目的：探究甘露糖结合凝集素2（LMAN2）在激素受体（HR）阳性乳腺癌组织中的表达水平与乳腺癌患者预后的关系及其对MCF-7 细胞增殖和迁移的影响。方法：通过TCGA、Bc-GenExMiner、GEPIA 和Kaplan-Meier Plotter 数据库分析LMAN2在乳腺癌组织和正常乳腺组织中的差异性表达及其与患者预后的关系。采用小RNA干扰技术将si-LMAN2#1、si-LMAN2#2及si-NC 转染至MCF-7细胞，将过表达LMAN载体（pc-LMAN）及空载体pcDNA3.1阴性对照（pc-NC）转染至MCF-7 细胞，实验分为si-LMAN2#1、si-LMAN2#2、si-NC、pc-LMAN2 和pc-NC 组。通过qPCR 和WB实验检测各组细胞中LMAN2 mRNA和蛋白的表达水平，CCK-8、克隆形成、Transwell 迁移、WB等实验检测敲低和过表达LMAN 2对MCF-7细胞增殖、克隆形成、迁移及AKT信号通路相关蛋白表达的影响。结果：LMAN2在乳腺癌组织中的表达水平显著高于正常乳腺组织（P<0.001）。HR阳性乳腺癌组织中LMAN2表达水平显著高于HR阴性乳腺癌组织（P<0.001）；LMAN2高表达与HR阳性乳腺癌患者不良预后有关联。敲低LMAN2可显著降低MCF-7 细胞的增殖和迁移能力（P<0.01 或P<0.001），过表达LMAN2 可显著提高MCF-7细胞的增殖和迁移能力（均P<0.001）。敲低LMAN2 组MCF-7 细胞中PTEN 和P21 蛋白表达水平均显著升高，p-AKT 蛋白表达水平显著降低（均P<0.01）。结论：LMAN2在乳腺癌组织和HR阳性乳腺癌组织中高表达，且与不良预后有关联。LMAN2高表达与MCF-7细胞增殖和迁移有关联，其作用机制可能涉及AKT信号通路。

Objective: To explore the relationship between the expression level of mannose-binding lectin 2 (LMAN2) in hormone receptor (HR)-positive breast cancer tissues and patient prognosis as well as its effects on the proliferation and migration of MCF-7 cells. Methods: The differential expression of LMAN2 in breast cancer tissues and normal breast tissues as well as its relationship with patients' prognosis were analyzed by TCGA, Bc-GenExMiner, GEPIA and Kaplan-Meier Plotter databases. si-LMAN2#1, si-LMAN2#2 and si-NC were transfected into MCF-7 cells using small RNA interference technology, and the LMAN overexpression vector (pc-LMAN) and empty vector pcDNA3.1 negative control (pc-NC) were transfected into MCF-7 cells; and accordingly, the experimental groups were named si-LMAN2#1 group, si-LMAN2#2 group, si-NC group, pc-LMAN2 group and pc-NC group. The mRNA and protein expression levels of LMAN2 in MCF-7 cells of each group were detected by qPCR and WB assay, respectively. The effects of knockdown and overexpression of the LMAN2 on the proliferation, colony formation and migration as well as the expression of AKT signaling pathway-related proteins in MCF-7 cells were detected using CCK-8, colony formation, Transwell migration and WB assay, etc. Results: The expression level of LMAN2 in breast cancer tissues was significantly higher than that in normal breast tissues (P<0.001), and the expression of LMAN2 in HR-positive breast cancer tissues was significantly higher than that in HR-negative breast cancer tissues (P<0.001). In contrast to low LMAN2 expression, high expression of LMAN2 was associated with poor prognosis in HR-positive breast cancer patients. Knockdown of LMAN2 significantly inhibited the proliferation and migration abilities of MCF-7 cells (P<0.01 or P<0.001), while overexpression of LMAN2 significantly enhanced the proliferation and migration abilities of MCF-7 cells (all P<0.001). The protein expression levels of PTEN and P21 in MCF-7 cells with LMAN2 knockdown were significantly elevated, while the protein expression of p-AKT was significantly decreased (all P<0.01). Conclusion: LMAN2 is highly expressed in breast cancer tissues and HR-positive breast cancer tissues and is associated with poor prognosis. The high expression of LMAN2 is associated with the proliferation and migration of MCF-7 cells, and the mechanism may involve the AKT signaling pathway.

国家自然科学基金（No. 81572917）；陕西省重点研发计划（No. 2022ZDLSF02-07）；陕西省自然科学基础研究计划（No. 2023-JC-QN-0965）