Chromosomal Translocations as Biomarkers in Leukemia Diagnosis and Pharmacogenomics

Chromosomal translocations are primary events in the development of leukemias and are used as biomarkers of various hematological malignancies. Biomarkers enable rational modifications of primary cancer therapies and provide new opportunities for early intervention. A biomarker is a gene/altered gene, protein, or other change that acts as a precursor of a biomedical phenotype before that phenotype is clinically apparent. Tests based on biomarkers have been around for more than half a century, but interest in their application for diagnostics and drug discovery as well as development, has increased remarkably since the beginning of the 21st century. Biomarkers are useful not only for diagnosis of some diseases but also for understanding pathogenetic mechanisms as well as the basis for development of therapeutics. Chromosome translocations are important in both diagnosis and targeted therapy in leukemia. Currently only a few translocations are being used for diagnostic and targeted therapy purposes (e.g., Philadelphia chromosome in CML and PML/RARα in APL), but several others may be identified in the future. Selecting chromosome translocations as biomarkers for targeted therapy for leukemia is an important area for evaluation. Some patents disclosing chromosomal translocations and their role in diagnosis and therapy of leukemia are also reviewed in this article.