去甲基化的MDS细胞系和2例MDS患者的ID4基因甲基化的临床意义

Clinical Significance of ID4 Gene Mehtylation in DemethylationTreated MDS Cell Line and 2 MDS Patients

目的:探讨去甲基化的骨髓增生异常综合征(myelodysplastic syndrome MDS)患者来源的细胞系MUTZ-1和2例MDS患者的ID4基因表达及去甲基化状态影响的临床意义,为MDS患者去甲基化治疗提供理论依据。方法:采用甲基化特异性PCR(methylation-specific PCR,MS-PCR)及逆转录PCR(reverse transcription-PCR,RT-PCR)方法检测MDS细胞系MUTZ1中ID4基因,及1例AA患者骨髓细胞及NBM细胞中的甲基化及表达情况。应用RT-PCR方法检测ID4基因在去甲基化药物地西他滨处理的MUTZ-1中的表达情况。运用亚硫酸氢盐测序PCR(bisulfite sequencing PCR,BSP)方法检测2例MDS患者去甲基化治疗前后ID4基因甲基化状态。结果:ID4基因在MUTZ1中呈完全甲基化且表达极弱,在AA患者骨髓细胞和NBM细胞呈完全非甲基化且有较强表达。去甲基化处理MUTZ-1后,随着地西他滨浓度增强ID4基因的表达呈现逐渐增强的表现;BSP检测2例MDS患者表明,去甲基化药物地西他滨治疗后其ID4基因甲基化阳性频率均较初治时明显降低。结论:ID4基因启动子区的高甲基化状态抑制了ID4表达,但这种抑制状态可以通过去甲基化药物处理而改变。ID4作为MDS抑癌基因,进一步提示其甲基化可以成为MDS患者治疗方案选择及疗效评估的指标。

Objective ： To evaluate significance of ID4 gene mehtylation in demethylating myelodysplastic syndrome （MDS） cell Line MUTZ1 and 2 patients with MDS. Methods ：The methylation-specific PCR （MS-PCR） and reverse transcription-PCR （RT-PCR） were applied to identify the methylation status and gene expression of ID4 gene in MDS cell line MUTZI, a patient with aplastic anemia（AA） and a donor with normal bone marrow （NBM）. RT-PCR was applied to detect the ID4 gene expression status in MUTZ1 cell line treated with decitabine at 3 different concentrations. Then bisulfite sequencing PCR （BSP） was applied to detect 11）4 gene methylation status in 2 MDS patients treated with decitabine. Results.The MDS cell line MUTZ-1 displayed a complete methylation of ID4 gene promoter with little mRNA expression. Inversely, bone marrow of an AA patient and NBM showed complete unmethylation of this gene with intensity mRNA expression. With the increase of decitabine concentration, ID4 gene mRNA expression was more and more increased. After decitabine treatment, 1/94 gene methylation-positive frequencies of both the 2 MDS patients were much more decreased than that of the first treatment. So, ID4 gene mRNA expression inhibited by promoter hypemethylation could be recovered by using demethylation medicine. Conclusion： 1/94 as a new potential antioncogene suggests that its methylation may become a marker for selection and assessment of therapeutic schedules in patients with MDS.