IDENTIFICATION OF A SUBCLASS OF DOUBLE MINUTE CHROMOSOMES CONTAINING CENTROMERE-ASSOCIATED DNA

In a study of abnormal chromosomes in non-Hodgkin's lymphoma (NHL) cel ls we have identified one case which contained extrachromosomal chroma tin bodies that, on the basis of their morphology and negative C-bandi ng, appeared to be double minute chromosomes (dmin). However, fluoresc ence in-situ hybridization (FISH) analysis using an X-specific centrom eric alphoid repeat probe and a pan-centromere probe, clearly demonstr ated the presence of centromere-associated DNA in these dmin. FISH ana lysis with the pan-centromere probe of the dmin in neuroblastoma and s arcoma cells failed to reveal the presence of centromere-associated DN A, but analysis of two cases of acute myeloid leukaemia cells revealed centromere-associated DNA in 25% of their dmin. These data indicate t he existence of dmin that contain centromere-associated DNA and sugges t that such dmin might represent a new class of extrachromosomal chrom atin bodies. (C) 1994 Wiley-Liss, Inc.