MAL gene overexpression as a marker of high-grade serous ovarian carcinoma stem-like cells that predicts chemoresistance and poor prognosis

BACKGROUND

The existence of cancer stem cells (CSCs) within a tumor bulk has been demonstrated for many solid tumors including epithelial ovarian carcinoma (EOC). CSCs have been associated to tumor invasion, metastasis and development of chemoresistant recurrences. In this context, we aim to characterize EOC CSCs from the molecular point of view in order to identify potential biomarkers associated with chemoresistance.

METHODS

We isolated a population of cells with stem-like characteristics (OVA-BS4 spheroids) from a primary human EOC cell line under selective conditions. OVA-BS4 spheroids were characterized for drug response by cytotoxicity assays and their molecular profile was investigated by microarray and RT-qPCR. Finally, we performed a gene expression study in a cohort of 74 high-grade serous EOC (HGSOC) patients by RT-qPCR.

RESULTS

Spheroids exhibited properties of self-renewal and a pronounced expression of well-known stem cell genes. Moreover, they demonstrated greater resistance towards several anticancer drugs compared to parent cell line, consistent with their higher ABCG2 gene expression. From microarray studies MAL (T-cell differentiation protein) emerged as the most up-regulated gene in spheroids, compared to parent cell line. In HGSOC patients, MAL was significantly overexpressed in platinum-resistant compared to platinum-sensitive patients and resulted as an independent prognostic marker of survival.

CONCLUSIONS

This investigation provides an important contribution to the identification of molecular markers of ovarian CSCs and chemoresistance. Successful translation of molecular findings would lead to a better comprehension of the mechanisms triggering chemoresistant recurrences, to the individuation of novel therapeutic targets and to the personalization of treatment regimens.

FOXM1 expression is significantly associated with chemotherapy resistance and adverse prognosis in non-serous epithelial ovarian cancer patients

BACKGROUND

Epithelial ovarian cancer (EOC) is a spectrum of different diseases, which makes their treatment a challenge. Forkhead box M1 (FOXM1) is an oncogene aberrantly expressed in many solid cancers including serous EOC, but its role in non-serous EOCs remains undefined. We examined FOXM1 expression and its correlation to prognosis across the three major EOC subtypes, and its role in tumorigenesis and chemo-resistance in vitro.

METHODS

Gene signatures were generated by microarray for 14 clear-cell and 26 endometrioid EOCs, and 15 normal endometrium snap-frozen biopsies. Validation of FOXM1 expression was performed by RT-qPCR and immunohistochemistry in the same samples and additionally in 50 high-grade serous EOCs and in their most adequate normal controls (10 luminal fallopian tube and 20 ovarian surface epithelial brushings). Correlations of FOXM1 expression to clinic-pathological parameters and patients' prognosis were evaluated by Kaplan-Meier and Cox proportional-hazards analyses. OVCAR-3 and two novel deeply characterized EOC cell lines (EOC-CC1 and OSPC2, with clear-cell and serous subtype, respectively) were employed for in vitro studies. Effects of FOXM1 inhibition by transient siRNA transfection were evaluated on cell-proliferation, cell-cycle, colony formation, invasion, and response to conventional first- and second-line anticancer agents, and to the PARP-inhibitor olaparib. Gene signatures of FOXM1-silenced cell lines were generated by microarray and confirmed by RT-qPCR.

RESULTS

A significant FOXM1 mRNA up-regulation was found in EOCs compared to normal controls. FOXM1 protein overexpression significantly correlated to serous histology (p = 0.001) and advanced FIGO stage (p = 0.004). Multivariate analyses confirmed FOXM1 protein overexpression as an independent indicator of worse disease specific survival in non-serous EOCs, and of shorter time to progression in platinum-resistant cases. FOXM1 downregulation in EOC cell lines inhibited cell growth and clonogenicity, and promoted the cytotoxic effects of platinum compounds, doxorubicin hydrochloride and olaparib. Upon FOXM1 knock-down in EOC-CC1 and OSPC2 cells, microarray and RT-qPCR analyses revealed the deregulation of several common and other unique subtype-specific FOXM1 putative targets involved in cell cycle, metastasis, DNA repair and drug response.

