Human Kallikrein Gene 11 (KLK11) Mrna Overexpression Is Associated with Poor Prognosis in Patients with Epithelial Ovarian Cancer

2766 Vol. 10, 2766–2770, April 15, 2004 Clinical Cancer Research

Human Kallikrein Gene 11 (KLK11) mRNA Overexpression Is Associated with Poor Prognosis in Patients with Epithelial Ovarian Cancer

0.0225 ؍ Kazushi Shigemasa,1 Lijun Gu,1 significantly associated with overall survival (P ؍ Hirotoshi Tanimoto,2 Timothy J. O’Brien,3 and and P 0.0202, respectively) after multivariate analysis. Conclusions: KLK11 expression may play an important Koso Ohama1 role in ovarian cancer development and act as an independ- 1 Department of Obstetrics and Gynecology, Hiroshima University ent prognostic marker in ovarian cancer patients. Graduate School of Biomedical Sciences, Hiroshima, Japan; 2Department of Gynecology, National Hiroshima Hospital, Higashi Hiroshima, Japan; and 3Departments of Biochemistry and Molecular INTRODUCTION Biology and Obstetrics and Gynecology, University of Arkansas for Serine proteases comprise a family of protein-degrading Medical Sciences, Little Rock, Arkansas enzymes that serve a variety of biological functions, including induction of blood coagulation, activation of growth and angio- ABSTRACT genic factors, and degradation of extracellular matrix compo- nents (1–4). Purpose: The purpose of this study was to examine The human kallikrein gene family, a subfamily of serine expression levels of the human tissue kallikrein 11 gene proteases, is located at the chromosomal locus 19q13.3-q13.4. (KLK11) in epithelial ovarian tumors and to identify the Until recently, this family was thought to include only three relationship between KLK11 expression and patient sur- genes, the pancreatic renal kallikrein gene (KLK1), the human vival. glandular kallikrein gene (KLK2), and KLK3, which encodes Experimental Design: KLK11 mRNA expression was prostate-specific antigen (hK3). However, in the past few years examined by semiquantitative PCR in 64 epithelial ovarian several groups have reported the cloning of new serine proteases tumors (7 adenomas, 6 low malignant potential tumors, and that colocalized with and were homologous to the three known 51 adenocarcinomas) and in 10 normal ovaries. Semiquan- kallikreins, such that 15 members of human kallikrein gene titative PCR results were correlated with clinicopathologic family are now recognized (5, 6). KLKs share many common variables and overall survival. cDNA from human normal structural features, and a universal nomenclature for KLK struc- tissues and tumor tissues was also analyzed. ture has been established (7). There is now growing evidence Results: KLK11 mRNA expression was detected in var- that KLKs are involved in human malignancies. Prostate- ious human cancer tissues including breast, lung, colon, specific antigen (hK3) has been used successfully as a tumor prostate, pancreas, and ovarian carcinoma. The mean value marker for the early detection of prostate cancer due to its of relative KLK11 expression ratio was significantly higher abnormal prevalence in the peripheral blood of affected patients in ovarian tumor samples than in normal ovary samples (8). Prostate-specific antigen (hK3) is also recognized as a low favorable prognostic factor for breast cancer (9, 10). Recent ;0.0006 ؍ compared with normal samples: adenoma, P) -and carcinoma, P < reports have suggested that hK2 could be another useful diag ;0.0049 ؍ malignant potential tumor, P 0.0001). No statistically significant associations between nostic marker for prostate cancer (11, 12). We reported previ- KLK11 mRNA expression level and clinical stage, histologi- ously that protease M (KLK6) is highly overexpressed in ovarian cal type, or histological grade were observed. The log-rank tumors (13) and that the stratum corneum chymotryptic enzyme test showed that high KLK11 mRNA expression and ad- (KLK7) is expressed at abnormally high levels in ovarian cancer vanced clinical stage significantly correlated with poor pa- (14). We also reported the cloning of tumor-associated differ- respectively). entially