目的：探讨 miR-28-3p 在三 阴 性 乳 腺 癌（triple negative breast cancer，TNBC）组 织 和 细 胞 系 中 的 表 达 及 其 对MDA-MB-468细胞恶性生物学行为的影响。方法：收集2013年1月至2014年1月河北医科大学第四医院乳腺中心手术切除的、经病理证实的 83 例女性 TNBC 患者的癌组织和癌旁组织标本，以及 TNBC 细胞系 MDA-MB-468、HCC-1937、MDA-MB-231、MDA-MB-436、MDA-MB-453和人正常乳腺上皮细胞MCF10A，用qPCR检测组织和细胞系中miR-28-3p的表达水平并分析其表达与患者临床病理特征的相关性。用miR-28-3p抑制剂转染MDA-MB-468细胞后，用CCK-8、流式细胞术、细胞划痕和Transwell实验分别检测miR-28-3p抑制剂对MDA-MB-468细胞增殖、凋亡、侵袭和迁移能力的影响，用Western blotting检测MDA-MB-468细胞中桥接整合因子1（bridging integrator-1，BIN1）蛋白的表达水平。通过生物信息学工具预测miR-28-3p的靶基因BIN1，用双荧光素酶报告基因实验验证miR-28-3p对BIN1的调控作用。结果：TNBC组织及细胞系中miR-28-3p表达水平显著高于癌旁组织及MCF10A细胞（均P<0.01）；83例TNBC组织中共有56例（67.47%）高表达miR-28-3p，其高表达与患者的Ki-67表达水平、肿瘤大小和TNM分期密切相关（均P<0.05或P<0.01）。与miR-NC组比较，miR-28-3p抑制剂组MDA-MB-468细胞增殖、侵袭和迁移能力降低，凋亡率升高（均P<0.05或P<0.01）。双荧光素酶报告基因和实验证实BIN1是miR-28-3p的靶基因，miR-28-3p抑制剂可上调MDA-MB-468细胞中BIN1蛋白的表达（P<0.05）。结论：miR-28-3p在TNBC组织及细胞中呈高表达状态，miR-28-3p抑制剂上调BIN1表达进而抑制MDA-MB-468细胞的增殖、迁移和侵袭能力，并促进其凋亡。

Objective: To study the miR-28-3p expression in triple negative breast cancer (TNBC) tissues and cell lines, and explore its effect on the malignant biological behaviors of MDA-MB-468 cells. Methods：Tumor tissues and matched para-cancerous tissues were collected from 83 TNBC patients, who underwent tumor resection and pathological confirmation in the Fourth Hospital of Hebei Medical University between Jan. 2013 and Jan. 2014. TNBC cell lines (MDA-MB-468, HCC-1937, MDA-MB-231, MDA-MB-436, MDA-MB-453) and human normal breast epithelial cell line MCF10A were also used in this study. qPCR was used to detect the expression of miR-28-3p in above mentioned tissues and cell lines. The correlation between miR-28-3p expression and clinical parame‐ters was analyzed. After transfection with miR-28-3p inhibitor, the proliferation, apoptosis, invasion and migration ability of MDA-MB-468 cells were detected with CCK-8, Flow cytometry, Transwell and Wound-healing experiment, respectively. And Western blottingwas used to examine the protein expression of bridging integrator-1 (BIN1) in MDA-MB-468 cells. Bioinformatics BIN1 tool waere used to predict the target gene of miR-28-3p. Luciferase reporter gene assay was performed to validate the regulatory effect of miR-28-3p on BIN1. Results: The expression of miR-28-3p in TNBC tissues and cell lines was higher than that in matched para-cancerous tissues and MCF10A cells (all P<0.01), respectively. Among the total 83 TNBC tissues, 56 (67.47%) showed high miR-28-3p expression. High expression of miR-28-3p was closely correlated with the Ki-67 expression, tumor size and TNM stage (all P<0.05 or P<0.01). Compared with miR-NC group, transfection of miR-28-3p inhibitor significantly decreased the proliferation, invasion and mi‐gration of MDA-MB-468 cells while increased the apoptosis rate (all P<0.05 or P<0.01). Luciferase reporter gene assay confirmed that BIN1 was a target gene of miR-28-3p, and miR-28-3p inhibitor could up-regulate BIN1 expression in MDA-MB-468 cells (P<0.05).Conclusion: miR-28-3p is highly expressed in TNBC tissues and cell lines. miR-28-3p inhibitor up-regulates the expression of BIN1 to inhibit the proliferation, invasion and migration ability while promote the apoptosis of MDA-MB-468 cells.

国家自然科学基金资助项目（No. 81871894）；河北省自然科学基金资助项目（No. H2018206318）