CONCLUSIONS

FOXM1 is up-regulated in all three major EOCs subtypes, and is a prognostic biomarker and a potential combinatorial therapeutic target in platinum resistant disease, irrespective of tumor histology.

The HIV-protease inhibitor saquinavir reduces proliferation, invasion and clonogenicity in cervical cancer cell lines

Innovative therapies in cervical cancer (CC) remain a priority. Recent data indicate that human immunodeficiency virus (HIV)-protease inhibitors used in highly active antiretroviral therapy can exert direct antitumor activities also in HIV-free preclinical and clinical models. The aim of the present study was to evaluate the antineoplastic effects of various HIV-protease inhibitors (indinavir, ritonavir and saquinavir) on primary and established CC cell lines. Two CC cell lines established in our laboratory and four commercially available CC cell lines were treated with indinavir, ritonavir and saquinavir at different concentrations and for different times. Proliferation, clonogenicity and radiosensitivity were evaluated by crystal violet staining. Proteasomal activities were assessed using a cell-based assay and immunoblotting. Cell cycle was analyzed by propidium iodide staining and flow cytometric analysis. Invasion was tested with Matrigel chambers. A t-test for paired samples was used for statistical analysis. In all cell lines, saquinavir was more effective than ritonavir in reducing cell proliferation and inhibiting proteasomal activities (P≤0.05). Conversely, indinavir exerted a negligible effect. The saquinavir concentrations required to modulate the proteasome activities were higher than those observed to be effective in inhibiting cell proliferation. In HeLa cells, saquinavir was strongly effective in inhibiting cell invasion and clonogenicity (P≤0.05) at concentrations much lower than those required to perturb proteasomal activities. Saquinavir did not contribute to increase the sensitivity of HeLa cells to X-rays. In conclusion, the present results demonstrate that saquinavir is able to significantly reduce cell proliferation, cell invasion and clonogenicity in a proteasome-independent manner in in vitro models of CC, and suggest that saquinavir could be a promising CC therapeutic agent.

Evaluation of a novel human IgG1 anti-claudin3 antibody that specifically recognizes its aberrantly localized antigen in ovarian cancer cells and that is suitable for selective drug delivery

Membrane protein claudin3 has been recently suggested as a marker for biologically aggressive tumors and a possible target for the therapeutic delivery of active anti-cancer compounds. Claudin3-binding molecules such as the Clostridium perfringens enterotoxin (CPE), CPE-related molecules, and murine and chimeric antibodies have shown promising antitumor efficacy in preclinical oncological settings. We first engineered a fully human anti-claudin3 IgG1 antibody (IgGH6) by fusing the human IgG1 Fc-domain to the anti-claudin3 scFvH6 previously isolated from a pre-immune phage display library. The construct was expressed in mammalian cells and specifically targeted claudin3 endogenously expressed on the surface of different human ovarian cancer cell lines. No detectable cross-reactivity with other homologous claudins was observed. The epitope recognized by IgGH6 is located within the minor extracellular domain of claudin3 and becomes accessible only in tumor cells characterized by incomplete junction formation. Confocal microscopy experiments demonstrated that IgGH6 was actively internalized in tumor cells after binding to native claudin3 and co-localized, likely within intracellular vesicles, with the C-CPE peptide. Preliminary results indicate that IgGH6 accumulated in vivo in free claudin3 ovarian carcinoma xenografts. For its selective uptake in tumor cells and its human nature, IgGH6 represents a valuable candidate for antibody-drug conjugate therapeutic applications in ovarian cancer patients.

Identification of stably expressed reference small non-coding RNAs for microRNA quantification in high-grade serous ovarian carcinoma tissues

