Klotho expression in epithelial ovarian cancer and its association with insulin-like growth factors and disease progression.

Klotho is an anti-aging hormone and is able to suppress the action of IGFs. High IGF activities are associated with cancer risk and tumor progression. Klotho's role in cancer is unknown. To evaluate Klotho expression in ovarian cancer and its association with IGFs and ovarian cancer progression, a clinical follow-up study of 189 ovarian cancer patients was conducted. Patients were recruited from a teaching hospital at University of Turin in Italy. All patients were diagnosed with epithelial ovarian cancer and underwent surgery for the disease. Fresh tumor tissue was collected from each patient during surgery. Patient clinical and pathological information was collected, including patient age at surgery, disease stage, tumor grade, tumor histology, residual tumor size, debulking result, post-operative chemotherapeutic agent, treatment response, follow-up time and survival outcome. Expressions of total and secreted Klotho as well as IGFs in tumor tissue were analyzed using quantitative real-time PCR. Survival analysis was performed to evaluate the association of Klotho expression with the risk of disease progression and death using Cox proportional hazards regression model. High expression of secreted Klotho was associated with increased risk of disease progression and death. These associations were independent of patient clinical and pathological characteristics. Expression of secreted Klotho was positively correlated with the expression of IGF-I and IGFBP-3 but not with IGF-II. In conclusion, Klotho expression is associated with epithelial ovarian cancer progression, and the protein may serve as an independent marker for ovarian cancer prognosis. Klotho's role in cancer warrants further elucidation.

Expression of MDR1 in epithelial ovarian cancer and its association with disease progression.

The purposes of this study were to analyze MDR1 expression in ovarian tumors prior to chemotherapy, to correlate the expression with p16, IGFs, ERalpha, and BRCA1, and to examine the association of MDR1 expression with ovarian cancer prognosis. A primary ovarian cancer cohort of 206 patients after surgery was followed up. MDR1, IGFs, ERalpha, p16, and BRCA1 expressions were analyzed in ovarian tumor samples using quantitative real-time PCR. MDR1 was detected in 177 of 206 specimens. MDR1 expression was positively correlated with IGFBP3, ERalpha, p16, and BRCA1, but not correlated with IGF-II, age, and other clinicopathological parameters. MDR1 expression significantly elevated the risk for disease progression (p = 0.02), and this association remained statistically significant after controlling for patient age and clinicopathological parameters or other correlated genes. No association was found between MDR1 expression and overall survival. MDR1 expression may be an independent marker for ovarian cancer progression and combination of different agents targeting different molecules may improve the outcome of ovarian cancer treatment and prevent drug resistance.

The relationship of insulin-like growth factor-II, insulin-like growth factor binding protein-3, and estrogen receptor-alpha expression to disease progression in epithelial ovarian cancer.

PURPOSE: The insulin-like growth factor (IGF) system plays important roles in cancer; blocking IGF signaling has been shown to have therapeutic effects on tumor growth. Many studies have focused on the effect of IGF-I, but few have addressed IGF-II. To assess the role of IGF-II in cancer, we analyzed IGF-II expression in ovarian cancer and examined its association with disease characteristics and prognosis. EXPERIMENTAL DESIGN: Included in the study were 215 patients with primary epithelial ovarian cancer. Fresh tumor specimens were collected during surgery, and the patients were followed for a median of 31 months. Total RNA was extracted from the tumor and analyzed for IGF-II, IGF binding protein 3 (IGFBP-3), and estrogen receptor-alpha expressions using quantitative reverse transcription PCR. Survival analysis was done to examine the associations of IGF-II with disease progression. RESULTS: IGF-II expression was found to be higher in tumors with poor prognosis; this included tumors with advanced stage, poor differentiation, serous histology, and large residual lesions. Patients with high IGF-II had elevated risk for disease progression and death, although the significance became less evident when the analysis was adjusted for clinical and pathologic variables. IGFBP-3 expression was higher in less aggressive tumors, but was not associated with disease progression. The expression of estrogen receptor-alpha had no effect on survival. CONCLUSION: This study found evidence that IGF-II expression is associated with disease progression, suggesting that IGF-II and IGF signaling are potential targets for ovarian cancer treatment. The study also indicates that IGF-II and IGFBP-3 have limited value in prognosis because of their strong associations with disease stage and tumor grade.

Prognostic value of the human kallikrein gene 15 expression in ovarian cancer.

