Differential display as an approach to study differentiation and differentiation therapy in AML

Different subgroups of acute myeloid leukemia (AML) can be defined by the specific non-random chromosomal translocation that is present within the abnormal cell types. In one type of AML, acute promyelocytic leukemia (APL), the block in the normal process of differentiation can be circumvented by the addition of a chemical inducer, in this case retinoic acid. This is due to the defect in APL affecting the retinoic acid receptor gene. This type of therapy has become known as differentiation therapy. However, most types of leukemia do not respond to the retinoic acid, and therefore methods of differentiation therapy need to be developed by targeting other genes involved in the leukemia process. This requires the molecular characterizations of the genes that are expressed during differentiation and in particular those genes that show a differential expression in inducer sensitive cells and those resistant to induced differentiation. Therefore, therapeutic agents could be developed to specifically target these genes. This article describes how the technique of differential display, as one of several possible methods of molecular screening, may allow the identification of genes which can be targeted to induce differentiation.