June 6, 2011

Fighting Cancer With Cancer?

(Ivanhoe Newswire) -- Mayo Clinic researchers have found a mutant gene, which was long thought to accelerate tumor growth in thyroid cancer patients, actually inhibits the spread of cancerous cells.

Thyroid cancer is the sixth most common cancer in the world. Between 15 percent and 20 percent of all thyroid cancers are follicular, which is a type that is more aggressive. Distinguishing between benign and malignant follicular thyroid cancer is often challenging for doctors because an accurate diagnosis of malignant follicular cancer cannot be made until the cancerous material is removed. This has led to many unnecessary surgeries.

In this new research, investigators found that the PAX8/PPARy fusion protein, developed from a mutated fusion gene found in many follicular thyroid cancers, functions as a tumor suppressor by encouraging the production of microRNA-122 and PTEN, which are both naturally-occurring anti-tumor agents.

In vivo animal studies showed PAX8/PPARy upregulates PTEN as well as microRNA-122. PAX8/PPARy does not boost tumor progression when exposed to cancer cells. Rather, its facilitation of other native anti-cancer molecules appears to outweigh the tumor propagation, according to the researchers. Tumors grew about four-times slower in the mice that were exposed to the PAX8/PPARy gene than those that were deprived of the protein's cancer-fighting qualities.

"There are many complications from thyroid surgery, and having early detection markers could save thousands of unnecessary surgeries every year. We're just getting started and look towards a rapid translation from bench to bedside," Mayo Clinic researcher Honey Reddi, Ph.D., was quoted as saying.

SOURCE: The Endocrine Society Meeting in Boston, June 4, 2011