Quantitative expression of the human kallikrein gene 9 (KLK9) in ovarian cancer: a new independent and favorable prognostic marker.
Cancer Res. 2001 Nov 01; 61(21):7811-8.CR

Abstract

Many members of the human kallikrein gene family were found to be differentially expressed in various malignancies and some are useful cancer diagnostic/prognostic markers. KLK9 is a newly discovered human kallikrein gene that is expressed in several tissues including thymus, testis, spinal cord, salivary gland, ovary, and skin. Like other kallikreins, the KLK9 gene was found to be regulated by steroid hormones in cancer cell lines. Our purpose is to examine whether quantitative analysis of KLK9 expression has prognostic value in ovarian cancer. We studied the expression of KLK9 by quantitative reverse transcription-PCR in 168 consecutive ovarian tumors of different stages, grades, and histological types, and correlated the expression with clinicopathological parameters, response to chemotherapy, and patients' survival. We found that KLK9 expression was significantly higher in patients with early disease stages (I or II; P = 0.044) and in patients with optimal debulking (P = 0.019). Kaplan-Meier survival curves demonstrated that patients with KLK9-positive tumors have substantially longer progression-free and overall survival (P < 0.001 and P = 0.016, respectively). When the Cox proportional hazard regression analysis was applied to subgroups of patients, KLK9 expression was found to be a significant predictor of progression-free survival in the subgroup of patients with low-grade tumors [hazard ratio (HR), 0.13; P = 0.0015], early stage (HR, 0.099; P = 0.031); and those with optimal debulking (HR, 0.26; P = 0.012). After adjusting for other known prognostic variables, KLK9 retained its independent prognostic value in all of these subgroups of patients. A negative correlation was found between the expression levels of CA125 and KLK9 (rs, 0.350; P = 0.002). Our results indicate that KLK9 is under steroid hormone regulation in ovarian and breast cancer cell lines. Immmunohistochemically, human kallikrein protein (hK9) was localized in the cytoplasm, but not in the nuclei, of the epithelial cells of ovarian cancer tissues. We conclude that KLK9 is a potential new independent favorable prognostic marker for early stage, low-grade, optimally debulked ovarian cancer patients.

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Authors+Show Affiliations

Yousef GM
Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada.
Kyriakopoulou LG
No affiliation info available
Scorilas A
No affiliation info available
Fracchioli S
No affiliation info available
Ghiringhello B
No affiliation info available
Zarghooni M
No affiliation info available
Chang A
No affiliation info available
Diamandis M
No affiliation info available
Giardina G
No affiliation info available
Hartwick WJ
No affiliation info available
Richiardi G
No affiliation info available
Massobrio M
No affiliation info available
Diamandis EP
No affiliation info available
Katsaros D
No affiliation info available

MeSH

AdultAgedAged, 80 and overAnalysis of VarianceBiomarkers, TumorEstrogensFemaleGene Expression Regulation, NeoplasticHumansImmunohistochemistryKallikreinsMiddle AgedNeoplasm ProteinsNeoplasm StagingOvarian NeoplasmsProgestinsPrognosisSurvival RateUp-Regulation

Pub Type(s)

Journal Article

Language

eng

PubMed ID

11691797