Sarcosine as a Metabolic Biomarker of Prostate Cancer
Sarcosine, an N-methyl derivative of the amino acid glycine, has been identified as a differential metabolite that is elevated during prostate cancer progression to metastasis and can be detected noninvasively in urine (Sreekumar et al. 2009). Sarcosine levels are also increased in invasive prostate cancer cell lines relative to benign prostate epithelial cells. Knockdown of glycine-N-methyl transferase, the enzyme that generates sarcosine from glycine, attenuates prostate cancer invasion. Addition of exogenous sarcosine or knockdown of the enzyme that leads to sarcosine degradation, sarcosine dehydrogenase, induced an invasive phenotype in benign prostate epithelial cells. Androgen receptor and the ERG gene fusion product coordinately regulate components of the sarcosine pathway. Profiling of the metabolomic alterations of prostate cancer progression, has revealed sarcosine as a potentially important metabolic intermediary of cancer cell invasion.