儿童急性髓系白血病9P21区基因甲基化的研究

Methylation of the genes in the 9P21 region in children with acute myeloid leukemia

摘要:

目的 研究9P21 区的CDKN2A 和CDKN2B 基因甲基化在儿童急性髓系白血病(AML)中的发生率及其与临床特征及预后的相关性.方法 回顾性分析2010 年4 月至2012 年12 月被诊断为AML 的58 例患儿的临床资料.选取38 例健康志愿儿童为对照组,采集两组儿童的骨髓或外周血,常规提取基因组DNA;应用甲基化特异性- 多重连接酶依赖性探针扩增法(MS-MLPA)检测CDKN2A 和CDKN2B 基因甲基化情况.结果 进行检测的健康儿童未发现基因甲基化.58 例患儿中,44 例检测到甲基化探针.CDKN2A 基因甲基化涉及136 bp 和237 bp 探针;CDKN2B 基因甲基化涉及130 bp、210 bp、220 bp 和417 bp 探针.CDKN2A 基因甲基化率仅为5%,而CDKN2B 基因甲基化率为76%.部分探针甲基化与初诊时的性别、血红蛋白和血小板水平有关.结论 儿童AML 患者CDKN2B 基因甲基化率较高,而CDKN2A 基因甲基化率较低.

Abstract:

Objective To investigate the methylation rate of cyclin-dependent kinase inhibitor 2A (CDKN2A) and cyclin-dependent kinase inhibitor 2B (CDKN2B) in the 9P21 region in children with acute myeloid leukemia (AML) and the association of gene methylation with clinical features and outcomes. Methods The clinical data of 58 children who were newly diagnosed with AML between January 2010 and December 2012 were retrospectively analyzed. Thirtyeight healthy children were recruited as the control group. Genomic DNA was extracted from bone marrow or peripheral blood of the 58 patients and 38 healthy children. The methylation status of CDKN2A and CDKN2B was analyzed by methylation-specific multiplex ligation-dependent probe amplification. Results Gene methylation was not found in healthy children. Methylation probes of 44 patients were detected in 58 patients. The methylation of CDKN2A was detected with 136 bp and 237 bp methylation probes. The methylation of CDKN2B was detected with 130 bp, 210 bp, 220 bp, and 417 bp methylation probes. The methylation rate of CDKN2A was 5%, while the methylation rate of CDKN2B was 76%. The methylation detected by some probes was associated with sex, hemoglobin, and platelet count at the first visit. Conclusions The methylation of CDKN2B is a common event in children with AML, while the methylation of CDKN2A is relatively rare.