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急性髓系白血病(acute myeloid leukemia, AML)是一类严重危害人类健康的异质性血液系统恶性肿瘤,发病率占我国成人白血病首位。DNA甲基化转移酶3A(DNA methyltransferase 3A, DNMT3A)位于人类2号染色体短臂2区3带(2p23),是重要的甲基化转移酶之一,主要负责基因组DNA从头甲基化,在多种恶性肿瘤的发病机制中发挥重要作用[1-3]。研究[4-13]发现,在成人AML病人中DNMT3A R882位点高频突变,且常合并某些高危因素,是病人预后不良的重要分子生物学标志。本研究旨在通过收集临床骨髓标本及检测DNMT3A R882位点突变情况,探讨DNMT3A R882突变与AML发生、发展的相关性。
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根据基因测序检测结果显示在116例初发AML病人中,DNMT3A R882突变者共16例,突变率为13.8%,而良性对照组中无突变,2组间差异无统计学意义(χ校正2= 3.34,P>0.05)。16例DNMT3A R882突变者中包括9例DNMT3A R882H突变及7例DNMT3A R882C突变,均为杂合突变,突变率分别为7.8%、6.0%。DNMT3A R882H突变在所有16例突变病人中占56.3%(见图 1)。
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DNMT3A R882在核型正常的AML组(NK-AML组)病人中突变率为19.4%,高于在核型异常的AML组病人中突变率的4.5%(P < 0.05)。M4、M5分型人数在DNMT3A R882突变型AML组(Mut-DNMT3A组)中占75.0%,在DNMT3A野生型AML组(Wild-DNMT3A组)中占30.0%,2组间差异有统计学意义(P < 0.01)(见表 1)。
变量 DNMT3A R882突变 t P (+) (-) 性别 男
女11
560
400.45* >0.05 年龄/岁 59.5±13.5 45.0±15.2 2.32 < 0.05 骨髓原始细胞数/% 69.2±21.6 62.1±18.3 0.87 >0.05 白细胞数/(×109/L) 43.2±21.9 26.4±23.4 2.08 < 0.05 血红蛋白/(g/L) 83.9±26.9 75.2±21.1 0.57 >0.05 血小板/(×109/L) 74.3±40.1 37.8±39.7 3.02 < 0.01 NK-AML组
非NK-AML组14
258
425.91* < 0.05 M4、M5分型组
M1、M2分型组12
430
7012.09* < 0.01 *示χ2值 表 1 Mut-DNMT3A组与Wild-DNMT3A组间病人基本资料的比较
另外,Mut-DNMT3A组病人年龄大于Wild-DNMT3A组(uc=2.32,P < 0.05);Mut-DNMT3A组病人外周血白细胞数、血小板数高于Wild-DNMT3A组(P < 0.05),但2组间病人性别、骨髓原始细胞数、外周血血红蛋白数差异均无统计学意义(P>0.05)(见表 1)。
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检测成人AML病人中融合基因的表达是判断病人病情与预后的重要指标,本实验中发现CBFβ-MYH阳性者在Mut-DNMT3A组中占12.5%,在Wild-DNMT3A组中占8.0%,2组间差异无统计学意义(P>0.05);AML1-ETO阳性者在Wild-DNMT3A组中占18.0%,而在Mut-DNMT3A组中未发现表达阳性者,2组间差异无统计学意义(P>0.05)(见表 2)。
融合基因 DNMT3A R882突变 校正χ2 P (+) (-) CBFβ-MYH 阳性
阴性2
148
920.01 >0.05 AML1-ET0 阳性
阴性0
1618
822.17 >0.05 表 2 Mut-DNMT3A组与Wild-DNMT3A组间病人融合基因的比较
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Mut-DNMT3A组与Wild-DNMT3A组细胞表面CD117、CD13、CD33、CD36、CD14、CD15、CD56、CD64、MPO、HLA-DR表达差异无统计学意义(P>0.05)(见表 3)。
CD抗原 DNMT3A R882突变 χ2 P (+) (-) CD117 阳性
阴性8
856
440.20 >0.05 HLA-DR 阳性
阴性15
185
150.89 >0.05 CD13 阳性
阴性12
478
220.07 >0.05 CD33 阳性
阴性11
575
250.28
>0.05CD15 阳性
阴性11
553
471.38 >0.05 MPO 阳性
阴性13
372
280.60 >0.05 CD56 阳性
阴性3
1322
780.09 >0.05 CD36 阳性
阴性4
1213
871.59
>0.05CD64 阳性
阴性3
139
911.41 >0.05 CD14 阳性
阴性8
838
620.83 >0.05 表 3 Mut-DNMT3A组与Wild-DNMT3A组间病人细胞免疫表型比较
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116例AML病人住院期间接受诱导缓解治疗后,16例Mut-DNMT3A病人中有7例CR,CR率为43.8%,100例Wild-DNMT3A组病人中有47例CR,CR率为47.0%,2组间CR率差异无统计学意义(χ2=0.06,P>0.05)。
进一步分析Mut-DNMT3A组与Wild-DNMT3A组之间的OS率及DFS率,结果显示,Mut-DNMT3A组病人中位生存时间为12个月,Wild-DNMT3A组病人中位生存时间为28个月,Mut-DNMT3A组病人OS率及DFS率均低于Wild-DNMT3A组病人,且差异有统计学意(χ2=4.29、6.16,P < 0.05)。
DNMT3A R882突变在急性髓系白血病中的临床意义
Clinical significance of DNMT3A R882 mutation in acute myeloid leukemia
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摘要:
目的研究初发急性髓系白血病(AML)病人中DNA甲基化转移酶3A(DNMT3A)R882位点突变情况,并分析其相关临床资料特征。 方法运用DNA基因测序法检测116例AML病人与30例缺铁性贫血病人骨髓样本中DNMT3A R882突变情况。 结果116例初发AML病人中,DNMT3A R882突变共16例,包括R882H突变9例,R882C突变7例,且均为杂合突变,而良性对照组中无突变;DNMT3A R882突变型AML(Mut-DNMT3A)组病人核型正常的AML(NK-AML)人数及M4、M5人数多于DNMT3A野生型AML组(Wild-DNMT3A组)(P < 0.05)。Mut-DNMT3A组病人年龄、外周血白细胞数及血小板数高于Wild-DNMT3A组(P < 0.05)。Mut-DNMT3A组病人总生存率、无病生存率均低于Wild-DNMT3A组(P < 0.05)。 结论DNMT3A R882突变易发生于AML病人,特别是NK-AML及M4、M5病人,且常合并高龄、高白细胞危险因素;DNMT3A R882突变是AML病人预后不良的生物学标志。 -
关键词:
- 急性髓系白血病 /
- DNA甲基化转移酶3A /
- 突变
Abstract:ObjectiveTo investigate the mutation of DNA methyltransferase 3A(DNMT3A) R882 in patients with acute myeloid leukemia(AML), and analyze the characteristics of related clinical data. MethodsThe mutations of DNMT3A R882 in 116 patients with AML and 30 patients with iron deficiency anemia were detected using DNA gene sequencing. ResultsAmong 116 patients with AML, 16 cases with DNMT3A R882 mutation were identified, which included 9 cases with R882H mutation and 7 cases with R882C mutation, all mutations were heterozygous mutations, while there was not mutation in benign control group.The number of patients with normal karyotype AML(NK-AML), and M4 and M5 in DNMT3A R882 mutation AML(Mut-DNMT3A) group were significantly higher than that in DNMT3A wild type AML(Wild-DNMT3A) group(P < 0.05).The patient age, and white blood cell amount and platelet amount in peripheral blood in Mut-DNMT3A group were significantly higher than those in Wild-DNMT3A group(P < 0.05).The overall survival rate and disease-free survival rate in Mut-DNMT3A group were significantly lower than those in Wild-DNMT3A group(P < 0.05). ConclusionsDNMT3A R882 mutation is easy to occur in AML patients, especially NK-AML, M4 and M5 patients, and complicated with risk factors of old age and high white blood cell amonut.DNMT3A R882 mutation is a biological marker of poor prognosis in AML patients. -
Key words:
- acute myeloid leukemia /
- DNA methyltransferase 3A /
- mutation
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表 1 Mut-DNMT3A组与Wild-DNMT3A组间病人基本资料的比较
变量 DNMT3A R882突变 t P (+) (-) 性别 男
女11
560
400.45* >0.05 年龄/岁 59.5±13.5 45.0±15.2 2.32 < 0.05 骨髓原始细胞数/% 69.2±21.6 62.1±18.3 0.87 >0.05 白细胞数/(×109/L) 43.2±21.9 26.4±23.4 2.08 < 0.05 血红蛋白/(g/L) 83.9±26.9 75.2±21.1 0.57 >0.05 血小板/(×109/L) 74.3±40.1 37.8±39.7 3.02 < 0.01 NK-AML组
非NK-AML组14
258
425.91* < 0.05 M4、M5分型组
M1、M2分型组12
430
7012.09* < 0.01 *示χ2值 表 2 Mut-DNMT3A组与Wild-DNMT3A组间病人融合基因的比较
融合基因 DNMT3A R882突变 校正χ2 P (+) (-) CBFβ-MYH 阳性
阴性2
148
920.01 >0.05 AML1-ET0 阳性
阴性0
1618
822.17 >0.05 表 3 Mut-DNMT3A组与Wild-DNMT3A组间病人细胞免疫表型比较
CD抗原 DNMT3A R882突变 χ2 P (+) (-) CD117 阳性
阴性8
856
440.20 >0.05 HLA-DR 阳性
阴性15
185
150.89 >0.05 CD13 阳性
阴性12
478
220.07 >0.05 CD33 阳性
阴性11
575
250.28
>0.05CD15 阳性
阴性11
553
471.38 >0.05 MPO 阳性
阴性13
372
280.60 >0.05 CD56 阳性
阴性3
1322
780.09 >0.05 CD36 阳性
阴性4
1213
871.59
>0.05CD64 阳性
阴性3
139
911.41 >0.05 CD14 阳性
阴性8
838
620.83 >0.05 -
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