Omega-3 (n-3) fatty acids inhibit breast and prostate cancer cell growth.

We previously showed that N-acylethanolamine derivatives of n-3 (n-3-NAE) are endocannabinoids, which regulate cancer cell proliferation. These n-3-NAE are synthesised in certain cells/tissues, after supplementing with fatty acids, however, no one has assessed whether and to what extent this occurs in cancer cells.

We determined levels of endogenous n-3-NAEs in hormone sensitive and insensitive prostate and breast cancer cells and subsequent effects on other endocannabinoids (anandamide and 2-arachidonoylglycerol), before and after supplementing with DHA and EPA fatty acids, using HPLC tandem mass spectrometry.

This is the first study reporting that n-3-NAEs are synthesised from their parent n-3 fatty acids in cancer cells, regardless of tumour type, hormone status or the presence of fatty acid amide hydrolase.

This could have important implications for the use of n-3 fatty acids as therapeutic agents in breast and prostate cancers expressing cannabinoid receptors.