中文摘要：

目的：结合生物信息学分析手段，筛选乳腺癌转移相关微RNA（microRNA，miRNA）-200c调控的基因网络。方法：采用Affymetrix miRNA生物芯片分析12株乳腺细胞中差异表达的miRNA；应用脂质体转染法将miR-200c模拟物（mimic）转入4株高转移性的乳腺癌细胞株（BT549、HS578T、MDA-MB-231和SUMl59PT）中，再用Affymetrix mRNA生物芯片检测转染miR-200cmimic后高转移性乳腺癌细胞株中差异表达的基因。采用生物分子功能注释系统（CapitalBio Molecule Annotation System，MAS），筛选miR-200c调控的信号通路与基因网络。结果：12个乳腺细胞株中筛选出9个差异表达的miRNA（P〈0．01，倍数值≥20或≤-20），其中以miR-200c在高转移性乳腺癌细胞株中下调幅度最显著。4个转染miR-200cmimic的乳腺癌细胞株中共有33个共上调基因及13个共下调基因。实时荧光定量-PCR与蛋白质印迹法验证结果显示，共调基因锌指E框结合同源框1（zincfinger E-box binding homeobox1，ZEB1）mRNA和蛋白在4个转染细胞株中均下调。MAS生物信息学分析结果显示，转染miR-200cmimic的乳腺癌细胞株中共有的差异表达基因相关信号通路包括嗅觉传导（olfactory transduction）通路、细胞因子-细胞因子受体关联（cytokine-cytokine receptor interaction）通路和细胞黏附分子（cell adhesion mo1ecules，CAMs）通路等，不同的信号通路可以通过共调基因相互联系，在特定的信号通路中，共调基因间也存在密切的相互联系。结论：以高通量生物芯片检测为基础，运用生物信息学分析手段，多元化筛选获得miR-200c调控的基因网络，为后续展开miR-200c作用机制的研究提供了明确的方向。

英文摘要：

Objective： To screen for the gene network regulated by breast cancer metastasis-related miR- 200c （microRNA-200c） using bioinformatics means. Hethods： The miRNAs differentially expressed in 12 types of breast cell lines were screened out using Affymetrix miRNA Array. Lipofectamine was supplied in the transfection of miR-200c mimic into four breast cancer cell lines with high-metastatic capability （BT549, HS578T, MDA-MB-231 and SUM159PT cells）. The genes differentially expressed in these four breast cancer cell lines were screened through mRNA expression profiling. The signalling pathways and the gene network regulated by miR-200c were screened using MAS （Molecule Annotation System） （CapitalBio Molecule Annotation System）. Results： Nine miRNAs were differentially expressed among 12 types of breast cell lines （P 〈 0.01, fold change ≥20 or ≤-20）, and the expression of miR-200c was decreased most significantlyin breast cancer cell lines of high metastatic potential. There were 33 co-upregulated genes and 13 co- downregulated genes shared through the four breast cancer cell lines of high metastatic potential after transfection with miR-200c mimic. The results of real-time fluorescence quantitative PCR and Western blotting confirmed that the expressions of ZEB1 （zinc finger E-box binding homeobox 1） mRNA and protein were decreased in four transfected cell lines. The bioinformatics analysis using MAS suggested that the common signalling pathways related to the genes differentially expressed in breast cancer cells transfected with miR-200c mimic included pathways olfactory transduction, cytokine-cytokine receptor interaction, cell adhesion molecules, etc. The different signalling pathways could be in interconnection with each other through co-regulated genes, and co-regulated genes had a close interrelationship within a specific pathway. Conclusion： Based on high-throughput screening using Biochip technology, the bioinformatics analysis is able to demonstrate the gene network regula