expressed gene-14 (TADG-14; KLK8), a novel serine ,0.0043 ؍ and P 0.0185 ؍ tient survival (P High KLK11 mRNA expression and clinical stage remained protease overexpressed in ovarian cancer (15). In addition, hK6, hK10, and hK11 have been shown to be potential serum biomarkers in ovarian cancer (16–19). The KLK11 gene was originally cloned from human hip- pocampus cDNA, using PCR with primers targeted to conserved Received 9/23/03; revised 11/25/03; accepted 12/01/03. serine protease regions, and was originally named trypsin-like Grant support: Tsuchiya Medical Research Foundation, Japan. serine protease (20). With the newly established kallikrein gene The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked nomenclature, this gene was renamed as KLK11 (7). KLK11 advertisement in accordance with 18 U.S.C. Section 1734 solely to mRNA expression has been demonstrated in many tissues, in- indicate this fact. cluding brain, skin, salivary gland, stomach, prostate, and intes- Requests for reprints: Kazushi Shigemasa, Department of Obstet- tine (21). Diamandis et al. (19) have developed an immunoflu- rics and Gynecology, Hiroshima University Graduate School of Biomedical Sciences, 1-2-3, Kasumi, Minami-ku, Hiroshima 734- orometric procedure for measuring hK11 in biological fluids 8551, Japan. Phone: 81-82-257-5262; Fax: 81-82-257-5264; E-mail: and tissue extracts. They reported that elevated serum levels of [email protected]. hK11 were found in 70% of women with ovarian cancer and in

60% of men with prostate cancer, which suggested that hK11 Semiquantitative PCR. Extraction of mRNA from ovar- may be of potential value as an ovarian and prostate cancer ian tissue specimens and cDNA synthesis were carried out biomarker (19). In addition, a recently published article by according to methods described previously (25–28). mRNA was Borgon˜o et al. (22) reported that higher hK11 concentration in isolated using a RiboSep mRNA isolation kit (Becton Dickinson ovarian tumor cytosolic extract is a marker of favorable prog- Labware, Bedford, MA) and the amount of mRNA recovered nosis in patients with ovarian cancer. measured using a UV spectrophotometer. cDNA was synthe- The aim of the present study was to determine the potential sized from 2.0 ␮g mRNA by random hexamer priming using the role of KLK11 mRNA expression in ovarian cancer develop- Advantage RT-for-PCR kit (Clontech). ment and/or progression. KLK11 mRNA expression in various KLK11 mRNA expression levels were determined by semi- normal and cancer tissues was investigated by the application of quantitative PCR, which was performed according to a method semiquantitative PCR to samples of epithelial ovarian tumors described previously with some modifications (25–28). The oligo- and normal ovaries. The results were analyzed in terms of tumor nucleotide primer sequences used for PCR were KLK11 sense type, clinical stage, histological grade, and histological type. primer, 5Ј-CCG CTA CAT AGT TCA CCT GG-3Ј; and KLK11 The prognostic significance of KLK11 mRNA expression level antisense primer, 5Ј-AGG TGT GAG GCA GGC GTA ACT-3Ј. in ovarian cancer patients was also analyzed. ␤-Tubulin cDNA was coamplified with target sequence and used as an internal PCR control. The ␤-tubulin sense primer was 5Ј- TGC ATT GAC AAC GAG GC-3Ј, and the antisense primer was MATERIALS AND METHODS 5Ј-CTG TCT TGA CAT TGT TG-3Ј. The predicted sizes of the Tissue Samples and Clinical and Pathological Data. amplified genes were 284 bp for KLK11 and 454 bp for ␤-tubulin. For semiquantitative PCR analysis, fresh surgical epithelial Thirty cycles of PCR were carried out in a Thermal Cycler (Perkin- ovarian tumor tissue samples were collected from 64 patients Elmer, Foster City, CA). Each PCR cycle involved 30-s denatur- treated surgically between 1993 and 2001. Patients were diag- ation at 94°C, 60-s primer annealing at 60°C, and 60-s extension at nosed histologically and received follow-up care in the Depart- 72°C. We confirmed that amplification under these conditions ment of Obstetrics and Gynecology at Hiroshima University resulted in the linear