上海交通大学学报（医学版）

›› 2009, Vol. 29 ›› Issue (9): 1062-.

• 论著（基础研究） • 上一篇    下一篇

胰岛素样生长因子结合蛋白7基因在胃癌细胞中的表达及甲基化调控

赵丹瑜, 李 霞, 钟 捷, 齐晓光, 董文杰, 乔敏敏   

  1. 上海交通大学 |医学院瑞金医院消化科, 上海 200025
  • 出版日期:2009-09-25 发布日期:2009-09-29
  • 通讯作者: 钟捷, 电子信箱: jimmyzj64@yahoo.com。
  • 作者简介:赵丹瑜（1983—）, 女, 硕士生；电子信箱: zhaodanyu1983@163.com。

Expressions of insulin-like growth factor binding protein 7 in human gastric cancer cell lines and methylation regulation

ZHAO Dan-yu, LI Xia, ZHONG Jie, QI Xiao-guang, DONG Wen-jie, QIAO Min-min   

  1. Department of Gastroenterology, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200025, China
  • Online:2009-09-25 Published:2009-09-29

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摘要：

目的 研究胰岛素样生长因子结合蛋白7（IGFBP7）mRNA在胃癌细胞中的表达及其甲基化调控。方法 分别培养胃癌细胞株高分化MKN-28、中分化SGC-7901和AGS、低分化MKN-45以及胃黏膜正常上皮细胞（GES-1）。提取细胞RNA，采用RT-PCR法检测IGFBP7 mRNA在各细胞株中的表达。提取细胞基因组DNA，甲基化修饰后采用甲基特异性PCR（MSP）分析其CpG岛甲基化状态。采用不同浓度去甲基化药物5'-杂氮-2'-脱氧胞嘧啶（5-aza-dc）处理细胞株后，经Real-time PCR定量药物处理前后各细胞株IGFBP7 mRNA的相对表达量。结果 各肿瘤细胞株中IGFBP7 mRNA表达较GES-1降低或消失。MSP检测IGFBP7 mRNA表达降低和消失的细胞株均有CpG岛不同程度的甲基化。不同浓度5-aza-dc处理细胞后，IGFBP7 mRNA的表达量呈剂量依赖性增高。结论 IGFBP7 mRNA在胃癌细胞株中低表达或不表达，其表达下调与其CpG岛甲基化有关。5-aza-dc可使IGFBP7 mRNA表达降低的胃癌细胞株重新表达IGFBP7 mRNA，提示IGFBP7基因CpG岛甲基化可能是IGFBP7在胃癌细胞系中表达缺失的分子机制。

关键词: 胰岛素样生长因子结合蛋白7基因, 胃癌细胞株, 甲基化

Abstract:

Objective To investigate the insulin-like growth factor binding protein 7 (IGFBP7) gene expressions in gastric cancer cell lines and methylation regulation. Methods Four gastric cancer cell lines, high-differentiated MKN28, middle-differentiated SGC-7901 and AGS, poorly differentiated MKN-45, and normal gastric epithelial cell line (GES-1) were cultured. The IGFBP7 mRNA expressions in different cell lines were detected by RT-PCR. The DNA methylation status was assayed by methylation-specific PCR (MSP). Gastric cancer cell line was treated with DNA methyltransferase inhibitor, 5'-aza-2'-deoxycytidine (5-aza-dc). And the IGFBP7  mRNA expression was detected using real-time PCR. Results Compared with the GES-1, the expression of the IGFBP7  mRNA decreased or disappeared in gastric cell lines. Through the MSP, the aberrant methylation of IGFBP7 mRNA in exon 1 was found. After the 5-aza-dc treatment, the IGFBP7 expression was up-regulated dose-dependently. Conclusion Hypermethylation is responsible for the tumor-specific loss of IGFBP7 gene expression. Treatment with a demethylating agent, 5-aza-dc, can lead to the reexpression of IGFBP7 mRNA in the gastric cancer cell lines. It suggests an important role of hypermethylation in the loss of IGFBP7 mRNA expression.

Key words: insulin-like growth factor binding protein 7 gene, gastric cancer cell lines, methylation

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