甲基化CpG结合结构蛋白2在胃癌的表达及靶向抑制

Expressions of methyl-CpG-binding domain protein 2 in gastric cancer and their RNA interferences

摘要:

目的：研究甲基化CpG 结合结构蛋白2（methyl-CpG-binding domain protein 2，MBD2）在胃癌的表达及靶向抑制。方法：免疫组化法对40例胃癌及配对胃黏膜组织，免疫荧光法对胃癌细胞SGC-7901行MBD2表达研究。构建3个靶向抑制MBD2的siRNA（MBD2-siRNA-1、MBD2-siRNA-2、MBD2-siRNA-3）。转染MBD2-siRNA入SGC-7901，RT-PCR及Western blot验证MBD2的抑制效果。噻唑蓝比色法检测SGC-7901增殖率。结果：胃癌组织MBD2表达较对照胃黏膜组织增强（χ2=6.646，P=0.010）；且低分化胃癌与伴幽门螺杆菌感染的胃癌中MBD2表达更强（ χ2值分别为9.730、8.700，P值分别为0.01和0.04）。MBD2蛋白在胃癌胞核分布。MBD2-siRNA可成功转染SGC-7901，并成功筛选靶向抑制MBD2的siRNA（MBD2-siRNA-2）。发现转染MBD2-siRNA-2后96 h，SGC-7901增值率被抑制。结论：MBD2在胃癌表达增强，抑制MBD2可能抑制胃癌增殖。

Abstract:

Objective：To investigate the expressions of methyl-CpG-binding domain protein 2（MBD2） and their RNA interfer－ences（RNAi） in gastric cancer. Methods：Immunohistochemistry was used to detect MBD2 expressions in tissues of 40 gastric can－cer cases and matched non-cancerous tissues. Immunofluorescence was used to detect the MBD2 distribution in gastric cancer cell（SGC-7901）. Three siRNAs（MBD2-siRNA-1，MBD2-siRNA-2，MBD2-siRNA-3） targeting MBD2 were designed. LipofectamineTM2000 was used to transfect MBD2-siRNAs into SGC-7901. RT-PCR and Western blot were used to evaluate the efficiency of MBD2 inhibition. MTT assay was carried out to detect the growth rate of SGC-7901. Results：Expressions of MBD2 were higher in gastric cancer tissues than in matched gastric mucosa tissues（χ2=6.646，P=0.010）. MBD2 expressions were much higher in gastric cancer tissues with low histological grade and H.pylori infection（χ2=9.730，8.700；P=0.01，0.04）. MBD2 protein was distributed in nucleus of gastric cancer cell. Three MBD2-siRNAs all could be transfected into SGC-7901 perfectly and MBD2-siRNA-2 could inhibit the MBD2 mRNA and protein expressions best. At last，96 h after the MBD2-siRNA-2’s transfection，growth rate of SGC-7901 was inhibited. Conclusions：MBD2 protein expresses higher in gastric cancer tissues. MBD2 inhibition could suppress the proliferation of gastric cancer cell.