胃癌组织血管内皮生长因子C启动子甲基化状态检测及意义

The significance of vascular endothelial growth factor C promoter methylation status in gastric carcinoma

目的探讨胃癌组织血管内皮生长因子C(VEGF-C)启动子序列的甲基化状态及其在胃癌发生发展过程中VEGF-C甲基化状态的改变。方法胃癌细胞株BGC-823、SGC-7901、MGC-803及MKN-45,正常胃黏膜、慢性萎缩性胃炎及胃癌组织,RT-PCR、Western blot,检测胃癌细胞株中VEGF-C mRNA与蛋白表达;亚硫酸氢盐-基因组测序法检测胃癌细胞株、正常胃黏膜、慢性萎缩性胃炎及胃癌组织VEGF-C甲基化状态。结果胃癌细胞株BGC-823、SGC-7901、MGC-803及MKN-45中VEGF-C启动子序列的38个CpG岛未发现明显的甲基化位点;BGC-823、SGC-7901、MGC-803细胞株中VEGFC mRNA呈阳性表达,BGC-823、SGC-7901、MGC-803及MKN-45蛋白呈阳性表达;正常胃黏膜发现VEGF-C启动子序列的甲基化状态,慢性萎缩性胃炎组织中VEGF-C启动子序列的甲基化程度降低,胃癌组织发现VEGF-C启动子序列高度去甲基化。甲基化率的比较,正常胃黏膜组织-萎缩性胃炎组织:x^2=205.5,P<0.001;正常胃黏膜组织-胃癌组织:x^2=262.6,P<0.001;胃癌组织-萎缩性胃炎组织:x^2=7.219,P=0.007。结论VEGF-C的甲基化状态与胃癌的发生发展密切相关,调节VEGF-C的甲基化状态对抑制胃癌发生发展有重要作用。

Objective To explore the vascular endothelial growth factor C（VEGF-C） promoter methylation status in the process of gastric carcinoma growth.Methods The expression level of VEGF-C mRNA and protein were determined by RT-PCR and Western blot.The VEGF-C promoter methylation status in gastric cancer cell lines,normal gastric mucosa tissues,chronic atrophic gastritis tissues and gastric cancer tissues were detected by bisulfite-genome sequencing（BGS）.Results Significant methylation sites were not found from 38 CpG sites in VEGF-C promoter sequence in gastric cancer cell lines BGC-823.SGC-7901.MGC-803 and MKN-45.We detected mRNA expression of VEGF-C in BGC-823,SGC-7901,MGC-803 and protein expression of VEGF-C in BGC-823,SGC-7901,MGC-803 and MKN-45.BGS showed that VEGF-C promoter was methylated in normal gastric mucosa tissues,which were hypomethylated in chronic atrophic gastritis tissues and highly hypomethylated in gastric cancer tissues.Comparison of the rate of methylation in normal gastric mucosa-atrophic gastritis：χ^2=205.5,P 0.001;normal mucosa-gastric carcinoma：χ^2=262.6,P 0.001;gastric carcinoma-atrophic gastritis：χ^2=7.219,P=0.007.Conclusion VEGF-C methylation is closely related to the development of gastric cancer.Methylated regulation of VEGF-C is important for inhibiting gastric cancer growth.