Expression of a bcr-1 isoform of RARalpha-PML does not affect the penetrance of acute promyelocytic leukemia or the acquisition of an interstitial deletion on mouse chromosome 2.

Blood. 2007 Feb 1;109(3):1237-40. Epub 2006 Sep 28.


Expression of a bcr-3 isoform of retinoic acid receptor alpha-promyelocytic leukemia (RARalpha-PML) in mice expressing a bcr-1 isoform of PML-RARalpha is associated with increased penetrance of murine acute promyelocytic leukemia (APL) and the frequent acquisition of an interstitial deletion of one copy of mouse chromosome 2 (del(2)). To determine whether the isoform of RARalpha-PML is important for these effects, we created mice that expressed a bcr-1 isoform of RARalpha-PML. Coexpression with the bcr-1 isoform of PML-RARalpha did not increase the penetrance of APL (7 of 45 animals developed APL with PML-RARalpha alone vs 12 of 44 with both transgenes; P=.19). Furthermore, the frequency of del(2) in APL cells from doubly transgenic mice was not different from that of mice expressing PML-RARalpha alone (3 of 6 vs 6 of 12, respectively-P=1.38-compared with 11 of 11 for mice coexpressing PML-RARalpha and bcr-3 RARalpha-PML). The bcr-1 and bcr-3 isoforms of RARalpha-PML, therefore, have different biological activities that may be relevant for the pathogenesis of murine APL.


Walter MJ, Ries RE, Armstrong JR, Park JS, Mardis ER, Ley TJ.

Institute Authors

Timothy Ley, M.D.