Anti-metastatic effects of arctigenin are regulated by MAPK/AP-1 signaling in 4T-1 mouse breast cancer cells

Abstract

Arctigenin is a natural lignan that is found in burdock with anti-viral, -oxidative, -inflammatory and anti-tumor activities. In the current study, the effect of arctigenin on metastatic potential was examined in 4T-1 mouse triple-negative breast cancer cells. The results indicated that arctigenin inhibited cell motility and invasiveness, which was determined using wound healing and transwell invasion assays. Arctigenin suppressed matrix metalloprotease-9 (MMP-9) activity via gelatin zymography, and protein expression of cyclooxygenase-2 (COX-2) and MMP-3. Furthermore, arctigenin attenuated the mRNA expression of metastatic factors, including MMP-9, MMP-3 and COX-2. Based on these results, the effect of arctigenin on the mitogen-activated protein kinase (MAPK)/activating protein-1 (AP-1) signaling pathway was assessed in an attempt to identify the regulatory mechanism responsible for its anti-metastatic effects. Arctigenin was demonstrated to inhibit the phosphorylation of extracellular signal-regulated protein kinase (ERK) and c-Jun N-terminal kinase (JNK), and the nuclear translocations of the AP-1 subunits, c-Jun and c-Fos. In summary, the present study demonstrated that in 4T-1 mouse triple-negative breast cancer cells the anti-metastatic effect of arctigenin is mediated by the inhibition of MMP-9 activity and by the inhibition of the metastasis-enhancing factors MMP-9, MMP-3 and COX-2, due to the suppression of the MAPK/AP-1 signaling pathway. The results of the current study demonstrated that arctigenin exhibits a potential for preventing cell migration and invasion in triple negative breast cancer.