[Identification of low-molecular weight prostate-specific antigen(PSA) and lactoferrin in the prostatic secretion of benign prostatic hyperplasia].
OBJECTIVE
To investigate the expression of low-molecular-weight PSA(lw-PSA) and lactoferrin in the expressed prostatic secretion (EPS) from both benign prostatic hyperplasia (BPH) and normal prostate.


METHODS
Forty human EPS samples obtained from 20 BPH patients and 20 normal males were subjected to two-dimensional gel electrophoresis (2-DE). Mass spectrometry was performed to confirm the nature of the secreted proteins in EPS.


RESULTS
One uniquely expressed protein in BPH was detected and mass spectrometry determined its nature as lw-PSA (molecular weight 10x10(3), pI 8.5-9.3). More importantly, Western blotting analysis also revealed that lw-PSA detected in BPH-EPS, but was undetectable in BPH-free EPS. In addition, up-regulation of Lactoferrin (molecular weight 35x10(3), pI 7-7.5) in BPH-EPS, as compared with BPH-free EPS, was also observed. More interestingly, lactoferrin was absent in prostate cancer tissues.


CONCLUSIONS
Our results indicate lw-PSA may be produced specifically by BPH epithelium and it has a potential to be used as a specific biological marker for the diagnosis of BPH. In addition, benign prostatic epithelium can produce more lactoferrin while prostate cancer tissues go without its lactoferrin secretion.
Xu
Ke-xin
KX
Department of Urology, Peking University People's Hospital, Beijing 100044, China. cavinx@hotmail.com
Wang
Xiao-feng
XF
D000368:Aged; D015415:Biomarkers / Q000032:analysis; D015153:Blotting, Western; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D007781:Lactoferrin / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D011467:Prostate / Q000378:metabolism* / Q000473:pathology; D017430:Prostate-Specific Antigen / Q000032:analysis* / Q000737:chemistry; D011470:Prostatic Hyperplasia / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization
D015415:Biomarkers; D007781:Lactoferrin; D017430:Prostate-Specific Antigen