MicroRNAs (miRNAs) belong to a family of small non-coding RNAs (sncRNAs) playing important roles in human carcinogenesis. Multiple investigations reported miRNAs aberrantly expressed in several cancers, including high-grade serous ovarian carcinoma (HGS-OvCa). Quantitative PCR is widely used in studies investigating miRNA expression and the identification of reliable endogenous controls is crucial for proper data normalization. In this study, we aimed to experimentally identify the most stable reference sncRNAs for normalization of miRNA qPCR expression data in HGS-OvCa. Eleven putative reference sncRNAs for normalization (U6, SNORD48, miR-92a-3p, let-7a-5p, SNORD61, SNORD72, SNORD68, miR-103a-3p, miR-423-3p, miR-191-5p, miR-16-5p) were analysed on a total of 75 HGS-OvCa and 30 normal tissues, using a highly specific qPCR. Both the normal tissues considered to initiate HGS-OvCa malignant transformation, namely ovary and fallopian tube epithelia, were included in our study. Stability of candidate endogenous controls was evaluated using an equivalence test and validated by geNorm and NormFinder algorithms. Combining results from the three different statistical approaches, SNORD48 emerged as stably and equivalently expressed between malignant and normal tissues. Among malignant samples, considering groups based on residual tumour, miR-191-5p was identified as the most equivalent sncRNA. On the basis of our results, we support the use of SNORD48 as best reference sncRNA for relative quantification in miRNA expression studies between HGS-OvCa and normal controls, including the first time both the normal tissues supposed to be HGS-OvCa progenitors. In addition, we recommend miR-191-5p as best reference sncRNA in miRNA expression studies with prognostic intent on HGS-OvCa tissues.

Functional characterization of epithelial ovarian cancer histotypes by drug target based protein signaling activation mapping: implications for personalized cancer therapy

Epithelial ovarian carcinoma (EOC) is a deadly disease, with a 5-year survival of 30%. The aim of the study was to perform broad-scale protein signaling activation mapping to evaluate if EOC can be redefined based on activated protein signaling network architecture rather than histology. Tumor cells were isolated using laser capture microdissection (LCM) from 72 EOCs. Tumors were classified as serous (n = 38), endometrioid (n = 13), mixed (n = 8), clear cell (CCC; n = 7), and others (n = 6). LCM tumor cells were lysed and subjected to reverse-phase protein microarray to measure the expression/activation level of 117 protein drug targets. Unsupervised hierarchical clustering analysis was utilized to explore the overall signaling network. ANOVA was used to detect significant differences among the groups (p < 0.05). Regardless of histology, unsupervised analysis revealed five pathway-driven clusters. When the EOC histotypes were compared by ANOVA, only CCC showed a distinct signaling network, with activation of EGFR, Syk, HER2/ErbB2, and SHP2 (p = 0.0007, p = 0.0021, p < 0.0001, and p = 0.0410, respectively). The histological classification of EOC fails to adequately describe the underpinning protein signaling network. Nevertheless, CCC presents unique signaling characteristics compared to the other histotypes. EOC may need to be characterized by functional signaling activation mapping rather than pure histology.

Identification of optimal reference genes for gene expression normalization in a wide cohort of endometrioid endometrial carcinoma tissues

Accurate normalization is a primary component of a reliable gene expression analysis based on qRT-PCR technique. While the use of one or more reference genes as internal controls is commonly accepted as the most appropriate normalization strategy, many qPCR-based published studies still contain data poorly normalized and reference genes arbitrarily chosen irrespective of the particular tissue and the specific experimental design. To date, no validated reference genes have been identified for endometrial cancer tissues. In this study, 10 normalization genes (GAPDH, B2M, ACTB, POLR2A, UBC, PPIA, HPRT1, GUSB, TBP, H3F3A) belonging to different functional and abundance classes in various tissues and used in different studies, were analyzed to determine their applicability. In total, 100 endometrioid endometrial cancer samples, which were carefully balanced according to their tumor grade, and 29 normal endometrial tissues were examined using SYBR Green Real-Time RT-PCR. The expression stability of candidate reference genes was determined and compared by means of geNorm and NormFinder softwares. Both algorithms were in agreement in identifying GAPDH, H3F3A, PPIA, and HPRT1 as the most stably expressed genes, only differing in their ranking order. Analysis performed on the expression levels of all candidate genes confirm HPRT1 and PPIA as the most stably expressed in the study groups regardless of sample type, to be used alone or better in combination. As the stable expression of HPRT1 and PPIA between normal and tumor endometrial samples fulfill the basic requirement of a reference gene to be used for normalization purposes, HPRT1 expression showed significant differences between samples from low-grade and high-grade tumors. In conclusion, our results recommend the use of PPIA as a single reference gene to be considered for improved reliability of normalization in gene expression studies involving endometrial tumor samples at different tumor degrees.

