Lymph node involvement is the most important prognostic factor in breast cancer, but little is known about the underlying molecular changes. First, to identify a molecular signature associated with nodal metastasis, gene expression analysis was performed on a homogeneous group of 96 primary breast tumors, balanced for lymph node involvement. Each tumor was diagnosed as a poorly differentiated, estrogen positive, her2-neu negative invasive ductal cancer. (Affymetrix Human U133 Plus 2.0 microarray chips). A model, including 241 genes was built and validated on an internal and external dataset performed with Affymetrix technology. All samples used for validation had the same characteristics as the initial tumors. The area under the ROC curve (AUC) for the internal dataset was 0.646 and 0.651 for the external datasets. Thus, the molecular profile of a breast tumor reveals information about lymph node involvement, even in a homogeneous group of tumors. However, an AUC of 0.65 indicates only a weak correlation. Our model includes multiple kinases, apoptosis related and zinc ion binding genes. Pathway analysis using the Molecular Signatures Database revealed relevant gene sets (BAF57, Van 't Veer). Next, miRNA profiling was performed on 82/96 tumors using Human MiRNA microarray chips (Illumina). Eight miRNAs were significantly differentially expressed according to lymph node status at a significance level of 0.05, without correcting for multiple testing. The analysis of the inverse correlation between a miRNA and its computationally predicted targets point to general deregulation of the miRNA machinery potentially responsible for lymph node invasion. In conclusion, our results provide evidence that lymph node involvement in breast cancer is not a random process.
Prediction of lymph node involvement in breast cancer from primary tumor tissue using gene expression profiling and miRNAs.
Disease, Disease stage
View Samples16 replication error proficient (RER-/MSI-) and 14 replication error deficient (RER+/MSI+) colorectal cancer cell lines
Replication error deficient and proficient colorectal cancer gene expression differences caused by 3'UTR polyT sequence deletions.
Cell line
View SamplesPericryptal myofibroblasts in the colon and rectum play an important role in regulating the normal colorectal stem cell niche and facilitating tumour progression. Myofibroblasts have previously mostly been distinguished from normal fibroblasts only by the expression of smooth muscle actin (SMA). We now identify AOC3, a surface monoamine oxidase, as a new marker of myofibroblasts by showing that it is the target protein of the myofibroblast reacting monoclonal antibody (mAb), PR2D3. The normal and tumour tissue distribution and the cell line reactivity of AOC3 match that expected for myofibroblasts. We have shown that the surface expression of AOC3 is sensitive to digestion by trypsin and collagenase and that anti-AOC3 antibodies can be used for FACS sorting of myofibroblasts obtained by non-enzymatic procedures. Whole genome microarray mRNA expression profiles of myofibroblasts and skin fibroblasts revealed four additional genes that are significantly expressed differentially between these two cell types; NKX2-3 and LRRC17 are expressed in myofibroblasts and SHOX2 and TBX5 in skin fibroblasts. Transforming Growth Factor (TGF) substantially down-regulated AOC3 expression in myofibroblasts but not in skin fibroblasts, in which it dramatically increased the expression of SMA. A knockdown of NKX2-3 in myofibroblasts caused a decrease of myofibroblast-related gene expression and an increased expression of the fibroblast associated gene, SHOX2, suggesting that NKX2-3 is a key mediator for maintaining myofibroblast characteristics. Our results show that colorectal myofibroblasts, as defined by the expression of AOC3, NKX2-3 and other markers, are a distinctly different cell type from TGF activated fibroblasts.
Myofibroblasts are distinguished from activated skin fibroblasts by the expression of AOC3 and other associated markers.
Specimen part
View SamplesIn the past decade, several transcription factors critical for pancreas development have been identified. Despite this success, many of the cell surface and extracellular factors necessary for proper islet morphogenesis and function remain uncharacterized. Previous studies have shown that transgenic over-expression of the transcription factor HNF6 specifically in the pancreatic endocrine cell lineage resulted in the disruption of islet morphogenesis, including dysfunctional endocrine cell sorting, increased islet size, and failure of islets to migrate away from the ductal epithelium. We exploited the dysmorphic islets in pdx1PBHnf6 animals as a tool to identify factors important for islet morphogenesis. Genome-wide microarray analysis was used to identify differences in the gene expression profiles of late gestation and early postnatal pancreas tissue from wild type and pdx1PBHnf6 animals. We report the identification of genes with an altered expression in HNF6 Tg animals and highlight factors with potential importance in islet morphogenesis.
