Abstract
Kallikrein-related peptidases (KLKs) have been proposed as potential cancer biomarkers. Kallikrein-related peptidase 5 (KLK5) is a secreted trypsin-like protease of the KLKs. Until now, detection of KLK5 in both biological fluids and tissues has been described frequently due to the potential of being a new cancer biomarker. Our objective was to prepare KLK5 antibodies and establish an ELISA method for KLK5 to study the possible clinical application of KLK5 as a biomarker for malignancies. In this study, recombinant KLK5 protein was produced and purified using a prokaryotic expression system, and then used as immunogen to generate antibodies. High titers of specific antibodies were measured in serum of rabbits after the forth booster injection. And the titer of the antiserum reached 1:106. We have also generated monoclonal antibodies using hybridoma technology and the titer reached 1:105. The activity of KLK5 antibodies was characterized by Western blot and immunohistochemistry. To quantitatively examine KLK5 in serum samples, we established double antibody sandwich ELISA method using mouse mAb as capture and rabbit pAb as tracer antibody. We have detected KLK5 levels in ovarian cancer serum to ensure that our sandwich ELISA measurement to have high sensitivity and specificity. The ranges of linearity reached by the standard curves of the newly developed ELISA were 0.45 ng/mL to 125 ng/mL. The detection limit of the method, defined as the concentration of KLK5 can be distinguished, was 0.20 ng/mL. Median serum KLK5 levels were 3.77 ng/mL and 0.86 ng/mL in ovarian cancer patients and normal female, respectively (P ELISA assay for KLK5. Our preliminary findings prompt that KLK5 may be a new potential biomarker for the diagnosis and prognosis in patients with ovarian.
Highlights
The kallikrein family is a group of 15 serine protease genes, which have been mapped on the 19q13.3-4 chromosomal region [1,2,3]
The present study focus on evaluating the Kallikreinrelated peptidase 5 (KLK5) as new serum biomarker in ovarian cancer, which may serve as a screening tool, may allow assessment of prognosis in patients with ovarian cancer and may be as a potential new target for therapy [13,18]
The results showed that KLK5 is significantly elevated in serum of ovarian cancer patients (n = 40) compared with normal female (n = 40, with one sample below detection limit)
Summary
The kallikrein family is a group of 15 serine protease genes, which have been mapped on the 19q13.3-4 chromosomal region [1,2,3]. Each of the family encodes a secreted serine protease, showing significant homologies at both the DNA and the protein level [4]. Human kallikrein-related peptidases are secreted serine protease with trypsin-like or chymotrypsin-like activity. Preproenzymes are induced by other KLKs or nonKLK proteases to become active extracellular enzymes [5]. Most of genes are regulated by steroid hormones and abnormally expressed in hormone-related malignancies [6,7]. A few members of the family are potential cancer biomarkers for diagnostic and prognostic [8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