PURPOSE: KLK15 is a newly cloned human kallikrein gene. Many kallikreins were found to be differentially expressed in ovarian cancer. Like other kallikreins, KLK15 is regulated by steroid hormones in cancer cell lines. KLK15 is upregulated mainly by androgens and to a lesser extent by progestins. The purpose of this study was to examine the prognostic value of KLK15 in ovarian cancer tissues. MATERIALS AND METHODS: We studied KLK15 expression by quantitative reverse transcriptase polymerase chain reaction (RT-PCR) in 168 consecutive patients with epithelial ovarian cancer. Ten patients with benign ovarian tumors were also included in the study. An optimal cutoff point equal to the 50th percentile was defined based on the ability of KLK15 to predict progression-free survival and overall survival of the study population. RESULTS: KLK15 expression levels were significantly higher in cancerous tissues compared with benign tumors. Kaplan-Meier survival curves showed that KLK15 overexpression is a significant predictor of reduced progression-free survival (PFS; P <.001) and overall survival (OS; P <.009). Univariate and multivariate analyses indicate that KLK15 is an independent prognostic factor for PFS and OS. A weak positive correlation was found between KLK15 expression and serum CA-125 levels. CONCLUSION: KLK15 expression, as assessed by quantitative RT-PCR, is an independent marker of unfavorable prognosis for ovarian cancer.

Steroid hormone regulation and prognostic value of the human kallikrein gene 14 in ovarian cancer.

To study KLK14 gene expression in endocrine-related cancers, we studied its hormonal regulation in breast and ovarian cancer cell lines. Our kinetic and blocking experiments suggest that this up-regulation is mediated through the androgen receptor. We then studied the expression of KLK14 by quantitative reverse transcriptase-polymerase chain reaction in 155 consecutive ovarian tumors and correlated these findings with clinicopathologic parameters, response to chemotherapy, and survival. A stepwise reduction was observed in the levels of KLK14 messenger RNA in normal, benign, and cancerous tissues (P < .001). Expression levels were significantly higher in patients with early stage disease and optimal debulking and in patients who responded to chemotherapy. Kaplan-Meier survival curves demonstrated longer progression-free and overall survival in patients with KLK14-positive tumors than in patients with KLK14-negative tumors (P < .001). When all other prognostic variables were controlled in the multivariate analysis, KLK14 retained its prognostic significance (progression-free and overall survival, respectively, hazard ratios, 0.43 and 0.53; P = .027 and .014). A weak negative correlation was found between KLK14 expression and serum CA-125. KLK14 is a new, independent, and favorable prognostic marker for ovarian cancer.

ERCC1 genotype and phenotype in epithelial ovarian cancer identify patients likely to benefit from paclitaxel treatment in addition to platinum-based therapy.

PURPOSE: To investigate the effect of excision repair cross-complementation group 1 (ERCC1) on treatment response and survival of patients treated with platinum chemotherapy with or without paclitaxel. PATIENTS AND METHODS: Tumor samples from epithelial ovarian cancer patients were evaluated for ERCC1 mRNA expression and a single nucleotide polymorphism at codon 118 (C>T). Of 178 patients treated with postoperative platinum-based chemotherapy, 75 were also given paclitaxel. For all of these patients, ERCC1 expression and genotype were analyzed for associations with treatment response and survival. RESULTS: Among the 103 patients treated with platinum without paclitaxel, the C/C genotype, compared with C/T and T/T, was associated with greater risk of disease progression and death (hazard ratio [HR], 1.95, P = .051; HR, 2.01, P = .033, respectively); high levels of ERCC1 mRNA, compared with low levels, were associated with greater risk of disease progression (HR, 2.41; P = .014). Similarly, when the ERCC1 data were combined, patients with the C/C genotype and high ERCC1 expression had greater risk for disease progression (HR, 3.73; P = .003) compared with those with low expression and non-C/C genotype. However, for the 75 patients treated with platinum plus paclitaxel, the C/C genotype and high ERCC1 expression were not associated with poor prognosis, suggesting that paclitaxel may help to alleviate ERCC1-related platinum resistance. CONCLUSION: Ovarian cancer patients with high ERCC1 expression or the C/C genotype at codon 118 may benefit from the combination of platinum and paclitaxel, while those with low ERCC1 expression or the C/T or T/T genotype may respond well to platinum without paclitaxel.

Promoter-specific transcription of insulin-like growth factor-II in epithelial ovarian cancer.

OBJECTIVES: The IGF-II gene has four promoters (P1-P4); each initiates promoter-specific transcription. Studies have shown that IGF-II promoters normally active during fetal growth, but silent in postnatal life, are reactivated in cancer. In a previous study, we found IGF-II transcription evaluated at a common translated region was associated with ovarian cancer progression. This study was conducted to further determine which IGF-II promoters were responsible for the association. METHODS: Promoter-specific transcription at each IGF-II promoter was analyzed in 201 ovarian tumor samples using quantitative RT-PCR. Cox regression analysis was performed to determine the association of IGF-II promoter-specific expression with patient survival. RESULTS: P3 and P4 transcripts were detected more frequently and at significantly higher levels than the transcripts of P1 and P2. P3 and P4 transcripts were strongly correlated with the common IGF-II translated region and were significantly higher in patients with late stage disease, large residual tumor, suboptimal debulking or serous histology compared to those with early stage, small residual tumor, optimal debulking or non-serous histology. Survival analysis showed that patients with high P3 or P4 expression had a 2-fold increase in risk for death compared to those with low P3 or P4. These associations remained significant after adjustment for patient age at surgery, disease stage, tumor grade and histology. P1 and P2 transcripts, however, were not associated with disease characteristics or survival. CONCLUSIONS: These findings suggest that IGF-II transcription from P3 and P4 promoters is important in ovarian cancer and evaluation of IGF-II promoter-specific transcription may have clinical implications in ovarian cancer prognosis and treatment.