Cancer antigen 125, human epididymis 4, kallikrein 6, osteopontin and soluble mesothelin-related peptide immunocomplexed with immunoglobulin M in epithelial ovarian cancer diagnosis

BACKGROUND

Human epididymis protein 4 (HE4), kallikrein 6 (KLK6), osteopontin (OPN) and soluble mesothelin-related peptide (SMRP) are new promising biomarkers that could integrate CA125 in epithelial ovarian cancer (EOC) diagnosis. The autoantibody response to tumor antigens is a potential tool for improving the diagnostic performances of biomarkers. The aim of this study was to assess the diagnostic potential of these biomarkers in the form of free markers and immunocomplexed with immunoglobulin M (IgM). Moreover, we analyzed the association between these markers and clinico-pathological characteristics of EOC patients.

METHODS

Serum and plasma samples of 60 healthy controls, 60 ovarian benign cysts, 60 endometriosis and 60 EOCs, collected before any treatment, were tested for CICs and free antigens by immunoassays.

RESULTS

Immunocomplexes were characterized by poor sensitivity and specificity, since they allowed the detection only of a small number of EOC patients and were increased in patients with benign gynecological pathologies. However, the markers in the form of free antigens showed good diagnostic performances. Of note, CA125 and HE4 showed high sensitivity in the detection of the malignancy and HE4 emerged as a useful biomarker in differential diagnosis between EOC and endometriosis. Finally, elevated KLK6 and OPN, were associated with advanced FIGO stage, high grade disease, suboptimally debulked tumor and ascites.

CONCLUSIONS

This study confirms the diagnostic role of CA125, HE4, KLK6, OPN and SMRP, and for the first time showed that CA125, HE4, KLK6, OPN and SMRP immunocomplexed with IgM are not a potential tool for EOC diagnosis.

Human epididymis protein 4 as a serum marker for diagnosis of endometrial carcinoma and prediction of clinical outcome

BACKGROUND

The purpose of this study was to assess the diagnostic and prognostic impact of preoperative serum determination of human epididymis protein 4 (sHE4), and to investigate its potential correlation with clinicopathological features and survival endpoints in endometrial cancer patients.

METHODS

Preoperative serum samples from 193 endometrial cancer patients and 125 women with normal endometrium were measured for sHE4 and serum CA125 (sCA125) concentrations by quantitative chemiluminescent microparticle immunoassays on the automated Architect instrument.

RESULTS

sHE4 concentrations were significantly higher in endometrial cancer patients regardless of tumour stage and grade compared with normal controls. Setting the specificity at 95 % , the sensitivities in detecting endometrial cancer patients were 66 % for HE4, 33 % for CA125 and 64 % for the combination of the two markers. High concentrations of both HE4 and CA125 significantly correlated with all clinicopathological features characterising a more aggressive tumour phenotype.In multivariate analysis, only high preoperative sHE4 concentrations, but not sCA125, were independent prognostic factors for shorter Overall Survival, Disease-Free Survival and Progression-Free Survival.

CONCLUSIONS

HE4 is more sensitive and specifi c than CA125in distinguishing endometrial cancer patients from women with normal endometrium, regardless of tumour stage and grade. sHE4 appears to be associated with a more aggressive tumour variant and it could be clinically useful, in identifying high-risk endometrial cancer patients, for a tailored surgical and postoperative therapy. HE4 significant correlation with decreased Overall Survival, Disease Free Survival and Progression Free Survival suggests its potential role as a novel prognostic marker for endometrial cancer.

Mammaglobin B (SCGB2A1) is a novel tumour antigen highly differentially expressed in all major histological types of ovarian cancer: implications for ovarian cancer immunotherapy

Background:

We studied the genetic fingerprints of ovarian cancer and validated the potential of Mammaglobin b (SCGB2A1), one of the top differentially expressed genes found in our analysis, as a novel ovarian tumour rejection antigen.

Methods:

We profiled 70 ovarian carcinomas including 24 serous (OSPC), 15 clear-cell (CC), 24 endometrioid (EAC) and 7 poorly differentiated tumours, and 14 normal human ovarian surface epithelial (HOSE) control cell lines using the Human HG-U133 Plus 2.0 chip (Affymetrix). Quantitative real-time PCR and immunohistochemistry staining techniques were used to validate microarray data at RNA and protein levels for SCGB2A1. Full-length human-recombinant SCGB2A1 was used to pulse monocyte-derived dendritic cells (DCs) to stimulate autologous SCGB2A1-specific cytotoxic T-lymphocyte (CTL) responses against chemo-naive and chemo-resistant autologous ovarian tumours.

