Mouse models of human cancer are a potential preclinical setting for drug testing and for development of methods for delivery of macromolecular drugs to tumors. We have assessed a mouse model of leukemia caused by Mll-Enl protein fusion as a preclinical situation in which myeloid-lineage leukemia results from de novo occurrence of chromosomal translocations between Mll and Enl genes. Here, we show that the mouse leukemias respond to cytosine arabinoside, a frontline treatment for human leukemia. The observations show that the myeloid cells are susceptible to the drug and the mice undergo a remission that comprises a reduction of the myeloid population of cells and recovery of the lymphoid population. This translocator model should therefore prove useful for future drug assessments against the recurrent mixed-lineage leukemia-associated translocations. [Mol Cancer Ther 2008;7(3):730-5].

Cano F, Pannel R, Follows GA, Rabbitts TH.

Leeds Institute of Molecular Medicine, Section of Experimental Therapeutics, Wellcome Trust Brenner Building, St. James’s University Hospital, Leeds, LS9 7TF, United Kingdom. thr@leeds.ac.uk.