SCREENING FOR THE GENES RESPONSIBLE FOR THE SURVIVAL ADVANTAGE OF PNH CLONES

在所有PNH病例中都发现了PIG-A基因的体细胞突变。因此，PNH的发生与PIG-A基因突变有关。然而，最近的研究表明，罕见的PNH细胞也存在于健康个体中(Arten，DJ等人)。1996年)。因此，除PIG-A基因突变外，PNH克隆的生长优势和/或生存优势对PNH的发生发展也是不可或缺的。本研究旨在阐明与PNH无性系生长优势和/或生存优势相关的基因。本研究采用基因消减技术和基因芯片技术筛选PNH患者CD59~+粒细胞中上调的基因。半定量RT-PCR检测发现1例PNH患者CD59~+粒细胞中3个基因表达上调2倍以上。但在其他3例PNH患者中，未发现CD59~+粒细胞中上述基因表达上调的明显趋势。此前已有4个基因在PNH患者中表达上调。我们用半定量RT-PCR方法检测了7例PNH患者和5例健康献血员这4个基因的表达。我们没有发现这4个基因在我们的PNH患者中表达上调的趋势。

Somatic mutations in the PIG-A gene have been found in all PNH cases. Therefore PIG-A gene mutation has been considered to be responsible for the development of PNH. However, recent study revealed that rare PNH cells are present also in healthy individuals (Araten, DJ et al. 1996). Therefore, it is postulated that growth advantage and/or survival advantage of PNH clones is indispensable for the development of PNH, in addition to PIG-A gene mutation. The purpose of this study is to clarify the genes concerned in growth advantage and/or survival advantage of PNH clones. We performed a cDNA subtraction and a cDNA macro array to screen for the genes up-regulated in CD59^- granulocytes of PNH patient compared to CD59^+ granulocytes of PNH patient. Three genes were up-regulated more than 2 times in CD59^- granulocytes of one PNH patient by semi-quantitative RT-PCR assay. However we could not find remarkable tendency that these genes are up-regulated in CD59^- granulocytes compared to CD59^+ granulocytes in 3 other PNH patients. Already, 4 genes were reported up-regulated in PNH patients before. We have checked the expression of these 4 genes in 7 PNH patients and in 5 healthy donors by semi-quantitative RT-PCR. We could not find tendency that these 4 genes were up-regulated in our PNH patients.