Unknown,Transcriptomics,Genomics,Proteomics

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Identification of biomarkers for tumor endothelial cell proliferation through gene expression profiling

ABSTRACT: Extensive efforts are underway to identify anti-angiogenic therapies for the treatment of human cancers. Many proposed therapeutics target vascular endothelial cell growth factor (VEGF) or the kinase insert domain receptor (KDR/VEGFR-2/FLK-1), the mitogenic VEGF receptor tyrosine kinase expressed by endothelial cells. Inhibition of KDR catalytic activity blocks tumor neo-angiogenesis, reduces vascular permeability, and, in animal models, inhibits tumor growth and metastasis. Using a gene expression profiling strategy in rat tumor models, we identified a set of six genes that are selectively overexpressed in tumor endothelial cells relative to tumor cells, and whose pattern of expression correlates with the rate of tumor endothelial cell proliferation. In addition to being potential targets for anti-angiogenesis tumor therapy, the expression patterns of these genes or their protein products may aid the development of pharmacodynamic assays for small molecule inhibitors of the KDR kinase in human tumors. Total RNA isolated from cultured cells or tumor tissue samples was used to make fluorescently labeled cRNA that was hybridized to DNA oligonucleotide microarrays. Briefly, 4 Âµg of total RNA from an individual tumor sample or endothelial cell culture were used to synthesize dsDNA through RT. cRNA was produced by in vitro transcription and labeled postsynthetically with Cy3 or Cy5. Two populations of labeled cRNA, a reference population and an experimental population, were compared with each other by competitive hybridization to microarrays. For animal tumor studies, reference cRNA pools were made by pooling equal amounts of cRNA from each tumor in the appropriate vehicle-dosed group. Species-specific microarrays were used throughout this study. Human microarrays contained 23,916 oligonucleotide probes corresponding to individual genes or expressed sequence tags. Rat microarrays contained probes to 22,592 genes or expressed sequence tags. Oligonucleotide probe sequences were chosen to maximize gene specificity and minimize the 3' replication bias inherent in RT of mRNA. In addition, both microarray formats contained 1,000 control probes for quality control purposes. All oligonucleotide probes on the microarrays were synthesized in situ with inkjet technology (Agilent Technologies, Palo Alto, CA). After hybridization, arrays were scanned and fluorescence intensities for each probe were recorded. Ratios of transcript abundance (experimental to control) were obtained following normalization and correction of the array intensity data. Gene expression data analysis was done with the Rosetta Resolver gene expression analysis software (version 3.2, Rosetta Biosoftware, Seattle, WA). For each gene sequence present on the microarrays, statistical significance of differential gene expression was determined by calculating P values.

ORGANISM(S): Homo sapiens

SUBMITTER: Laura Sepp-Lorenzino

PROVIDER: E-GEOD-3299 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Identification of biomarkers for tumor endothelial cell proliferation through gene expression profiling.

Hardwick James S JS Yang Yi Y Zhang Chunsheng C Shi Bin B McFall Rosemary R Koury Elizabeth J EJ Hill Susan L SL Dai Hongyue H Wasserman Robert R Phillips Robert L RL Weinstein Edward J EJ Kohl Nancy E NE Severino Michael E ME Lamb John R JR Sepp-Lorenzino Laura L

Molecular cancer therapeutics 20050301 3

Extensive efforts are under way to identify antiangiogenic therapies for the treatment of human cancers. Many proposed therapeutics target vascular endothelial growth factor (VEGF) or the kinase insert domain receptor (KDR/VEGF receptor-2/FLK-1), the mitogenic VEGF receptor tyrosine kinase expressed by endothelial cells. Inhibition of KDR catalytic activity blocks tumor neoangiogenesis, reduces vascular permeability, and, in animal models, inhibits tumor growth and metastasis. Using a gene expre ...[more]

PMID: 15767550

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Identification of biomarkers for tumor endothelial cell proliferation through gene expression profiling

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Identification of biomarkers for tumor endothelial cell proliferation through gene expression profiling.

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