Differential expression of genes in retinoblastoma.

Retinoblastoma is a pediatric eye tumor that serves as a paradigm for understanding the genetic basis of cancer. Mutations and/or epigenetic alterations inactivating both alleles of the retinoblastoma gene (RB) are associated with retinoblastoma. There are many other genes which express differentially in the preneoplastic retinal cells after RB loss, as cells progress to form tumors. These genetic changes and the pathways involved can provide valuable insight into the development and progression of this cancer. Conventional molecular and genetic methods for studying cancer are limited to the analysis of one locus at a time. A cluster of genes that are regulated together can be identified by DNA microarray, and the functional relationships can uncover new aspects of cancer biology. Meta analysis is an important tool for the identification and validation of differentially expressed genes to increase power in clinical and biological studies across different sets of data. Recently, meta analysis approaches have been applied to large collections of microarray datasets to investigate molecular commonalities of multiple cancer types not only to find the common molecular pathways in tumor development but also to compare the individual datasets to other cancer datasets to identify new sets of genes. The outcome of these analyses might accelerate the application of basic research findings into daily clinical practice through translational research and may have an impact on foreseeing the clinical outcome, predicting tumor response to specific therapy, identification of new prognostic biomarkers, discovering targets for the development of novel therapies and providing further insights. These and related research efforts reveal novel data that enhance our understanding of the biology of retinoblastoma. These observations may facilitate new therapeutic approaches to further decrease the morbidity and mortality associated with retinoblastoma and other more common forms of cancer.