Results:

Gene expression profiling identified SCGB2A1 as a top differentially expressed gene in all histological ovarian cancer types tested. The CD8+ CTL populations generated against SCGB2A1 were able to consistently induce lysis of autologous primary (chemo-naive) and metastatic/recurrent (chemo-resistant) target tumour cells expressing SCGB2A1, whereas autologous HLA-identical noncancerous cells were not lysed. Cytotoxicity against autologous tumour cells was significantly inhibited by anti-HLA-class I (W6/32) monoclonal antibody. Intracellular cytokine expression measured by flow cytometry showed a striking type 1 cytokine profile (i.e., high IFN-γ secretion) in SCGB2A1-specific CTLs.

Conclusion:

SCGB2A1 is a top differentially expressed gene in all major histological types of ovarian cancers and may represent a novel and attractive target for the immunotherapy of patients harbouring recurrent disease resistant to chemotherapy.

Protein network mapping of platinum-resistant and poor-survival ovarian cancer

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Background: Epithelial ovarian carcinoma (EOC) is the fifth leading cause of tumor related death in the female population, with only 30% of patients alive at 5 years after diagnosis. Platinum resistance is a major cause of treatment failure. The aim of the study was to perform broad-scale drug target activation mapping of EOC to identify new druggable targets for personalized therapy. Methods: 72 ovarian primary lesions collected from chemo-naïve EOC patients were analyzed. Highly enriched tumor epithelial cells were isolated by laser capture microdissection, lysed and subjected to reverse phase protein microarray analysis for multiplexed protein pathway activation mapping. The activation/phosphorylation level of 156 key signaling proteins was analysed. Based on the disease-free interval to platinum therapy, 61 stage II-IV patients were segregated into platinum-resistant (<6 months), platinum-sensitive (6-12 months), and platinum-supersensitive disease (>12 months). One-way analysis of variance was used to detect significant differences among the three groups in the drug target activation profile. Results: Expression of the drug target PDGF Receptor β and activation of ErbB2/HER2 (Y1248) were significantly higher in patients with resistant disease compared to sensitive groups (respectively, p 0.0033 and p 0.0134), while the expression of Estrogen receptor α was greater in the supersensitive group (p 0.0295). Moreover, overall survival analysis including all stages revealed that the expression level of Cox2 is significantly higher in patients with shorter survival (HR: 2.48, p 0.0179). Conclusions: Functional drug target activation mapping revealed the unique signaling architecture of platinum-resistant EOC. If confirmed in independent study sets, these results suggest that the utilization of drugs targeting PDGF Receptor β and ErbB2/HER2 could be evaluated in platinum resistant EOC and/or in combination with platinum therapy in order to overcome acquired resistance. Finally, this study indicates that Cox2 may play an important role in aggressive EOC, and that the addition of Cox-inhibitors to standard of care could be rationally evaluated as a novel therapeutic regimen for ovarian cancer.

Trop-2 protein overexpression is an independent marker for predicting disease recurrence in endometrioid endometrial carcinoma

Background

Endometrial cancer is the most common gynecologic malignancy in developed countries. Trop-2 is a glycoprotein involved in cellular signal transduction and is differentially overexpressed relative to normal tissue in a variety of human adenocarcinomas, including endometrioid endometrial carcinomas (EEC). Trop-2 overexpression has been proposed as a marker for biologically aggressive tumor phenotypes.

Methods

Trop-2 protein expression was quantified using tissue microarrays consisting of formalin-fixed paraffin-embedded specimens from 118 patients who underwent surgical staging from 2001–9 by laparotomy for EEC. Clinicopathologic characteristics including age, stage, grade, lymphovascular space invasion, and medical comorbidities were correlated with immunostaining score. Univariate and multivariate analyses were performed for overall survival, disease-free survival, and progression-free survival in relation to clinical parameters and Trop-2 protein expression.

