骨髓增生异常综合征患者DNMT3A基因突变的情况及临床意义

目的:了解DNMT3A基因突变在骨髓增生异常综合征（MDS）患者中的发生率、分布情况及临床意义。方法:选取2012年 4月至2018年6月在湘雅二医院和湘潭市中心医院住院的85例MDS患者为研究对象。提取患者外周血基因组DNA,针对DNMT3A基因突变热点R882位点设计合成引物,采用聚合酶链式反应法扩增DNMT3A基因23号外显子整个编码区基因片段,再将扩增产物纯化后测序,分析DNMT3A基因突变在本组患者中的发生率、分布情况及临床意义。结果:85例MDS患者中检测到5例DNMT3A基因突变,突变阳性率5.9%,其中R882H和R882C基因突变各2例,R882P基因突变1例,未见R882S基因突变。常规化疗联合去甲基化药物地西他滨治疗后,1例患者一度获得血液学完全缓解,复杂染色体核型恢复正常,但是1月后转为急性白血病并发严重感染死亡,1例治疗后稳定,2例治疗后疾病进展,1例死于肺部感染。结论:MDS中DNMT3A基因突变率低,其突变多预示预后较差,并可能更快地向急性髓性白血病转化,选择去甲基化药物治疗可能获益。     

TET2合并DNMT3A突变及其他共存基因突变对急性髓系白血病患者预后的影响

  目的  探究TET2合并DNMT3A突变及其他共存基因突变对成人非M3型急性髓系白血病（acute myeloid leukemia,AML）患者预后的影响。  方法  回顾性分析2018年1月至2021年9月于南昌大学第一附属医院确诊的初治且行血液肿瘤相关突变基因外显子二代测序检测的512例成人 AML（非 M3 型）患者的临床资料,分析患者的临床特征、疗效及生存情况。  结果  本研究共纳入110例AML患者,TET2突变组64例,DNMT3A单突变组46例。男性50例（45.5%）,中位年龄54（15～79）岁。TET2基因突变频率为12.5%（64/512）,98.4%（63/64）患者突变基因数≥2个,每例患者平均合并5.2个突变基因。NPM1（43.8%）、DNMT3A（42.2%）、FLT3-ITD/TKD（40.6%）、CEBPA（26.6%）、TTN（20.3%）为TET2突变常见的共存突变基因。TET2合并DNMT3A突变患者初次诱导完全缓解（complete response,CR）率为46.2%,略低于TET2单突变患者的76.9%（P=0.077）,与DNMT3A单突变患者无显著性差异（P=0.952）。TET2合并DNMT3A突变患者的中位总生存（median overall survival,mOS）时间为9.5个月,明显低于TET2单突变患者（P=0.002）,而与DNMT3A单突变患者无显著性差异（P=0.414）。三者的中位无复发生存（median relapse- free survival,mRFS）时间无显著性差异（P>0.05）。在TET2突变背景下,合并K/NRAS突变患者的CR率为28.6%,明显低于无K/NRAS突变患者的75.0%（P=0.030）,合并FLT3-ITD突变患者的mOS明显短于无FLT3-ITD突变患者（P=0.030）。多因素分析显示年龄≥60岁、合并FLT3-ITD突变、初次诱导未达CR是影响TET2突变AML患者总生存时间（overall survival,OS）的独立危险因素,DNMT3A突变不影响TET2突变患者OS。  结论  TET2突变是AML患者常见突变,且常合并共存基因突变。共存基因突变与TET2突变共同影响AML患者预后。基于二代测序的基因突变检测对指导AML精确分层及精准治疗具有重要意义。      

DNMT3A、FLT3-ITD合并NPM1基因突变正常核型急性髓系白血病患者的临床特征及预后分析

目的 分析DNMT3A、FLT3-ITD合并NPM1基因突变的正常核型急性髓系白血病(AML)患者的临床特征,探讨该类患者的预后.方法 回顾性分析2005年12月至2014年6月就诊的109例正常核型AML患者的临床特征及预后.其中DNMT3A/FLT3-ITD/NPM1+AML患者共25例,单独FLT3-ITD+ AML患者共32例,单独NPM1+AML患者24例,单独DNMT3A+ AML患者28例.结果 25例DNMT3A/FLT3-ITD/NPM1+ AML患者平均年龄46岁,伴有高白细胞(81.7×109/L)及较高的骨髓原始细胞(66.3％).其中,17例选择大剂量化疗,8例行异基因造血干细胞移植,与DNMT3A+、FLT3-ITD+、NPM1+AML组比较,差异均无统计学意义.25例DNMT3A/FLT3-ITD/NPM1+患者的3年总生存率为17.65％,3年无病生存率为13.88％,与DNMT3A+、FLT3-ITD+、NPM1+AML组差异均有统计学意义(P值分别为0.049 9、0.036 1、0.013 4),3年无病生存率差异无统计学意义(均P＞ 0.05).结论 DNMT3A、FLT3-ITD合并NPM1基因突变的正常AML患者往往合并高的外周血白细胞及骨髓原始细胞,预后较差.     