production of each product. Tubes containing Hospital. In addition, 10 normal ovaries were obtained from all of the ingredients except templates were included in all of the patients before undergoing surgery for benign gynecological runs as a negative control. PCR products were separated on 2.0% disease. Informed consent was obtained from each subject ac- agarose gels, and the density of each PCR product determined cording to institutional guidelines. Specimens were obtained using a Printgraph-Densitograph system (ATTO Corp., Tokyo, immediately after surgery and were cut in half, with one half Japan). The expression ratio of KLK11:␤-tubulin was measured by processed for histological examination to determine the percent- densitometry to evaluate gene expression and the results expressed age of tumor cells, which was never Ͻ80%, whereas the other as the mean Ϯ SD. Differences in the mean value of the KLK11 half was used for mRNA preparation. Tissues were frozen in expression ratio between groups were assessed with respect to liquid nitrogen and stored at Ϫ80°C before mRNA isolation. tumor type, clinical stage, histological grade, and histological type. The histological subtype of each ovarian tumor sample was In addition, in ovarian cancer cases, cases were classified into the diagnosed according to accepted criteria (23). The primary following two groups according to the KLK11 expression ratio, pathological diagnoses were adenocarcinoma for 51 patients (26 low-expression cases, Ͻmedian value; and high-expression cases, serous, 10 mucinous, 8 endometrioid, and 7 clear cell), low Ͼmedian value. A Kaplan-Meier survival curve of ovarian cancer malignant potential tumor for 6 patients (3 serous and 3 muci- patients was categorized according to the high or low KLK11 nous), and adenoma for 7 patients (2 serous and 5 mucinous). expression. All of the adenocarcinoma patients underwent complete surgical Statistical Analysis. For statistical analysis, an unpaired t staging to exclude the presence of occult metastatic disease. test was used to assess the differences in mean values of KLK11: Clinical staging was determined in accordance with the criteria ␤-tubulin mRNA expression ratios between groups. Statistically of the International Federation of Gynecology and Obstetrics significant differences in overall survival rates were determined staging system (24). Initial disease diagnoses were stage I for 21 using the log-rank test. Overall survival time was defined as the patients, stage II for 4 patients, stage III for 23 patients, and period between the time of initial surgery and time of death. stage IV for 3 patients. Although most patients with stage Ic, Survival times of patients who were still alive were noted along stage II, stage III, or stage IV ovarian cancer had received with the date of the last follow-up appointment. For multivariate cisplatin-containing chemotherapy after surgery, none of the analyses, we used the Cox proportional hazards model. All of the patients had received chemotherapy before surgery. The mean Ps quoted are two-sided. Significance was defined as P Ͻ 0.05. follow-up time was 45.0 months (range, 1.7–112.7 months), The Statview 5 program (Abacus Concepts, Inc., Berkeley, CA) with 80% of the patients followed for Ͼ2 years. was used to perform all of the statistical analyses. Normal human tissue cDNA from heart, brain, placenta, lung, liver, skeletal muscle, kidney, pancreas, spleen, thymus, prostate, testis, ovary, small intestine, colon, and peripheral blood leuko- RESULTS cytes, and human tumor tissue cDNA from breast carcinoma, lung KLK11 mRNA Expression in Normal Adult Human carcinoma, colon carcinoma, prostate carcinoma, pancreas carci- Tissues and Human Tumor Tissues. Fig. 1A shows the noma, and ovarian carcinoma (Multiple Tissue cDNA Panels; KLK11 mRNA expression pattern in normal adult tissues. K1420–1, K1421–1, and K-1422–1; Clontech, Palo Alto, CA) KLK11 mRNA expression was detected in normal adult heart, were included in the semiquantitative PCR analysis. brain, lung, liver, skeletal muscle, kidney, pancreas, spleen,