Results

Clinical outcome data were available for 103 patients. Strong Trop-2 immunostaining was significantly associated with higher tumor grade (p=0.02) and cervical involvement (p<0.01). Univariate analyses showed a significant association with reduced disease-free survival (DFS) (p=0.01), and a trend towards significance for overall and progression-free survival (p=0.06 and p=0.05, respectively). Multivariate analyses revealed Trop-2 overexpression and advanced FIGO stage to be independent prognostic factors for poor DFS (p=0.04 and p <0.001, respectively).

Conclusions

Trop-2 protein overexpression is significantly associated with higher tumor grade and serves as an independent prognostic factor for DFS in endometrioid endometrial cancer.

Prognostic significance of vascular endothelial growth factor serum determination in women with ovarian cancer

Introduction. We performed a review of the literature to elucidate the potential prognostic significance of serum vascular endothelial growth factor (sVEGF) levels in ovarian cancer. Methods. Eligible studies in English and Italian were identified in MEDLINE/PubMed from VEGF discovery to October 2011. All studies evaluating: (i) sVEGF levels before any surgical and chemotherapeutic treatment; (ii) the association between sVEGF levels and the established prognostic variables; (iii) the value of sVEGF levels in predicting patients' outcomes, were selected for this review. Results. The search resulted in 758 titles. Nine studies met the inclusion criteria. A statistically significant association between the level of sVEGF and FIGO stage, tumour grade, residual tumour size, lymph node involvement, and presence of ascites was found in at least one study. sVEGF, in comparison with the established prognostic factors, appears to be the best prognostic marker for overall survival, since it stands out as an independent prognostic factor in most of the studies considered. Moreover, sVEGF levels were shown to be independent prognostic factors by 2 out of the 3 studies that considered DFS as an end point. Conclusion. High levels of sVEGF identify a subgroup of patients with higher risk of death and/or recurrence. These patients should be eligible for individually tailored therapeutic interventions.

Serum human epididymis protein 4 and risk for ovarian malignancy algorithm as new diagnostic and prognostic tools for epithelial ovarian cancer management

BACKGROUND

The aim of this work was to analyze the diagnostic and prognostic value of serum human epididymis protein 4 (HE4) and Risk for Ovarian Malignancy Algorithm (ROMA) in epithelial ovarian cancer (EOC).

METHODS

Preoperative serum samples of 419 women (140 healthy controls, 131 ovarian benign cysts, 34 endometriosis, and 114 EOC) were tested for CA125 and HE4 using fully automated methods (Abbott ARCHITECT) and validated cutoff values.

RESULTS

For the discrimination of benign masses from EOC, in premenopausal women, the sensitivity and specificity were 92.3% and 59.4% for CA125, 84.6% and 94.2% for HE4, and 84.6% and 81.2% for ROMA, whereas in postmenopausal women, the sensitivity and specificity were 94.3% and 82.3% for CA125, 78.2% and 99.0% for HE4, and 93.1% and 84.4% for ROMA. In patients with EOC, elevated CA125, HE4, and ROMA levels were associated with advanced Federation of Gynaecologists and Obstetricians (FIGO) stage, suboptimally debulking, ascites, positive cytology, lymph node involvement, and advanced age (all P ≤ 0.05). Elevated HE4 and ROMA (both P ≤ 0.01), but not CA125 (P = 0.0579), were associated with undifferentiated tumors. In multivariable analysis, elevated HE4 and ROMA (all P ≤ 0.05) were independent prognostic factors for shorter overall, disease-free, and progression-free survival.

CONCLUSIONS AND IMPACT

This study underlines the high specificity of HE4 in discriminating endometriosis and ovarian benign cysts from EOC and the high sensitivity of CA125 in detecting EOC. We showed HE4 and ROMA as independent prognostic factors. Multicenter studies are needed to draw firm conclusions about the applicability of HE4 and ROMA in clinical practice.

HE4 and epithelial ovarian cancer: comparison and clinical evaluation of two immunoassays and a combination algorithm

BACKGROUND

Two commercial immunoassays for HE4 have been compared and the diagnostic accuracy of HE4, CA 125 and the combinatory ROMA algorithm for epithelial ovarian cancer (EOC) has been evaluated.

METHODS

HE4 and CA125 were measured on sera obtained from 259 women (73 healthy, 90 with benign ovarian or adnexal diseases, 96 with EOC). The ARCHITECT CMIA HE4 assay was compared with the Fujirebio EIA HE4, and the risk for EOC by the combinatory ROMA algorithm (HE4+CA 125) was assessed with both HE4 assays.

