[Investigation on MS-PCR as a method for detecting minimal residual disease in acute leukemia]

The aim of this study was to investigate the feasibility of monitoring minimal residual disease (MRD) of leukemia with methylation specified-polymerase chain reaction (MS-PCR). The HL-60 cells with Id4 gene complete methylation and Hek937 cells with Id4 gene complete unmethylation were mixed in accordance with different ratios of cells and were divided into 3 groups: group A (10% HL-60 + 90% Hek937), group B (1% HL-60 + 99% Hek937) and group C (0.1% HL-60 + 99.9% Hek937). The MS-PCR technique was used to detect the methylation status of Id4 gene in different ratios of leukemia cells. The results indicated that the methylation specific amplification of Id4 gene with 155 bp was observed in HL-60 cells showing complete methylation of Id4 gene; while the unmethylation specific amplication of Id4 gene with 156 bp was found in Hek937 cells, showing complete unmethylation. The methylation specific amplification of Id4 gene with 155 bp and unmethylation specific amplification of Id4 gene with 156 bp were simultaneously detected in A, B and C groups, which showed the expression of Id4 gene methylation. In conclusion, the MS-PCR technique can detect the Id4 gene methylation in leukemia cell sample containing 0.1% of HL-60 cells, moreover the Id4 gene methylation in various leukemia cells shows no significant difference, thereby use of MS-PCR to detect the Id4 methylation level may be a potential approach for monitoring of MRD. Id4 gene promoter methylation is a candidate of biomarker for MRD detection in acute leukemias.