Glypican-1 as a Biomarker for Prostate Cancer: Isolation and Characterization

• Published in: Journal of Cancer Vol. 7; no. 8; pp. 1002 - 1009
• Main Authors: Truong, Quach, Justiniano, Irene O, Nocon, Aline L, Soon, Julie T, Wissmueller, Sandra, Campbell, Douglas H, Walsh, Bradley J
• Format: Journal Article
• Language: English
• Published: Australia Ivyspring International Publisher 01.01.2016
• Subjects: Research Paper; Proteoglycan; Prostate Cancer; Glypican 1; Theranostic
• DOI: 10.7150/jca.14645
• ISSN: 1837-9664

Prostate cancer is the most frequently diagnosed male visceral cancer and the second leading cause of cancer death in the United States. Standard tests such as prostate-specific antigen (PSA) measurement have poor specificity (33%) resulting in a high number of false positive reports. Consequently there is a need for new biomarkers to address this problem. The MIL-38 antibody was first described nearly thirty years ago, however, until now, the identification of the target antigen remained elusive. By a series of molecular techniques and mass spectrometry, the MIL-38 antigen was identified to be the highly glycosylated proteoglycan Glypican-1 (GPC-1). This protein is present in two forms; a membrane bound core protein of 55-60 kDa and secreted soluble forms of 40 kDa and 52 kDa. GPC-1 identification was confirmed by immuno-precipitation, western blots and ELISA. An ELISA platform is currently being developed to assess the levels of GPC-1 in normal, benign prostatic hyperplasia (BPH) and prostate cancer patients to determine whether secreted GPC-1 may represent a clinically relevant biomarker for prostate cancer diagnosis.