T细胞非霍奇金淋巴瘤微卫星不稳定性及hMSH2、hMLH1蛋白表达研究

STUDY OF MICROSATELLITE DNA INSTABILITY AND hMSH2,hMLH1 PROTEIN EXPRESSION IN T-CELL LYMPHOMA

目的:探讨微卫星不稳定性(Microsatellite instability,MSI)及DNA错配修复基因系统(Mismatch repair gene system,MMR)功能缺陷在T细胞非霍奇金淋巴瘤(Non-Hodgkins lymphoma,NHL)发病机制中的意义。方法:对38例T细胞NHL采用PCR扩增,变性聚丙烯酰胺凝胶垂直电泳,银染方法检测17号染色体p53基因周围4个微卫星位点多态标志D17S945、D17S938、D17S947、D17S926的MSI,并运用免疫组织化学SP法检测肿瘤细胞hMSH2、hMLH1蛋白表达情况。结果:38例T细胞NHL中MSI的阳性率为23.68%(9/38),LOH为7.89%(3/38)。各位点MSI、LOH频率介于2.86%～18.42%和0.00%～5.26%。各位点MSI阳性率差异无统计学意义(P>0.05);肿瘤组织中,hMSH2、hMLH1蛋白表达缺失率分别为52.63%(20/38)、42.11%(16/38)。结论:T细胞NHL中存在MSI和MMR蛋白表达缺陷。

Objective：To study the role of the microsatellite instability and the defects of mismatch repair system genes in T cell Non-Hodgkins lymphoma. Methods： We detected microsatellite instability at 4 microsatellite loci （D17S945,D17S938, D17S947 and D17S926） around the p53 gene on chromosome 17 by PCR, polyacrylamide gel electrophoresis and silver staining methods and analyzed hMSH2, hMLH1 protein expression by immunohistochemistry in 38 cases of T-cell Non-Hodgkins lymphoma. Results：The positive rate of MSI was 23.68% （9/38）, the rate of LOH was 7.89% （3/38）. At the 4 mirosatellite loci, frequency of MSI and LOH varied from 2.86% to 18.42%, and from 0 to 5.26%, respectively. No significant difference was found in MSI incidence between different mirosatellite loci（ P 〉0.05）. The absent expression rate of hMSH2, hMLH1 prontein was 52.63%（20/38）and 42.11%（16/38）, respectively, in tumor tissues. Conclusion. MSI and the absent expression of mismatch repair genes are present in T-cell Non- Hodgkin＇ s lymphoma.