The molecular biology of metastatic potential in melanoma has been studied many times previously and changes in the expression of many genes have been linked to metastatic behaviour. What is lacking is a systematic characterization of the regulatory relationships between genes whose expression is related to metastatic potential. Such a characterization would produce a molecular taxonomy for melanoma which could feasibly be used to identify epigenetic mechanisms behind changes in metastatic behaviour. To achieve this we carried out three separate DNA microarray analyses on a total of 86 cultures of melanoma. Significantly, multiple testing correlation revealed that previous reports describing correlations of gene expression with activating mutations in BRAF or NRAS were incorrect and that no gene expression patterns correlate with the mutation status of these MAPK pathway components. Instead, we identified three different sample cohorts (A, B and C) and found that these cohorts represent melanoma groups of differing metastatic potential. Cohorts A and B were susceptible to TGFbeta-mediated inhibition of proliferation and had low motility. Cohort C was resistant to TGFb and demonstrated high motility. Meta-analysis of the data against previous studies linking gene expression and phenotype confirmed that cohorts A and C represent transcription signatures of weakly and strongly metastatic melanomas, respectively. Gene expression co-regulation suggested that signalling via TGFbeta-type and Wnt pathways underwent considerable change between cohorts. These results suggest a model for the transition from weakly to strongly metastatic melanomas in which TGFbeta-type signalling upregulates genes expressing vasculogenic/extracellular matrix remodeling factors and Wnt signal inhibitors, coinciding with a downregulation of genes downstream of Wnt signalling.
Metastatic potential of melanomas defined by specific gene expression profiles with no BRAF signature.
Sex, Age, Specimen part
View SamplesThe molecular biology of metastatic potential in melanoma has been studied many times previously and changes in the expression of many genes have been linked to metastatic behaviour. What is lacking is a systematic characterization of the regulatory relationships between genes whose expression is related to metastatic potential. Such a characterization would produce a molecular taxonomy for melanoma which could feasibly be used to identify epigenetic mechanisms behind changes in metastatic behaviour. To achieve this we carried out three separate DNA microarray analyses on a total of 86 cultures of melanoma. Significantly, multiple testing correlation revealed that previous reports describing correlations of gene expression with activating mutations in BRAF or NRAS were incorrect and that no gene expression patterns correlate with the mutation status of these MAPK pathway components. Instead, we identified three different sample cohorts (A, B and C) and found that these cohorts represent melanoma groups of differing metastatic potential. Cohorts A and B were susceptible to TGFbeta-mediated inhibition of proliferation and had low motility. Cohort C was resistant to TGFb and demonstrated high motility. Meta-analysis of the data against previous studies linking gene expression and phenotype confirmed that cohorts A and C represent transcription signatures of weakly and strongly metastatic melanomas, respectively. Gene expression co-regulation suggested that signalling via TGFbeta-type and Wnt pathways underwent considerable change between cohorts. These results suggest a model for the transition from weakly to strongly metastatic melanomas in which TGFbeta-type signalling upregulates genes expressing vasculogenic/extracellular matrix remodeling factors and Wnt signal inhibitors, coinciding with a downregulation of genes downstream of Wnt signalling.
Metastatic potential of melanomas defined by specific gene expression profiles with no BRAF signature.
No sample metadata fields
View SamplesSympathetic neurons of SCG (Superior Cervical Ganglia) send axonal projections either along the external carotid arteries to innervate the salivary glands, or along the internal carotid arteries to the lacrimal and pineal glands, the eye, blood vessels and skin of the head, and the mucosa of the oral and nasal cavities. Previous studies using Wnt1Cre and R26R have defined the neural crest and mesodermal origins of vascular smooth muscle in the heart outflow tract and great vessels, although not specifically of the segments that are relevant for the projections of the SCG neurons. The third pharyngeal arch arteries are lined by neural crest-derived smooth muscle, and consequently, their derivatives, including the entirety of the external carotid arteries and only the base of the internal carotid arteries, also have a neural crest origin. In contrast, the dorsal aortae are lined by smooth muscle that is mesodermal in origin, and as a result, the internal carotid arteries from just above their origination from the common carotid arteries have a mesoderm-derived smooth muscle layer. To address the possibility that guidance cues for SCG neurons are selectively expressed by the external carotid vs. the internal carotid arteries, we isolated these segments of the vasculature from mouse embryos at E13.5 and extracted RNA to screen microarrays for differentially expressed genes.
