摘要
目的探讨正常上皮细胞特异性-1基因(NES1)在胃正常上皮细胞和胃癌细胞株中的表达及其受甲基化调控的影响。方法分别培养胃癌细胞株MKN-28(高分化)、SGC-7901(中分化)、AGS (中分化)、MKN-45(低分化)、HGC-27(未分化)和原代正常胃上皮细胞。提取细胞RNA,荧光定量PCR检测NES1在各细胞株中的表达。以不同浓度的DNA甲基化酶抑制剂5′杂氮-2′-脱氧胞嘧啶(5-aza- dC)处理胃癌细胞株,荧光定量PCR检测处理后NES1mRNA表达。同时提取细胞基因组DNA,甲基化修饰后甲基特异性PCR(MSP)分析其CpG岛甲基化状态。结果NES1mRNA在肿瘤细胞株中的表达较胃正常上皮细胞明显降低。甲基化检测显示,NES1在胃癌细胞株中均存在不同程度的外显子3 CpG岛甲基化。NES1表达降低的胃癌细胞株经5-aza-dC去甲基化药物处理后NES1表达均有所上调。结论NES1在一些胃癌细胞株中的低表达与该基因外显子3 CpG岛甲基化有关。5-aza-dC可使NES1表达降低的胃癌细胞株重新表达NES1mRNA,再次证明了NES1基因在胃癌细胞株中的低表达与甲基化有关。
Objective To investigate the expression of normal epithelial cell specific-1 （NES1） gene in normal gastric epithelial cells and different gastric cancer cell lines and the effects of 5-aza 2-de- oxycytidine （5-aza-dC） on the expression of NES1 gene. Methods Expression of NES1 mRNA in five gastric cancer cell lines （MKN 28, SGC 7901, AGS, MKN-45 and HGC 27） and normal human gastric epithelial cells were detected by real-time PCR. After treatment with 5-aza-dC, a DNA methyltransferase inhibitor, the expression of NES1 mRNA in gastric cancer cell lines was detected by real time PCR. DNA methylation status of NES1 gene was assayed by methylation-specific PCR（MSP）. Results The expression of NES1 mRNA was decreased in all gastric cancer cell lines. A strong correlation between exon 3 hypermethylation and loss of NES1 mRNA expression in gastric cancer cell lines was noted. 5-aza-dC treatment of NESl-nonexpressing tumor cell lines resulted in a close-dependent induction （SGC-7901, MKN-45, MKN-28 and AGS）and increase（HGC-27） of NESlmRNA expression in gastric cancer cells. Conclusions The study suggested that hypermethylation was a responsible factor for tumor-specific loss of NES1 gene expression in gastric cancer cells. Treatment of gastric cancer cell lines with a demethylating agent led to reexpression of NES1 suggesting an important role of hypermethylation in loss of NES1 gene expression.
出处
《中华消化杂志》
CAS
CSCD
北大核心
2006年第8期535-538,共4页
Chinese Journal of Digestion
