Kaempferol suppresses cell metastasis via inhibition of the ERK-p38-JNK and AP-1 signaling pathways in U-2 OS human osteosarcoma cells
Kaempferol suppresses cell metastasis via inhibition of the ERK-p38-JNK and AP-1 signaling pathways in U-2 OS human osteosarcoma cells
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DOI：
10.3892/or.2013.2490
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发表时间：
2013-08-01
期刊：
影响因子：
4.2
通讯作者：
Yang, Jai-Sing
中科院分区：
文献类型：
--
作者：
Chen, Hui-Jye;Lin, Chung-Ming;Yang, Jai-Sing
山奈酚是一种天然黄酮类化合物，在多种癌细胞系中具有抗增殖和诱导细胞凋亡的活性。在本研究中，我们研究了山奈酚的抗转移活性及其在人骨肉瘤细胞中作用的分子机制。 Matrigel Transwell 实验和细胞粘附实验显示，山奈酚对 U-2 骨肉瘤 (OS) 细胞的侵袭和粘附具有浓度依赖性抑制作用。通过伤口愈合测定，山奈酚在不同治疗时间点也以浓度依赖性方式抑制 U-2 OS 细胞的迁移。其他实验表明，通过明胶和酪蛋白纤溶酶原酶谱分析和蛋白质印迹分析，山奈酚处理降低了基质金属蛋白酶 (MMP)-2、MMP-9 和尿激酶纤溶酶原激活剂 (uPA) 的酶活性和蛋白质水平。通过定量 PCR 分析，山奈酚还下调了 MMP-2 和 MMP-9 的 mRNA 水平。此外，通过蛋白质印迹分析，山奈酚能够降低 ERK、p38 和 JNK 的蛋白磷酸化。通过电泳迁移率变化测定 (EMSA)，我们证明山奈酚降低了 AP-1 的 DNA 结合活性，这一作用可能导致 MMP-2、MMP-9 和 uPA 的表达减少。总的来说，我们的数据表明，山奈酚减弱了包括ERK、JNK和p38在内的MAPK信号通路，导致AP-1的DNA结合能力降低，从而下调MMP-2、MMP-9和uPA的表达和酶活性，有助于抑制U-2 OS细胞的转移。我们的结果表明山奈酚在治疗 OS 肿瘤转移中具有潜在作用。
Kaempferol is a natural flavonoid that possesses anti-proliferative and apoptosis-inducing activities in several cancer cell lines. In the present study, we investigated the anti-metastatic activity of kaempferol and its molecular mechanism(s) of action in human osteosarcoma cells. Kaempferol displayed inhibitory effects on the invasion and adhesion of U-2 osteosarcoma (OS) cells in a concentration-dependent manner by Matrigel Transwell assay and cell adhesion assay. Kaempferol also inhibited the migration of U-2 OS cells in a concentration-dependent manner at different treatment time points by wound-healing assay. Additional experiments showed that kaempferol treatment reduced the enzymatic activities and protein levels of matrix metalloproteinase (MMP)-2, MMP-9 and urokinase plasminogen activator (uPA) by gelatin and casein-plasminogen zymography assays and western blot analyses. Kaempferol also downregulated the mRNA levels of MMP-2 and MMP-9 by quantitative PCR analyses. Furthermore, kaempferol was able to reduce the protein phosphorylation of ERK, p38 and JNK by western blotting. By electrophoretic mobility-shift assay (EMSA), we demonstrated that kaempferol decreased the DNA binding activity of AP-1, an action likely to result in the reduced expression of MMP-2, MMP-9 and uPA. Collectively, our data showed that kaempferol attenuated the MAPK signaling pathways including ERK, JNK and p38 and resulted in the decreased DNA binding ability of AP-1, and hence, the downregulation in the expression and enzymatic activities of MMP-2, MMP-9 and uPA, contributing to the inhibition of metastasis of U-2 OS cells. Our results suggest a potential role of kaempferol in the therapy of tumor metastasis of OS.