双色双融合与额外信号探针在BCR/ABL融合基因检测中的比较及其意义

目的 探讨DCCF(dual color dual fusion)探针与ES(extra signal)探针在BCR/ABL融合基因检测中信号表现的特点,并明确其信号特征与染色体核型的相互关系.方法 对初治65例慢性粒细胞白血病(chronic myelocytic leukemia,CML)及50例急性淋巴细胞白血病(acute lymphoblastic leukemia,ALL)患者骨髓标本进行BCR/ABL的DCDF探针的荧光原位杂交(fluorescence in situ hybridization,FISH)检测,FISH阳性标本则使用ES探针再次进行荧光原位杂交进行BCR断裂点的检测,同时对其中47例CML和40例ALL进行了核型分析.结果 FISH结果示65例CML均为BCR/ABL阳性,DCDFFISH中有17例为非典型信号表现,ES-FISH有12例为非典型信号表现;50例ALL中7例BCR/ABL阳性,ES探针显示5例BCR断裂点位于m-bcr,2例位于M-bcr.核型分析CML检出Ph阳性98%(43/44),ALL检出Ph阳性22%(7/32).结论 DCDF-FISH、ES-FISH以及核型分析各有其特性.根据每种方法的特性,对实验结果进行综合分析可对遗传学特征作出更准确判断.     

双色双融合与额外信号探针在BCR/ABL融合基因检测中的比较及其意义

目的 探讨DCCF(dual color dual fusion)探针与ES(extra signal)探针在BCR/ABL融合基因检测中信号表现的特点,并明确其信号特征与染色体核型的相互关系.方法 对初治65例慢性粒细胞白血病(chronic myelocytic leukemia,CML)及50例急性淋巴细胞白血病(acute lymphoblastic leukemia,ALL)患者骨髓标本进行BCR/ABL的DCDF探针的荧光原位杂交(fluorescence in situ hybridization,FISH)检测,FISH阳性标本则使用ES探针再次进行荧光原位杂交进行BCR断裂点的检测,同时对其中47例CML和40例ALL进行了核型分析.结果 FISH结果示65例CML均为BCR/ABL阳性,DCDFFISH中有17例为非典型信号表现,ES-FISH有12例为非典型信号表现;50例ALL中7例BCR/ABL阳性,ES探针显示5例BCR断裂点位于m-bcr,2例位于M-bcr.核型分析CML检出Ph阳性98%(43/44),ALL检出Ph阳性22%(7/32).结论 DCDF-FISH、ES-FISH以及核型分析各有其特性.根据每种方法的特性,对实验结果进行综合分析可对遗传学特征作出更准确判断.     

荧光原位杂交技术检测BCR/ABL融合基因的研究

目的建立荧光原位杂交技术平台,应用FISH技术检测在CML检测BCR/ABL融合基因,探讨FISH技术在在CML中应用的价值。方法应用FISH对BCR/ABL探针进行前期的验证,建立正常阈值,再应用该探针检测CML中BCR/ABL融合基因,进行临床检测评估。结果主要假阳性信号模式的正常阈值为1G1R1F 11%、1G1R2F 2%。75例样本FISH检测出48例阳性,15例经细胞遗传学检测,12例检测结果与FISH结果一致,3例CG为阴性,FISH检测为阳性。结论荧光原位杂交技术应用于临床检测之前应进行探针的前期验证,制定一套规范实验流程,且FISH技术在CML诊断、分型、临床治疗方案的制定、预后的判断以及微小残留病变检测上均有重要的价值。     

