Most carotenoids have anti-cancer properties, but the status of lycopene is unclear. Lycopene is a red pigmented carotenoid present in fruits and vegetables such as grapefruit, watermelon and tomatoes. Population studies have reported conflicting findings regarding lycopene and the risk of breast cancer. There is some evidence that lycopene might reduce breast cancer risk for women with high breast density, in particular. Like many other micronutrients, lycopene appears to be most effective when consumed in food along with other micronutrients. Lycopene supplements may not be safe for breast cancer patients and survivors, although the evidence is limited. Now a new study has reported the mechanism of action by which lycopene inhibits proliferation in hormone receptor positive (ER+/PR+) breast cancer cells.

Latest research explains how lycopene inhibits breast cancer proliferation

The study referenced at the beginning of this news article was designed to investigate the mechanism of action by which lycopene inhibits breast cancer cell proliferation. To conduct the study, the authors treated ER+/PR+ MCF-7 breast cancer cells and normal MCF-10 breast cells with various levels (0, 2, 4, 6, 8, and 10 μM) of lycopene for 72 hours. Levels of cell proliferation and changes in protein expression were then measured.

Lycopene was found to inhibit the growth of the breast cancer cells, but not the normal breast cells. Certain proteins in the breast cancer cells responded differently to lycopene compared to the normal cells. Lycopene was shown to modulate cell cycle proteins such as beta tubulin, CK8/18, and CK19, as well as heat shock proteins. The authors conclude that lycopene selectively influences cell cycle and heat shock proteins in MCF-7 breast cancer cells.

Please see our article on what ER+/PR+ breast cancer patients and survivors should eat for more information.