versus grade 2/3), and KLK11 mRNA expression status for overall survival of ovarian cancer patients is summarized in Table 2. The log-rank test revealed that advanced clinical stage was significantly correlated with poor patient survival (P ϭ 0.0043), whereas histological grade was not correlated with patient survival (P ϭ 0.2791). When ovarian cancer patients were categorized along a Kaplan-Meier survival curve according to low versus high expression of KLK11, a statistically significant association between high KLK11 mRNA expression levels and poor patient survival was observed (P ϭ 0.0185; Table 2; Fig. 3). Multivariate analysis was performed using representative parameters as listed in Table 2, with clinical stage (stage I versus stage II/III/IV) and KLK11 expression status (low versus high) selected as covariables (Table 3). Both clinical stage and KLK11 expression were identified as significant and independent variables (clinical stage, P ϭ 0.0202; KLK11 expression, P ϭ 0.0225). High KLK11 mRNA expression yielded a hazard ratio of 3.907, with a 95% confidence interval ranging from 1.212 to 12.594. Fig. 1 A, expression pattern of KLK11 mRNA in normal adult tissues. KLK11 mRNA expression was detected in normal adult heart, brain, DISCUSSION lung, liver, skeletal muscle, kidney, pancreas, spleen, thymus, prostate, A previous study has already documented the expression of testis, and colon. B, KLK11 mRNA expression was observed in all types of human cancer examined, including breast, lung, colon, prostate, hK11 in the serum of patients with prostate or ovarian primary pancreas, and ovarian carcinoma. cancers (19). The present study showed that KLK11 mRNA was expressed by a wide variety of human cancer tissues, including breast, lung, colon, prostate, pancreas, and ovarian carcinoma. It should be stressed that our study found that KLK11 mRNA thymus, prostate, testis, and colon. Other normal tissues, including normal placenta, ovary, small intestine, and peripheral blood leukocytes did not express KLK11 mRNA. Fig. 1B shows KLK11 mRNA expression in various human cancer tissues. KLK11 mRNA expression was observed in all types of human cancer examined, including breast, lung, colon, prostate, pancreas, and ovarian carcinoma. KLK11 mRNA Expression in Normal Ovaries and Ovarian Tumors. To evaluate KLK11 expression in ovarian tumors and normal ovaries, we performed semiquantitative PCR. Typical semiquantitative PCR results are shown in Fig. 2A, and ratios of KLK11 mRNA expression relative to ␤-tubulin in ovarian tumors and normal ovaries are shown in Fig. 2B. Means and SD of KLK11 mRNA expression ratios determined for various tumor subtypes are shown in Table 1. The KLK11: ␤-tubulin expression ratio (mean Ϯ SD) was 0.25 Ϯ 0.24 for normal ovaries, 1.25 Ϯ 0.67 for ovarian adenomas, 1.92 Ϯ 1.58 for ovarian low malignant potential tumors, and 1.96 Ϯ 1.07 for ovarian adenocarcinomas. Thus, mean relative KLK11 expression ratios in adenomas, in low malignant potential tumors, and in adenocarcinomas were significantly higher than that in normal ovaries (compared with normal ovaries: adenoma, P ϭ 0.0006; low malignant potential tumor, P ϭ 0.0049; and adenocarcinoma, P Ͻ 0.0001). Mean and SD of KLK11 expression ratios determined for the various ovarian adenocarcinoma subtypes are also shown in Table 1. There were no statistical significant differences in KLK11 mRNA expression level with Fig. 2 A, typical semiquantitative PCR results for KLK11 and ␤-tubu- respect to clinical stage, histological type, and histological lin mRNA expression in normal ovaries, ovarian adenomas, ovarian low grade. malignant potential tumors, and ovarian adenocarcinomas (S, serous subtype; M, mucinous subtype; E, endometrioid subtype). B, relative Survival Analysis of KLK11 Expression in Ovarian Car- KLK11:␤-tubulin ratios as determined by semiquantitative in normal cinoma Patients. Univariate analysis with respect to clinical ovaries, ovarian adenomas, ovarian low malignant potential tumors, and stage (stage I versus stage II/III/IV), histological grade (grade 1 ovarian adenocarcinomas.

