Inhibitory effects of lycopene on the adhesion, invasion and migration of SK‐Hep1 human hepatoma cells

Abstract

Lycopene, which is the predominant carotenoid in tomatoes and tomato-based foods, may protect humans against various cancers. Effects of lycopene on the adhesion, invasion, migration, and growth of the SK-Hep1 human hepatoma cell line were investigated. Lycopene inhibited cell growth in dose- and time-dependent manners, with growth inhibition rates of 5% and 40% at 0.1 μM and 50 μM lycopene, respectively, after 24 hr of incubation. Similarly, after 48 hr of incubation, lycopene at 5 μM and 10 μM decreased the cell numbers by 30% and 40%, respectively. Lycopene decreased the gelatinolytic activities of both matrix metalloproteinase (MMP)-2 and MMP-9, which were secreted from the SK-Hep1 cells. Incubation of SK-Hep1 cells with 1-10 μM of lycopene for 60 min significantly inhibited cell adhesion to the Matrigel-coated substrate in a concentration-dependent manner. To study invasion, SK-Hep1 cells were grown either on Matrigel-coated Transwell membranes or in 24-well plates. The cells were treated sequentially for 24 hr with lycopene before the start of the invasion assays. Cell growth and death were assessed under the same conditions. The invasion of SK-Hep1 cells treated with lycopene was significantly reduced in comparison with the control. In the migrationassay, lycopene-treated cells showed lower levels of migration than untreated cells. These results demonstrate the anti-metastatic properties of lycopene in inhibiting the adhesion, invasion, and migration of SK-Hep1 human hepatoma cells.