Matrix metalloproteinase-9 (MMP-9) plays an important role in the invasion and metastasis of cancer cells. The synthesis and secretion of MMP-9 can be stimulated by a variety of stimuli, including cytokines and phorbol 12-myristate 13-acetate (PMA), during various pathological processes, such as tumor invasion, atherosclerosis, inflammation, and rheumatoid arthritis, whereas MMP-2 is usually expressed constitutively. Delphinidin, an anthocyanidin present in pigmented fruits and vegetables, possesses potent antioxidant, anti-inflammatory, and antiangiogenic properties. In this study, we investigated the antiproliferative and antiinvasive effects of delphinidin on PMA-induced MMP-9 expression in MCF-7 human breast carcinoma cells using zymography, western blotting, reverse transcription-polymerase chain reaction, and Matrigel invasion assay. Delphinidin significantly suppressed PMA-induced MMP-9 protein expression in MCF-7 human breast carcinoma cells, and it also inhibited the MMP-9 gene transcriptional activity by blocking the activation of NFkappaB (NF-κB) through MAPK signaling pathways. Moreover, the Matrigel invasion assay showed that delphinidin reduces PMA-induced cancer cell invasion. These results suggest that delphinidin is a potential antimetastatic agent that suppresses PMA-induced cancer cell invasion through the specific inhibition of NF-κB-dependent MMP-9 gene expression.
Keywords: MCF-7 cells; MMP-9; NFkappaB; delphinidin; phospho-JNK; phospho-p38.