Transcripts with Ecotropic Viral Insertion Site I in Leukemia

We have identified a novel gene, GR6, located Withinthe leukemia breakpoint region of 3q21, that is normally expressed in early fetal developmentbut not in adult peripheral blood. CR6 is activated in the UCSD-AML1cell line and in a leukemic sample, both of which carry a t(3;3)(q21;q26). In UCSD-AML1, we have also identified fusion tran scripts between the ecotropic viral insertion site I (EVIl) gene In 3q26 and GR6 and between EVIl and RlbophorinI that maps 30 kb telomeric to GR6 in 3q21. All fusions splice the 5' ends of the 3q21 genes Into exon 2 of the EVil gene, an event that is similar to the normalintergenicsplicing of MDS1-EVI1and to those previously documentedin leukemias with t(3;21) and t(3;12), in which acute myelogenous leukemia 1-EVIl fusions and ETV6-EVI1 fusions, respectively, occur. The Ribophorin I-EVIl fusion in particularmay be a commonoccurrencein t(3;3).