【摘要】 目的　筛选并鉴定重症肌无力 (MG)的相关基因。方法　测定由差别显示PCR(DDPCR)获得的、来自于正常人骨骼肌的cDNA差异片段 (暂命名为N9)的序列并进行同源性分析。运用半定量RT PCR方法分析该片段在MG病人和正常人胸腺与骨骼肌中的表达差异。结果　N9片段与GeneBank中已知非小细胞肺癌和肝癌的抑癌基因同源性高达 99% ;半定量RT PCR揭示 ,该基因在正常人和MG伴胸腺增生病人的肌肉中表达上调 ,而在MG伴胸腺瘤病人的肌肉中表达下调 ;正常人和病人的胸腺中均有该基因表达 ,但在伴胸腺瘤MG患者中的表达高于伴胸腺增生MG患者和正常人。结论　N9可能是已知的基因片段 ,它可能在伴不同类型胸腺异常MG的发病或发展中起某种作用 ,其具体作用还有待于进一步研究更多还原

【Abstract】 Objective To identify and analyze the correlated gene expression of myasthenia gravis (MG). Methods A differential cDNA fragment from the skeletal muscle of normal individual demonstrated by the differential display polymerase chain reaction (DDPCR) was selected. The fragment named N9 was sequenced and compared with the known sequence of the gene bank and EMBL DNA database. Reverse transcription polymerase chain reaction (RT PCR) was used to identify and analyze the differential expression of N9 in the muscle and thymus tissues of both MG Patients and normal individuals. Results The fragment had 99% homology when compared with a known antioncogene segment of hepatocellular and non small cell lung cancer in genebank and EMBL DNA database. Through RT PCR, N9 was upregulated in the muscle of normal individuals and MG patients with thymus hyperplasia, the muscle of MG patients with thymoma showed downregulated. On the contrary, N9 was found upregulated in the thymus of MG patients with thymoma and was downregulated in the thymus of normal individuals and MG patients with thymus hyperplasia. Conclusions N9 is probably a known gene segment, which may play a role in the pathogenesis and progress of MG with different types of thymus abnormalities. Further studies are needed to confirm this mechanism.更多还原