mir-200c通过靶向dnmt3b抑制胃癌mgc-803细胞生长word论文.docxVIP

miR-200c 通过靶向 DNMT3B 抑制胃癌 MGC-803 细胞生长研究生：伍菲菲 指导老师：张志伟副教授中文摘要目的：探讨 miR-200c 在胃癌组织中的表达及胃癌 MGC-803 细胞中的生物学功 能。方法：采用原位杂交检测 40 例正常胃粘膜组织以及 121 例胃癌组织中 miR-200c 的表达；运用荧光素报告系统检测 DNMT3B 是 miR-200c 的靶基因，采用 MTT 法检测 miR-200c 对胃癌 MGC-803 细胞的生长的影响。结果：原位杂交证实 miR-200c 在胃癌组织中下调；121 例胃癌组织中，miR-200c 的表达水平与胃癌的临床分期（P=0.003）以及淋巴结转移（P=0.004）相关；荧 光素报告载体系统证实 DNMT3B 是 miR-200c 直接调控的靶基因；Western blot 结果显示，miR-200c 高表达可抑制 DNMT3B 蛋白的表达；MTT 检测发现， miR-200c 高 表达 或干扰 DNMT3B 表达 可 抑 制 胃 癌 MGC-803 细 胞 的 生 长 (P0.05)。结论：1.miR-200c 在胃癌组织中下调，miR-200c 下调与胃癌临床分期及淋巴结转移 有关。2.miR-200c 可通过靶向 DNMT3B 抑制胃癌 MGC-803 细胞生长。 关键词：miR-200c；胃癌；DNA 甲基化转移酶 3B；细胞生长2miR-200c inhibits gastric cancer MGC-803 cell growth by targeting DNMT3BAbstractObjective: To analyze the expression of miR-200c in the gastric cancer and investigate the role of miR-200c in the gastric cancer cells.Methods: The expression of miR-200c was tested by ISH. DNMT3B 3UTR-luciferase vector was constructed and luciferase reporter gene assay was employed to examine the effect of miR-200c on luciferase activity. MGC-803 cells were transfected with miR-200c mimics, and next Western blot was performed to detect the expressions of DNMT3B protein. Cell growth was evaluated by MTT. Results: miR-200c was down-regulated in gastric cancer tissues. miR-200c levels were significantly correlated with the clinical stage (P=0.003), lymph node metastasis (P=0.004) in gastric cancer patients. Luciferase reporter vector system confirmed that DNMT3B was a target gene of miR-200c. Western blot showed that the expression of DNMT3B protein was inhibited by restored miR-200c or si-DNMT3B in MGC803 cells. miR-200c could inhibit gastric cancer cell proliferation identified by MTT assay(P0.05).Conclusions:The expression level of miR-200c was down-regulated in gastric cancer and had a close correlation to lymph node metastasis and advanced clinical stage.miR-200c can inhibit gastric cancer cell growth by inhibiting the expression of DNMT3B.Key words: miR-200c; gastric cancer; DNMT3B