Microarray tools for deciphering complex diseases.

Individual genetic findings associated with complex diseases are unlikely to fully explain their substantial impact or provide new comprehensive insights into disease pathogenesis. These also lack the comprehensive data much needed for development of new effective drugs in majority of the disease cases in a population. In fact multilevel etiologic factors underlie almost all human diseases, including: environmental causes, epigenetic factors, DNA mutations, amplifications, and deletions, RNA expression levels, protein (translation, post translation modification, localization) and combinations thereof. Each individual might consist of different combinations of these multiple etiologic factors. Integrative evaluation of all these modifications will shed light on the whole identity of the disease and the underlying molecular mechanisms. Until now it was inconceivable to have a full grasp of such a complex etiology. Microarrays enable us to interrogate the individualized various factors (DNA, RNA and protein content) involved in disease state on genome-wide scale simultaneously and expeditiously in single cell or the tissue of interest (Figure 1). The new disciplines of microarray studies in combination hold the promise of effective, current, and comprehensive understanding of complex diseases and may be a good approach for reducing the costs and time lines associated with discovery and efficacy improvement of therapeutic drugs. In the future, through utilizing the colossal amount of microarray data findings, defining the structure, function, and dynamics of entire biological pathways and cellular networks under various physiological states, and the development of robust and efficient methods for analyzing and interpreting high dimensional data, it will be possible to connect combination of experimental results with individualized disease state. This will facilitate precise diagnosis prognosis and therapy.