Department of Gastroenterology, Tenth People's Hospital of Tongji University, Shanghai 200072, China.
Med Oncol. 2011 Dec;28 Suppl 1:S189-96. doi: 10.1007/s12032-010-9691-0. Epub 2010 Nov 5.
There has been few report discussing the expression and function of miR-212 in gastric cancer (GC). The aim of this pilot study was to investigate the expression of miR-212 in both gastric cancer tissues and gastric cancer cells and further explores the possible reasons for this change and the impact on the development of gastric cancer. qRT-PCR was used to detect the expression of miR-212 in primary GC tissues, adjacent normal tissues, gastric cancer cell lines BGC-823, SGC-7901, MKN-45, and normal gastric mucosa cell line GES. The expression of miR-212 was evaluated before and after treatment with methylation inhibitor-5-Aza-2'-deoxycitidine (5-Aza-dC), finally anti-miRNA and dual luciferase reporter assay were used to prove that MYC is a target gene of miR-212. The results showed that a significant reduction of miR-212 expression in GC tissues was observed compared to that in normal tissues (P = 0.002). At the same time, miR-212 expression level in normal gastric mucosa cell line GES was higher than that of in gastric cancer cell lines BGC-823, SGC-7901, and MKN-45 (P = 0.015, 0.008, 0.044, respectively). Computer sequence analysis showed the hypermethylation of CpG islands(CPI) in the promoter regions of miR-212 led to the lower expression of miR-212 in gastric cell strains (BGC-823 and SGC-7901). MiR-212 expression was significantly recovered after treatment with methylation inhibitor 5-Aza-dC (P = 0.016, 0.000, 0.015, respectively). Then, the results of AMOs transfection and dual luciferase reporter assay showed that Myc is a target of miR-212, which will be helpful to verify the function of miR-212 in carcinogenesis. The conclusion could be deduced from the study that decreased expression of miR-212 may be due to hypermethylation of CPI in gastric cancer cells, and miR-212 might act on the progression of gastric cancer through the potential target gene Myc.
目前鲜有研究报道探讨 miR-212 在胃癌（GC）中的表达和功能。本初步研究旨在检测 miR-212 在胃癌组织和胃癌细胞中的表达，并进一步探讨其变化的可能原因及其对胃癌发展的影响。采用 qRT-PCR 检测原发性 GC 组织、相邻正常组织、胃癌细胞系 BGC-823、SGC-7901、MKN-45 和正常胃黏膜细胞系 GES 中 miR-212 的表达。用甲基化抑制剂 5-氮杂-2'-脱氧胞苷（5-Aza-dC）处理后评估 miR-212 的表达，最后用抗 miRNA 和双荧光素酶报告基因检测证实 MYC 是 miR-212 的靶基因。结果表明，与正常组织相比，GC 组织中 miR-212 的表达明显降低（P = 0.002）。同时，正常胃黏膜细胞系 GES 中 miR-212 的表达水平高于胃癌细胞系 BGC-823、SGC-7901 和 MKN-45（P = 0.015、0.008、0.044）。计算机序列分析显示，miR-212 启动子区域 CpG 岛（CPI）的过度甲基化导致胃细胞株（BGC-823 和 SGC-7901）中 miR-212 的表达降低。用甲基化抑制剂 5-Aza-dC 处理后，miR-212 的表达明显恢复（P = 0.016、0.000、0.015）。然后，AMOs 转染和双荧光素酶报告基因检测结果表明，Myc 是 miR-212 的靶基因，这将有助于验证 miR-212 在致癌作用中的功能。从研究中可以推断，miR-212 的表达降低可能是由于胃癌细胞中 CPI 的过度甲基化，miR-212 可能通过潜在的靶基因 Myc 作用于胃癌的进展。
