Project description:Comparative oncology is a developing research discipline that is being used to assist our understanding of human neoplastic diseases. Companion canines are a preferred animal oncology model due to spontaneous tumor development and similarity to human disease at the pathophysiological level. We use a paired RNA sequencing (RNA-Seq)/microarray analysis of a set of four normal canine lymph nodes and ten canine lymphoma fine needle aspirates to identify technical biases and variation between the technologies and convergence on biological disease pathways. Surrogate Variable Analysis (SVA) provides a formal multivariate analysis of the combined RNA-Seq/microarray data set. Applying SVA to the data allows us to decompose variation into contributions associated with transcript abundance, differences between the technology, and latent variation within each technology. A substantial and highly statistically significant component of the variation reflects transcript abundance, and RNA-Seq proved more sensitive for detection of transcripts expressed at low levels. Latent random variation among RNA-Seq samples is also distinct in character from that impacting microarray samples. In particular, we observed variation between RNA-Seq samples that reflects transcript GC content. Platform-independent variable decomposition without a priori knowledge of the sources of variation using SVA represents a generalizable method for accomplishing cross-platform data analysis. We identified genes differentially expressed between normal lymph nodes of disease free dogs and a subset of the diseased dogs diagnosed with B-cell lymphoma using each technology. There is statistically significant overlap between the RNA-Seq and microarray sets of differentially expressed genes. Analysis of overlapping genes in the context of biological systems suggests elevated expression and activity of PI3K signaling in B-cell lymphoma biopsies compared with normal biopsies, consistent with literature describing successful use of drugs targeting this pathway in lymphomas.
Project description:Comparative oncology is a developing research discipline that is being used to assist our understanding of human neoplastic diseases. Companion canines are a preferred animal oncology model due to spontaneous tumor development and similarity to human disease at the pathophysiological level. We use a paired RNA sequencing (RNA-Seq)/microarray analysis of a set of four normal canine lymph nodes and ten canine lymphoma fine needle aspirates to identify technical biases and variation between the technologies and convergence on biological disease pathways. Surrogate Variable Analysis (SVA) provides a formal multivariate analysis of the combined RNA-Seq/microarray data set. Applying SVA to the data allows us to decompose variation into contributions associated with transcript abundance, differences between the technology, and latent variation within each technology. A substantial and highly statistically significant component of the variation reflects transcript abundance, and RNA-Seq proved more sensitive for detection of transcripts expressed at low levels. Latent random variation among RNA-Seq samples is also distinct in character from that impacting microarray samples. In particular, we observed variation between RNA-Seq samples that reflects transcript GC content. Platform-independent variable decomposition without a priori knowledge of the sources of variation using SVA represents a generalizable method for accomplishing cross-platform data analysis. We identified genes differentially expressed between normal lymph nodes of disease free dogs and a subset of the diseased dogs diagnosed with B-cell lymphoma using each technology. There is statistically significant overlap between the RNA-Seq and microarray sets of differentially expressed genes. Analysis of overlapping genes in the context of biological systems suggests elevated expression and activity of PI3K signaling in B-cell lymphoma biopsies compared with normal biopsies, consistent with literature describing successful use of drugs targeting this pathway in lymphomas. RNA was extracted from 10 lymphoma fine needle aspirates attained from companion canines. 4 normal lymph node samples were obtained from a Beagle breeding colony at Pfizer, including two samples that were taken from the same dog but different lymph nodes. This Series represents the Affymetrix gene expression only, not RNA-Seq referenced above. RNA-Seq data have been submitted to SRA as SRA059558.
Project description:In order to gain insight into epithelial morphogenesis and the influence of culture geometry on gene expression patterns, Madin Darby Canine Kidney (MDCK) epithelial cells where grown in 2-dimensional (2D) culture or 3-dimensional (3D) culture . MDCK cells cultured in 2D were plated atop a pre-solidified type I collagen gel. Cells cultured under these conditions grew as flat monolayer sheets. In 3D culture, cells are embedded within type I collagen gel. Cells grown under these conditions form large spherical cysts with hollow central lumens. We anticipate, therefore, that these results provide insight into the mechanisms that regulate epithelial cystogenesis. Cells grown in the 2D or 3D geometries were collected from digested type I collagen gels on day 8. The 2D MDCK cells were treated as the control condition and there gene expression patterns were compared to those of 3D grown cells, which served as the experimental condition.
Project description:In these microarray experiments, we characterize the gene expression of mammary epithelial cells (MCF10A cells) grown in either a traditional monolayer cell culture setting (2D) or on Matrigel, which induces single MCF10A cells to form organized acinar structures (3D). Morphogenesis of mammary epithelial cells into organized acinar structures in vitro is accompanied by widespread changes in gene expression patterns, including a substantial decrease in expression of Myc. The purpose of this study was to analyze the impact of morphogenesis and organization on gene expression with respect to changes in overall gene expression and Myc target gene expression. MCF10A cells were cultured in 2D for either 2 or 5 days (3 biological replicates each) or in 3D for 8 or 16 days (3 or 5 biological replicates, respectively)
Project description:Expression data from HIF1A WT vs KD Madin-Darby canine kidney epithelial cells (MDCK strain II cells (ATCC:CCL-34)) under normoxic and hypoxic conditions