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目的:检测分析微小RNA(miR)-324-5p在胰腺癌中的表达情况及临床意义，并探究其对胰腺癌细胞增殖和迁移能力的影响及潜在分子机制。方法:实时定量PCR方法检测34对2018年10月至2019年9月在北京大学第一医院手术切除的胰腺癌和癌旁组织中miR-324-5p表达水平，结合癌症基因组图谱(TCGA)数据库分析其与胰腺癌临床病理特征及预后的相关性。实时定量PCR方法检测miR-324-5p在胰腺癌细胞系中表达情况，在PANC-1细胞中转染miR-324-5p mimic后通过细胞增殖实验(CCK8)、细胞迁移实验(Transwell)和划痕实验检测miR-324-5p对胰腺癌细胞增殖、迁移能力的影响，蛋白质电泳检测相关蛋白表达变化并结合miRNA在线靶点预测分析工具和基因功能分析，寻找miR-324-5p直接调控的下游靶基因。结果:TCGA数据库资料显示miR-324-5p在胰腺癌中的表达水平显著低于正常胰腺组织，且低表达miR-324-5p的胰腺癌患者预后更差；34对胰腺癌及癌旁组织检测结果证实miR-324-5p在胰腺癌中的表达水平(11.7±2.0)低于癌旁胰腺组织(70.9±14.4)，低表达miR-324-5p的患者神经侵犯率(82.1%，23/28)高于高表达患者(33.3%，2/6)，差异具有统计学意义(n P<0.05)。胰腺癌细胞系中miR-324-5p表达水平降低，上调PANC-1细胞中miR-324-5p表达后细胞增殖能力显著下降，细胞垂直迁移数量(30.11±5.2)个和水平运动能力(174.6±27.0)μm也较对照组(63.6±4.2)个和(458.3±22.3)μm降低，差异有统计学意义(均n P<0.05)。在线靶点预测工具和基因功能分析结果发现4个与肿瘤转移或EMT调控相关的基因(KLF3、MGAT3、PBX1、ZNRF2)可能是miR-324-5p直接调控的下游靶基因。n 结论:胰腺癌中miR-324-5p具有抑癌作用，其低表达与肿瘤神经侵犯、预后差相关。胰腺癌细胞中miR-324-5p可能直接调控KLF3、MGAT3、PBX1、ZNRF2等基因表达，进而抑制细胞增殖、迁移能力。“,”Objective:To investigate the expression and clinical relevance of micro RNA (miR)-324-5p in pancreatic cancer tissues, and to explore the effects and potential mechanisms of miR-324-5p on the proliferation and migration of pancreatic cancer cells.Methods:Real-time quantitative PCR was used to detect the expression of miR-324-5p in 34 pairs of pancreatic cancer and adjacent normal tissues resected at Peking University First Hospital from October 2018 to September 2019. The correlations between miR-324-5p expression and clinicopathological characteristics and prognosis of pancreatic cancer were analyzed using data from the Cancer Genome Atlas (TCGA) database. Real-time PCR was used to detect the expression of miR-324-5p in pancreatic cancer cell lines, and PANC-1 cell was used for functional study by overexpressing miR-324-5p via mimic transfection. CCK8 assay was used to evaluate cell proliferation. Both transwell and scratch wound healing assay were used to assess the cancer cell migration ability. Related proteins were detected by Western blot. The potential downstream target genes of miR-324-5p were selected using data from miRNA target genes predicted webs, in combination with functional analysis and their expressional correlation with miR-324-5p.Results:Data from TCGA database showed that the expression of miR-324-5p in tumor tissues was significantly lower than that in normal pancreatic tissues. And low level of miR-324-5p in pancreatic cancer was correlated with poor prognosis. Analysis of 34 pairs pancreatic cancer and adjacent normal tissues showed that miR-324-5p expression in tumor tissues (11.7±2.0) was significantly lower than that in adjacent normal tissues (70.9±14.4), and the pancreatic cancer patients who had the nerve invasion cancer showed low level of miR-324-5p (82.1%, 23/28) was significantly higher than that patients with high level of miR-324-5p (33.3%, 2/6). The expression of miR-324-5p in human pancreatic cancer cell line was also significantly lower than that in normal pancreatic ductal cells. CCK-8 assay showed that the proliferation ability of PANC-1 cell was significantly decreased when miR-324-5p was overexpressed. Transwell and wound healing assays showed that the capabilities of vertical migration and the horizontal movement were significantly inhibited in PANC-1 cell with miR-324-5p overexpressed [(30.11±5.2) and (174.6±27.0) μm, respectively] than those in control groups [(63.6±4.2) and (458.3±22.3) μm, respectively]. Moreover, Western blots showed a significant overexpression of miR-324-5p inhibited epithelial-mesenchymal transition (EMT). According to the data from miRNA target genes prediction and the functional analysis we found KLF3, MGAT3, PBX1 and ZNRF2 were considered as the potential downstream target genes of miR-324-5p.Conclusions:Our results indicated that miR-324-5p is lowly expressed and acts as the tumor suppressor gene in pancreatic cancer, and low level of miR-324-5p is correlated to a higher rate of nerve invasion and poor prognosis. In human pancreatic cancer cell, miR-324-5p may regulate EMT by directly inhibiting target genes such as KLF3, MGAT3, PBX1, ZNRF2, which in turn suppresses cancer cell proliferation and migration.