DLX genes as targets of ALL-1: DLX 2,3,4 down-regulation in t(4;11) acute lymphoblastic leukemias.

Dlx genes constitute a gene family thought to be essential in morphogenesis and development. We show here that in vertebrate cells, Dlx genes appear to be part of a regulatory cascade initiated by acute lymphoblastic leukemia (ALL)-1, a master regulator gene whose disruption is implicated in several human acute leukemias. The expression of Dlx2, Dlx3, Dlx5, Dlx6, and Dlx7 was absent in All-1 -/- mouse embryonic stem cells and reduced in All-1 +/- cells. In leukemic patients affected by the t(4;11)(q21;q23) chromosomal abnormality, the expression of DLX2, DLX3, and DLX4 was virtually abrogated. Our data indicate that Dlx genes are downstream targets of ALL-1 and could be considered as important tools for the study of the early leukemic cell phenotype.