Table 1 KLK11 mRNA expression in epithelial ovarian tumors and An article reporting the association between hK11 concen- normal ovaries tration of ovarian cancer cytosolic extracts and clinicopatholog- KLK11 mRNA ical characteristics in patients with ovarian cancer has been expression published recently (22). Interestingly, this report shows a cor- N Mean SD relation between higher hK11 concentration and favorable outcome in patients with ovarian cancer. It is difficult to explain Normal ovary 10 0.25a,b,c 0.24 Ovarian adenoma 7 1.25a 0.67 this discrepancy between the present data showing unfavorable Ovarian LMPd tumor 6 1.92b 1.58 outcome with KLK11 mRNA elevation and the published data Ovarian adenocarcinoma 51 1.96c 1.07 showing favorable outcome with elevated hK11 protein levels. Clinical stage Clearly, it is recommended to additionally evaluate the differ- Stage I 21 1.75 1.04 ences between mRNA expression levels and protein expression Stage II/III/IV 30 2.10 1.08 Histological type status in the same series of the ovarian cancer samples. Serous 26 2.13 0.89 All of the KLKs are thought to possess serine protease Mucinous 10 1.88 1.15 catalytic activity and may be able to activate each other as well Endometrioid 8 2.01 1.46 as other molecules, such as growth factors and cytokines, in a Clear cell 7 1.38 1.10 Histological grade cascade of events associated with tumorigenesis (5). This cas- Grade 1 26 1.84 0.85 cade seems to be highly complicated, and it will be worthwhile Grade 2/3 25 2.08 1.27 to clarify the various mechanisms that underlie cancer invasion a Significant; normal ovary versus adenoma: P ϭ 0.0006 (unpaired and metastasis. It has been reported that in cancer cell lines t test). many KLKs are under steroid hormone regulation, such that b Significant; normal ovary versus LMP tumor: P ϭ 0.0049 (un- KLK 5–12 are up-regulated mainly by estrogens, whereas KLK paired t test). 1-4 and KLK 13-15 are mainly up-regulated by androgens (5). c Significant; normal ovary versus adenocarcinoma: P Ͻ 0.0001 (unpaired t test). Thus, KLK family genes are thought to be associated with d LMP, low malignant potential. endocrine-related malignancies (6). Indeed, prostate-specific antigen (hK3) and human glandular kallikrein (hK2) are widely used tumor markers for prostate cancer diagnosis (8, 11, 12).

Table 2 Univariate analysis of survival with respect to clinical stage, histological grade, and KLK11 mRNA expression status in ovarian cancer patients Factors Pa Clinical stage (stage I vs. stage II/III/IV) 0.0043 Histological grade (grade I vs. grade 2/3) 0.2791 KLK11 mRNA expression (low vs. high) 0.0185 a Log-rank test.

expression levels in normal ovaries were quite low, and that KLK11 mRNA expression was increased significantly in ovarian tumor tissues. This suggested that KLK11 expression may play an important role in epithelial ovarian tumor development. The most striking association we observed in our ovarian cancer patient group was a significant correlation between increased Fig. 3 Ovarian cancer patients were categorized along a Kaplan-Meier KLK11 mRNA expression level and poor prognosis, according survival curve according to low versus high expression of KLK11, to both univariate and multivariate analysis. The present report showing a statistically significant association between high KLK11 ϭ shows that KLK11 is associated with an aggressive clinical mRNA expression levels and poor patient survival (P 0.0185, log- rank test). behavior of ovarian carcinoma and that KLK11 is an independent prognostic marker for ovarian cancer patients. Previous studies have reported an association between kallikrein gene mRNA expression and cancer prognosis. KLK4 and KLK5 have Table 3 Multivariate analysis of survival with respect to clinical been shown to be associated with poor prognosis in ovarian stage and KLK11 mRNA expression status in ovarian cancer patients cancer (29–31), and KLK5 has also been associated with poor Factors RRa 95% CI P prognosis in breast cancer (32). In contrast, KLK8 and KLK9 expression have been reported to be markers for favorable Clinical stage (stage I vs. 11.191 1.458–85.833 0.0202 stage II/III/IV) prognosis in ovarian cancer (33, 34). In addition, KLK13 is KLK11 mRNA expression 3.907 1.212–12.594 0.0225 reported to be an independent and favorable prognostic marker (low vs. high)b for breast carcinoma (35). This study supports the increasing a RR, risk ratio; CI, confidence interval. body of literature demonstrating the expression of KLK family b KLK11 mRNA expression was categorized as low versus high gene involvement in the prognosis of human cancers (6). expression.

