Human kallikrein 6 (zyme/protease M/neurosin): a new serum biomarker of ovarian carcinoma.
BACKGROUND
There is an urgent need for discovery and validation of new serum biomarkers for ovarian carcinoma. Early diagnosis of ovarian cancer with serologic analysis may improve clinical outcomes through administration of effective treatment. Human kallikrein 6 (hK6, encoded by the KLK6 gene) is a serine protease of the kallikrein gene family. Recently, we were able to develop an immunofluorometric procedure for the quantitative measurement of hK6 in biologic fluids, including serum.


METHODS
We have used an hK6-specific immunofluorometric assay to quantify hK6 protein in a large number of serum samples from normal individuals, as well as from patients with various malignancies.


RESULTS
We report for the first time, significant increase of serum hK6 concentration in a large proportion of patients with ovarian carcinoma. The elevations of hK6 appear to be relatively specific for ovarian cancer because other malignancies did not cause any increase in the concentration of this biomarker in serum. Serial hK6 measurements appear to correlate with CA125 levels in patients monitored postsurgery.


CONCLUSIONS
This is the first report describing significant elevations of hK6 concentration in serum of ovarian cancer patients. These data suggest that hK6 may represent a potential new biomarker for diagnosis and monitoring of ovarian carcinoma.
Diamandis
E P
EP
Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada.
Yousef
G M
GM
Soosaipillai
A R
AR
Bunting
P
P
D014408:Biomarkers, Tumor; D018394:CA-125 Antigen / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D005455:Fluorescent Antibody Technique / Q000379:methods; D006801:Humans; D007610:Kallikreins / Q000097:blood* / Q000378:metabolism*; D008297:Male; D009369:Neoplasms / Q000097:blood; D010051:Ovarian Neoplasms / Q000097:blood* / Q000378:metabolism*; D013997:Time Factors
D014408:Biomarkers, Tumor; D018394:CA-125 Antigen; C103551:KLK6 protein, human; D007610:Kallikreins