Pinolenic acid inhibits human breast cancer MDA-MB-231 cell metastasis in vitro

Pinolenic acid (PNA), a naturally-occurring polyunsaturated fatty acid (PUFA), is found mainly in pine seeds. Although many studies have demonstrated beneficial effects of pine seed oil, there are no reports of the biological effects of PNA on cancer metastasis. The objective of this study was to investigate the effect of PNA on human breast cancer MDA-MB-231 cell proliferation and metastasis in vitro. We found that PNA did not affect cell viability and cell-matrix adhesion, but it inhibited cell metastasis by suppressing cell invasiveness and motility. Suppression could in part be associated with the modification of the n−6 PUFA composition of cells by PNA which significantly decreased the percentage of arachidonic acid (AA) in phospholipids from 12.6% to 4.9%. The lower AA content of the cancer cells might result in less synthesis of prostaglandin E2 (PGE2), and subsequent down-regulation of inducible cyclooxygenase (COX-2) expression. Thus, PNA represents a potential anti-cancer agent.