[摘要] 目的：探讨miR-455-3p 对卵巢癌细胞SKOV-3 增殖、迁移能力及上皮间质转化（epithelial-mesenchymal transition，EMT）的影响，并研究其作用机制。方法：人卵巢上皮细胞株IOSE80、卵巢细胞系SKOV-3 和A2780 细胞培养完成后，将miR-455-3p mimic 及其阴性对照分别瞬时转染至细胞中。qPCR 实验检测IOSE80、SKOV-3 和A2780 细胞miR-455-3p 和转脂蛋白4（fatty acid-binding protein 4，FABP4）mRNA表达水平，Wb检测FABP4 和EMT相关蛋白的表达水平，CCK-8 法检测细胞增殖活性，Transwell 实验用于评估细胞迁移能力，生物信息学预测miR-455-3p 的靶基因，应用双荧光素酶报告基因验证miR-455-3p 与FABP4 的靶向关系。结果：与正常卵巢上皮细胞IOSE80 相比，卵巢癌细胞SKOV-3 和A2780 中miR-455-3p 低表达（均P<0.05），而FABP4 高表达（均P<0.05）。此外，过表达miR-455-3p 明显抑制SKOV-3 细胞的增殖和迁移能力（均P<0.05）。过表达miR-455-3p 通过上调E-cadherin 表达、下调N-cadherin 和Vimentin 表达而抑制EMT进程（均P<0.05）。FABP4 是miR-455-3p 的靶基因，且miR-455-3p 能特异性结合FABP4 3’-UTR，并负调控其表达水平（P<0.05）。过表达FABP4 能够明显逆转miR-455-3p 对SKOV-3细胞增殖和迁移的抑制作用（均P<0.05）。结论：miR-455-3p 在卵巢癌中作为一个抑癌蛋白，通过靶向调控FABP4 从而抑制卵巢癌细胞增殖、迁移及EMT，有望成为卵巢癌新的潜在治疗靶点。

[Abstract] Objective: To investigate the potential effects of miR-455-3p on proliferation, invasion and epithelial-mesenchymal transition (EMT) process of ovarian cancer cells, and explore its molecular mechanism. Methods: The IOSE80, SKOV-3 and A2780 cells were transfected with miR-455-3p mimics and negative controls (NC) by using LipofectamineTM 2000. Quantitative polymerase chain reaction (qPCR) assay was performed to detect the mRNA expressions of miR-455-3p and fatty acid-binding protein 4 (FABP4) in IOSE80, SKOV-3 and A2780 cells. The expression levels of FABP4 and EMT-associated proteins were detected by Wb. CCK-8 assay was applied to measure cell proliferation. Cell migration was analyzed by using Transwell assay. Bioinformatics analysis was used to predict the potential target of miR-455-3p, and the targeting effect of miR-455-3p on FABP4 was verified by the dual-luciferase reporter assay system. Results: The expression of miR-455-3p was declined (all P<0.05), while the expression of FABP4 was elevated (all P<0.05) in ovarian cancer cells (SKOV-3 and A2780) in comparison with normal ovarian IOSE80 cells. Additionally, over-expression of miR-455-3p obviously inhibited cell proliferation and migration capacity of SKOV-3 cells (all P<0.05). Furthermore, over-expression of miR-455-3p impeded EMT progress by up-regulating E-cadherin expression and down-regulating N-cadherin and vimentin expression (all P<0.05). Importantly, the dual-luciferase reporter system, qPCR and Wb validated that FABP4 was a specific target gene of miR-455-3p, and miR-455-3p showed specific binding with FABP4 3’-UTR and negatively regulated the expression of FABP4 at both mRNA and protein levels. Mechanistically, over-expression of FABP4 apparently reversed the inhibitory effects of miR-455-3p on cell proliferation and migration of SKOV-3 cells (all P<0.05). Conclusion: miR-455-3p, acting as a tumor suppressor protein, can inhibit ovarian cancer cell proliferation, migration and EMT process by targeting FABP4, suggesting that miR-455-3p may be a new potential therapeutic target for ovarian cancer treatment.