p15基因甲基化在骨髓增生异常综合征中的变化

目的:探索p15基因异常甲基化在骨髓增生异常综合征中的变化及其在各亚型中的表达。方法:采用MSP(Methylation-specific-PCR)的方法,研究p15基因异常甲基化在32例骨髓增生异常综合征(MDS)及其各亚型中的发生率。结果:在MDS中p15基因异常甲基化占50%(16/32);在各亚型中的比例为:难治性贫血(RA)为0%,难治性贫血伴环状铁粒幼细胞(RA-S)为20%(1/5),难治性贫血伴原始细胞增多(RAEB)为57.1%(4/7),慢性粒单核细胞白血病(CMML)为71.4%(5/7),难治性贫血伴原始细胞转化型(RAEB-T)为85.7%(6/7)。其中4例是在亚型间转型或进展为急性髓性白血病(AML)时发生p15基因异常甲基化。结论:p15基因甲基化可能是MDS发病的原因之一,并与MDS病程进展有关;其各亚型并非独立的分型,亚型间因病情的进展而转型时易有p15基因异常甲基化的发生。

Study on methylation of p15 INK4B in myelodysplastic syndrome

AIM: To investigate the variation and distribution of abnormaly methylated p15 INK4B in myelodysplastic syndrome (MDS) and its subgroups. METHODS: The abnormal methylation of p15 INK4B in 32 cases with MDS was studied using methylation-specific PCR (MSP). RESULTS: The positive rate of abnormal methylation of p15 INK4B was about 50% in MDS. The ratios in subtypes were: 0% (0/6) in RA,20% (1/5) in RA-S,57.1% (4/7) in RAEB,74.1% (5/7) in CMML,85.7% (6/7) in RAEB-t, respectively.It was worth noticing that 4 cases represented abnormal methylation of p15INK4B during their transformation and progression into AML. CONCLUSION: The abnormal methylation in p15 INK4B might be one of the causes of MDS, which was related to pathologial process of MDS.Every subtype was not solitary classification completely. Abnormal methylation of p15 INK4B was apt to occur accompanying the progression and transformation of the subtypes.