癌基因及癌发育基因在裸小鼠人肝癌移植瘤中表达

Expression of Oncogenes and Oncodevelopmental Genes in Human Hepatoma Xenografts in Nude Mice

本文采用Northern blot,斑点杂交,western Immunoblot,凝集素亲和电泳及聚丙烯酰胺梯度电泳方法分别检测裸小鼠肝癌移植瘤中C-ras基因簇(N-ras,H-ras及K-ras),甲种胎儿蛋白以及γ谷氨酰转肽酶(GGT)基因及其产物的表达。结果提示C-ras基因簇均有不同程度的表达,其中N-ras基因表达水平要比H-ras高8倍,比K-ras高20倍左右,同样AFP及GGT基因均有较高水平的表达。经ras-p21单克隆抗体检测,发现肝癌组织抽提液中p21呈现阳性反应;AFP亚型分析提示AFP分子变异体属肝癌特异性分子亚型;GGT同Ⅰ酶酶谱分析表明组织中仅合成肝癌特异性GGT同Ⅰ酶酶谱(Ⅰ’,Ⅱ’)。上述结果充分表明癌基因及癌发育基因的高表达可能与癌细胞去分化性,分裂旺盛程度及细胞恶性度相关。最后文内还对裸小鼠人肝癌移植瘤中二类基因的相关性作一定的讨论。

The expression of C-ras gene family, H-ras, K-ras and N-ras, as well as Alpha-fetoprotein (AFP) and Gamma-Gluiamyl transferase (GGT) were determined at m-RNA from human hepatoma xenografts in nude mice by Northern blot.Their products, including ras-P21 protein, AFP variants and GGT isoenzymes were measured in tissue extracts from human hepatoma using Western immunoblotting, Lectin affinity immunoelectrophoresis and polyacrylamide gradient electrophoresis respectively .The expression of all members of C-ras gene family was detected, but the level of expression was 8 times higher in N-ras than in H-ras and almost 20 times than in K-ras, due to desity of dot hybridization on x-ray film.The C-ras-P21 protein in extracts of tumor tissue was detectable with Western immunoblotting.AFP and GCT genes were expressed at m-RNA from human hepatoma by use of Northern blot.However, only human hepatoma specific AFP variants and GGT enzymograms were observed in human hepatoma xenografts in nude mice after analysis of AFP subunit and GGT isoenzymograms.These results showed that both high level expression of oncogenes and oncodev-elopmental genes may relate to proliferation, dedifferentiation and malignancy of tumor cells.The relationship between oncodevelopmental genes and oncogenes in human hepatoma xenografts in nude mice was discussed in this paper.