More recently, hK6 and hK10 have emerged as potential new 15. Underwood LJ, Tanimoto H, Wang Y, Shigemasa K, Parmley TH, serum biomarkers for ovarian cancer (16–18). In addition, Dia- O’Brien TJ. Cloning of tumor-associated differentially expressed gene- mandis et al. (19) reported that hK11 may be a biomarker for 14, a novel serine protease overexpressed by ovarian carcinoma Cancer Res 1999;59:4435–9. prostate and ovarian carcinoma. Therefore, analysis of hK11 in 16. Diamandis EP, Yousef GM, Soosaipillai AR, et al. Immunofluoro- serum may aid in the diagnosis and monitoring of ovarian metric assay of human kallikrein 6 (zyme/protease M/neurosin) and carcinoma. preliminary clinical applications. Clin Biochem 2000;33:369–75. Our present study showed that increased mRNA expression 17. Diamandis EP, Yousef GM, Soosaipillai AR, Bunting P. Human of the KLK11 gene may indicate ovarian adenocarcinomas with kallikrein 6 (zyme/protease M/neurosin): a new serum biomarker of ovarian carcinoma. Clin Biochem 2000;33:579–83. aggressive phenotypes. Thus, KLK11 mRNA expression analy- 18. Luo LY, Bunting P, Scorilas A, Diamandis EP. Human kallikrein sis may aid in the prognosis of ovarian cancer. Although the 10: a novel tumor marker for ovarian carcinoma? Clin Chim Acta molecular mechanisms underlying increased KLK11 expression 2001;306:111–8. levels in many cancer cells have not yet been elucidated, KLK11 19. Diamandis EP, Okui A, Mitsui. S., et al. Human kallikrein 11: a may represent a novel molecular target for ovarian cancer pre- new biomarker of prostate and ovarian carcinoma. Cancer Res 2002; vention or treatment. The results presented here would suggest 62:295–300. that the use of KLK11 inhibitors and/or KLK11 regulatory 20. Yoshida S, Taniguchi M, Suemoto T, Oka T, He X, Shiosaka S. cDNA cloning and expression of a novel serine protease, TLSP. Bio- sequences as therapeutic agents for the treatment and prevention chim Biophys Acta 1998;1399:225–8. of ovarian cancers may be useful. 21. Yousef GM, Scorilas A, Diamandis EP. Genomic organization, mapping, tissue expression, and hormonal regulation of trypsin-like serine protease (TLSP PRSS20), a new member of the human kallikrein REFERENCES gene family. Genomics 2000;63:88–96. 1. Neorath H. The diversity of proteolytic enzymes. In: Beynon RJ, 22. Borgon˜o CA, Fracchioli S, Yousef GM, et al. Favorable prognostic Bond JS, editors. Proteolytic enzymes. Oxford, United Kingdom: IRL value of tissue human kallikrein 11 (hK11) in patients with ovarian Press, 1989. p. 1–13. carcinoma. Int J Cancer 2003;106:605–10. 2. Liotta LA, Steeg PS, Stetler-Stevenson WG. Cancer metastasis and 23. Russel P. Surface epithelial-stromal tumors of the ovary. In: Kur- angiogenesis: an imbalance of positive and negative regulation. Cell man RJ, editor. Blaustein’s pathology of the female genital tract. New 1991;64:327–36. York: Springer-Verlag., 1995. p. 705–82. 3. Duffy MJ. The role of proteolytic enzymes in cancer invasion and 24. Benedet JL, Bender H, Jones, III H., Ngan HYS, Pecorelli S. FIGO metastasis. Clin Exp Metastasis 1992;10:145–55. staging classifications and clinical practice guidelines in the manage- 4. Tryggvason K, Hoyhtya M, Salo T. Proteolytic degradation of ex- ment of gynecological cancers. Int J Gynecol Obstet 2000;70:209–62. tracellular matrix in tumor invasion. Biochim Biophys Acta 1987;907: 25. Shigemasa K, Hu C, West CM, et al. p16 overexpression: a poten- 191–217. tial early indicator of transformation in ovarian carcinoma. J Soc Gy- 5. Yousef GM, Diamandis EP. The new human tissue kallikrein gene necol Invest 1997;4:95–102. family: structure, function, and association to disease. Endocr Rev 26. Shigemasa K, Hu C, West CM, et al. p21: a monitor of p53 2001;22:184–204. dysfunction in ovarian neoplasia. Int J Gynecol Cancer 1997;7:296– 6. Diamandis EP, Yousef GM. Human tissue kallikreins: a family of 303. new cancer biomarkers. Clin Chem 2002;48:1198–205. 