REARRANGEMENT AND EXPRESSION OF MDM(2) ONCOGENE IN CHRONIC LYMPHOCYTIC-LEUKEMIA

Since trisomy 12 is the most common chromosome abnormality found in CL L and MDM(2) has been mapped to this chromosome, we examined the possi ble association of MDM, in the pathogenesis of CLL. A rearrangement of the MDM(2) gene was observed in 4 of 11 peripheral blood mononuclear cells (PBMC) from patients with CLL by Southern blot hybridization. Ex pression of MDM(2) was detected in all of the CLL samples examined by Northern blot. However, neither gross amplification nor overexpression of the MDM(2) gene was found in CLL. The data suggest that MDM(2) may play a role in the pathogenesis of CLL and may help to explain how ab normalities of chromosome 12 are related to CLL. (C) 1994 Wiley-Liss, Inc.