Olive oil suppresses Her-2/neu expression in breast cancer cells

Her-2/neu (Human Epidermal growth factor Receptor 2) is a cell membrane receptor that transduces signals leading to increased growth. Overexpression of Her-2/neu is associated with more aggressive disease, so it is routinely checked for and treated with the monoclonal antibody trastuzumab (Herceptin™). This excellent and often overlooked study published in the Annals of Oncology reveals how olive oil dramatically improves the response to Herceptin™ therapy. Using multiple methods the authors...

"...characterized the effects of exogenous supplementation with OA [oleic acid, the main constituent of olive oil] on the expression of Her-2/neu oncogene, which plays an active role in breast cancer etiology and progression. In addition, we investigated the effects of OA on the efficacy of trastuzumab (Herceptin™)."

What did their data show?

"...a dramatic (up to 46%) reduction of cell surface-associated p185Her-2/neu following treatment...with OA. Indeed, this effect was comparable to that found following exposure to optimal concentrations of trastuzumab... Remarkably, the concurrent exposure to OA and suboptimal concentrations of trastuzumab (5 μg/ml) synergistically down-regulated Her-2/neu expression...Moreover, OA co-exposure synergistically enhanced trastuzumab efficacy towards Her-2/neu overexpressors by promoting DNA fragmentation associated with apoptotic cell death...OA co-exposure significantly enhanced the ability of trastuzumab to inhibit signaling pathways downstream of Her-2/neu..."

That's pretty good for a delicious culinary oil! So the authors conclude:

"These findings demonstrate that OA, the main monounsaturated fatty acid of olive oil, suppresses Her-2/neu overexpression, which, in turn, interacts synergistically with anti-Her-2/neu immunotherapy by promoting apoptotic cell death of breast cancer cells with Her-2/neu oncogene amplification."