The epithelial to mesenchymal transition (EMT) of malignant hepatocytes is a crucial event in hepatocellular carcinoma (HCC) progression and recurrence. We aimed to establish a human model of EMT to examine drug efficacy and specificity in HCC progression. Human HCC cell populations were characterized by immunofluorescence analysis, migration and invasion assays, array comparative genomic hybridization, whole-genome expression profiling and promoter methylation. Therapeutic agents clinically used against HCC were examined for efficacy by determination of IC50 values. Liver cancer cell lines showed either an epithelial or mesenchymal phenotype of which latter showed strong migratory and invasive abilities in vitro. The common cellular origin of both cell types indicated that mesenchymal HCC cells have been derived from epithelial hepatocytes through EMT in the HCC patient. Drug exposure of mesenchymal HCC cells showed higher resistance to the targeted therapeutic agents sorafenib and erlotinib as compared to epithelial HCC cells, which were slightly more resistant to cytostatic drugs. Most remarkably, combined treatment with doxorubicin and sorafenib caused increased susceptibility of both HCC cell types resulting in enhanced drug efficacy. Taken together, this novel model of human HCC allows to monitor the differential effect of liver cancer progression on drug efficacy in pre-clinical studies.
A human model of epithelial to mesenchymal transition to monitor drug efficacy in hepatocellular carcinoma progression.
Cell line
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 SamplesPurpose: We applied cDNA molecule counting using unique molecular identifiers combined with high-throughput sequencing to study the transcriptome of individual mouse embryonic stem cells, with spike-in controls to monitor technical performance. We further examined transcriptional noise in the embryonic stem cells. Overall design: One 96-well plate of single-stranded cDNA libraries generated from 96 single R1 mouse embryonic stem cells sequenced on two lanes, and one 96-well plate of the same libraries further amplified by 9 PCR cycles sequenced on one lane.
Quantitative single-cell RNA-seq with unique molecular identifiers.
No sample metadata fields
View SamplesWe obtained full transcriptome data from single cortical neurons after whole-cell patch-clamp recording (termed “Patch-seq”). By applying “Patch-seq” to cortical neurons, we reveal a close link between biophysical membrane properties and genes coding for neurotransmitter receptors and channels, including well-established and hitherto undescribed subtypes. Overall design: RNA sequencing was performed on a total of 83 individual cells
Integration of electrophysiological recordings with single-cell RNA-seq data identifies neuronal subtypes.
No sample metadata fields
View SamplesMicroRNAs (miRs) function primarily as post-transcriptional negative regulators of gene expression through binding to their mRNA targets. Reliable prediction of a miRs targets is a considerable bioinformatic challenge of great importance for inferring the miRs function. Sequence-based prediction algorithms have high false-positive rates, are not in agreement, and are not biological context specific. Here we introduce CoSMic (Context-Specific MicroRNA analysis), an algorithm that combines sequence-based prediction with miR and mRNA expression data. CoSMic differs from existing methodsit identifies miRs that play active roles in the specific biological system of interest and predicts with less false positives their functional targets. We applied CoSMic to search for miRs that regulate the migratory response of human mammary cells to epidermal growth factor (EGF) stimulation. Several such miRs, whose putative targets were significantly enriched by migration processes were identified. We tested three of these miRs experimentally, and showed that they indeed affected the migratory phenotype; we also tested three negative controls. In comparison to other algorithms CoSMic indeed filters out false positives and allows improved identification of context-specific targets. CoSMic can greatly facilitate miR research in general and, in particular, advance our understanding of individual miRs function in a specific context.
Context-specific microRNA analysis: identification of functional microRNAs and their mRNA targets.
Cell line
View SamplesDerivation and expansion of human umbilical cord blood-derived endothelial colony forming cells under serum-free conditions - a transcriptome analysis.
Optimization of the culturing conditions of human umbilical cord blood-derived endothelial colony-forming cells under xeno-free conditions applying a transcriptomic approach.
