Prostein, p501s

Prostein is a prostate-specific marker that is expressed in the cytoplasm of benign and malignant prostatic glandular cells. Prostein is a 553 amino acid protein which contains 11 potential transmembrane spanning domains2. It has not been detected in any other normal or malignant tissues3. There is no correlation between prostein gene expression and the prostatic carcinoma Gleason score. Further, no gross difference in the level of protein expression between primary and metastatic prostatic carcinomas is observed.

Immunohistochemical expression

Staining is granular in a perinuclear distribution identified with the Golgi aparatus.


Normal prostate



prostatic hyperplasia


high-grade prostatic intraepithelial neoplasia


acinar type prostatic adenocarcinoma

94% of 135 cases1

metastatic adenocarcinoma of prostate



Diagnostic utility


1 Yin M, Dhir R,Parwani AV Diagnostic utility of p501s (prostein) in comparison to prostate specific antigen (PSA) for the detection of metastatic prostatic adenocarcinoma. Diagn Pathol 2007; 2:41 FULL TEXT

2 Xu J, Kalos M, Stolk JA, et al. Identification and characterization of prostein, a novel prostate-specific protein. Cancer Res 2001; 61:1563-8 FULL TEXT

3 Kalos M, Askaa J, Hylander BL, et al. Prostein expression is highly restricted to normal and malignant prostate tissues. Prostate 2004; 60:246-56

This page last revised 17.5.2008.

5SMUHT/PW Bishop