Human lung tumors have the ability to eliminate Vitamin D, a hormone with anti-cancer activity, a new study from the University of Pittsburgh Cancer Institute (UPCI) suggests. Results of the study, Abstract Number 2402, are being presented at the 100th annual meeting of the American Association for Cancer Research (AACR), April 18 to 22, in Denver.

"High levels of Vitamin D help the body produce proteins with anti-tumor activity," explained principal investigator Pamela Hershberger, Ph.D., a research assistant professor in UPCI's Department of Pharmacology and Chemical Biology. "We've discovered that lung cancer cells make an enzyme called CYP24, which counteracts the positive effects of Vitamin D. To better study it, we developed the first radioactive-free assay that measures the amount of Vitamin D in tissues and blood."

According to Dr. Hershberger, this test is sensitive enough to have clinical potential. "We hope this new assay will help identify the best approaches to maintain therapeutic levels of Vitamin D in tissues," she said.

Lung cancer is the leading cause of cancer death in the United States in both men and women, killing 160,000 people annually, and remains one of the most difficult cancers to treat. The five-year survival rate remains low, and better treatments are much needed. According to Dr. Hershberger, it is possible that one day Vitamin D could be used as a chemopreventive agent to improve patient outcomes.

This study was supported by UPCI's Lung Cancer Specialized Program of Research Excellence.