ABSTRACT

Microarrays provide scientists with tools to study whole genome expression in organisms ranging from humans to flies to bacteria. By comparing genome-wide expression patterns, researchers have a practical method for surveying an entire genome and obtaining a better understanding of the dynamic relationship between gene expression and biological function. The whole genome sampling assay (WGSA) for microarray-based genotyping requires only one primer to amplify a deoxyribonucleic acids (DNA) sequence, making large-scale single-nucleotide-polymorphism (SNP) analysis practical. WGSA uses a simple restriction enzyme to digest genomic DNA, creating various sizes of DNA fragments, each containing their respective SNPs. Gene expression profiling of cancers offers important prognostic indications for outcome and recurrence as well as patient response to treatment. Several studies have identified gene expression classification systems based on lymph node status and estrogen receptor status. A key theme that has emerged is the value of whole genome analysis for the discovery of accurate expression profiles with diagnostic value.