Current prostate cancer (PCa) diagnosis based on prostate-specific antigen (PSA) has been gradually losing its credibility over the last decade due to contradictory results in published literature and clinical practice.
Recently, a group of potential PCa biomarkers in urine, particularly sarcosine, was found to increase significantly as the cancer progressed to metastasis. We report a simple, robust, and reproducible CE-ESI-MS/MS method for the determination of sarcosine and other representative potential biomarkers in pooled urine. The pooled urine was obtained from 20 healthy adult volunteers between the ages of 23-30 years old. A solid phase extraction (SPE) technique was optimized for maximum recovery of sarcosine. With no derivatization step, excellent resolution between sarcosine and its isomers (α-alanine and β-alanine) was achieved. A separate non-SPE method was also developed for quantitative determination of highly concentrated urinary metabolites. CE separation was performed on a positively-charged, polyethyleneimine (PEI)-coated capillary using 0.4-2% formic acid in 50% methanol. Precision for intra- and inter-day standard addition calibration of sarcosine were found to be within 15%, whereas intra-day precisions for the rest of the metabolites varied from 0.03 to 13.4%. Acceptable intra-day and inter-day accuracies, ranging from 80 to 124%, were obtained for sarcosine and the other metabolites.
Written by:
Soliman LC, Hui Y, Hewavitharana AK, Chen DD. Are you the author?
Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada.
Reference: J Chromatogr A. 2012 Jul 14. Epub ahead of print.
doi: 10.1016/j.chroma.2012.07.021
PubMed Abstract
PMID: 22824219
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