A precursor form of prostate-specific antigen is more highly elevated in prostate cancer compared with benign transition zone prostate tissue

Citation
Sd. Mikolajczyk et al., A precursor form of prostate-specific antigen is more highly elevated in prostate cancer compared with benign transition zone prostate tissue, CANCER RES, 60(3), 2000, pp. 756-759
Citations number
28
Categorie Soggetti
Oncology,"Onconogenesis & Cancer Research
Journal title
CANCER RESEARCH
ISSN journal
00085472 → ACNP
Volume
60
Issue
3
Year of publication
2000
Pages
756 - 759
Database
ISI
SICI code
0008-5472(20000201)60:3<756:APFOPA>2.0.ZU;2-8
Abstract
Prostate-specific antigen (PSA) is a widely used serum marker for prostate cancer (PCa), but in the critical diagnostic range of 4-10 ng/ml it has lim ited specificity for distinguishing early PCa from benign prostatic hyperpl asia (BPH), PSA in serum is comprised of a variety of both "free" and "comp lexed" forms that have been used to improve the specificity of PSA for pros tate cancer detection. We previously reported that pro PSA (pPSA), the zymo gen or precursor form of PSA, is a component of free PSA in the serum of PC a patients. In the current study, we examined prostate tissues to understan d the origin and specificity of pPSA, PSA was immune-affinity purified from matched sets of prostate tissues including peripheral zone cancer (PZ-C); peripheral zone noncancer; and benign tissue from the transition zone (TZ), the primary site of BPH within the prostate,We found that pPSA is differen tially elevated in PZ-C, but is largely undetectable in TZ, N-terminal sequ encing revealed that the pPSA was comprised primarily of [-2]pPSA and minor levels of [-4]pPSA, containing pro leader peptides of 2 and 4 amino acids, respectively. The median value of pPSA was 3% in PZ-C and 0% (undetectable ) in TZ (P < 0.0026), No pPSA was detected in 13 of 18 transition zone spec imens (72%), but only 2 of the 18 matched cancer specimens (11%) contained no measurable pPSA, These results demonstrate that pPSA is more highly corr elated with prostate cancer than with BPH, The pPSA in serum may represent a more cancer-specific form of PSA that could help distinguish prostate can cer from BPH.