In this study, the team wanted to combine the curcumin with the chemotherapeutic drug Cisplatin, which is very toxic at the doses needed to fight head and neck cancers, damaging kidneys, the ears and the bone marrow. They hoped that if they added curcumin to the mix, they might be able to lower the Cisplatin dose and cause less organ damage. Their finding, that the curcumin made the Cisplatin work better, was very promising, Wang said.

"We knew that both the curcumin and the Cisplatin, when given alone, had an effect against head and neck cancers," Wang said. "This finding that curcumin enhances Cisplatin means that, in the future, we may be able to give this chemotherapy in lower doses."


The study noted that "the mechanisms of the two agents through different growth signaling pathways suggest potential for the clinical use of sub-therapeutic doses of Cisplatin in combination with curcumin, which will allow effective suppression of tumor growth while minimizing the toxic side effects."

The study found that curcumin suppressed head and neck cancer growth by regulating cell cycling, Srivatsan said. It binds to an enzyme and prevents the enzyme IKK, an inhibitor of kappa B kinase, from activating a transcription factor called nuclear factor kappa B (NFκ[<03BA>][<03BA>]B), which promotes cancer growth. Cisplatin's suppressive action involves a different pathway through the tumor suppressor proteins p16 and p53, both proteins that again inhibit the activity of cancer growth promoter NFκ[<03BA>][<03BA>]B.

"We needed to know the mechanism to help us translate this from the lab into the clinic," Wang said. "That information will help us make better decisions on how to design therapies."

The next step in the clinical setting is to give patients oral curcumin prior to surgery and, after surgery, study the excised tumors to determine curcumin's effect on tumor markers, specifically whether there is reduced expression of markers such as growth promoting NFκ[<03BA>][<03BA>]B. They also will be monitoring to determine if the curcumin results in any side effects. After that, the team would give curcumin to patients also getting chemotherapy and radiation to see if the tumor suppression found in the cells lines and mouse models can be replicated in humans.

Although turmeric is used in cooking, the amount of curcumin needed to produce a clinical response is much larger, about 500 milligrams. Expecting a positive effect through eating foods spiced with turmeric is not realistic, the researchers said.

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