双色双融合与额外信号探针在BCR/ABL融合基因检测中的比较及其意义

目的 探讨DCCF(dual color dual fusion)探针与ES(extra signal)探针在BCR/ABL融合基因检测中信号表现的特点,并明确其信号特征与染色体核型的相互关系.方法 对初治65例慢性粒细胞白血病(chronic myelocytic leukemia,CML)及50例急性淋巴细胞白血病(acute lymphoblastic leukemia,ALL)患者骨髓标本进行BCR/ABL的DCDF探针的荧光原位杂交(fluorescence in situ hybridization,FISH)检测,FISH阳性标本则使用ES探针再次进行荧光原位杂交进行BCR断裂点的检测,同时对其中47例CML和40例ALL进行了核型分析.结果 FISH结果示65例CML均为BCR/ABL阳性,DCDFFISH中有17例为非典型信号表现,ES-FISH有12例为非典型信号表现;50例ALL中7例BCR/ABL阳性,ES探针显示5例BCR断裂点位于m-bcr,2例位于M-bcr.核型分析CML检出Ph阳性98%(43/44),ALL检出Ph阳性22%(7/32).结论 DCDF-FISH、ES-FISH以及核型分析各有其特性.根据每种方法的特性,对实验结果进行综合分析可对遗传学特征作出更准确判断.

Abstract：

Objective To investigate the signal patterns of dual color dual fusion (DCDF) probe and extra signal (ES) probe in the detection of BCR/ABL fusion gene, and illustrate the relation between the fluorescence in situ hybridization (FISH) pattern and the karyotype. Methods Sixty-five cases of chronic myelocytic leukemia(CML) and 50 cases of acute lymphoblastic leukemia (ALL) were detected by FISH with DCDF probe, the BCR/ABL positive samples were detected by FISH with ES probe. Among these cases, 47 cases of CML and 40 cases of ALL perform conventional cytogenetics simultaneously. Results All 65 cases of CML were all BCR/ABL positive by FISH. 17 cases showed the atypical pattern by DCDFFISH, and 12 cases showed the atypical pattern by ES-FISH. There were 7 cases of BCR/ABL positive in 50 cases of ALL by FISH. By ES-FISH, there were 5 cases in which the break-point of BCR gene was located in m-bcr, 2 cases in which the break-point of BCR gene was located in M-bcr. Conventional cytogenetics demonstrated that 43/44(98 %) cases of CML and 7/32(22 %) cases of ALL were Ph positive.Conclusion The features of DCDF-FISH, ES-FISH and conventional eytogenetic are different from each other. According to the features of these method, it can increase the precision of the adjustment of genetic feature to analyze these results comprehensively.     

慢性粒细胞白血病患者骨髓来源Flk1+CD31-CD34-间充质干细胞中 BCR/ABL融合基因的检测

背景：免疫表型为Flk1+CD31-CD34-的间充质干细胞体内外实验研究均证实在单细胞水平可以向造血及内皮细胞分化。 目的：观察慢性粒细胞白血病患者骨髓BCR/ABL融合基因的表达情况。 方法：体外培养扩增慢性粒细胞白血病患者骨髓来源原始间充质干细胞,测定其生长曲线,分析其细胞周期及免疫表型,使用RT-PCR和FISH的方法检测其BCR/ABL融合基因的表达情况。 结果与结论：慢性粒细胞白血病患者骨髓来源的原始间充质干细胞呈成纤维样生长,大部分细胞处于G0/G1期,并且高表达Flk1,CD13,CD29,CD44,用RT-PCR和FISH的方法能够检测出BCR/ABL融合基因的表达。提出慢性粒细胞白血病的白血病基因转化可能发生在比造血干细胞更高的血液血管干细胞水平上。     

BCR-ABL融合基因检测在CML诊断及治疗中的应用进展

BCR-ABL融合基因是慢性粒细胞白血病(CML)的特异性肿瘤标志物,在CML的诊断和治疗监测中有重要作用。费城阳性(Ph+)染色体细胞或BCR-ABL融合基因数量的变化是评估CML的重要手段,临床常用检测方法有常规染色体分析、荧光原位杂交(FISH)和荧光定量PCR。常规染色体检测用于CML初始治疗获得完全细胞学缓解(CCyR)的评价;FISH较常规染色体检测更敏感且能可视化观测Ph+染色体细胞;荧光定量PCR更加利于CML微小残留病监测。这些技术方法正在不断满足辅助诊断CML的临床要求及进一步提升CML疗效监测和微小残留病诊断水平。     

