Schenker T, Trueb B
MEM-Institute, University of Bern, Switzerland.
Exp Cell Res. 1998 Feb 25;239(1):161-8. doi: 10.1006/excr.1997.3896.
To identify proteins that are lost during the establishment of the transformed phenotype of a tumor cell, we have prepared a subtracted cDNA library with mRNA from normal human fibroblasts and from their matched SV40 transformed counterparts. More than 40 clones were obtained that showed a dramatic reduction in their relative expression after oncogenic transformation. The proteins encoded by these clones could be grouped into four distinct classes: extracellular matrix proteins (fibronectin, beta ig-h3, collagen VI), enzymes (collagenase, urokinase), cytoskeletal proteins (vinculin, SM22) and regulatory proteins (beta-glycan, integrin-associated protein, myosin kinase, IGFBP-5). Six novel gene products were discovered during these experiments, including a novel serine protease, a zyxin-like protein, an ankyrin-like protein and a GTP-binding protein. Only four of all the transformation-sensitive cDNAs were consistently down-regulated when a variety of cell lines derived from spontaneous mesenchymal tumors was investigated: beta ig-h3, collagen VI, the novel ankyrin-like protein, and IGFBP-5. It is likely that these gene products play an important role in the maintenance of the normal phenotype.
为了鉴定肿瘤细胞转化表型建立过程中缺失的蛋白质，我们用正常人成纤维细胞及其匹配的SV40转化细胞的mRNA构建了一个消减cDNA文库。获得了40多个克隆，这些克隆在致癌转化后其相对表达显著降低。这些克隆编码的蛋白质可分为四个不同类别：细胞外基质蛋白（纤连蛋白、βig-h3、胶原蛋白VI）、酶（胶原酶、尿激酶）、细胞骨架蛋白（纽蛋白、SM22）和调节蛋白（β-聚糖、整合素相关蛋白、肌球蛋白激酶、胰岛素样生长因子结合蛋白-5）。在这些实验中发现了6种新的基因产物，包括一种新型丝氨酸蛋白酶、一种类斑联蛋白、一种类锚蛋白和一种GTP结合蛋白。当研究源自自发性间充质肿瘤的多种细胞系时，所有转化敏感的cDNA中只有4种持续下调：βig-h3、胶原蛋白VI、新型类锚蛋白和胰岛素样生长因子结合蛋白-5。这些基因产物可能在维持正常表型中起重要作用。
