采用甲基化特异性聚合酶链反应研究急性白血病p15基因CpG？…

目的 探讨ｐ１５基因ＣｐＧ岛甲基化作为各型急性白血病通用的基因标志物的可行性。方法 采用甲基化特异性聚合链反应（ＭＳＰ）法检测４０例初治或复发急性白血病、５例完全缓解白血病及８例（份）正常骨髓的ｐ１５基因ＣｐＧ岛甲基化，并对ＭＳＰ产物进行序列测定。结果 急性白血病患ｐ１５基因ＣｐＧ岛甲基化阳性率为８０％，ＡＭＬ与ＡＬＬ的阳性率（分别为８３％和７３％）差异无显性；５例完全缓解期白血病患中１例ｐ

Study on the methylation of p15 gene CpG islands in acute leukemia: using methylation-specific PCR method]

OBJECTIVE: To explore the feasibility of the methylation of p15 gene CpG islands as a common gene marker for all types of acute leukemias(AL). METHODS: The methylation of p15 gene CpG islands in bone marrow from 40 cases of newly diagnosed or relapsed AL, 5 cases of AL in CR and 8 of normal subjects was analyzed by using methylation-specific PCR methods(MSP), and the product of MSP was sequenced. RESULTS: p15 gene CpG islands were methylated in 80% (32/40) of the newly diagnosed or relapsed AL, no difference between AML and ALL was observed. One positive result was found in the 5 AL patients in CR and this patient soon relapsed. The bone marrow cells from 8 normal subjects did not have p15 gene CpG islands methylation, which suggested that such methylation was peculiar to AL cells. DNA sequencing confirmed the right expected sequence. The sensitivity of MSP was 10(-3). CONCLUSION: The methylation of p15 gene CpG islands occurs very commonly in every types of AL. It can be used as a gene marker for ALs and for minimal residual disease in CR. MSP needs neither special methylation-sensitive restricted sites, nor high volume of DNA. There is no radioactive pollution, and the sample need not be fresh. MSP is a very sensitive, simple and specific method for the detection of DNA methylation.