STABILITY OF MICROSATELLITES IN MYELOID NEOPLASIAS

Microsatellites are short, repeated DNA sequences that exist throughou t the genome. Instability of these sequences, associated with defects in the DNA mismatch repair system, is the hallmark of hereditary non-p olyposis colorectal cancer (HNPCC), and is also found in many sporadic cancers. Although many types of solid tumors exhibit this type of gen etic instability, its involvement in hematologic cancers is less evide nt. We have investigated whether microstatellite instability (MSI) is involved in the transformation of myeloid cells to myelodysplastic syn drome (MDS) and/or acute myelogenous leukemia (AML). Both de novo and treatment-associated neoplasias were studied. Only one example of MSI was found in 48 patients, using a panel of 14 different microsatellite loci consisting of repeats of one to four base pairs. These results s uggest that the genes responsible for MSI are not involved in the tran sformation of normal myeloid cells to MDS or AML. (C) Elsevier Science , Inc., 1998.