胃癌转移相关miRNA的差异表达谱及miR-218的生物学分析

目的 探讨胃癌转移相关微小RNA（miRNA）的差异表达情况并进行miR-218的生物学分析。方法 采用实时荧光定量PCR（qPCR）及miRNA芯片法检测低转移潜能的胃癌细胞亚系（SGC7901-NM、MKN28-NM）与高转移潜能的胃癌细胞亚系（SGC7901-M、MKN28-M）间miRNA的差异表达。提取不同转移潜能胃癌细胞系和10例胃癌冰冻组织及相应的转移淋巴结中的总RNA，利用qPCR检测miR-218在不同细胞及组织中的表达情况。结果 对不同转移潜能的胃癌细胞亚系进行芯片检测发现，与SGC7901-NM细胞比较，SGC7901-M 细胞有47个分子表达下调，15个分子表达上调。与MKN28-NM细胞比较，MKN28-M细胞有41个分子表达下调，83个分子表达上调。在SGC7901-M及MKN28-M细胞中，34个分子表达均出现下降，11个分子表达均出现上升。对不同转移潜能的胃癌细胞亚系以及人永生化正常胃黏膜细胞系GES进行检测可以发现，4种不同转移潜能的胃癌细胞亚系中miR-218的表达均低于正常胃黏膜细胞系GES，差异有统计学意义（P＜0.05），且在高转移潜能胃癌细胞亚系中miR-218的表达均低于低转移潜能胃癌细胞系，差异有统计学意义（P＜0.05）。胃癌转移淋巴结中miR-218的表达水平为0.23±0.02，低于胃癌原发灶的1.09±0.05，差异有统计学意义（P＜0.05）。结论 胃癌转移相关miRNA会出现差异表达情况，高转移潜能胃癌细胞中的miR-218表达水平上调可能与胃癌转移存在一定关系。

Differential expression profile of miRNA associated with metastasis of gastric cancer and biological analysis of miR-218

Objective To screen the microRNA(miRNA) associated with metastasis of gastric cancer and understand the differential expression as well as the biological analysis of miR-218.Methods The differential expression of miRNA in gastric cancer cell lines with low metastatic potential(SGC7901-NM and MKN28-NM) and high metastatic potential(SGC7901-M and MKN28-M) were detected by real-time fluorescence PCR(qPCR) and miRNA microarray.The total RNA was extracted in 10 cases of gastric cancer tissues and corresponding metastatic lymph nodes as well as the gastric cancer cell lines with different metastatic potential.The expression of miR-218 was detected in different cells and tissues by qPCR.Results Microarray detection of gastric cancer cell lines with different metastatic potential found that compared with SGC7901-NM cells,47 miRNAs were down-regulated and 15 miRNAs were up-regulated in SGC7901-M cells.Moreover,compared with MKN28-NM cells,41 miRNAs were down-regulated and 83 miRNAs were up-regulated in MKN28-M cells.Totally,34 miRNAs were down-regulated and 11 miRNAs were up-regulated in SGC7901-M and MKN28-M cells.As for gastric cancer cell lines with different metastatic potential and normal human immortalized gastric epithelial cell line GES,the miR-218 expression was lower in 4 gastric cancer cell lines with different metastatic potential than that in GES,and the difference was statistically significant(P<0.05).The expression of miR-218 in gastric cancer cell lines with high metastatic potential was significantly lower than that of low metastatic potential,and the difference was statistically significant(P<0.05).The expression level of miR-218 in gastric cancer lymph node metastasis was 0.23±0.02,which was significantly lower than 1.09±0.05 of primary gastric cancer,and the difference was statistically significant(P<0.05).Conclusion The expression of miRNA in gastric cancer is different,and there is a certain relationship between the up-regulation of miR-218 expression and metastasis of gastric cancer.