Aberrant promoter methylation of multiple genes in malignant ovarian tumors and in ovarian tumors with low malignant potential.

BACKGROUND: Methylation-mediated suppression of detoxification, DNA repair, and tumor suppressor genes has been implicated in cancer development and progression. Studies also have indicated that concordant methylation of multiple genes (methylator phenotypes), rather than a single gene, may predict cancer prognosis. The current study was designed to determine whether a methylator phenotype exists in ovarian cancer, whether methylation frequencies differ between malignant ovarian tumors and ovarian tumors with low malignant potential (LMP or borderline), and whether methylation of multiple genes affects patient survival. METHODS: The current study included 234 consecutively diagnosed patients with either LMP (n = 19 patients) or malignant (n = 215 patients) ovarian tumors. DNA samples were extracted from fresh frozen tissues and were analyzed for methylation in the promoter region of 6 genes (p16, breast cancer 1 [BRCA1], insulin-like growth factor-binding protein 3 [IGFBP-3], glutathione S-transferase pi 1 [GSTP1], estrogen receptor-alpha [ER-alpha], and human MutL homologue 1 [hMLH1]) by using methylation-specific polymerase chain reaction analysis. RESULTS: The frequencies of methylation in malignant tumors and LMP tumors were 0% and 0% for GSTP1, respectively; 9% and 0% for hMLH1, respectively; 21% and 5% for BRCA1, respectively; 42% and 21% for p16, respectively; 44% and 26% for IGFBP-3, respectively; and 57% and 42% for ER-alpha, respectively. A methylator phenotype was not detected, but a calculated methylation index (MI) that was based on the total number of genes methylated in each tumor was associated with ovarian cancer risk and progression. A higher MI was associated with malignant tumors (odds ratio, 10.11; 95% confidence interval [95% CI], 1.19-85.75) and disease progression (hazards ratio, 6.53; 95% CI, 1.39-30.65). CONCLUSIONS: Although a methylator phenotype was not identified, the current results suggested that methylation of multiple genes may play an important role in ovarian cancer development and progression and may have clinical implications in prognosis.

Favorable prognostic value of tissue human kallikrein 11 (hK11) in patients with ovarian carcinoma.

Human kallikrein 11 (hK11/trypsin-like serine protease/TLSP, encoded by the KLK11 gene) is a member of the kallikrein family of secreted serine proteases. Recently, we developed a highly sensitive and specific immunoassay for hK11 and found that this protease is expressed in the prostate, stomach and trachea as well as in amniotic fluid and milk of lactating women. Elevated serum hK11 levels were found in 60% of men with prostate cancer and 70% of women with ovarian cancer. Also, hK11 expression was found to be under the regulation of steroid hormones, particularly estrogens, at the level of KLK11 transcription. We hypothesized that hK11 may be implicated in endocrine-related malignancies and serve as a novel prostate and ovarian cancer serological marker. The aim of our study was to examine if hK11 expression in ovarian tumors bears any prognostic significance. The concentration of hK11 (ng per mg of total protein) in 104 ovarian tumor cytosolic extracts was quantified and correlated with clinicopathologic variables and outcome over a median follow-up period of 67 months. Outcome was defined as progression-free survival (PFS) and overall survival (OS). hK11 concentration in ovarian tumor cytosols ranged from 0-21 ng/mg of total protein, with a median of 0.54 ng/mg. An optimal cutoff value of 0.54 ng/mg was selected to categorize tumors as hK11-positive or -negative. hK11-positive tumors were more frequently associated with early stage (Stage I/II) disease, pre-/peri-menopausal status and patients who exhibited complete or partial response to chemotherapy (p < 0.05). Univariate analysis revealed that patients with hK11-positive tumors had a significantly decreased risk of relapse with a hazard ratio (HR) of 0.45 (p = 0.007) and death (HR of 0.34, p = 0.005). Cox multivariate analysis indicated that hK11 was an independent prognostic indicator of OS (HR of 0.41, p = 0.025). Kaplan-Meier survival curves further confirmed that women with hK11-positive tumors have longer PFS and OS (p = 0.005 and p = 0.003, respectively). Similarly, in the subgroup of patients with grade 1-2 tumors, hK11-positivity was associated with higher OS in both univariate and multivariate analysis (HR of 0.23 and 0.17, p < 0.05). Finally, in women with optimal debulking after surgery (<1 cm residual tumor), hK11 positivity was associated with a slower disease progression. These results indicate that hK11 is a novel, independent marker of favorable prognosis in patients with ovarian cancer.