Gene expression profiling in hematological malignancies

In hematological malignancies, gene expression profiling using DNA-microarrays led to the discovery of novel lymphoma and leukemia subgroups. The heterogeneous entity of diffuse large B-cell lymphoma could be subdivided into the germinal center B-cell-like and the activated B-cell-like subtype which differ in pathogenesis and clinical behavior. In leukemia, existing entities defined by morphological, cytogenetic, molecular and immunophenotypic criteria were confirmed on the global gene expression level; in addition, new important molecular subgroups could be identified. In retrospective clinical lymphoma and leukemia studies, robust gene expression signatures were discovered that predict the clinical course at the time of diagnosis. Given the huge potential of the DNA-microarray technology, application in the routine diagnostic setting appears possible.