急性淋巴细胞白血病常见融合基因检测的研究

Study on detection of common fusion genes in acute lymphoblastic leukemia

目的探讨联合应用多重巢式反转录聚合酶链反应（RT-PCR）技术和染色体核型分析对急性淋巴细胞白血病（ALL）常见融合基因的表达和克隆性染色体异常的检出情况。方法采用多重巢式RT-PCR技术对189例ALL患者进行检测，同时进行染色体R或G显带。结果189例ALL患者中69例（36．5％）检出10种融合基因（E2A-PBX1、TEL—AML1、bcr-abl、MLL-AF4、MLL—AF6、MLL-AF9、MLL—AF10、MLL-ELL、SIL-TAL1、TLS-ERG），染色体R或G显带可供分析的152例中，86例（56．6％）检出染色体结构和数目异常；二者联合可使ALL克隆性染色体异常检出率增至69．3％（131例）。90例成年ALL患者中33例（36．7％）检测阳性，其中bcr-abl22例，未见TEL-AML1，99例儿童ALL患者中阳性36例（36．4％），其中TEL—AML124例，bcr-abl 2例。成年人组与儿童组bcr-abl、TEL-AML1的表达率差异有统计学意义（均P〈0．01）。MLL相关融合基因、E2A-PBX1、SIL—TAL1、TLS-ERG等表达率差异无统计学意义（均P〉0．05）。66例正常核型的ALL患者检测出有bcr-abl、TEL-AML1融合基因的存在。结论成年人和儿童ALL融合基因表达各有侧重，多重巢式RT—PCR可用于初诊时染色体畸变的筛选，可在核型正常的ALL患者中检出隐匿的染色体易位，提供与预后相关的重要信息。

Objective To investigate combined application of multiplex reverse transcriptionpolymerase chain reaction （mRT-PCR） and karyotype analysis detect of clonal chromosomal aberrations in acute lymphoblastic leukemia （ALL）, and explore the expression of common fusion genes. Methods 189 ALL patients were examined by multiplex RT-PCR and R or G banding techniques. Results 10 fusion genes were detected in 69 out of 189 ALL patients（36.5 %）, including E2A/PBX1, TEL/AML1, BCR/ABL, MLL/AF4, MLL/AF6, MLL/AF9, MLL/AF10, MLL/ELL, SIL/TAL1, TLS/ERG. R or G banding techniques could find chromosome structural and numeracy abnormalities in 86 out of 152 patients （56.6 %） available for analysis. Combination of mRT-PCR and R or G banding could raise the rate of detecting clonal chromosomal abnormalities to 69.3 %. Fusion genes were detected in 33 out of 90 （36.7 %） patients with adult ALL and 36 out of 99 （36.4 %） patients with children ALL, there were 22 patients with positive BCR/ABL but no TEL/ AMLI in adult ALL group, while there were 24 patients with positive TEL/AML1 and 2 with positive BCR/ ABL in children ALL group. There was significant statistical difference for the expression of BCR/ABL and TEL/AML1 between adult ALL and children ALL （P〈0.01）, but no difference for MLL related fusion gene, E2A/PBX1, SIL/TAL1 and TLS/ERG（P〉0.05）. BCR/ABL and TEL/AML1 fusion gene could be detected in 66 ALL patients with normal karyotype （36.3 %）. Conclusion There were different biological characteristics between adults and children with ALL. mRT-PCR technique can quickly screen chromosome structural aberrations in patients with newly diagnosed leukemia. It is useful in detection of fusion genes in ALL with normal karyotypes and it would refine the karyotype analysis and provide important prognosis-relevant information.