Prostein is a novel prostate-specific protein expressed in normal and malignant prostate tissues. This protein appears to be a type IIIa plasma membrane protein with a cleavable signal peptide and 11 transmembrane-spanning regions. Prostein expression is androgen responsive since treatment of LNCaP cells with androgen up-regulates prostein message and protein expression levels. Thus, prostein is a prostate-specific marker whose detection and quantitation may be useful in diagnosing and monitoring prostate cancer.