应用FISH、FCM检测APL PML/RARA融合基因及临床应用的研究

目的　研究应用荧光原位杂交技术 (FISH)、流式细胞技术 (FCM)检测急性早幼粒细胞白血病 (APL)PML/RARa融合基因及残留白血病细胞的意义。方法　应用CG、M -FISH、FCM对 30例APL患者初发和缓解期的骨髓标本进行分析 ,分别检测t(15 ;17)易位和PML/RARa融合基因及残留白血病细胞的存在。结果　对初发期骨髓标本进行CG和FISH分析发现 ,10 0 %具有t(15 ;17)易位 ,阳性核型占 6 8%～ 10 0 % ,其中有 8例还伴有其他异常 ;10 0 %具有PML/RARa融合基因 ,且阳性中期相的比例高达 96 %～ 10 0 % ;结果具有显著差异 (P <0 0 0 1)。对CR期的骨髓标本进行CG、FISH分析 ,CG为正常核型 ,FISH仍可检出 0 %～ 4 5 %的PML/RARa融合基因。对CR后 12个月的标本进行CG、FISH分析 ,CG均为正常核型 ;FISH仍可检出 0 %～ 37%的PML/RARa融合基因 ,较CR期有所降低。对这 30例APL患者初发期、完全缓解期及完全缓解后 12个月时进行了FCM检测 ,并得出定性结果。完全缓解期检测结果与M -FISH分析一致 ;对完全缓解后 12个月时M -FISH结果进行定性分析发现 30例患者中有 6例为融合基因阴性 ,相应的FCM定性分析结果却发现只有其中的 2例呈现阴性 ,其余 4例仍然为阳性。随访至CR后 2年 ,发现 7例PML/RARa融合基因阳性中期相比例较高 (CG分     

两种BCR/ABL探针在Ph阳性白血病荧光原位杂交检测中的不同信号模式及其意义

目的 比较BCR/ABL双色额外信号探针(dual color extra-signal BCR/ABL probe,ESFISH探针)及BCR/ABL双色双融合探针(dual color dual fusion BCR/ABL probe,D-FISH探针)在Ph阳性白血病荧光原位杂交(fluorescence in situ hybridization,FISH)检测中信号模式的差异,探讨它们的诊断价值.方法 分别采用D-FISH和ES-FISH探针对74例伴有单纯t(9;22)(q34;q11)及37例伴有变异Ph易位或复杂核型异常的Ph阳性白血病患者骨髓细胞进行间期FISH检测.结果 所有单纯t(9;22)(q34;q11)易位的白血病患者应用两种探针均检测到BCR/ABL阳性信号,ES-FISH探针显示2个橙色信号、1个绿色信号和1个黄色信号模式,而D-FISH探针显示1个橙色信号、1个绿色信号和2个黄色信号模式.ES-FISH探针在9例(12.2%)Ph阳性白血病患者中识别次要BCR断裂位点(1个橙色信号、1个绿色信号和2个黄色信号),而D-FISH探针不能识别主要BCR和次要BCR断裂位点;D-FISH探针在8例(10.8%)Ph阳性白血病中区分ABL基因单独缺失(1个橙色信号、2个绿色信号、1个黄色信号)和ABL、BCR基因共同缺失(1个橙色信号、1个绿色信号和1个黄色信号),ES-FISH则不能区分之.检测变异Ph易位和含Ph易位的复杂核型异常时,两种探针的信号模式分别有4种和6种之多,且以不典型者居多,对于它们的精确解释必须依赖常规染色体分析和中期FISH结果 .结论 ES-FISH及D-FISH探针由于BCR探针大小及覆盖区域不同,在Ph阳性白血病的FISH检测中显示不同信号模式,可分别作为Ph+急性淋巴细胞白血病和慢性髓系白血病患者FISH检测的首选.若采用伊马替尼治疗,主要BCR断裂点和次要BCR断裂点、伴或不伴有衍生9号染色体部分序列缺失均不影响预后,但鉴于ES-FISH探针性价比优于D-FISH探针,推荐其作为Ph阳性白血病FISH检测的首选.     

