Prostate Secretory Protein 94 (PSP94) Human ELISA

Summary

PSP94 (prostatic secretory protein-94), also known as β-microseminoprotein or prostatic inhibin-like protein, is a small, nonglycosylated peptide consisting of 94 amino acids with molecular mass 10.7 kDa, and is one of the major secretory proteins of the prostate glands. PSP94 is synthesized as a preprotein of 114 amino acid residues, from which a 20-residue signal peptide is cleaved off to form the mature protein. PSP94 along with PSA (Prostate-specific Antigen) and PAP (Prostate Acid Phosphatase) are the three most abundant proteins in seminal fluid. As with other prostate-secreted proteins, PSP94 can leak into the blood upon benign or malignant prostate epithelial disruption and can be measured within serum. PSP94 is not solely synthethized by the prostate epithelium, as the protein can also be detected in nonreproductive organs such as in the respiratory and gastrointestinal tracts, where the gastric mucosa particularly shows high expression. Accordingly, PSP94 can be measured in serum of both men and women, but the levels in serum from women were found to be around two-thirds of those measured in men. PSP94 forms high-affinity complex with two related Cys-rich proteins: PSP94-binding protein in blood plasma and cysteine-rich secretory protein 3 (CRISP-3) in semen. PSP94 has postulated systemic function including growth regulation and induction of apoptosis in prostate cancer cells in vitro and in vivo, and regulation of calcium levels during hypercalcemia secondary to malignancy. Several studies have demonstrated a progressive decrease in PSP94 expression as prostate cancer progresses from a hormone-dependent to a hormone-independent state with complete lack of PSP94 production in highly advanced metastatic prostate cancer. This differential expression could make PSP94 a prognostic clinical marker for prostate cancer and could help distinguish patients with aggressive forms of prostate cancer. In a recent study demonstrated a close correlation between PSP94 in serum and seminal plasma, which supports the potential use of PSP94 as a serum marker of prostate secretory function as well.

Research topic

Oncology, Reproduction

Assay format

Sandwich ELISA, Biotin-labelled antibody

Applications

Plasma-Citrate, Plasma-EDTA, Plasma-Heparin, Serum

Sample requirements

50 µl/ well

Calibration Curve

Calibration range

0.5 – 16 ng/ml

Limit of detection

0.12 ng/ml

Intra-assay

CV = 6,5%

Inter-assay

CV = 4,7%

Spiking Recovery

94,4%

Dilution Linearity

104,2%

Cross-Reactivity

References to summary

• Daigneault L, Panchal C, Dulude H, Reeves JR, Ramnani DM. Prognostic value of prostate secretory protein of 94 amino acids and its binding protein after radical prostatectomy. Clin Cancer Res. 2006 Oct 15;12 (20 Pt 1):6018-22
• Giwercman A, Lilja H, Fernlund P, Savblom C, Valtonen-Andre C, Lundwall A. Beta-microseminoprotein in serum correlates with the levels in seminal plasma of young, healthy males. J Androl. 2008 May-Jun;29 (3):330-7
• Murne A, Lilja H, Fernlund P, Bjork T, Andersson C, Abrahamsson PA, Weiber H. Radioimmunoassay of beta-microseminoprotein, a prostatic-secreted protein present in sera of both men and women. Clin Chem. 1989 Jul;35 (7):1497-503
• Narod SA, Jewett MA, Sugar L, Panchal C, Daigneault L, Emami M, Trachtenberg J, Dulude H, Toi A, Reeves JR, Nam RK. A novel serum marker, total prostate secretory protein of 94 amino acids, improves prostate cancer detection and helps identify high grade cancers at diagnosis. J Urol. 2006 Apr;175 (4):1291-7
• Reuter VE, Lilja H, Vickers AJ, Gerald WL, Udby L, Fine SW, Eggener SE, Eastham JA, Serio AM, Al-Ahmadie H, Bjartell AS, Scardino PT. Association of cysteine-rich secretory protein 3 and beta-microseminoprotein with outcome after radical prostatectomy. Clin Cancer Res. 2007 Jul 15;13 (14):4130-8
• Schroder FH. Prostate specific antigen and other markers for prostate cancer. J Urol. 2006 Apr;175 (4):1199-200
• Weiber H, Anderson Ch, Murne A, Rannevic G, Lindstrom C, Lilja H, Fernlund P. β Microseminoprotein is not a prostate-specific protein. American Journal of Pathology. 1990 ;137 (3):593-602

By research topic:

• Oncology
• Reproduction

By molecule:

• Prostate Secretory protein 94 (PSP94)

Registration form