ANALYSIS OF CELL GROWTH AND TRANSFORMATION BY ORNITHINE DECARBOXYLASE

为了筛选腐胺（Putrescine）在细胞增殖调控和肿瘤发生中的差异表达基因，我们采用多胺生物合成抑制剂α-二氟甲基鸟氨酸（DFMO）处理人肝母细胞瘤细胞株HepG 2，提取总RNA，进行mRNA差异显示分析。腐胺对25个基因表达上调，32个基因表达下调。在腐胺诱导的差异表达基因中，我们选择了三个与呼吸链和氧化磷酸化酶相关的基因，并对它们进行了北方印迹分析。细胞色素氧化酶submit 1、低分子量泛醌结合蛋白和NADH脱氢酶亚基2被腐胺下调。我们检测了Hep G2细胞内ATP水平，发现DFMO处理的细胞内ATP水平被外源性腐胺增加。

In order to identify gene differentially expressed by putrescine, a polyamine, which play important roles in the regulation of cell proliferation and the development of cancer, we performed mRNA differential display analysis using total RNA extracted from HepG2 cells (human hepatoblastoma cell line) treated with a specific inhibitor of polyamine biosynthesis, α-difluoromethyl ornithine (DFMO). A total of 25 genes were up-regulated and 32 genes down-regulated by putrescine. Of the genes differentially expressed by putrescine, we chose three that were related to the respiratory chain and oxidative phosphorylase and analyzed them by Northern blot analysis. Cytichrome oxidase submit 1, low molecular mass ubiquinone- binding protein, and NADH dehydrogenase subunit 2 were found to down- regulated by putrescine. We examined intracellular ATP level in Hep G2 cells, and found that ATP level in DFMO- treated cells was increased by exogenous putrescine.