The Role of Conjugated Linoleic Acid in Breast Cancer Growth and Development

ABSTRACT

Conjugated linoleic acid (CLA) consists of a group of naturally occurring and synthetic positional and geometric (cis-trans) stereoisomers of the polyunsaturated fatty acid linoleic acid. The cis-9,trans-11 (c9,t11) CLA isomer (the most prevalent form found in ruminant-derived foods) and the trans-10,cis-12 (t10,c12) CLA isomer (present in commercial preparations) are the two most widely studied CLA isomers in breast cancer. Studies using both animal and cell culture models indicate that these CLA isomers, when added to the diet or included in the cell culture medium, inhibit mammary tumour initiation, promotion and progression in rodents, and alter tumour cell viability in vitro. The mechanism of CLA’s anticancer effect is not well understood, but may involve interference with the cell cycle, induction of apoptosis, modulation of gene expression via the activation of peroxisome proliferator-activated receptors, lipid peroxidation, modulation of the tumour microenvironment, changes to the structure and/or function of the cell membrane, and interference with growth factor receptor signaling. A greater understanding of the mechanism of action of CLA will support the development of clinical trials to evaluate the potential effectiveness of CLA in the treatment of breast cancer.

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