FLT3、NPM1、DNMT3A及IDH基因突变对非M3型急性髓系白血病预后影响的研究进展

非M3型急性髓系白血病(AML)是一组异质性恶性血液系统疾病,无论在形态学、免疫学、细胞遗传学、分子生物学及临床特点上都存在很大差异.细胞遗传学检测结果已经成为AML精确诊断、治疗选择和预后判断的主要依据之一,但由于在分子水平上存在高度的异质性,常规细胞遗传学技术检出率不高.有40%~50%的AML患者在初诊时用标准的染色体显带分析方法检测不到克隆性染色体畸变,被称为正常核型AML.非M3型AML较常见的分子遗传学改变为FLT3、NPM1、DNMT3A、IDH基因突变.文章主要就四种基因的特点、发病机制及对非M3型AML的预后影响作一综述.     

DNA甲基转移酶3A基因突变阳性的T淋巴母细胞淋巴瘤/白血病一例临床分析

目的 分析DNA甲基转移酶3A(DNMT3A)基因突变阳性的T淋巴母细胞淋巴瘤/白血病(T-LBL/ALL)的临床及预后特征.方法 报道1例DNMT3A基因突变阳性的T-LBL/ALL的发生、发展及对治疗的反应并复习相关文献.结果 DNMT3A基因突变可出现在T-LBL/ALL患者中,该患者具有病程长、白细胞计数不高、伴纵隔病变和肝脾大等特征,且对治疗的反应较差.结论 DNMT3A基因突变可能是T-LBL/ALL患者预后不良的一个指标.     

恶性血液病患者游离Fas的检测及意义

目的　了解游离Ｆａｓ（ｓＦａｓ）在恶性血液病中的水平及临床意义。方法　用酶联免疫吸附法测定６０ 例恶性血液病患者血清中ｓＦａｓ水平。结果　恶性血液病患者血清ｓＦａｓ水平高于正常人,治疗后ｓＦａｓ水平下降,下降的程度与疗效有关,但治疗前水平高低与疗效无关。结论　ｓＦａｓ对恶性血液病的诊断及疗效判定有一定意义,并可能对其发病机制产生影响。     

胃癌弱差异基因表达谱中DNMT3A基因表达和生物学作用的探讨

目的:明确胃癌差异基因表达谱中弱差异表达基因的敏感性和特异性;探讨胃癌弱差异表达基因DNMT3A在胃癌发生发展中的生物学作用和意义.方法:利用半定量RT/PCR方法验证了胃癌弱差异基因表达谱中DNMT3A基因的表达水平,并利用GoMiner软件研究了DNMT3A的生物学功能.结果:DNMT3A基因在胃癌组织中比癌旁正常组织表达微弱升高,基因表达变化倍数为1.13,与基因芯片的表达变化(1.10)一致GoMiner软件功能注释表明DNMT3A在甲基化和转录调控等方面具有重要生物学功能.结论:可以在实验室中利用分子生物学方法验证胃癌差异基因表达谱中的弱差异表达基因;弱差异表达基因DNMT3A的异常表达与多种肿瘤的发生有密切的联系,并且可能在胃癌的发生发展中具有重要的生物学作用.     

