Zhang Tie-wa, Wang Sheng-fa, Cong De-gang, Fu Song-bin, Meng Xiang-ning, Yu Liang, Wang Ju
Harbin Medical University, Harbin 150081, China.
Zhonghua Yi Xue Za Zhi. 2007 May 8;87(17):1214-6.
To investigate the effect of Ras association domain family 1A (RASSF1A) gene, a new tumor suppressor gene (TSG), on tumorigenesis of human esophageal carcinoma cells.
pcDNA3.1 (+)-RASSF1A, a plasmid containing RASSF1A gene, and the blank plasmid pcDNA3.1 (+) were transfected into human esophageal carcinoma cells of the line EC9706. The expression of RASSF 1A protein was examined by Western blotting. The changes of cell cycle of stably-transfected cells were determined by flow cytometry (FCM), and the cellular proliferation was analyzed by MTT assay. Fifteen nude mice were randomly divided into 3 groups to be inoculated subcutaneously with EC9706 cells transfected with pcDNA3.1 (+)-RASSF1A, EC9706 cells transfected with pcDNA3.1 (+), and untransfected EC9706 cells respectively. Other 5 nude mice were used as controls. Four weeks later, the mice were killed to take out the carcinoma tissues. FCM was used to analyze the cell cycle.
Western blotting showed that RASSF1A protein was expressed highly in the stably transfected cells. The cell viability and growing speed were decreased obviously in the cells expressing of RASSF1A (both P < 0.01); FCM showed that the proportion of cells at the G(1) phase of the EC9706 cells expressing RASSF1A was significantly higher than those in the blank plasmid group and untransfected group (both P < 0.01). The size of the EC9706 cells obtained from the nude mice inoculated with the EC9706 cells transfected with pcDNA3.1 (+)-RASSF1A was significantly smaller than those of the pcDNA3.1 (+) group and blank plasmid group (both P < 0.05).
Expression of exogenous RASSF1A inhibits the progression of human esophageal carcinoma cells in vitro and in vivo. As a tumor suppressor gene, it plays an important role in origination, progression and metastasis of esophageal carcinoma.
研究新型抑癌基因Ras关联结构域家族1A（RASSF1A）基因对人食管癌细胞肿瘤发生的影响。
将含RASSF1A基因的质粒pcDNA3.1(+)-RASSF1A及空质粒pcDNA3.1(+)转染至人食管癌细胞系EC9706。采用蛋白质免疫印迹法检测RASSF1A蛋白的表达。通过流式细胞术（FCM）检测稳定转染细胞的细胞周期变化，采用MTT法分析细胞增殖情况。将15只裸鼠随机分为3组，分别皮下接种转染pcDNA3.1(+)-RASSF1A的EC9706细胞、转染pcDNA3.1(+)的EC9706细胞及未转染的EC9706细胞。另取5只裸鼠作为对照。4周后，处死小鼠并取出癌组织。采用FCM分析细胞周期。
蛋白质免疫印迹法显示，稳定转染细胞中RASSF1A蛋白高表达。RASSF1A表达细胞的细胞活力和生长速度明显降低（均P<0.01）；FCM显示，表达RASSF1A的EC9706细胞G(1)期细胞比例显著高于空质粒组和未转染组（均P<0.01）。接种转染pcDNA3.1(+)-RASSF1A的EC9706细胞的裸鼠所获EC9706细胞的大小显著小于pcDNA3.1(+)组和空质粒组（均P<0.05）。
外源性RASSF1A的表达在体外和体内均抑制人食管癌细胞的进展。作为一种抑癌基因，其在食管癌的发生、发展及转移中发挥重要作用。
