The hopeful anticancer role of oleuropein in breast cancer through histone deacetylase modulation.

Breast cancer (BC) is one of the most common cancers among women worldwide. Genetic, epigenetic, and environmental factors play a crucial role in BC development. Because epigenetic imbalance occurs earlier than expression in carcinogenesis and is reversible, epigenetic reprogramming strategies could be more useful for cancer prevention and therapy. There is evidence indicating that the use of herbal compounds with low toxicity can offer a real benefit in the prevention or treatment of cancer. Oleuropein (OLE), as a natural polyphenol, has shown the anticancer property in cancers. In this study, we investigated for the first time the link between histone deacetylase (HDAC) and OLE to have an anticancer effect in BC. The potential apoptotic and anti-invasive effects of OLE were tested using MCF-7 cells. Transcript expression of HDAC1 and HDAC4 genes after treatment was determined using quantitative reverse transcription polymerase chain reaction. OLE obviously reduced invasiveness and cell viability and simultaneously induced cell apoptosis in MCF-7 cancer cells. Dose-dependent reduction of HDAC4 was observed, whereas apparent changes could not be observed in HDAC1 expression. The current research indicated that OLE can inhibit proliferation and invasion of cells by inducing apoptosis likely through modulation of an important epigenetic factor, HDAC4, in MCF-7 cells. OLE has the potential to be a therapeutic drug for BC prevention and treatment.