Human glandular kallikrein 2 (hK2) expression in prostatic intraepithelial neoplasia and adenocarcinoma: A novel prostate cancer marker

doi:10.1016/S0090-4295(97)00108-8

Urology

Volume 49, Issue 6, June 1997, Pages 857-862

https://doi.org/10.1016/S0090-4295(97)00108-8 Get rights and content

Abstract

Objectives. We describe the expression of a potentially new tumor marker, human glandular kallikrein 2 (hK2), that may be useful as an adjunct to prostate-specific antigen (PSA) in the diagnosis and monitoring of prostate cancer.

Methods. We evaluated 257 radical prostatectomy specimens removed at the Mayo Clinic with pathologic Stage T2 adenocarcinoma to compare the cytoplasmic expression of hK2, PSA, and prostatic acid phosphatase (PAP) in benign tissue, high-grade prostatic intraepithelial neoplasia (PIN), and adenocarcinoma. Two monoclonal antibodies, hK2-A523 and hK2-G586, specific for hK2 were used, as well as antibodies against PSA (PSM-773) and PAP (polyclonal).

Results. Intense epithelial cytoplasmic immunoreactivity was observed in every case for hK2-A523, hK2-G586, PSA, and PAP (100% of cases, respectively). The intensity and extent of hK2 expression for both antibodies were greater in cancer than high-grade PIN; furthermore, high-grade PIN was greater than benign epithelium. Cases of Gleason primary grade 4 and 5 cancer showed hK2 staining in almost every cell, whereas there was greater heterogeneity of staining in lower grades of cancer. In marked contrast to hK2, PSA and PAP immunoreactivity was most intense in benign epithelium and stained to a lesser extent in PIN and carcinoma. The number of immunoreactive cells for hK2 and PSA was not predictive of cancer recurrence.

Conclusions. hK2 was expressed in every cancer, and the expression incrementally increased from benign epithelium to high-grade PIN and adenocarcinoma. PSA and PAP displayed inverse immunoreactivity compared with hK2. The expression of hK2 and PSA was not predictive of cancer recurrence in patients with Stage T2 carcinoma. Expression of hK2 indicates that this kallikrein antigen is both prostate localized and tumor associated. Tissue expression of hK2 appears to be regulated independently of PSA and PAP. Further studies are needed to determine whether tissue immunoreactivity of hK2 will prove clinically useful in the diagnosis and monitoring of prostate cancer.

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Citation Excerpt :
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Adult urologyHuman glandular kallikrein 2 (hK2) expression in prostatic intraepithelial neoplasia and adenocarcinoma: A novel prostate cancer marker

Abstract

Urology

Mayo Clin Proc

FEBS Lett

J Urol

Dual monoclonal antibody immunoassay for free prostate-specific antigen

Prostate

Evaluation of percentage of free serum prostate-specific antigen to improve specificity of prostate cancer screening

JAMA

Characterization and evaluation of hK2: a potential prostate cancer marker, closely related to PSA

Detection of a prostate-specific protein, human glandular kallikrein 2 (hK2), in sera of patients with elevated prostate specific antigen levels

Urology

Structure, function and regulation of the enzyme activity of prostate-specific antigen

World J Urol

Tissue-specific and hormonal regulation of human prostate-specific glandular kallikrein

Biochemistry

Adult urology
Human glandular kallikrein 2 (hK2) expression in prostatic intraepithelial neoplasia and adenocarcinoma: A novel prostate cancer marker