目的：探讨miR-143-3p 通过靶向果蝇zeste 基因增强子同源物2（enhancer of zeste homolog 2, EZH2）调控结肠癌RKO细胞增殖、迁移和侵袭的分子机制。方法：选用2015 年3 月至2017 年7 月昆明医科大学第一附属医院手术切除的40 例结肠癌患者的癌及癌旁组织标本，以及结肠癌细胞系COLO320、RKO、CL-11 和正常肠黏膜细胞株NCM460，用qPCR 法检测结肠癌组织和细胞系中miR-143-3p 的表达水平。分别将miR-143-3p mimics、miR-143-3p inhibitor、EZH2 shRNA 及阴性对照质粒转染进RKO细胞，用CCK-8 法、Transwell 小室法分别检测miR-143-3p/EZH2 分子轴对RKO细胞增殖、迁移和侵袭的影响，用Western blotting 检测RKO细胞中EZH2蛋白的表达。用双荧光素酶报告基因实验验证miR-143-3p 和EZH2 的靶向关系。结果：miR-143-3p在结肠癌组织和细胞系中均低表达（均P<0.01）。过表达miR-143-3p 显著抑制RKO 细胞的增殖、迁移和侵袭能力（均P<0.01）。双荧光素酶报告基因实验证实miR-143-3p 靶向EZH2。同时敲降miR-143-3p 和EZH2 可逆转敲降EZH2 对RKO细胞增殖、迁移和侵袭能力的抑制作用。结论：miR-143-3p 通过靶向EZH2并下调其表达水平进而抑制结肠癌细胞的增殖、迁移与侵袭。

Objective: To investigate the molecular mechanism of miR-143-3p regulating the proliferation, migration and invasion of colon cancer RKO cells via targeting enhancer of zeste homolog 2 (EZH2). Methods: A total of 40 pairs of colon cancer tissues and corresponding para-cancerous tissues resected in the First Affiliated Hospital of Kunming Medical University from March 2015 to July 2017 were collected for this study. In addition, colon cancer cell lines (COLO320, RKO and CL-11) and normal intestinal mucosa NCM460 cells were also collected. qPCR was applied to detect the expression level of miR-143-3p in colon cancer tissues and cell lines. miR-143-3p mimics, miR-143-3p inhibitor, EZH2 siRNA and negative control plasmids were transfected into RKO cells,respectively. The effect of miR-143-3p/EZH2 axis on the proliferation, migration and invasion of RKO cells were detected by CCK-8 and Transwell assay, respectively.Western blotting was used to detect the expression level of EZH2 protein in RKO cells. The targeting relationship between miR-143-3p and EZH2 was verified by Dual luciferase reporter gene assay. Results: The expression level of miR-143-3p was downregulated in colon cancer tissues and cell lines (all P<0.01). Overexpression of miR-143-3p significantly inhibited the proliferation, migration and invasion of RKO cells (all P<0.01). Dual luciferase reporter gene assay confirmed that EZH2 was a target gene of miR-143-3p. Simultaneous knockdown of miR-143-3p and EZH2 attenuated the inhibition of EZH2 knockdown on the proliferation, migration and invasion of RKO cells. Conclusion: miR-143-3p suppresses the proliferation, migration and invasion of colon cancer cells via targetedly down-regulating EZH2.

云南省卫生厅内机构资助项目（No. 2016NS003，No. 2017NS003）；中国健康促进基金会黎介寿院士基金资助项目（No. LJS-201707）