Specimen part
View SamplesThe transition from progenitor to differentiated cells is critical for successful organogenesis; subtle alterations in this process can lead to developmental disorders. The anterior heart field (AHF) encompasses a niche in which cardiac progenitors maintain their multipotent and undifferentiated nature by signals from the surrounding tissues, which thus far have been poorly defined. Using systems biology approaches and perturbations of signaling molecules in chick embryos, we revealed a tight crosstalk between the bone morphogenic protein (BMP) and fibroblast growth factor (FGF) signaling pathways within the AHF: BMP4 promotes myofibrillar gene expression and cardiomyocyte contractions, by blocking FGF signaling. Furthermore, inhibition of the FGF-ERK pathway is both sufficient and necessary for these processes, suggesting that FGF signaling blocks premature differentiation of cardiac progenitors in the AHF. Investigating the molecular mechanisms downstream to BMP signaling revealed that BMP4 induced a set of neural crest-related genes; including MSX1, which was sufficient to induce cardiomyocyte differentiation. We suggest that BMP and FGF signaling pathways act via inter- and intra-regulatory loops in multiple tissues, to coordinate the balance between proliferation and differentiation of cardiac progenitors.
BMP-mediated inhibition of FGF signaling promotes cardiomyocyte differentiation of anterior heart field progenitors.
No sample metadata fields
View SamplesOocyte quality is a well- established determinant of embryonic fate. However, the molecular participants and biological markers that affect and predict adequate embryonic development are largely elusive. We have previously reported that oocyte- directed Connexin 43 (Cx43) depletion leads to embryo implantation defects, although both the morphology of the oocyte and processes presiding embryo implantation appear to undergo normally. In the context of previous data determining Cx43 indispensability to oocyte and embryonic development, we show here that the timing of Cx43 depletion from the oocyte and the ovarian follicle is crucial in determining the severity of subsequent embryonic defects. Specifically, we show that the implantation defects of blastocysts resulting from oocyte- directed Cx43- depleted follicles (depletion occurs at day 3 postnatal), is not due to maternal luteal insufficiency but rather depends solely on the defective blastocysts. Gene expression microarray analysis revealed global defects in the expression of ribosomal proteins, translation initiation factors and other genes associated with cellular biosynthetic and metabolic processes in these defective oocytes and specifically blastocysts. We therefore propose that timely expression of Cx43 in the oocyte and ovarian follicles is a major determinant of oocyte developmental competence, by determining the ability of the resulting blastocyst to facilitate biomass expansion and undergo adequate embryo implantation
Blastocyst implantation failure relates to impaired translational machinery gene expression.
Specimen part
View SamplesA549 cells were grown at air liquid interphase (ALI) and exposed to airborne formaldehyde for three days. An exposure platform was developed for this purpose, which provided the volatile analyte in a humidified atmosphere. The platform was composed of a reference and an exposure chamber.
Cellular reactions to long-term volatile organic compound (VOC) exposures.
Cell line
View SamplesTranscriptional responses to stimuli are regulated by tuning rates of transcript production and degradation. Here we show that stimulation-induced changes in transcript production and degradation rates can be inferred from simultaneously measured precursor mRNA (pre-mRNA) and mature mRNA profiles. Our studies on the transcriptome-wide responses to extracellular stimuli in different cellular model systems revealed hitherto unanticipated dynamics of transcript production and degradation rates. Intriguingly, genes with similar mRNA profiles often exhibit marked differences in the amplitude and onset of their production. Moreover, we identify a group of genes, which take advantage of the unexpectedly large dynamic range of production rates to expedite their induction by a transient production overshoot. These findings provide an unprecedented quantitative view on processes governing transcriptional responses, and may have broad implications for understanding their regulation at the transcriptional and post-transcriptional levels.
Coupled pre-mRNA and mRNA dynamics unveil operational strategies underlying transcriptional responses to stimuli.
Cell line, Treatment
View Samples