EMORY RESEARCHER STUDIES COMMON SPICE AND A DECREASE IN SKIN, COLON CANCER

An Emory Univesity researcher is exploring the link between a spice commonly found in Indian food and a lower incidence of skin and colon cancer.

When Jack Arbiser, M.D., Ph.D, assistant professor of dermatology, first picked up the spice turmeric in a local farmer's market, he was interested in the yellow substance found in the middle of the root. After some research, he learned the substance, called curcumin, has been found to prevent skin and colon cancer in mice.

What led researchers to look for this link was the fact that in the country where the spice is most used, India, the incidence of skin and colon cancers is very low. What research had not found by the time Dr. Arbiser became interested in curcumin is why it prevents these cancers and whether the results in mice could be replicated in humans.

Dr. Arbiser began his own research into the properties of curcumin while working with renowned cancer researcher Judah Folkman at Harvard. Through animal trials, Dr. Arbiser and his team found that curcumin acts as an antiangiogenic agent, meaning it stops or prevents the production of blood vessels that feed tumors.

"We showed that curcumin inhibits blood vessel growth and that's at least part of its affect on cancer," Arbiser said.

In cancerous tissue, tumors cannot grow beyond the size of a pinhead or spread to other parts of the body without the development of new blood vessels. Endothelial cells, the cells that form the walls of blood vessels, are the source of new blood vessels.

Endothelial cells normally lie dormant until needed, as after an injury or during pregnancy. At that point short bursts of blood vessel growth occur in localized parts of tissues. Curcumin was found to inhibit endothelial cell growth, preventing new blood vessels from forming.

As a dermatologist, Dr. Arbiser is especially interested in investigating the role curcumin plays in decreasing the incidence of skin cancers as well as other skin diseases. He is planning clinical trials that he expects to get underway within the year. One will focus on recessive dystrophic epidermolysis bullosa. Patients with this disease, in which the epidermis, or outer layer of skin, does not adhere to the next layer, or dermis, have constant itching and blistering. These patients also are highly susceptible to squamous cell carcinoma. Dr. Arbiser has developed a curcumin cream and plans to use it to treat these patients. The short term goal of the study will be to prevent the constant itching and the long term goal will be to prevent the development of skin cancer.

"By showing that curcumin can lower the incidence of squamous cell carcinoma in these patients, then we can start to look at its use in other patient populations and with other types of skin cancer and skin disease," Dr. Arbiser says. "This is something that could be as a preventive agent, just as we prevent cavities by putting flouride in the water."