急性白血病9号染色体微卫星复制错误的研究

STUDY OF MICROSATELLITE REPLICATION ERROR ON CHROMOSOME 9 IN ACUTE LEUKEMIA

目的研究急性白血病(AL)9号染色体微卫星复制错误(RER)现象,探讨微卫星在白血病发病过程中的作用和用于检测染色体微小缺失的意义。方法选取AL病人53例,其中急性髓细胞白血病(AML)33例,急性淋巴细胞白血病(ALL)20例。在9号染色体共选择5个微卫星位点,对骨髓细胞DNA及作为对照的自身口腔黏膜细胞DNA进行多重PCR扩增,通过聚丙烯酰胺凝胶电泳、银染,观察微卫星不稳定性(MSI)和杂合性缺失(LOH)的发生情况。结果53例AL中,共36例发生了至少1个位点的MSI,AML中有15例发生了MSI,10例发生了LOH;ALL中有5例发生了MSI,4例发生了LOH。其中位于9p21上的D9Sl62、D9S1748、D9S171微卫星位点LOH发生率分别为0(0/53)、5.7%(3/53)和7.5%(4/53),MSI发生率分别为15.1%(8/53)、7.6%(4/53)和11.3%(6/53);位于9q34上的D9S61和D9S67位点在AL中LOH发生率分别为11.3%(6/53)和5.6%(3/53),MSI发生率分别为5.6%(3/53)和9.4%(5/53)。其中D9S61位点LOH均发生于AML,发生率为18.1%,显著高于ALL,差异有显著性(P=0.046)。至少发生2个位点MSI即RER+的有6例,占11.3%。结论AL较高的RER+表达率提示,广泛的MSI与AL的发生发展有关;AML在D9S61上检测出较高的LOH提示,该区域可能存在与AML发生有关的基因改变;微卫星标记技术为研究AL一种新的、有价值的方法。

Objective To study the function of microsatellite replication error （RER） in chromosome 9 during the pathogenesis of acute leukemia and to investigate the significance of MSI and LOH in detecting the minima deletions of chromosome. Methods Fifty-three cases of acute leukemia were studied, which included 33 cases of acute myeloblasticleukemia （AMID and 20 cases of acute lymphocytic leukemia （ALL）. MSI and LOH in acute leukemia were detected with marrow cells at five microsatel lites on chromosome 9 by multi PCR amplification, gel electrophoresis and argentine dye. Normal oral mucosa cells served as con trois. Results Thirty six cases of acute leukemia demonstrated MSI at one or more loci. In AML, 115 cases showed MSI and 10 cases showed LOH. In AML. five cases showed MSIand four showed LOH. The frequencies of LOH was0（0.53）, 5.7 3%（3 53） and 7.5%（4 53） at D9S162.DgS1718 and D9S171 on 9p21, respectively. The frequencies of MSI in the three microsatellite was 15. 1%（8 53）. 7.6%（.1 53） and 11.3%（6 53）. respectively. The frequencies of LOH at D9S61 and D9S67 is 11.3%（6 53） and 5.6%（3 53）. respectively. The six cases detected LOH at D9S61 were all AML, the frequency of LOH in AML （18. 1%） was significantly higher than that in ALL. There were six cases （11. 3%,RER＋） found MSI at no less than two microsatellites. Conclusion The high frequencies of RER- in acute leukemia indicate that thepathogenesis and progress of acute leukemia is rela ted to the extensive MSh AMI. showed significantly higher I.OH frequency than ALL. at D9S61, which suggests that there may be some gene alterations in AMI.. The mierosatellite technology＇ is a new and valuable method to investigate acute leukemia.