Biotechnology Institute, Ankara University, Ankara, Turkey.
Department of Medical Pharmacology, Faculty of Medicine, Ankara University, Ankara,Turkey.
PLoS One. 2019 Apr 22;14(4):e0215894. doi: 10.1371/journal.pone.0215894. eCollection 2019.
miRNAs may play effective roles in breast cancer so modulating their expression levels could have therapeutic benefits. Recent studies have found the combination of miRNA-based therapeutics with conventional drugs as promising. This study aimed to find drug-responsive miRNAs, and explore their anticancer activities in HER2+ breast cancer cells and regulatory role in the trastuzumab response. qRT-PCR-array analysis was performed with effective concentrations of tamoxifen and trastuzumab treated BT-474, SK-BR-3 and MCF-7 cells. Motility and invasion analyses were performed with wound healing and xCELLigence impedance-based assays respectively. Viability of cells following mimic transfection and drug treatment was assessed by WST-1 assay. Western blot analysis was used to assess miR-770-5p regulation of proteins and their phosphorylated forms. The clinical relevance of miR-770-5p was examined by TCGA data analysis. The qRT-PCR-array results indicated that miR-770-5p was responsive in a drug and cell line independent manner. Overexpression of miR-770-5p inhibited the motility and cell invasion through regulation of AKT and ERK proteins. Additionally, miR-770-5p potentiated the effectiveness of trastuzumab. Thus, regulating the expression level of miR-770-5p in combination with trastuzumab treatment may simultaneously inhibit the downstream elements of PI3K and MAPK signalling, thereby blocking the proliferation, motility and invasion capacities of HER2+ breast cancer cells.
miRNAs 可能在乳腺癌中发挥有效作用，因此调节其表达水平可能具有治疗益处。最近的研究发现，将 miRNA 治疗与传统药物联合使用具有很大的潜力。本研究旨在寻找药物反应性 miRNAs，并探索它们在 HER2+乳腺癌细胞中的抗癌活性及其对曲妥珠单抗反应的调节作用。采用 qRT-PCR 微阵列分析，用有效浓度的他莫昔芬和曲妥珠单抗处理 BT-474、SK-BR-3 和 MCF-7 细胞。采用划痕愈合和 xCELLigence 阻抗测定法分别进行细胞迁移和侵袭分析。通过 WST-1 检测细胞活力，评估模拟转染和药物处理后细胞的活力。采用 Western blot 分析评估 miR-770-5p 对蛋白质及其磷酸化形式的调节作用。通过 TCGA 数据分析评估 miR-770-5p 的临床相关性。qRT-PCR 微阵列结果表明，miR-770-5p 以药物和细胞系独立的方式发生反应。miR-770-5p 的过表达通过调节 AKT 和 ERK 蛋白抑制了细胞的迁移和侵袭。此外，miR-770-5p 增强了曲妥珠单抗的疗效。因此，调节 miR-770-5p 的表达水平与曲妥珠单抗治疗相结合可能同时抑制 PI3K 和 MAPK 信号通路的下游元件，从而阻断 HER2+乳腺癌细胞的增殖、迁移和侵袭能力。