伴NRAS基因突变的急性髓系白血病患者的临床特征及生存分析北大核心

目的:探讨伴有NRAS基因突变的急性髓系白血病(acute myeloid leukemia,AML)患者的临床特征及生存分析。方法:回顾性分析2016年05月至2019年12月就诊于空军军医大学唐都医院血液内科的225例初诊AML患者的临床资料,采用二代测序技术进行基因突变检测,分析NRAS基因突变患者的临床特征并进行预后分析。结果:共有36例(16%)患者检测到NRAS基因突变,全部为错义突变,33例突变位点位于2号外显子12、13号密码子,2例位于3号外显子61号密码子,1例位于4号外显子109密码子。中位突变比例为21.99%(1%~49.85%)。伴有NRAS基因突变的患者中位年龄为44(9~85)岁。年龄分布、前期血液病史、初诊时外周血细胞计数、骨髓原始细胞比例等与无NRAS患者差异相比均无统计学意义。伴有NRAS突变组的患者一疗程诱导化疗完全缓解率高于NRAS野生型组(P=0.033),但复发率也较高(P=0.055)。伴NRAS基因突变组患者的中位OS时间为22个月,无NRAS基因突变组患者的中位OS时间为28个月,两组OS时间无统计学差异(P=0.485);两组患者的RFS时间存在统计学差异(P=0.036)。采用“3+7”方案诱导治疗的患者中位OS时间40个月,8例采用DEC+CAG方案诱导化疗的患者中位OS时间为15个月(P=0.027)。36例患者中31例伴有其他基因突变,生存分析显示NRAS同时伴DNMT3A突变组患者的预后更差(P=0.019)。结论:AML患者NRAS突变率16%,均为错义突变,大部分位于2号外显子12、13号密码子。伴有NRAS突变的患者CR率高,复发率也高,RFS时间短于无NRAS突变组。“3+7”方案诱导治疗缓解率更高。NRAS伴DNMT3A突变提示预后差。     

慢性粒细胞性白血病FLT3基因及FLT3/ITD基因突变的检测及意义

背景与目的:大部分急性髓细胞性白血病(acutemyeloidleukemia,AML)患者出现FLT3基因异常表达,20%～30%AML患者会出现FLT3/ITD基因突变并与临床预后相关。本研究旨在了解慢性粒细胞白血病(chronicmyeloidleukemia,CML)患者FLT3基因及FLT3/ITD基因突变情况。方法:采用聚合酶链反应(polymerasechainreaction,PCR)检测53例CML慢性期和34例CML加速期或急变期患者DNA水平FLT3基因及FLT3/ITD基因突变。结果:53例CML慢性期患者3例(5.7%)出现FLT3基因阳性,34例加速期或急变期患者有19例(55.9%)出现FLT3基因阳性,CML加速期和急变期患者FLT3基因阳性率显著高于慢性期患者(P<0.001),87例CML患者,仅2例(2.3%)出现FLT3/ITD基因突变。结论:在CML患者中,FLT3基因表达主要见于加速期或急变期患者;CML很少发生FLT3/ITD基因突变;FLT3基因及FLT3/ITD基因突变阳性CML患者可能提示预后不佳,此方面研究尚需深入。     

c-FLIP mRNA 在恶性血液病中的表达及其意义

目的：探讨C—FLIPmRNA在恶性血液病中的表达及其意义。方法：用采用半定量逆转录聚合酶链反应（RT—PCR）检测42例恶性血液病骨髓单个核细胞C—FLIPmRNA的表达。包括急性白血病（AL）27例，其中初治21例及复发和完全缓解（CR）后AL各3例、慢性粒细胞性白血病（CML）5例、慢性中性粒细胞性白血病（CNL）1例和慢性淋巴细胞性白血病（CLL）4例，多发性骨髓瘤（MM）3例，骨髓增生异常综合征-难治性贫血伴原始细胞增多2型（MDS—RAEB-2）2例。结果：在初治和复发AL、初治CML、CNL、CLL、MDS—RAEB-2、MM中C—FLIPmRNA均呈异常增高表达，初治AL中c—FLIPmRNA的表达与复发AL比较差异无统计学意义（P〉0．05），其FAB各亚型之间的表达差异亦无统计学意义（P〉0．05）。初治AL与CLLC—FLIPmRNA的表达显著高于初治CML（P〈0．001），但初治AL与初治CLLE魄磋淠呒统计学意义（P〉0．05）。MDS—RAEB-2、MMC—FLIPmRNA的表达与AL的cFLIPmRNA表达均无统计学差异（P〉0．05）。对照组和CR后AL均为阴性表达。C—FLIPmRNA的表达与初治AL患者年龄、性别、初诊白细胞数、LDH以及核型、免疫表型无关。初治未达CR的AL患者其c—FLIPmRNA表达高于CR者，但并无统计学意义（尸〉0．05）。结论：恶性血液病C—FLIPmRNA的表达异常增高。C—FLIPmRNA能反映恶性血液病骨髓细胞的凋亡抑制情况，并与恶性血液病的类型、疾病状态、临床疗效和预后密切相关。     

Mutational analysis of DNMT3A improves the prognostic stratification of patients with acute myeloid leukemia

