Characterization of a t(I0; II) (pI3-I4; qI4-2I) in the monoblastic cell line U937

Previous analysis of the monoblastic cell line U937 has shown that several sublines contain a rearranged chromosome arm I I q. In order to determine the true nature of the rearrangement, fluorescence in situ hybridization (FISH) was carried out with various combinations of single copy anonymous markers, clones containing genes, a chromosome 10 paint, and an I I centromere specific sequence. The rearrangement was deduced to be a reciprocal translocation between chromosomes 10 and 11 described as t( 10; 11 )(p 13- 14;q 14-21 ). The breakpoint on chromosome 11 is telomeric to the /NT2 gene and the pHS11 probe at 11 q 13, and centromeric to the marker D 11536 localized to 11q 14.3-q22. 1 and the MLL gene at 11 q23. Similar translocations have been reported in various acute leukemias, principally of the monocytic lineage, and also in T-cell precursor acute lymphocytic leukemias. Further characterization of the genetic rearrangements in U937 may lead to the isolation of genes important in leukemogenesis and provide an in vitro system for their study. © 1995 Wiley-Liss, Inc.