Expression genomics and cancer drug development

Expression genomics describes the investigation of transcription in a genome-wide scale, including the study of comprehensive gene regulation. The type of technologies used include microarrays, tag libraries such as serial analysis of gene expression (SAGE), full-length cDNA cloning and sequencing, chromatin immunoprecipitation coupled with cloning/sequencing or applied to genomic chips [Ruan et al., 2004]. However, since microarrays are the most widely used technology in expression genomics for the study of cancer biology and pharmacology, our discussion will concentrate on studies using expression arrays. Regardless of the methodologies used, information regarding candidate targets, pathways, prognostic markers, and pharmacodynamic responses can be extracted from these experiments. Our premise is that these are powerful tools that can accelerate target identification, validation, and therefore drug discovery. Optimizing this potential will require a different approach to experimental design. (C) 2004 Wiley-Liss, Inc.