急性髓系白血病中的DNMT3A基因突变研究

表观遗传学改变,包括DNA甲基化水平异常在肿瘤的发生、发展阶段起着重要作用。近期,多位研究者在急性髓系白血病（AML）患者中发现了DNA甲基转移酶3A（DNMT3A）基因突变可能与DNA甲基化水平异常有关。该基因突变比例为20%左右,形式多种多样,以点突变为主,热点突变位于882位精氨酸。DNMT3A突变主要发生在大于60周岁的AML-M4、M5亚型中的危核型患者,预后均较差。有学者在骨髓异常增生综合症（MDS）和原发性骨髓纤维化（PMF）的患者中也发现有该基因突变,表明DNMT3A突变已先于白血病阶段存在,并提出从表观遗传学改变研究白血病发病机制的观点。然而,目前尚缺大样本调查以明确DNMT3A突变能否成为微小残留病（MRD）检测的分子标记物及能否成为药物作用的新靶点,因此对上述问题尚需进一步探讨。本文总结了近年来DNMT3A基因突变的研究进展,并作一综述。

DNMT3A gene mutations in acute myeloid leukemia

Epigenetic changes, including abnormal DNA methylation, have been identified to play significant roles in tumor initiation and progression. Recently, mutations of DNMT3A were identified in acute myeloid leukemia (AML), which possibly caused changes in DNA methylation, and indicated a poor prognosis. Sequencing analysis showed that most of the mutations were single nucleotide variations, including a hotspot Arg882. DNMT3A mutations were detected in about 20% AML patients, and closely associated with the age over 60, the M(4), M(5) subtypes and intermediate-risk cytogenetics. Others showed that these alterations also present in myelodysplastic syndrome (MDS) and primary myelofibrosis (PMF) prior to development of the obvious leukemia, indicating that these mutations might contribute to leukemogenesis. However, its prognostic value of minimal residual disease and role of therapeutic targets are still unclear, focusing on a large cohort of AML patients will solve these issues. In this review, the achievement in studying DNMT3A gene mutation are summarized, and the latest research progress is briefly discussed.