VEGF-C的表观遗传学调控及S-腺苷甲硫氨酸对胃癌生长的影响

发布时间：2018-07-07 12:30

本文选题：S-腺苷甲硫氨酸 + VEGF-C　；参考：《宁夏医科大学》2015年硕士论文

【摘要】：目的观察S-腺苷甲硫氨酸(S-adenosylmethionine,SAM)对血管内皮生长因子-C(Vascular Endothelial Growth Factor-C,VEGF-C)基因启动子序列甲基化状态及表达的影响,以及对胃癌细胞MGC803、SGC7901及裸鼠移植瘤生长的影响。探讨其抗肿瘤效应及可能机制,寻求胃癌治疗的新途径。方法亚硫酸氢盐基因组测序法(Bisulfite Genomic DNA Sequencing Analysis,BGS)检测胃癌细胞中VEGF-C基因启动子序列在SAM作用前后的甲基化状态;RT-q PCR和Western blotting分别检测胃癌细胞中VEGF-C m RNA和蛋白在SAM作用前后的表达水平;MTT法和流式细胞术分别检测SAM对胃癌细胞增殖和凋亡的影响;建立裸鼠移植瘤模型检测SAM在体内对肿瘤生长的影响;免疫组织化学法检测人胃癌裸鼠移植瘤在SAM作用前后VEGF-C的表达。结果VEGF-C在胃癌细胞MGC803、SGC7901中呈低甲基化状态,经SAM处理后其甲基化程度增高;SAM处理MGC803、SGC7901细胞后,VEGF-C m RNA和蛋白表达明显降低(P0.05);随药物浓度增大,肿瘤细胞增殖受到明显抑制(P0.05),凋亡率也明显增加(P0.05);SAM对人胃癌裸鼠移植瘤的生长有明显的抑制作用,作用前后移植瘤体积有显著差异(P0.05);SAM抑制了人胃癌裸鼠移植瘤中VEGF-C的表达。结论SAM可以改变胃癌细胞中VEGF-C启动子序列的低甲基化状态,并且抑制其表达,最终抑制胃癌的生长。SAM作为一种潜在的抗肿瘤药物,表观遗传学调控可能是其抗肿瘤作用的一个新机制。
[Abstract]:Objective to investigate the effects of S-adenosylmethionine (SAM) on the methylation and expression of vascular endothelial growth factor-C (VEGF-C) gene promoter, and on the growth of gastric cancer cell line MGC803SGC7901 and xenografts in nude mice. To explore the anti-tumor effect and possible mechanism of gastric cancer and seek a new approach to the treatment of gastric cancer. Methods Bisulfite Genomic DNA sequencing assay (BGS) was used to detect the methylation status of VEGF-C promoter sequence in gastric cancer cells before and after SAM. RT-PCR and Western blotting were used to detect VEGF-C mRNA and protein in gastric cancer cells before and after SAM. The effect of SAM on proliferation and apoptosis of gastric cancer cells was detected by MTT assay and flow cytometry. The effect of SAM on the growth of human gastric carcinoma xenografts in vivo and the expression of VEGF-C before and after SAM in nude mice were detected by immunohistochemical method. Results VEGF-C was hypomethylated in gastric cancer cell line MGC803hSGC7901. The methylation degree of VEGF-C was increased after SAM treatment. The expression of VEGF-C mRNA and protein in gastric cancer cell line MGC803 + SGC7901 was significantly decreased after SAM treatment (P0.05), and the expression of VEGF-C mRNA and protein decreased with the increase of drug concentration. Tumor cell proliferation was significantly inhibited (P0.05) and apoptosis rate was significantly increased (P0.05). SAM significantly inhibited the growth of human gastric carcinoma xenografts in nude mice (P0.05). (P0.05) SAM inhibited the expression of VEGF-C in human gastric carcinoma xenografts. Conclusion SAM can change the hypomethylation of VEGF-C promoter sequence and inhibit the expression of VEGF-C promoter in gastric cancer cells, and ultimately inhibit the growth of gastric cancer. SAM is a potential antitumor drug. Epigenetic regulation may be a new mechanism of its anti-tumor effect.
【学位授予单位】：宁夏医科大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R735.2

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