Omega-3, the fatty acid found in oily fish, could be combined with a commonly used anesthetic to develop drugs to treat breast cancer, according to research published today in the journal Breast Cancer Research. Compounds of Omega-3 fatty acids and propofol reduce the ability of breast cancer cells to develop into malignant tumours, inhibiting cancer cell migration by 50% and significantly reducing their metastatic activity. These new compounds could be developed into a new family of anti-cancer drugs.

Dr Rafat Siddiqui, from the Methodist Research Institute and Indiana University in Indianapolis, and his colleagues studied the effect of two Omega-3 fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), combined with propofol on a breast cancer cell line in vitro. Omega-3 fatty acids such as DHA and EPA have a minimal effect on cancer cells when applied alone. Propofol is a potent anti-oxidant known to inhibit cancer cell migration by only 5-10%.

The results of the study show that propofol and DHA or EPA have a much more significant effect on cancer cells when used in combination, as conjugates, than when used alone. The conjugates inhibit cancer cell adhesion by 15% and 30% respectively, reduce cell migration by 50% and increase apoptosis by 40%.

"These results suggest that the novel propofol-DHA and propofol-EPA conjugates reported here may be useful for the treatment of breast cancer" conclude Siddiqui and colleagues.

Malignant cancer cells are highly invasive cells that have lost the ability to sense cues from their environment. As a result, they start dividing abnormally, migrate and accumulate into malignant tumours, in a process called metastasis, which is potentially life-threatening. The aim of anti-cancer drugs is therefore to prevent the cells from dividing abnormally and from spreading, to kill the cells, or to cause the cells to kill themselves.

Fatty acids are often attached to drugs, because they facilitate the absorption of the drugs by the cells. Siddiqui and colleagues explain that DHA and EPA might have had this effect on propofol. They add "It is possible that these conjugates provide a mechanism whereby propofol can be retained in cell membranes for a longer duration and therefore enhance its anticancer effects".

Omega-3 fatty acids, like those found in oily fish such as tuna, salmon, herring, sardines and mackerel, are already known to have many positive health benefits. They are commonly recommended for maintaining a healthy heart, as they are known to reduce cholesterol levels and thought to help prevent cardiovascular disease. Research suggests that Omega-3 may also protect against arthritis, lupus, and asthma and help people with biopolar disorder.

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This press release is based on the article:

Anticancer properties of propofol-docosahexaenoate and propofol-eicosapentaenoate on breast cancer cells
Rafat A Siddiqui1, Mustapha Zerouga, Min Wu, Alicia Castillo, Kevin Harvey, Gary P Zaloga and William Stillwell
Breast Cancer Research 2005, 7:R645-R654 (7 June 2005)