Ras蛋白激活物类似物-1基因在胃癌细胞株中的表达及生物学意义

Expression and biological significance of Ras protein activator like-1 gene in gastric cancer cell lines

目的:研究Ras蛋白激活物类似物-1基因(Ras protein activator like-1,RASAL1)在正常胃黏膜上皮细胞、胃癌细胞株中的表达情况及其生物学意义。方法:采用RT-PCR和Western blot分别检测高分化胃腺癌细胞株MKN-28、中分化胃腺癌细胞株SGC-7901、低分化胃腺癌细胞株BGC-823和正常胃黏膜上皮细胞株GES-1中RASAL1基因在mRNA水平和蛋白水平的表达,应用基因测序法检测上述3种胃癌细胞株中K-Ras基因第一外显子第12密码子点突变情况,并分析其意义。结果:RT-PCR和Westernblot检测结果显示,与正常胃黏膜上皮细胞相比,在3种不同分化胃腺癌细胞株中,RASAL1基因的表达在mRNA水平和蛋白水平均下调(P<0.05),分化程度越低表达下调越明显;测序结果表明3种胃腺癌细胞株中均未发现K-Ras基因第一外显子第12密码子点突变。结论:RASAL1基因在含野生型K-Ras的胃癌细胞中呈低表达状态,其表达水平与胃癌的恶性程度有一定的关系。

OBJECTIVE：To investigate the expression and biological significance of Ras protein activator like—1 gene（RASAL1） in normal human gastric epithelial cell line and different differentiated gastric cancer cell lines. METHODS：The expressions of RASAL1 mRNA and protein were respectively detected by PT-PCR and Western blot in three kinds of gastric cancer cell lines,including well differentiated MKN-28,moderately differentiated SGC-7901,poorly differentiated BGC-823,and normal gastric epithelial cell line GES-1.The mutation of K-Ras gene codon 12 was detected by PCR and gene sequencing.RESULTS：The results of PT-PCR and Western blot showed that both of the expressions of RASAL1 mRNA and proteins were decreased in all three gastric cancer cell lines as compared with the normal gastric epithelial cell line GES-1.It＇s expression level was correlated with the differentiation：the poorest differentiation the lowest expression.The mutation of K-Ras gene codon 12 was not found in any of the gastric cancer cell lines. CONCLUSION：RASAL1 expression was reduced in the gastric cancer cell line that contain wild type K-Ras gene,and its expression level may be correlated with the degree of differentiation.