The routine workflow for invasive cancer diagnostics is based on biopsy processing by formalin fixation and subsequent paraffin embedding. Formalin-fixed paraffin-embedded (FFPE) tissue samples are easy to handle, stable and particularly suitable for morphologic evaluation, immunohistochemistry and in situ hybridization. However, it has become a paradigm that these samples cannot be used for genome-wide expression analysis with microarrays. To oppose this view, we present a pilot microarray study using FFPE core needle biopsies from breast cancers as RNA source. We found that microarray probes interrogating sequences near the poly-A-tail of the transcribed genes were well suitable to measure RNA levels in FFPE core needle biopsies. For the ER and the HER2 gene, we observed strong correlations between RNA levels measured in these probe sets and protein expression determined by immunohistochemistry (p = 0.000003 and p = 0.0022). Further, we have identified a signature of 364 genes that correlated with ER protein status and a signature of 528 genes that correlated with HER2 protein status. Many of these genes (ER: 60%) could be confirmed by analysis of an independent publicly available data set. Finally, a hierarchical clustering of the biopsies with respect to three recently reported gene expression grade signatures resulted in widely stable low and high expression grade clusters that correlated with the pathological tumor grade. These findings support the notion that clinically relevant information can be gained from microarray based gene expression profiling of FFPE cancer biopsies. This opens new opportunities for the integration of gene expression analysis into the workflow of invasive cancer diagnostics as well as translational research in the setting of clinical studies.
Genome-wide gene expression profiling of formalin-fixed paraffin-embedded breast cancer core biopsies using microarrays.
Disease stage
View SamplesOvarian carcinoma has the highest mortality rate among gynecological malignancies. In this project, we investigated the hypothesis that molecular markers are able to predict outcome of ovarian cancer independently of classical clinical predictors, and that these molecular markers can be validated using independent data sets. We applied a semi-supervised method for prediction of patient survival. Microarrays from a cohort of 80 ovarian carcinomas (TOC cohort) were used for the development of a predictive model, which was then evaluated in an entirely independent cohort of 118 carcinomas (Duke cohort). A 300 gene ovarian prognostic index (OPI) was generated and validated in a leave-one-out approach in the TOC cohort (Kaplan-Meier analysis, p=0.0087). In a second validation step the prognostic power of the OPI was confirmed in an independent data set (Duke cohort, p=0.0063). In multivariate analysis, the OPI was independent of the postoperative residual tumour, the main clinico-pathological prognostic parameter with an adjusted hazard ratio of 6.4 (TOC cohort, CI 1.8 23.5, p=0.0049) and 1.9 (Duke cohort, CI 1.2 3.0, p=0.0068). We constructed a combined score of molecular data (OPI) and clinical parameters (residual tumour), which was able to define patient groups with highly significant differences in survival. The integrated analysis of gene expression data as well as residual tumour can be used for optimised assessment of prognosis. As traditional treatment options are limited, this analysis may be able to optimise clinical management and to identify those patients that would be candidates for new therapeutic strategies.
A prognostic gene expression index in ovarian cancer - validation across different independent data sets.
Specimen part, Disease stage
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Influence of hyperthyroid conditions on gene expression in extraocular muscles of rats.
No sample metadata fields
View SamplesExtraocular muscles (EOMs) are a highly specialized type of tissue with a wide range of unique properties, including characteristic innervation, development, and structural proteins. Even though EOMs are frequently and prominently involved in thyroid-associated diseases, little is known about the immediate effects of thyroid hormone on these muscles. In order to create a comprehensive profile of changes in gene expression levels in EOMs induced by thyroid hormone, hyperthyroid conditions were simulated by treating adult Sprague-Dawley rats with intraperitoneal injections of 25 g T3 per 100 g body weight over the course of six weeks; subsequently, microarray analysis was used to determine changes in mRNA levels in EOMs from T3-treated animals relative to untreated controls.
Influence of hyperthyroid conditions on gene expression in extraocular muscles of rats.
No sample metadata fields
View SamplesExtraocular muscles (EOMs) are a highly specialized type of tissue with a wide range of unique properties, including characteristic innervation, development, and structural proteins. Even though EOMs are frequently and prominently involved in thyroid-associated diseases, little is known about the immediate effects of thyroid hormone on these muscles. In order to create a comprehensive profile of changes in gene expression levels in EOMs induced by thyroid hormone, hyperthyroid conditions were simulated by treating adult Sprague-Dawley rats with intraperitoneal injections of 25 g T3 per 100 g body weight over the course of six weeks; subsequently, microarray analysis was used to determine changes in mRNA levels in EOMs from T3-treated animals relative to untreated controls.
Influence of hyperthyroid conditions on gene expression in extraocular muscles of rats.
No sample metadata fields
View SamplesEquine lameller tissues were collected to compare normal vs laminitis generated differences in transcriptom level.
Gene expression in the lamellar dermis-epidermis during the developmental phase of carbohydrate overload-induced laminitis in the horse.
No sample metadata fields
View SamplesPURPOSE. To determine global mRNA expression levels in the corneal and conjunctival epithelia and identify transcripts that exhibit preferential tissue expression.
Comparative analysis of human conjunctival and corneal epithelial gene expression with oligonucleotide microarrays.
No sample metadata fields
View SamplesPurpose: To examine and characterize the expression profile of genes expressed at the neuromuscular junctions (NMJs) of extraocular muscles (EOMs) in comparison to the NMJs of tibialis anterior muscle (TA).
Identification of the neuromuscular junction transcriptome of extraocular muscle by laser capture microdissection.
Specimen part
View SamplesMany symptoms associated with allergic asthma result from the sequelae of type 2 inflammation. Interleukin (IL)-25 promotes type 2 inflammatory responses, and T2M cells represent an IL-4 and IL-13 producing granulocytic IL-25 responsive population.
Interleukin-25 induces type 2 cytokine production in a steroid-resistant interleukin-17RB+ myeloid population that exacerbates asthmatic pathology.
Specimen part
View SamplesKnockdowns of c-JUN and JUND had opposite effects on PC3 prostate cell migration. We predicted that c-JUN and JUND control the same set of cell migration genes, but in opposite directions. To test this hypothesis, mRNA with expression changes in c-JUN and JUND knockdown PC3 cell lines were compared to mRNA levels in control (luciferase knockdown) PC3 cells by RNA-seq. Overall design: mRNA profiles of luciferase knockdown (WT), c-Jun knockdown, and Jun-D knockdown in PC3 cells were generated using deep sequencing, in triplicate, using Illumina HiSeq. Knockdowns were stable shRNA expression from a lentiviral construct selected with puromycin.
Extracellular signal-regulated kinase signaling regulates the opposing roles of JUN family transcription factors at ETS/AP-1 sites and in cell migration.
No sample metadata fields
View Samples