Howard Hughes Medical Institute researchers have identified a new biological marker present in the urine of patients with prostate cancer that indicates whether the cancer is progressing and spreading.

In experiments reported in the February 12, 2009, issue of the journal Nature, the scientists identified 10 metabolites that become more abundant in prostate cells as cancer progresses. Their studies showed that one of these chemicals, sarcosine, helps prostate cancer cells invade surrounding tissue.

HHMI investigator Arul Chinnaiyan and colleagues at the University of Michigan showed that as prostate cancer develops and progresses, sarcosine levels increase in both tumor cells and urine samples, suggesting that measurements of the metabolite could aid in non-invasively diagnosing the disease. Researchers might also be able to inhibit prostate cancer's spread by designing drugs that manipulate the sarcosine pathway.

The study is the first to analyze the levels of more than 1,000 different metabolites in human tumors. Scientists know that cells undergo complex changes as cancer develops and progresses to metastatic disease. Chinnaiyan's lab, which has extensively analyzed how genes and proteins in prostate cancer cells reflect these changes, thought that profiling cells' metabolites would offer an even more "holistic picture of the molecular alterations that occur," he said…