Researchers found that curcumin, a compound found in turmeric, the Indian spice that gives curry its orange-yellow colour, may block nicotine from activating cancer causing cells in patients with head and neck cancer who continue to smoke or use nicotine products to help them quit. The researchers hope the findings will help to discover additional therapies for preventing and treating cancer.

The study was presented at the 2009 American Academy of Otolaryngology – Head and Neck Surgery Foundation (AAO-HNSF) Annual Meeting & OTO EXPO, that is taking place in San Diego Convention Center in San Diego, California from 4th to 7th October.

Every year, about 40,000 Americans join the list of diagnosed head and neck cancer cases and 13,000 die of the disease. Recurrence of second primary tumors is high because many patients continue to smoke, or they use nicotine replacement therapy to help them quit, after they have been successfully treated for the disease.

Although nicotine is not thought to cause cancer directly, it is known to encourage the formation of cancer cells, said the researchers.

For the study, the researchers mimicked a clinical situation by pre-treating cultured head and neck squamous cell carcinoma cells (HNSCC) with curcumin and then introducing nicotine. The cancer cells came from a variety of head and neck cancer cell lines developed in the lab.

The result showed that the curcumin was able to stop nicotine from activating the Akt/mTOR pathway, which plays a central role in carcinogenesis: the process where normal cells are transformed into cancer cells.

The researchers found fewer downstream targets of the pathway, resulting in fewer gene products involved in cell growth, proliferation, invasion and angiogenesis (production of a blood supply to the tumor).

They said that this is the first study to show that curcumin is an “exciting nutraceutical” (combination of pharmaceutical and nutrition) with “promising chemopreventive effects in HNSCC” by blocking nicotine-induced activation of the Akt/mTOR pathway.

They concluded that:

“A major cause of lethal progression of HNSCC is local regional migration and invasion of malignant cells, and curcumin significantly inhibited the invasive potential through inhibition of the Akt/mTOR pathway in a variety of HNSCC cell lines.”

“Curcumin Inhibits Nicotine-Induced Activation of HNSCC.”
Presenters: Cherie-Ann O. Nathan, Christopher Smelley, Cheryl Clark, Shivang Shah, Youhua Rong.
AAO-HNSF Annual Meeting & OTO EXPO 2009, San Diego.
Scientific Program Poster: General, poster number SP151.
DOI:10.1016/j.otohns.2009.06.429

Source: American Academy of Otolaryngology.

Written by: Catharine Paddock, PhD