目的：探究miR-32-5p通过靶向zeste基因增强子人类同源物2（EZH2）对胰腺癌PANC-1细胞恶性生物学行为的影响及其分子机制。方法：利用GEPIA数据库分析胰腺癌组织中EZH2的表达水平及其与患者的预后生存期的关系，并分析miR-32-5p表达与患者临床病理因素的关系。qPCR法检测正常胰腺HPDE6-C7细胞和胰腺癌PANC-1、AsPC-1、SW1990细胞中miR-32-5p和EZH2 mRNA的表达，通过LipofectamineTM 2000将miR-NC、miR-32-5p mimic、miR-32-5p inhibitor、pcDNA-NC、pcDNA EZH2质粒分别转染PANC-1细胞，其分为对照组（不转染）、miR-NC组（转染miR-NC）、miR-32-5p mimic组（转染miR-32-5p mimic）、Anti-miR-32-5p 组（转染miR-32-5p inhibitor）、miR-NC+pcDNA-NC组（转染miR-NC+pcDNA-NC）、miR-NC+pcDNA EZH2组（转染miR-NC+pcDNA EZH2）、miR-32-5p mimic+pcDNA-NC组（转染miR-32-5p mimic+pcDNA-NC）、miR-32-5p mimic+pcDNA EZH2组（转染miR-32-5p mimic+pcDNA EZH2）。双荧光素酶报告基因实验验证miR-32-5p与EZH2的靶向关系；MTT法及克隆形成实验检测各组细胞的增殖能力，划痕愈合实验检测各组细胞的迁移能力；Transwell小室实验检测各组细胞的侵袭能力，WB法检测各组细胞EZH2、E-cadherin、N-cadherin的表达；裸鼠成瘤实验检测转染后各组 PANC-1 细胞移植瘤的生长情况，免疫组化染色法观察移植瘤组织中Ki67和MMP-2的表达。结果：GEPIA数据库显示胰腺癌组织中EZH2的表达水平高于癌旁组织，患者预后生存期与EZH2的表达水平呈负相关（均P<0.05）；miR-32-5p表达水平与胰腺癌神经浸润、肿瘤分化程度、TNM 分期、淋巴结转移有明显的关联（均P<0.05）；与HPDE6-C7细胞相比，PANC-1、AsPC-1、SW1990细胞中miR-32-5p呈高表达、EZH2 mRNA呈低表达、miR-32-5p表达水平与EZH2 表达水平呈负相关（均P<0.05）。miR-32-5p靶向EZH2且抑制其表达（均P<0.05）；过表达miR-32-5p能够下调Ki67、MMP-2、N-cadherin 表达水平、上调 E-cadherin 表达水平，抑制 PANC-1 细胞的增殖、迁移和侵袭能力，抑制移植瘤质量增加（均 P<0.05）。结论：miR-32-5p能够靶向调控EZH2从而影响胰腺癌PANC-1细胞的增殖、迁移、侵袭、EMT进程及裸鼠体内移植瘤的生长。

Objective: To explore the effect of miR-32-5p on the malignant biological behaviors of pancreatic cancer PANC-1 cells via targeting zeste gene enhancer human homolog 2 (EZH2) and its molecular mechanism. Methods: The GEPIA database was used to analyze the expression level of EZH2 in pancreatic cancer tissues and its relationship with the prognostic survival of patients. The association between miR-32-5p expression and clinicopathological features of patients was also analyzed. qPCR was used to detect the expression of miR-32-5p and EZH2 mRNA in pancreatic cancer cells (PANC-1, AsPC-1, SW1990) and normal pancreatic HPDE6-C7 cells. With LipofectamineTM 2000, miR-NC, miR-32-5p mimic, miR-32-5p inhibitor, pcDNA-NC and pcDNA EZH2 plasmids were separately or jointly transfected into pancreatic cancer PANC-1 cells, namely control group (untransfected)，miR-NC group (transfected with miR-NC), miR-32-5p mimic group (transfected with miR-32-5p mimic), anti-miR-32-5p group (transfected with miR-32-5p inhibitor); miR-NC+pcDNA-NC group (transfected with miR-NC+pcDNA-NC), miR-NC+pcDNA EZH2 group (transfected with miR-NC+pcDNA EZH2), miR-32-5p mimic+pcDNA-NC group (transfected with miR-32-5p mimic+pcDNA-NC), and miR-32-5p mimic+pcDNA EZH2 group (transfected with miR-32-5p mimic+pcDNA EZH2). Dual-luciferase reporter gene assay was used to verify the targeting relationship between miR-32-5p and EZH2. MTT method and the clone formation assay were used to detect proliferation ability of the cells in each group; scratch healing test was used to detect cell migration ability; Transwell chamber test was used to detect cell invasion; Western blotting method was adopted to detect the expression of EZH2, epithelial cadherin (E-cadherin)and neural cadherin (N-cadherin) in cells. The tumorigenicity experiment in nude mice was used to detect the development of transplanted tumors; and the expression of Ki67 and metal matrix protease-2 (MMP-2) in tumor tissues was observed by immunohistochemical staining. Results: The GEPIA database showed that the expression level of EZH2 in pancreatic cancer tissues was higher than that in para-cancerous tissues, and the prognostic survival was negatively correlated with the expression level of EZH2 (all P<0.05). The miR-32-5p expression was significantly correlated with the nerve infiltration, tumor differentiation, TNM staging, lymph node metastasis of pancreatic cancer (all P<0.05). Compared with HPDE6-C7 cells, miR-32-5p was up-regulated and EZH2 mRNA was down-regulated in pancreatic cancer cells (PANC-1, AsPC-1, SW1990), and the level of miR-32-5p was negatively correlated with the level of EZH2. miR-32-5p targeted and down-regulated the expression of EZH2 (all P<0.05). Over-expression of miR-32-5p could down-regulate the expression levels of Ki67, MMP-2 and N-cadherin, up-regulate the level of E-cadherin, inhibit proliferation, migration and invasion of PANC-1 cells as well as the volume and weight of transplanted tumors (all P<0.05).Conclusion: miR-32-5p can inhibit the proliferation, migration, invasion, epithelial-mesenchymal transition (EMT) of pancreatic cancer PANC-1 cells as well as the development of nude mice transplanted tumors in vivo through targeting EZH2.