目的：探讨黏蛋白13（MUC13）在肺腺癌组织中的表达及其对A549细胞增殖、凋亡、迁移、侵袭及EMT的影响与可能的机制。方法：通过癌症基因组图谱（TCGA）和高通量基因表达（GEO）数据库分析MUC13在肺腺癌组织与正常肺组织、癌旁组织中的差异表达。qPCR法和WB法检测人肺腺癌细胞NCI-H1395、NCI-H1975、H1299、A549和人正常肺上皮细胞BEAS-2B中MUC13mRNA和蛋白的表达水平。利用siRNA技术敲低A549细胞中MUC13表达，实验分为si-MUC13组、NC组和si-MUC13+IGF-1组。通过克隆形成实验、流式细胞术和Transwell实验分别检测敲低MUC13对A549细胞增殖、细胞周期、凋亡、迁移和侵袭的影响，WB法检测敲低MUC13对A549 细胞上皮钙黏素（E-cadherin）、神经钙黏素（N-cadherin）、波形蛋白（vimentin）、EGFR、p-EGFR、PI3K、p-PI3K、AKT、p-AKT等蛋白表达的影响。结果：MUC13 mRNA和蛋白在肺腺癌组织和细胞中均呈高表达（均P<0.01），选取表达水平较高的A549细胞进行后续实验。敲低MUC13后，A549细胞的增殖能力显著降低，G0/G1期的细胞数量显著增多、G2/M期及S期的细胞数量显著减少，细胞凋亡率显著升高，细胞迁移及侵袭能力均显著降低（均P<0.01）；A549细胞中E-cadherin表达显著上调，N-cadherin、vimentin表达显著下调，p-EGFR/EGFR、p-PI3K/PI3K、p-AKT/AKT 比值均显著降低（均P<0.01）；再加入IGF-1处理后，A549细胞中p-EGFR/EGFR、p-PI3K/PI3K、p-AKT/AKT比值均显著升高（均P<0.01）。结论：MUC13在肺腺癌组织和细胞中均呈高表达，其可能通过激活EGFR/PI3K/AKT信号通路促进A549细胞增殖、迁移、侵袭和EMT。

Objective: To investigate the expression of mucin 13 (MUC13) in lung adenocarcinoma tissues and its effects on the proliferation, apoptosis, migration, invasion, and epithelial-mesenchymal transition (EMT) of A549 cells as well as the possible mechanism. Methods: The differential expression of MUC13 in lung adenocarcinoma tissues, normal lung tissues, and para-cancerous tissues was analyzed using The Cancer Genome Atlas (TCGA) and high throughput Gene Expression Omnibus (GEO) databases. The mRNA and protein expression levels of MUC13 in human lung adenocarcinoma cells (NCI-H1395, NCI-H1975, H1299 and A549) and normal lung epithelial BEAS-2B cells were detected using qPCR and WB methods. siRNA technology was used to knock down MUC13 expression in A549 cells, and the experimental cells were divided into si-MUC13 group, NC group and si-MUC13+IGF-1 group. The effects of MUC13 knockdown on the proliferation, cell cycle, apoptosis, migration and invasion of A549 cells were detected by clony formation assay, flow cytometry and Transwell assay, respectively. WB assay was used to detect the effect of MUC13 knockdown on the protein expression of E-cadherin, N-cadherin, vimentin, EGFR, p-EGFR, PI3K, p-PI3K, AKT and p-AKT in A549 cells. Results: MUC13 was highly expressed in lung adenocarcinoma tissues and cells at both mRNA and protein levels (all P<0.01),and A549 cells with higher MUC13 expression were selected for subsequent experiments. After knocking down MUC13, the proliferation ability of A549 cells was significantly weakened, the number of cells in G0/G1 phase was significantly increased while the number of cells in G2/M phase and S phase was significantly decreased, the apoptosis rate was significantly increased, and the cell migration and invasion abilities were significantly weakened (all P<0.01); Moreover, the protein expression of E-cadherin in A549 cells was upregulated, while the protein expression of N-cadherin and vimentin was downregulated, and the ratios of p-EGFR/EGFR, p-PI3K/PI3K, and p-AKT/AKT were all reduced (all P<0.01). However, after adding pathway activator IGF-1, the p-EGFR/EGFR, p-PI3K/PI3K, and p-AKT/AKT ratios in A549 cells all increased (all P<0.01). Conclusion: MUC13 is highly expressed in lung adenocarcinoma tissues and cells, and it promotes cell proliferation, migration, invasion and EMT of A549 cells, possibly through the activation of the EGFR/PI3K/AKT signaling pathway.

内蒙古医学科学院公立医院科研联合基金科技项目（No.2023GLLH0206)；包头市卫生健康科技计划（No. wsjkkj009）；包头医学院青年科技人才发展计划（No. BYJJ-DXX 2020025）