两种BCR/ABL探针在Ph阳性白血病荧光原位杂交检测中的不同信号模式及其意义

目的 比较BCR/ABL双色额外信号探针(dual color extra-signal BCR/ABL probe,ESFISH探针)及BCR/ABL双色双融合探针(dual color dual fusion BCR/ABL probe,D-FISH探针)在Ph阳性白血病荧光原位杂交(fluorescence in situ hybridization,FISH)检测中信号模式的差异,探讨它们的诊断价值.方法 分别采用D-FISH和ES-FISH探针对74例伴有单纯t(9;22)(q34;q11)及37例伴有变异Ph易位或复杂核型异常的Ph阳性白血病患者骨髓细胞进行间期FISH检测.结果 所有单纯t(9;22)(q34;q11)易位的白血病患者应用两种探针均检测到BCR/ABL阳性信号,ES-FISH探针显示2个橙色信号、1个绿色信号和1个黄色信号模式,而D-FISH探针显示1个橙色信号、1个绿色信号和2个黄色信号模式.ES-FISH探针在9例(12.2%)Ph阳性白血病患者中识别次要BCR断裂位点(1个橙色信号、1个绿色信号和2个黄色信号),而D-FISH探针不能识别主要BCR和次要BCR断裂位点;D-FISH探针在8例(10.8%)Ph阳性白血病中区分ABL基因单独缺失(1个橙色信号、2个绿色信号、1个黄色信号)和ABL、BCR基因共同缺失(1个橙色信号、1个绿色信号和1个黄色信号),ES-FISH则不能区分之.检测变异Ph易位和含Ph易位的复杂核型异常时,两种探针的信号模式分别有4种和6种之多,且以不典型者居多,对于它们的精确解释必须依赖常规染色体分析和中期FISH结果 .结论 ES-FISH及D-FISH探针由于BCR探针大小及覆盖区域不同,在Ph阳性白血病的FISH检测中显示不同信号模式,可分别作为Ph+急性淋巴细胞白血病和慢性髓系白血病患者FISH检测的首选.若采用伊马替尼治疗,主要BCR断裂点和次要BCR断裂点、伴或不伴有衍生9号染色体部分序列缺失均不影响预后,但鉴于ES-FISH探针性价比优于D-FISH探针,推荐其作为Ph阳性白血病FISH检测的首选.     

Fluorescence in situ hybridization: a highly efficient technique of molecular diagnosis and predication for disease course in patients with myeloid leukemias.

