The Analysis Of Microsatellite In-Stability Linked To The Mismatch Repair Gene On Chromosome 2 In Acute Leukemia

Object we carry out a study on microsatellite instability of the 4 sites linked to hM-SH2 and hPMSl on chromosome 2,in order to find out the role MMRgene playing in leukemia's initiation and it's progression.Method MSI and LOH in 58 cases of leukemia(including 33 cases of acute myeloblas-tic leukemia (AMD and 20 cases of acute lymphocytic leukemia (ALL) and 5 cases of chronic leukemia (CD)and 3 cases of myelodysplastic syndrome (MDS) were detected by multiplex-PCR amplification at 4 microsatellites linked to hMSH2 and hPMSl on chromosome 2, gel electrophoresis and argentine dye.Result we detected MSI and LOH in 37 cases out of 53 acute leukemia . the frequencies of MSI on D2sl23/ D2sll9 are 30. 2% (16/53) and 41. 5% (22/53) respectively, a-mong those datas, LOH are 9. 4% (5/53) and 7. 5% (4/53). another two microsatellites , D2sll7 and D2sll5, identify MSI at a similar frequency to D2sl23 and D2sll9 , 33. 9% (18/53) and 39. 6%(21/53) respectively 5 we find 4/5cases (7. 5%/9. 4%) on that two loci respectively, no less than 2 loci are abnormal in 28 cases. Only one case of accelerate CML show MSI in 3 loci , while the 4 other CML at diagnostic stage are normal at all the loci we detected. In addition, we've found MSI in 2 sites of a MDS(RAEB-T) patient.Conclusion since we get a high frequency of MSI and LOH on the loci linked to MMR gene on chromosome 2,the mutation of the MMR gene play a role in the inatiation and the development of acute leukemia, our finding of MSI in several sites at the same time means that leukemia is an accumulate result from a multi-sites/steps mutation of MMR gene.