Nucleophosmin1 (NPM1) mutations are the most frequently detected gene mutations in acute myeloid leukemia (AML) and are considered a favorable prognostic factor. We retrospectively analyzed the prognosis of 605 Japanese patients with de novo AML, including 174 patients with NPM1-mutated AML. Although patients with NPM1-mutated AML showed a high remission rate, this was not a favorable prognostic factor for overall survival (OS); this is contrary to generally accepted guidelines. Comprehensive gene mutation analysis showed that mutations in codon R882 of DNA methyltransferase 3A (DNMT3A^R882 mutations) were a strong predicative factor indicating poor prognosis in all AML (p < 0.0001) and NPM1-mutated AML cases (p = 0.0020). Furthermore, multivariate analysis of all AML cases showed that DNMT3A^R882 mutations and the co-occurrence of internal tandem duplication in FMS-like tyrosine kinase 3 (FLT3-ITD), NPM1 mutations, and DNMT3A^R882 mutations (triple mutations) were independent factors predicting a poor prognosis related to OS, with NPM1 mutations being an independent factor for a favorable prognosis (hazard ratios: DNMT3A^R882 mutations, 1.946; triple mutations, 1.992, NPM1 mutations, 0.548). Considering the effects of DNMT3A^R882 mutations and triple mutations on prognosis and according to the classification of NPM1-mutated AML into three risk groups based on DNMT3A^R882/FLT3-ITD genotypes, we achieved the improved stratification of prognosis (p < 0.0001). We showed that DNMT3A^R882 mutations are an independent factor for poor prognosis; moreover, when confounding factors that include DNMT3A^R882 mutations were excluded, NPM1 mutations were a favorable prognostic factor. This revealed that ethnological prognostic discrepancies in NPM1 mutations might be corrected through prognostic stratification based on the DNMT3A status.     

Quantitative detection of DNMT3A R882H mutation in acute myeloid leukemia

Background

DNMT3A mutations represent one of the most frequent gene alterations detectable in acute myeloid leukemia (AML) with normal karyotype. Although various recurrent somatic mutations of DNMT3A have been described, the most common mutation is located at R882 in the methyltransferase domain of the gene. Because of their prognostic significance and high stability during disease evolution, DNMT3A mutations might represent highly informative biomarkers for prognosis and outcome of disease.

Methods

We describe an allele-specific PCR with a Blocking reagent for the quantitative detection of DNMT3A R882H mutation providing the possibility to analyze the quantitative amount of mutation during the course of disease. Next, we analyzed 62 follow-up samples from 6 AML patients after therapy and allogeneic stem cell transplantation (alloSCT).

Results

We developed an ASB-PCR assay for quantitative analysis of R882H DNMT3A mutation. After optimization of blocker concentration, a R882H-positive plasmid was constructed to enhance the accuracy of the sensitivity of quantitative detection. The assay displayed a high efficiency and sensitivity up to 10⁻³. The reproducibility of assay analyzed using follow-up samples showed the standard deviation less than 3.1 %. This assay displayed a complete concordance with sequencing and endonuclease restriction analysis. We have found persistence of DNMT3A R882H mutations in complete remission (CR) after standard cytoreduction therapy that could be indicating presence of DNMT3A mutation in early pre-leukemic stem cells that resist chemotherapy. The loss of correlation between NPM1 and DNMT3A in CR could be associated with evolution of pre-leukemic and leukemic clones. In patients with CR with complete donor chimerism after alloSCT, we have found no DNMT3A R882H. In relapsed patients, all samples showed an increasing of both NPM1 and DNMT3A mutated alleles. This suggests at least in part the presence of NPM1 and DNMT3A mutations in the same cell clone.

Conclusion

We developed a rapid and reliable method for quantitative detection of DNMT3A R882H mutations in AML patients. Quantitative detection of DNMT3A R882H mutations at different time points of AML disease enables screening of follow-up samples. This could provide additional information about the role of DNMT3A mutations in development and progression of AML.     

胰腺黏液性囊腺癌基因突变的检测及其临床意义

[摘要] 目的:利用高通量测序平台研究胰腺黏液性囊腺癌（PMCC）组织中基因突变的分布特点及其临床意义。方法: 收集2012 年1 月至2016 年12 月经外科手术切除的4 例PMCC患者癌及癌旁组织石蜡标本,通过Illumina Hiseq 2500 平台进行二代基因测序（NGS）,结合患者临床病理资料分析PMCC患者癌组织的基因突变特征。结果: 在4 个PMCC样本中,均检测到7 个高频 突变基因（SMG）,分别是KRAS、AHNAK2、MUC16、MUC17、MUC19、MUC3A和MUC4。3 个样本中检测到24 个SMG,分别为ADAMTS9、ALDH3B1、CARD14、CSMD3、MKI67、OR1N2、PKHD1、PLCE1、RTL1、SIGLEC12、CCDC168、CEP295、CUBN、DST、HRNR、LAMA5、OR10G4、OR2T4、PLEKHG4B、RP1L1、SLC15A5、SVEP1、TAS1R1 和TNRC18。所有样本中均检测到KRAS驱动基因突变,其中3 例检测到KRAS 的K12 热点突变,另1 例检测到KRAS 的D33E 非热点突变。结论: PMCC患者的高突变KRAS和MUC家族,可能成为PMCC精准治疗的潜在靶点和生物标志物。     

