Gamma-linolenic acid (GLA), a substance in evening primrose oil and borage oil, inhibits the action of Her-2/neu, a cancer gene that is responsible for almost 30% of all breast cancers, Northwestern University researchers report.

“Breast cancer patients with Her-2/neu-positive tumours have an aggressive form of the disease and a poor prognosis,” said researcher Ruth Lupu, who led the study.

Lupu and co-investigator Javier Menendez showed that treating cancer cells that overexpressed Her-2/neu with GLA not only suppressed the gene, but also caused a 30- to 40-fold increased response in breast cancer cells to a common breast cancer drug (Herceptin or trastuzumab).

“In our tests, treating the cancer cell lines with both GLA and Herceptin led to a synergistic increase in apoptosis [cell death] and reduced cancer growth.”

GLA exerts selective toxic effects on cancer cells without affecting normal cells. Menendez’s earlier research showed that supplementation with GLA also sensitizes breast cancer cells to some chemotherapeutic drugs.

Northwestern University, Nov 1, 2005