<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A substance being studied in the treatment of myeloid leukemia (a disease in which too many immature non-lymphocyte white blood cells are found in the blood and bone marrow). DT388IL3 fusion protein is made by combining IL-3 with a toxic substance. The IL-3 attaches to the cancer cells and the toxic substance kills them.</n0:def-definition><n0:def-source>NCI-GLOSS</n0:def-source></n0:ComplexDefinition>
<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A recombinant protein consisting of human interleukin 3 (IL3) fused to the first 388 amino acids of diphtheria toxin [DT(388)] with potential antineoplastic activity. Upon administration, the IL3 moiety of the DT(388)IL3 fusion protein binds to IL3 receptors on cells expressing the receptor. Subsequently, the DT(388) toxin moiety, containing both translocation and catalytic domains, translocates across the cell membrane via endocytosis; within the cytosol, the catalytic domain catalyzes the ADP-ribosylation of, and inactivates, translation elongation factor 2 (EF-2), resulting in the inhibition of translation during protein synthesis. IL3 may be overexpressed by acute myeloid leukemia (AML) cells.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>