Gene expression profiling of a mouse model of pancreatic islet dysmorphogenesis.
Specimen part
View SamplesThis study is to identify downstream targets of homeobox gene CDX1. The study assayed the expression of 2 pairs of stably transfected colorectal cancer cell lines: The CDX1 nonexpressing CRC cell line HCT116 was stably transfected with either CDX1 cDNA in the pRC/CMV expression vector (HCT116-CDX1) or with vector control (HCT116-Vec). The CDX1-expressing CRC cell line LS174T was similarly transfected with either a pSilencer vector containing a short sequence of CDX1 siRNA (LS174T-siRNA) , or a pSilencer vector containing a scrambled siRNA sequence as a control (LS174T-Vec).
Gastrointestinal differentiation marker Cytokeratin 20 is regulated by homeobox gene CDX1.
No sample metadata fields
View SamplesThis experiment aims to identify the biological pathways and diseases associated with the cytokine Interleukin 13 (IL-13) using gene expression measured in peripheral blood mononuclear cells (PBMCs). Overall design: The experiment comprised of samples obtained from 3 healthy donors. The expression profiles of in vitro IL-13 stimulation were generated using RNA-seq technology for 3 PBMC samples at 24 hours. The transcriptional profiles of PBMCs without IL-13 stimulation were also generated to be used as controls. An IL-13R-alpha antagonist (Redpath et al. Biochemical Journal, 2013) was introduced into IL-13 stimulated PBMCs and the gene expression levels after 24h were profiled to examine the neutralization of IL-13 signaling by the antagonist.
Combining multiple tools outperforms individual methods in gene set enrichment analyses.
No sample metadata fields
View SamplesInduction of the transcription factor Sox2 from a doxycycline-inducible promoter in iSox2-DAOY medulloblastoma cells.
Elevating SOX2 levels deleteriously affects the growth of medulloblastoma and glioblastoma cells.
Specimen part
View SamplesTo elucidate host processes and components required for the sustained growth and reproduction of the obligate biotrophic fungus Golovinomyces orontii on Arabidopsis thaliana, laser microdissection was used to isolate cells at the site of infection at 5 days postinfection for downstream global Arabidopsis expression profiling. Site-specific profiling increased sensitivity dramatically, allowing us to identify specific host processes, process components, and their putative regulators hidden in previous whole-leaf global expression analyses. For example, 67 transcription factors exhibited altered expression at the powdery mildew (PM) infection site, with subsets of these playing known or inferred roles in photosynthesis, cold/dehydration responses, defense, auxin signaling, and the cell cycle. Using integrated informatics analyses, we constructed putative regulatory networks for a subset of these processes and provided strong support for host cell cycle modulation at the PM infection site. Further experimentation revealed induced host endoreduplication occurred exclusively at the infection site and led us to identify MYB3R4 as a transcriptional regulator of this process. Induced endoreduplication was abrogated in myb3r4 mutants, and G. orontii growth and reproduction were reduced. This suggests that, by increasing gene copy number, localized endoreduplication serves as a mechanism to meet the enhanced metabolic demands imposed by the fungus, which acquires all its nutrients from the plant host.
Laser microdissection of Arabidopsis cells at the powdery mildew infection site reveals site-specific processes and regulators.
Age, Specimen part
View SamplesIn plants, the activation of immunity is often inversely correlated with growth. Mechanisms that plant growth in the context of pathogen challenge and immunity are unclear. Investigating Arabidopsis infection with the powdery mildew fungus, we find that the Arabidopsis atypical E2F DEL1, a transcriptional repressor known to promote cell proliferation, represses accumulation of the hormone salicylic acid (SA), an established regulator of plant immunity. DEL1 deficient plants are more resistant to pathogens and slightly smaller than wild type. The resistance and size phenotypes of DEL1 deficient plants are due to the induction of SA and activation of immunity in the absence of pathogen challenge. Moreover, Enhanced Disease Susceptibility 5 (EDS5), a SA transporter required for elevated SA and immunity, is a direct repressed target of DEL1. Together, these findings indicate that DEL1 control of SA levels contributes to regulating the balance between growth and immunity in developing leaves.
Atypical E2F transcriptional repressor DEL1 acts at the intersection of plant growth and immunity by controlling the hormone salicylic acid.
Age, Specimen part
View SamplesEffects of hyperglycaemia and genetic background differences on renal gene expression
Comparative analysis of methods for gene transcription profiling data derived from different microarray technologies in rat and mouse models of diabetes.
Sex, Age, Specimen part, Disease, Subject
View Samples