Sarcosine, an N-methyl derivative of the amino acid glycine, can distinguish between slow-growing prostate cancers and those likely to spread and become lethal, playing a major role in cancer detection, according to scientists at the University of Michigan.
Led by Dr. Arun Sreekumar, the study not only proves that sarcosine is a marker of cancer aggressiveness, but also that it is highly associated with tumour development as well.
For the study, the researchers looked at more than 1,000 small molecules in tissues associated with prostate cancer.
It is very easy to identify sarcosine in urine, which is a less invasive test than the blood analysis needed for the standard prostate-specific antigen (PSA).
PSA is a protein produced by the cells of the prostate gland, and is present in small quantities in the serum of healthy men.
It is often elevated in the presence of prostate cancer, and thus invasive biopsy is needed to clarify a diagnosis.
But even when a biopsy reveals cancer, it's not clear if the cancer is aggressive and at risk of spreading, or indolent and likely to stay put.
Instead of looking for genes or proteins, the researchers measured the levels of chemical by-products of the reaction inside the human cells, which are called metabolites.
They analysed 42 tissue samples, 110 blood samples, and the same number of urine samples from patients with advanced prostate cancer, early prostate cancer, and men with benign disease.
It was found that 10 of the chemicals were at much higher levels in prostate cancer than normal samples.
The scientists observed that one of the metabolites stood out-sarcosine.
Dr. Chris Beecher, a colleague of Sreekumar, claimed that the esults were promising
"Sarcosine continues to predict the aggressiveness of the tumours," Nature magazine quoted him as saying.
The metabolomic analysis yielded the observation that sarcosine was highly associated with tumour development. The scientific data support a correlation and provide biological insights.