Department of Thyroid Gland and Breast Surgery, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
Eur Rev Med Pharmacol Sci. 2018 Nov;22(21):7323-7332. doi: 10.26355/eurrev_201811_16269.
The aim of this study was to investigate the effect of miR-155 on the proliferation and migration of breast cancer cells, and to explore the underlying mechanism.
The breast cancer cell line MDA-MB-231 was transfected with miR-155 mimics, inhibitor or negative control, respectively. The expression level of miR-155 was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Subsequently, the proliferation of MDA-MB-231 cells was detected by multi-cellular tumor spheroid (MTS) and colony formation assay. Cell migration was examined by transwell assay and scratch test. In addition, qRT-PCR was performed to analyze the expression of matrix metallopeptidase 16 (MMP16) after miR-155 mimics or inhibitor transfection in MDA-MB-231 cells. Meanwhile, Western blot was used to evaluate the protein expression levels of suppressor of cytokine signaling 1 (SOCS1) and MMP16 after miR-155 mimics or inhibitor transfection.
QRT-PCR results showed that miR-155 mimics significantly increased the expression of miR-155 in MDA-MB-231 cells, whereas miR-155 inhibitor markedly decreased miR-155 expression (p < 0.05). Meanwhile, MTS and colony formation assay indicated that the proliferation of MDA-MB-231 cells was remarkably increased after miR-155 mimics transfection. However, miR-155 inhibitor transfection exhibited the opposite result in cell proliferation (p < 0.05). Moreover, miR-155 overexpression significantly increased the migration of MDA-MB-231 cells (p < 0.05). Western blot further confirmed that miR-155 overexpression down-regulated the expression level of target protein SOCS1 and upregulated the expression level of MMP16.
We found that miR-155 significantly enhanced the proliferation and migration of MDA-MB-231 cells, which might serve as an oncogene in breast cancer. Therefore, it is preliminarily believed that miR-155 plays an important role in the proliferation and migration of breast cancer cells via down-regulating the expression of SOCS1 and up-regulating the expression of MMP16.
本研究旨在探讨 miR-155 对乳腺癌细胞增殖和迁移的影响，并探讨其潜在机制。
分别用 miR-155 模拟物、抑制剂或阴性对照转染乳腺癌细胞系 MDA-MB-231。采用实时定量聚合酶链反应 (qRT-PCR) 检测 miR-155 的表达水平。随后，通过多细胞肿瘤球体 (MTS) 和集落形成实验检测 MDA-MB-231 细胞的增殖。通过 Transwell 测定和划痕试验检测细胞迁移。此外，在 MDA-MB-231 细胞中转染 miR-155 模拟物或抑制剂后，通过 qRT-PCR 分析基质金属蛋白酶 16 (MMP16) 的表达。同时，Western blot 用于评估 miR-155 模拟物或抑制剂转染后 MDA-MB-231 细胞中 SOCS1 和 MMP16 的蛋白表达水平。
qRT-PCR 结果显示，miR-155 模拟物显著增加 MDA-MB-231 细胞中 miR-155 的表达，而 miR-155 抑制剂则显著降低 miR-155 的表达 (p<0.05)。同时，MTS 和集落形成实验表明，miR-155 模拟物转染后 MDA-MB-231 细胞的增殖显著增加。然而，miR-155 抑制剂转染则导致细胞增殖相反的结果 (p<0.05)。此外，miR-155 过表达显著增加 MDA-MB-231 细胞的迁移 (p<0.05)。Western blot 进一步证实，miR-155 过表达下调了靶蛋白 SOCS1 的表达水平，并上调了 MMP16 的表达水平。
我们发现 miR-155 显著增强了 MDA-MB-231 细胞的增殖和迁移，可能在乳腺癌中作为一种癌基因发挥作用。因此，初步认为 miR-155 通过下调 SOCS1 的表达和上调 MMP16 的表达，在乳腺癌细胞的增殖和迁移中发挥重要作用。
