Affymetrix Human Exon 1.0 ST Array [transcript (gene) version (huex10st)
Description
Alternative promoters (APs) occur in >30% protein-coding genes and contribute to proteome diversity. However, large-scale analyses of AP regulation are lacking, and little is known about their potential physiopathologic significance. To better understand the transcriptomic impact of estrogens, which play a major role in breast cancer, we analyzed gene and AP regulation by estradiol in MCF7 cells using pan-genomic exon arrays. We thereby identified novel estrogen-regulated genes, and determined the regulation of AP-encoded transcripts in 150 regulated genes. In <30% cases, APs were regulated in a similar manner by estradiol, while in >70% cases, they were regulated differentially. The patterns of AP regulation correlated with the patterns of estrogen receptor (ER) and CCCTC-binding factor (CTCF) binding sites at regulated gene loci. Interestingly, among genes with differentially regulated APs, we identified cases where estradiol regulated APs in an opposite manner, sometimes without affecting global gene expression levels. This promoter switch was mediated by the DDX5/DDX17 family of ER coregulators. Finally, genes with differentially regulated promoters were preferentially involved in specific processes (e.g., cell structure and motility, and cell cycle). We show in particular that isoforms encoded by the NET1 gene APs, which are inversely regulated by estradiol, play distinct roles in cell adhesion and cell cycle regulation, and that their expression is differentially associated with prognosis in ER+ breast cancer. Altogether, this study identifies the patterns of AP regulation in estrogen-regulated genes, demonstrates the contribution of AP-encoded isoforms to the estradiol-regulated transcriptome, as well as their physiopathologic significance in breast cancer.
Publication Title
Estrogen regulation and physiopathologic significance of alternative promoters in breast cancer.
Sample Metadata Fields
Disease, Disease stage, Cell line, Time
View Samples- Glycine max
- 11 Downloadable Samples
- Affymetrix Soybean Genome Array (soybean)
Description
This study was designed to identify candidate genes associated with iron efficiency in soybeans. Two genotypes, Clark (PI548553) and IsoClark (PI547430), were grown in both iron sufficient (100uM Fe(NO3)3) and iron deficient (50uM Fe(NO3)3) hydroponics conditions. The second trifoliate was harvested for RNA extraction for the microarray experiment. Candidate genes were identified by comparing gene expression profiles within genotypes between the two iron growth conditions.
Publication Title
Integrating microarray analysis and the soybean genome to understand the soybeans iron deficiency response.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 3 Downloadable Samples
- Affymetrix Human Gene 2.0 ST Array (hugene20st)
Description
Osteoarthritis (OA) of the hand is a common disease resulting in pain and impaired function. The pathogenesis of hand OA (HOA) is elusive and models to study it have not been described so far. Culture of chondrocytes is a model to study the development of cartilage degeneration, which is a hallmark of OA and well established in OA of the knee and hip. In the current study we investigated the feasibility human chondrocyte culture derived from proximal interphalangeal (PIP) finger joints of dissecting room cadavers. Index and middle fingers without signs of osteoarthritis were obtained from 30 cadavers using two different protocols. Hyaline cartilage from both articulating surfaces of the proximal interphalangeal (PIP) joint was harvested and digested in collagenase. Cultured chondrocytes were monitored for contamination, viability, and expression of chondrocyte specific genes. Chondrocytes derived from knee joints of the cadavers were cultured under identical conditions. Gene expression comparing chondrocytes from PIP and knee joints was carried out using Affymetrix GeneChip Human 2.0 ST arrays. The resulting differentially expressed genes were validated by real-time PCR and immunohistochemistry.Chondrocytes harvested up to 101 hours after death of the donors were viable. mRNA expression of collagen 2A1, aggrecan and Sox9 was significantly higher in chondrocytes as compared to cultured fibroblasts. Comparison of gene expression by chondrocytes from PIP and knee joints yielded 528 differentially expressed genes. Chondrocytes from the same joint region had a higher grade of similarity than chondrocytes of the same individual. These results were validated using real-time PCR and immunohistochemistry.We demonstrate for the first time a reliable method for culture of chondrocytes derived from PIP joints. PIP chondrocytes show a specific gene expression pattern and could be used as tool to study cartilage degeneration in HOA.
Publication Title
Chondrocyte cultures from human proximal interphalangeal finger joints.
Sample Metadata Fields
Sex, Specimen part
View Samples- Homo sapiens
- 32 Downloadable Samples
Illumina HiSeq 2500
Description
Differentiation events contribute to cellular heterogeneity within tumors and influence disease progression and response to therapy. Here we dissect the mechanisms controlling intratumoral heterogeneity within basal-like breast cancers. We show that cancer cells can transition between a differentiation state related to that of normal luminal progenitors and a state closer to that of mature luminal cells, and that this occurs through asymmetric cell divisions. The Polycomb factor EZH2 and the Notch pathway act to increase the rates of symmetric divisions that produce progenitor-like cells, while the FOXA1 transcription factor promotes asymmetric divisions that reduce the numbers of such cells. Through functional screening, we identified a group of regulators that control cancer cell differentiation state and the relative proportions of tumor cell subpopulations. Our findings highlight the regulation of asymmetric cell divisions as a mechanism controlling intratumoral heterogeneity, and identify molecular pathways that control breast cancer cellular composition. Overall design: Expression profiles of HCC70 cells expressing shRNAs targeting regulatory factors that influence basal-like cancer cell population composition
Publication Title
Regulation of Cellular Heterogeneity and Rates of Symmetric and Asymmetric Divisions in Triple-Negative Breast Cancer.
Sample Metadata Fields
Cell line, Subject
View Samples- Homo sapiens
- 6 Downloadable Samples
- Illumina HiSeq 2500
Description
Differentiation events contribute to cellular heterogeneity within tumors and influence disease progression and response to therapy. Here we dissect the mechanisms controlling intratumoral heterogeneity within basal-like breast cancers. We show that cancer cells can transition between a differentiation state related to that of normal luminal progenitors and a state closer to that of mature luminal cells, and that this occurs through asymmetric cell divisions. The Polycomb factor EZH2 and the Notch pathway act to increase the rates of symmetric divisions that produce progenitor-like cells, while the FOXA1 transcription factor promotes asymmetric divisions that reduce the numbers of such cells. Through functional screening, we identified a group of regulators that control cancer cell differentiation state and the relative proportions of tumor cell subpopulations. Our findings highlight the regulation of asymmetric cell divisions as a mechanism controlling intratumoral heterogeneity, and identify molecular pathways that control breast cancer cellular composition. Overall design: Expression profiles of three cell subpopulations – K18+, K18+K14+ and K18+Vim+ – sorted from the breast cancer cell lines HCC70 and MDA-MB-468
Publication Title
Regulation of Cellular Heterogeneity and Rates of Symmetric and Asymmetric Divisions in Triple-Negative Breast Cancer.
Sample Metadata Fields
Cell line, Subject
View Samples