The accuracy of cytogenetic diagnosis in the management of hematological malignancies has improved significantly over the past 10 years. Fluorescence in situ hybridization (FISH), a technique of molecular cytogenetics, has played a pivotal role in the detection of unique sub-microscopic chromosomal rearrangements that helped in the identification of chromosomal loci, which contain genes involved in leukemogenesis. We studied the feasibility and sensitivity of the FISH technique for molecular analysis of translocations markers, t(9;22) and t(15;17) for accurate molecular diagnosis and for monitoring the disease in 21 patients with chronic myeloid leukemia (CML) who received interferon-alpha and/or chemotherapy (7 patients), bone marrow transplantation (14 patients), and 14 patients with acute promyelocytic leukemia (APL) who received all-trans-retinoic acid (ATRA) and/or chemotherapy. We also applied conventional karyotyping (CK) for identification of t(9;22) and t(15;17) at diagnosis. All CML cases had a Ph; t(9;22) and except for two cases all APL had t(15;17). The FISH studies on CML marrows in complete cytogenetic remission (CCR) (100% Ph- by CK) achieved by IFN-alpha, showed 0-2.5% of cells with BCR-ABL fusion in first cytogenetic remission (Controls, range 0.5-1.5%). Repeat follow-up FISH studies could be done in two cases in remission, which demonstrated 0-10% of cells with BCR-ABL fusion. Evaluation of Ph positive status of CML marrow at diagnosis by CK (100% Ph+ cells) and FISH (80-92% BCR-ABL fusion) pointed the existence of dormant clone of normal residual hematopoietic cells along with actively proliferating clones of Ph positive cells. Fluorescence in situ hybridization analysis of post-BMT CML marrows in CCR (0% Ph+ mitoses) could detect MRD with range of 1-6%. Among 14 patients, 9 who showed percentage of BCR-ABL positive cells (0.0-1.5%) almost similar to normal controls, 6 patients had comparatively good prognosis (disease-free survival 7-14 months). Of five patients with residual leukemic cells in the range of 2-6%, 4 relapsed within a period of 3-24 months. Fourteen APL patients in CCR [100% t(15;17) negative cells by CK] were evaluated by FISH to check the presence of residual leukemic cells. In these patients FISH could efficiently detect 1-14.5% of residual cells with PML-RARA (patients mean MRD 5%, controls mean MRD 3.5%, P=.02). Since the time of FISH analysis, 5 to 7 patients with higher fraction of leukemic cells (5-11%) relapsed within a short period (1-7 months). On the contrary, 5 of 7 patients with either absence or low percentage of PML-RARA positive cells remained in complete remission for 11-24 months. Our data show that FISH has a potential to detect and measure the fraction of aberrant malignant cells in remission marrows, induced by BMT in CML and chemotherapy in APL. These findings encourage the investigations on a large scale to merit its potential for identification of patients at high risk. In the present studies, FISH on interphase cells also demonstrated its efficiency in the molecular diagnosis by its ability to detect BCR-ABL and PML-RARA fusion in CML with masked/variant Ph and t(15;17) negative APL, respectively. The efficiency of technique in molecular diagnosis was also proved in one of the CML patients who progressed to myeloid blastic phase where interphase FISH could identify an extra BCR-ABL fusion on both chromosomes 9 indicating insertion of BCR into ABL and its duplication.     

Deletion of any part of the BCR or ABL gene on the derivative chromosome 9 is a poor prognostic marker in chronic myelogenous leukemia

To evaluate the prognostic significance of submicroscopic deletions of the ABL or BCR gene associated with t(9;22) in chronic myelogenous leukemia (CML), we investigated the incidence of an ABL or BCR deletion on derivative chromosome 9 using fluorescence in situ hybridization (FISH). FISH was performed using the LSI BCR/ABL dual-fusion translocation probe on bone marrow cells of 86 patients with CML. Of 86 patients, ABL deletion was detected in 13 (15.1%) patients and BCR deletion in 8 patients (9.3%). Patients with ABL deletion showed shorter event-free survival time (EFS) than those without ABL deletion (P = 0.020). Patients with BCR deletion showed significantly short overall survival time (OS; P = 0.039). Patients with ABL and/or BCR deletion (14/86 patients, 16.3%) showed significantly short OS and EFS (median OS, 43.0 months; median EFS, 40.0 months), compared to the patients without any BCR or ABL gene deletions (median OS, 94.0 months; median EFS, 90.0 months; P = 0.041 for OS, P = 0.008 for EFS). All the patients with BCR deletion, except for one, had a concomitant ABL deletion, suggesting that BCR deletion occurs in conjunction with ABL deletion. In patients with ABL deletion only, BCR/ABL rearrangement with b2a2 mRNA type tended to be more frequent than in patients without any deletion of the two genes (P = 0.073). Deletion of any of the BCR or ABL genes on derivative chromosome 9 was associated with both short OS and EFS. We conclude that deletion of not only the ABL gene, but also of the BCR gene, is a poor prognostic marker that indicates rapid disease progression in CML.     

