论文部分内容阅读
目的:研究DNA甲基化转移酶(DNMT)各亚型DNMT1、DNMT2、DNMT3A、DNMT3B和DNMT3L在胃癌与胃黏膜中的表达特点,并分析DNMT抑制剂5-氮杂-2’-脱氧胞苷对胃癌和胃黏膜细胞的影响。方法:免疫组化法对60例胃癌与癌旁组织行5种DNMT表达研究。免疫荧光法和Western免疫印迹法对SGC-7901、MKN-45(胃癌细胞)和GES-1(胃黏膜细胞)行5种DNMT表达研究。噻唑蓝比色法和流式细胞术分析5-氮杂-2’-脱氧胞苷对SGC-7901、MKN-45和GES-1增殖、细胞周期和凋亡的影响。结果:胃癌与癌旁组织均有5种DNMT不同程度表达,但胃癌组织DNMT1和DNMT3A表达显著低于癌旁组织(P<0.01),DNMT2和DNMT3L表达也低于癌旁组织(P<0.05),只有DNMT3B在胃癌与癌旁组织中无显著差异(P>0.05)。胃癌细胞(SGC-7901和MKN-45)与胃黏膜细胞(GES-1)亦有部分DNMT表达,除DNMT3B在胃黏膜细胞表达较强外,余DNMT在胃癌与胃黏膜细胞中无显著差异。5-氮杂-2’-脱氧胞苷对胃癌与胃黏膜细胞的增殖率、周期分布和凋亡率并无显著影响。结论:DNMT在胃癌中表达呈降低趋势,抑制DNMT对胃癌细胞的增殖和凋亡无显著影响。
Objective: To investigate the expression of DNMT1, DNMT2, DNMT3A, DNMT3B and DNMT3L in gastric cancer and gastric mucosa and to analyze the role of DNMT inhibitor 5-aza-2’-deoxycytidine Effects on Gastric Cancer and Gastric Mucosal Cells. Methods: Immunohistochemistry was used to study the expression of 5 DNMT in 60 cases of gastric cancer and its adjacent tissues. Immunofluorescence and Western immunoblotting were used to study the expression of five DNMTs in SGC-7901, MKN-45 (gastric cancer cells) and GES-1 (gastric mucosal cells). The effects of 5-aza-2’-deoxycytidine on the proliferation, cell cycle and apoptosis of SGC-7901, MKN-45 and GES-1 were analyzed by MTT assay and flow cytometry. Results: The expressions of DNMT1 and DNMT3A were significantly lower in gastric cancer and paracancerous tissues than those in paracancer tissues (P <0.01), but also in DNMT2 and DNMT3L tissues (P <0.05) , Only DNMT3B in gastric cancer and adjacent non-significant difference (P> 0.05). There were also some DNMT expressions in gastric cancer cells (SGC-7901 and MKN-45) and gastric mucosal cells (GES-1), except that DNMT3B was strongly expressed in gastric mucosa. 5-Aza-2’-deoxycytidine had no significant effect on the proliferation, cell cycle distribution and apoptosis rate of gastric cancer and gastric mucosal cells. Conclusion: The expression of DNMT in gastric cancer showed a decreasing trend. Inhibition of DNMT had no significant effect on the proliferation and apoptosis of gastric cancer cells.