中文摘要：

多效生长因子（pleiotrophin,PTN指蛋白,Ptn指基因）是一种可同肝素结合的分泌性的生长/分化因子,具有刺激细胞粘附、迁移、存活、生长和分化等功能.我们前期研究发现,Ptn稳定沉默可以显著降低细胞的生长及成瘤能力.为进一步了解Ptn表达沉默后小鼠基因转录谱的变化,用小鼠表达谱芯片比较了对照及Ptn沉默细胞的基因表达差异.在检测的24 000个基因中,Ptn沉默后上调2倍以上的基因有240个,下调2倍以上的基因有129个.值得引起注意的是,在Ptn沉默的MEFs细胞中,同DDK综合症相关的基因家族,schlafen（Slfn）家族的Slfn2、Slfn3、Slfn4以及基质金属蛋白酶（matrix metalloproteinase,MMP）家族的Mmp3、Mmp10、Mmp13表达均显著上调;而可促进内皮细胞运动,参与血管发生的基因angiomotin（Amot）表达显著下调.通过研究,获得了一系列Ptn沉默后表达变化的基因信息.

英文摘要：

Pleiotrophin （PTN, the protein; Ptn, the gene） is a heparin binding secreted growth/differentiation factor that has diverse functions, involved in cell adhesion, migration, survival, growth and differentiation. We previously established Ptn stable knocking-down mouse embryonic fibroblasts （MEFs） by siRNA and found that knocking-down the expression of Ptn resulted in the suppression of the growth and the tumorigenicity of Pten null MEFs. In order to identify unknown target genes regulated by PTN, and to understand how PTN works in tumorigenesis, the gene expression profiles of Ptn knocking-down MEFs and their normal counterparts were compared using Agilent mouse oligochip. Out of 24 000 genes examined, 240 and 129 genes were up- regulated and down-regulated in Ptn stable knocking-down MEFs by two-fold or more, respectively. The interesting observations were that DDK syndrome related genes schlafen （Slfn） 2, Slfn 3 and Slfn 4, matrix metalloproteinase （Mmp） 3, Mmp 10 and Mmp 13 were all up-regulated, more than ten-fold ,respectively, which was further confirmed by Northern blot, while angiomotin （Amot）, an angiostatin-binding protein that promoted blood vessel endothelial cell motility and was involved in angiogenesis, was down-regulated in Ptn knocking-down MEF cells. The results showed us a series of genes which transcriptional profile were altered in Ptn knocking down MEFs. Considering Ptn is a proto-oncogene, determining the regulation mechanisms of novel target genes by PTN are the future challenges.