27. Shigemasa K, Tanimoto H, Parham GP, Parmley TH, Ohama K, 7. Diamandis EP, Yousef GM, Clements J, et al. New nomenclature for O’Brien TJ. Cyclin D1 overexpression and p53 mutation status in the human tissue kallikrein gene family. Clin Chem 2000;46:1855–8. epithelial ovarian cancer J Soc Gynecol Investig 1999;6:102–8. 8. McCormack RT, Rittenhouse HG, Finlay JA, et al. Molecular forms 28. Shigemasa K, Underwood LJ, Beard J, et al. Overexpression of of prostate-specific antigen and the human kallikrein gene family: a new testisin, a serine protease expressed by testicular germ cells, in epithelial era. Urology 1995;45:729–44. ovarian tumor cells. J Soc Gynecol Investig 2000;7:358–62. 9. Yu H, Giai M, Diamandis EP, Katsaros D, et al. Prostate-specific 29. Obiezu CV, Scorilas A, Katsaros D, et al. Higher human kallikrein antigen is a new favorable prognostic indicator for women with breast gene 4 (KLK4) expression indicates poor prognosis of ovarian cancer cancer. Cancer Res 1995;55:2104–10. patients. Clin Cancer Res 2001;7:2380–6. 10. Yu H, Levesque MA, Clark GM, Diamandis EP. Prognostic value 30. Dong Y, Kaushal A, Bui L, et al. Human kallikrein 4 (KLK4) is of prostate-specific antigen for women with breast cancer: a large highly expressed in serous ovarian carcinomas. Clin Cancer Res 2001; United States cohort study. Clin Cancer Res 1998;4:1489–97. 7:2363–71. 11. Magklara A, Scorilas A, Catalona WJ, Diamandis EP. The combi- 31. Kim H, Scorilas A, Katsaros D, et al. Human kallikrein gene 5 nation of human glandular kallikrein and free prostate-specific antigen (KLK5) expression is an indicator of poor prognosis in ovarian cancer. (PSA) enhances discrimination between prostate cancer and benign Br J Cancer 2001;84:643–50. prostatic hyperplasia in patients with moderately increased total PSA. 32. Yousef GM, Scorilas A, Kyriakopoulou LG, et al. Human kallikrein Clin Chem 1999;45:1960–6. gene 5 (KLK5) expression by quantitative PCR: an independent indi- 12. Kwiatkowski MK, Recker F, Piironen T, et al. In prostatism patients cator of poor prognosis in breast cancer. Clin Chem 2002;48:1241–50. the ratio of human glandular kallikrein to free PSA improves the 33. Magklara A, Scorilas A, Katsaros D, et al. The human KLK8 discrimination between prostate cancer and benign hyperplasia within (neuropsin/ovasin) gene: identification of two novel splice variants and the diagnostic “gray zone” of total PSA 4 to 10 ng/mL. Urology its prognostic value in ovarian cancer. Clin Cancer Res 2001;7:806–11. 1998;52:360–5. 34. Yousef GM, Kyriakopoulou LG, Scorilas A, et al. Quantitative 13. Tanimoto H, Underwood LJ, Shigemasa K, Parmley TH, O’Brien expression of the human kallikrein gene 9 (KLK9) in ovarian cancer: a TJ. Increased expression of protease M in ovarian tumors. Tumor Biol new independent and favorable prognostic marker. Cancer Res 2001; 2001;22:11–8. 61:7811–8. 14. Tanimoto H, Underwood LJ, Shigemasa K, et al. The stratum 35. Chang A, Yousef GM, Scorilas A, et al. Human kallikrein gene corneum chymotryptic enzyme that mediates shedding and desquama- 13 (KLK13) expression by quantitative RT-PCR: an independent tion of skin cells is highly overexpressed in ovarian tumor cells Cancer indicator of favourable prognosis in breast cancer. Br J Cancer 1999;86:2074–82. 2002;86:1457– 64.

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Kazushi Shigemasa, Lijun Gu, Hirotoshi Tanimoto, et al.

Clin Cancer Res 2004;10:2766-2770.

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