转化相关蛋白p86的鉴定

以转化细胞Rat3-3免疫大鼠,获得单克隆抗体E5(MeAb E5)。其对应抗原耐热,是分子量为86kD的蛋白质(P86)。它在c-Ha-ras癌基因转化的细胞上均有较高的阳性表达,而在其相应的非转化细胞上含量甚微。以人工合成的反义c-Ha-ras寡聚核苷酸As-Ⅱ处理Rat3-3细胞,该细胞生长受抑(44.2％),,此对p86的表达亦降低(39.1％)。P86在五种人胃癌细胞系中均有较高表达,在原发胃癌及其转移灶中阳性率达82.6％。p86不仅是一种与C-Ha-ras转化相关的蛋白,而且为胃癌相关抗原。

Identification of the Transformation-Related Protein p86

Rat3-3 is a secondary transformant of immortalized rat fibroblast cell line Rat1 that has been transfected with total DNAs from a human gastric cancer cell line BGC823. After immunization of LOU/c rat with Rat3-3 cells, the monoclonal antibody E5 that recognized a heat resistent protein with a molecular weight of 86 000 daltons (p86) was produced. This antigen was highly expressed on two transformed cell lines which were transfected with activated c-Ha-ras oncogene, but almost undetected on the parental cells. When treated with antisense oligodeoxynucleotide AS-II the growth of Rat3-3 and expression of p86 were suppressed by 44.2% (p<0.001) and 39.1% (p<0.001) . P86 was also expressedin five human gastric cancer cell lines. Out of 43 cases of gastric cancer tissues 38 of them showed positive reaction with McAb E5 (82.6%) . Therefore p86 is not only a transformation-related protein of c-Ha-ras oncogene but also a gastric cancer-associated antigen.