β-Caryophyllene oxide inhibits metastasis by downregulating MMP-2, p-p38 and p-ERK in human fibrosarcoma cells

Abstract

When cancer cells transform into malignant tumors, they gain the ability to ignore growth-inhibiting signals, have endless reproduction potential, resist apoptosis, and induce angiogenesis and invade other tissues. Matrix metalloproteinases (MMPs) allow tumor cells to move into surrounding tissues in many malignancies, but metastasis is blocked by MMPs inhibitors. Therefore, the effect of β-caryophyllene oxide (CPO) contained in Piper nigrum on Mitogen-activated protein kinase (MAPKs) related to MMPs signaling pathways in human fibrosarcoma was examined in HT1080 cells. The effect of CPO on cell viability was performed using the MTT assay. Cytotoxicity was observed in the presence of CPO above 16 μM. Next, gelatin zymography was performed in the cells activated with phorbol-12-myristate-13-acetate (PMA). It was found that CPO at 32 μM reduced MMP-9 activity by 28% and MMP-2 activity by 60%. To confirm the effect of CPO on MMPs, Western blot analyses for MMP-2, MAPKs were carried out in this study. The expression level of MMP-2 was reduced by 45% in the presence of CPO at 32 μM, but those of p-p38 and p-ERK were reduced by 50% and 40%, respectively. CPO decreased the expression levels of MMP-2 and MMP-9 in the immunofluorescence staining assay. Finally, an invasion assay was performed in PMA-treated human fibrosarcoma cells. It was demonstrated that CPO reduced cell invasion of HT1080 cells in a dose-dependent manner starting at a concentration of 2 μM. The above results suggest that CPO could be used as a potential candidate for the treatment of metastasis by inhibiting MMP-2, p-p38 and p-ERK. PRACTICAL APPLICATIONS: Cancer makes it easier for cells to spread to other tissue via blood and lymph systems. Tumor cells deplete nutrients and induce angiogenesis, which penetrates and spreads to other parts of the body. As a result, the effect of CPO against cell invasion was evaluated in this study. CPO reduced cancer cell invasion by inactivating p-ERK and p-p38, according to the findings. MMP-2 and MMP-9 activation and protein expression were also decreased by CPO. As a result, CPO might be used as an alternate treatment agent for preventing metastasis.

Keywords: MAPKs; MMP-2; MMP-9; metastasis; β-Caryophyllene oxide.