[Acute promyelocytic leukemia: molecular aspects]

Acute promyelocytic leukemia is a key model system in Cancer biology. Its ability to differentiate upon exposure to retinoic acid constitutes the first example of differentiation therapy. The molecular basis of leukemogenesis is the PML/RAR fusion resulting from the t(15, 17) translocation. The fusion protein likely acts through interference with the function of nuclear receptors (resulting in a differentiation block) and also through interference with PML which appear to be a growth suppressor. The exquisite sensitivity of this disease to retinoic acid represents the first example of a therapy directly targeted at a specific and causative genetic lesion.