FLT3/ITD基因突变在不同血液肿瘤患者的表达及其临床意义

Objective:To analyze Fms-like tyrosine kinase 3(FLT3)/intemal-tandem duplications(ITD)murations in various kinds of hematologic malignancy patients.Methods:FLT3/ITD gene mutations were detected by polymerase chain reaction (PCR)in 103 acute myeloid leukemia(AML)cases,63 acute lymphocytic leukemia(ALL)cases,53 chronic myelogenous leukemia(CML)cases in chronic phase(CML-CP),34 CML cases in biast crisis(CML-BC),11 chronic lymphatic leukemia(CLL)cases,36 myelodysplastic syndrome (MDS)cases,9 multiple myeloma(MM)cases and 13 non-hodgkin's lymphoma (NHL)cases with marrow infiltration.Results:The expressions of FLT3/ITD gene mutations were detected in 22.3% AML cases.in 6.5%CML-BC cases.in 5.6%MDS cases and in 2.6%ALL cases.The two ALL cases with FLT3/ITD mutation were diagnosed as ALL-L2 with morphology and both with myeloid antigen expression,but finally were diagnosed as acute mixed-lineage leukemia after immunology examination.FLT3/ITD gene muIations were not detected in CML-CP,MM.NHL and CLL cases.In the 23 AML patients with FLT3/ITD gene mutation,including 2 of 8 M1(2.5%),8 of 33 M2(24-2%),7 of 24 M3(29.3%),2 of 11 M4(18.2%).3 of 21 M5(14.3%),1 of 5 M6(20%),and 0 of 1 M7 cases,and there were no significant differences in the positive rates of FLT3/ITD mutations between the FAB subtypes(P＞0.05).Statistical analyses showed that in AML patients,FLT3/ITD was associated with a higher pefipheral blood white cell(WBC)counts[(41.23±32.56)x 100/L vs (11.36±9.89)x109/L(P＜0.01)],higher percentage of bone marrow blast cells[(72.78±21.79)%vs(51.26±20.78)%(P＜0.05)],and higher cumulative relapse rates(63.6%vs 27.7%,P＜0.025)than those negative.Conclusion:FLT3/ITD gene mutation mainly pccurred in AML patients.and might be a strong prognostic factor which was associated with high peripheral WBC counts.bone marrow blast cell proportion and a increased relapse risk in AML.Detection of FLT3/ITD gene mutation might provide insights to explore a more accurate genotyping of leukemia,differential diagnosis between AML and ALL.subdivide risk level in AML and estimate prognosis of leukemia.     

Prognostic significance of isochromosome 17q in hematologic malignancies

Isochromosome 17q [i(17q)] with its two identical long arms is formed by duplication of the q arm and loss of the short p arm. The breakpoint in chromosome 17 that allows the formation of this isochromosome is located at 17p11.2, and the ~240 kb region with its large, palindromic, low-copy repeat sequences are present here. The region is highly unstable and susceptible to a variety of genomic alterations which may be induced by or without toxic agents. One molecular consequence of i(17q) development is the obligatory loss of a single TP53 allele of the tumor suppressor P53 protein located at 17p13.1. Isochromosome 17q is involved in cancer development and progression. It occurs in combination with other chromosomal defects (complex cytogenetics), and rarely as a single mutation. The i(17q) rearrangement has been described as the most common chromosomal aberration in primitive neuroectodermal tumors and medulloblastomas. This isochromosome is also detected in different hematological disorders. In this article, we analyze literature data on the presence of i(17q) in proliferative disorders of the hematopoietic system in the context of its role as a prognostic factor of disease progression. The case reports are added to support the presented data. Currently, there are no indications for the use of specific treatment regimens in the subjects with a presence of the isochromosome 17q. Thus, it is of importance to continue studies on the prognostic role of this abnormality and even single cases should be reported as they may be used for further statistical analyses or meta-analyses.