Endothelins are vascular-derived axonal guidance cues for developing sympathetic neurons.
No sample metadata fields
View SamplesGene expression profiles of peripheral blood samples from C57BL/6 mice exposed with ionizing radiation.
Biological pathway selection through Bayesian integrative modeling.
Sex, Specimen part, Treatment, Time
View SamplesIn mouse, the adrenocortical dysplasia (acd) phenotype shows limb and body axis anomalies, as a result of p53-dependent apoptosis, and perinatal lethality. The p53 deficiency partially rescues anomalies, but not perinatal lethality, implicating the involvement of p53-independent mechanisms in the acd phenotype. Differentially expressed genes in acd mutant and double mutant embryos were identified. p53-dependent and independent pathways contributing to acd phenotype were characterized.
High-throughput gene expression analysis identifies p53-dependent and -independent pathways contributing to the adrenocortical dysplasia (acd) phenotype.
Specimen part
View SamplesmTOR inhibitor rapamycin is a well-known anticancer and immunosuppressant agent. Effects of rapamycin on zebrafish cells have not been previously studied using transcriptome analyses.
Functionally conserved effects of rapamycin exposure on zebrafish.
Cell line, Treatment
View SamplesTranscriptomic profiling of breast cancer cells incubated in vitro with surgical wound fluids from patients with breast cancer reveals similarities in the biological response induced by intraoperative radiation therapy and the radiation-induced bystander effect
Surgical Wound Fluids from Patients with Breast Cancer Reveal Similarities in the Biological Response Induced by Intraoperative Radiation Therapy and the Radiation-Induced Bystander Effect-Transcriptomic Approach.
Specimen part, Cell line
View SamplesWe used phytochemical profiling techniques to generate a list of compounds present in each of 13 Equisetum arvense samples sourced globally. We used microarrays to detail the global programme of gene expression underlying the treatment of the model system Saccharomyces cerevisiae to a chosen number of these extracts. A thorough bioinformatic analysis was performed to identify the relationship between phytochemical and gene expression response profiles.
The Saccharomyces cerevisiae transcriptome as a mirror of phytochemical variation in complex extracts of Equisetum arvense from America, China, Europe and India.
No sample metadata fields
View SamplesCoupling immunity and development is essential to ensure survival despite changing internal conditions in the organism. The metamorphosis of the fruit fly represents a striking example of drastic and systemic physiological changes that need to be integrated with the innate immune system. However, the mechanisms that coordinate development and immune cell activity in the transition from larva to adult in Drosophila remain to elucidate. The steroid hormone ecdysone is known to act as a key coordinator of metamorphosis. This hormone activates a nuclear receptor, the Ecdysone Receptor (EcR), which acts as a heterodimer with its partner Ultraspiracle (USP). Together, they activate the transcription of primary response genes, which in turn activate the transcription of a battery of late response genes. We have revealed that regulation of macrophage-like cells (hemocytes) by the steroid hormone ecdysone is essential for an effective innate immune response over metamorphosis. We have shown that in response to ecdysone signalling, hemocytes rapidly up regulate actin dynamics, motility and phagocytosis of apoptotic corpses, and acquire the ability to chemotax to damaged epithelia. Most importantly, individuals lacking ecdysone-activated hemocytes are defective in bacterial phagocytosis and are fatally susceptible to infection by bacteria ingested at larval stages, despite the normal systemic production of antimicrobial peptides. This decrease in survival is comparable to the one observed in pupae lacking immune cells altogether, indicating that ecdysone-regulation is essential to hemocyte immune functions and survival after infection.
Steroid hormone signaling is essential to regulate innate immune cells and fight bacterial infection in Drosophila.
Specimen part
View SamplesEnterotoxigenic Escherichia coli (ETEC) is a globally prevalent cause of diarrhea. We report the first gene expression analysis of the human host response to experimental challenge with ETEC.
Transcriptomic Analysis of the Host Response and Innate Resilience to Enterotoxigenic Escherichia coli Infection in Humans.
Time
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