荧光原位杂交检测慢性粒细胞白血病

目的 探讨对慢性粒细胞白血病进行荧光原位杂交(fluorescence in situ hybridization,FISH)检测的意义.方法 对158例慢性粒细胞白血病标本采用24 h短期培养法制备染色体,然后应用双色双融合BCR/ABL探针进行FISH检测,部分标本同时采用R显带技术进行染色体核型分析.结果 158例中共检出Ph阳性标本98例,其中69例(70.4%)为典型双色双融合BCR/ABL探针信号模式(1R1G2F),其余29例(29.6%)为3类12种非典型模式.各种非典型信号模式中出现频率较高的依次为:1R1G1F7例(7.1%)、2R1G1F 5例(5.1%)、1R1G2F&1R1G3F 4例(4.1%)、2R2G1F 3例(3.1%).对18例有核型资料的非典型信号的病例分析显示:其中3例特殊信号系由变异Ph易位引起;2例中出现的3个融合信号来源于附加的Ph染色体;4例核型与FISH结果不吻合,提示染色体分析存在错漏之处;3例染色体为典型Ph易位,而FISH结果为单个融合信号,系由der(9)号的部分缺失所致;3例核型中未发现Ph染色体.但FISH显示40%～64%的细胞中存在一个融合信号,从而明确慢性粒细胞白血病诊断;3例是移植或经格列卫治疗后的患者,染色体均为正常核型,而FISH检测到极小比例的阳性细胞.结论 FISH在慢性粒细胞白血病诊断、判断变异易位、隐匿Ph易位、衍生9号缺失、干扰素及格列卫的疗效观察以及移植后监测等诸多方面均具有重要价值.     

Automated Duet spot counting system and manual technologist scoring using dual-fusion fluorescence in situ hybridization (D-FISH) strategy: comparison and application to FISH minimal residual disease testing in patients with chronic myeloid leukemia

The automated BioView Duet system was compared with manual technologist scoring (MTS) using a BCR/ABL dual-fusion FISH (D-FISH) probe strategy for chronic myeloid leukemia (CML) specimens. In the first study, 500 nuclei were evaluated for 10 distinct signal patterns in various abnormal cell percentages from each of 89 specimens. The Duet system correctly identified all 27 normal specimens and the abnormal signal pattern of all 63 abnormal specimens. The percentage of abnormal nuclei detected was also concordant, with an average difference between MTS and the Duet system of only 2.7%. However, achievement of accurate quantitative results required reclassification by a technologist for nearly 50% of nuclei per specimen. Next, the Duet system was used to evaluate BCR/ABL D-FISH for FISH minimal residual disease (MRD) detection in CML patients. Up to 6,000 nuclei were evaluated for four signal pattern categories for each of 60 CML MRD samples. Excluding four abnormal specimens with insufficient samples, the Duet system correctly identified all of the abnormal specimens and identified four additional abnormal specimens previously diagnosed as normal by MTS. The technologist time required for evaluation and reclassification of the Duet system data for the FISH MRD samples averaged only 1 minute per case, saving significant technologist effort. We conclude that the Duet system appears to be more sensitive and cost-effective than MTS for CML FISH MRD testing.     

Studies of complex Ph translocations in cases with chronic myelogenous leukemia and one with acute lymphoblastic leukemia

The BCR/ABL gene fusion, the hallmark of chronic myelogenous leukemia (CML) is generated in 2-10% of patients by a variant Ph translocation involving 9q34, 22q11.2, and one or more additional genomic regions. The objective of this study was the characterization by conventional and molecular cytogenetics of complex variant Ph translocations present at diagnosis. FISH studies were performed in 7 cases using the LSI BCR/ABL ES probe allowing the detection of the fusion BCR/ABL gene on the Ph chromosome in all of them and 9q34 deletions in 2 cases. Three cryptic complex rearrangements were detected by FISH studies. The third and the fourth chromosome regions involved in the 8 complex variant translocations were: 1q21, 1p36, 5q31, 11q13, 12q13, 12p13, and 20q12. In conclusion, FISH studies have been useful in the detection of the BCR/ABL rearrangements and 9q34 deletions, and to identify complex rearrangements that differ from the ones previously established by conventional cytogenetics.