RESULTS

The CMIA HE4 assay showed a good linearity (r>0.9998) and precision (interassay and total CVs <4%). The correlation with EIA HE4 was linear (r=0.994), with an average bias of 0.4%. By ROC curve analysis, the sensitivity for EOC at a fixed specificity of 90%, 95% and 99% was 89.6%, 84.4% and 79.2% by CMIA HE4, 84.4%, 83.3% and 79.2% by EIA HE4, 86.5%, 76.0% and 59.4% by CMIA CA125. The accuracy of the ROMA algorithm determined by CMIA or EIA HE4 was very similar (AUC 87.1% vs. 87.6%; p=n.s.) and greater in menopause.

CONCLUSIONS

The two HE4 assays showed a good correlation and similar clinical value, with a greater precision for CMIA. HE4 was more specific and accurate than CA125, supporting its use in addition to clinical and imaging criteria for the discrimination of benign from malignant ovarian lesions. The ROMA algorithm showed a good accuracy for discriminating women at high risk for EOC.

Trop-2 overexpression as an independent marker for poor overall survival in ovarian carcinoma patients

BACKGROUND

Prognostic factors currently available are insufficient to predict the clinical course of epithelial ovarian cancer (EOC). In a previous microarray study we identified the human trophoblast cell surface antigen Trop-2 as one of the top differentially expressed genes in serous papillary EOCs compared to normal human ovarian surface epithelial (HOSE) short-term cultures. The aim of the present investigation was to analyse Trop-2 expression at mRNA and protein level and to assess its prognostic significance in EOC.

METHODS

Using quantitative real-time PCR we tested a total of 104 fresh-frozen EOC tissues and 24 HOSE for Trop-2 mRNA expression. Trop-2 protein expression was then examined by immunohistochemistry in matched formalin-fixed paraffin-embedded EOC samples and in 13 normal ovaries. Finally, we correlated Trop-2 expression to EOC conventional clinicopathological features and patient outcomes.

RESULTS

We found a significant Trop-2 mRNA and protein upregulation in EOCs compared to normal controls (p<0.001). Trop-2 protein overexpression was significantly associated with the presence of ascites (p=0.04) and lymph node metastases (p=0.04). By univariate survival analysis, Trop-2 protein overexpression was significantly associated with decreased progression-free (p=0.02) and overall survival (p=0.01). Importantly, Trop-2 protein overexpression was an independent prognostic marker for shortened survival time in multivariate Cox regression analysis (p=0.04, HR=2.35, CI(95%)=1.03-5.34).

CONCLUSIONS

Our results indicate, for the first time, that Trop-2 protein overexpression correlates with an aggressive malignant phenotype and may constitute a novel prognostic factor for EOC. The targeting of Trop-2 overexpression by immunotherapeutic strategies may represent an attractive and potentially effective approach in patients harbouring EOC.

Human kallikrein 5: an interesting novel biomarker in ovarian cancer patients that elicits humoral response

INTRODUCTION

Kallikrein-related peptidases are secreted serine proteases that exert stimulatory or inhibitory effects on tumor progression. A recent study demonstrated that kallikrein-related peptidase 5 (KLK5) concentration is elevated in serum of patients with ovarian carcinoma. At the moment, the presence of KLK5 in other ovarian pathological lesions is not clearly determined. Moreover, the possibility of a spontaneous humoral immune response to KLK5 has not been studied yet.

METHODS

In this study, we examined KLK5 levels and antibody (IgG and IgM) response to KLK5 in the serum of 50 healthy women, 50 patients with benign pelvic masses, 17 patients with ovarian borderline tumors, and 50 patients with ovarian carcinomas, using 3 enzyme-linked immunosorbent assay tests available in-house.

RESULTS

At 95% specificity on healthy controls, 52% of patients with ovarian carcinoma showed high serum KLK5 (sKLK5) levels, whereas patients with benign pathological lesions or borderline tumors showed almost undetectable sKLK5 levels. Moreover, sKLK5 levels were positively associated to International Federation of Gynaecologists and Obstetricians stage suggesting a possible role of sKLK5 in ovarian cancer progression. Our results about humoral response showed elevated levels of KLK5-specific antibodies in 20% of patients with benign masses, 26% of patients with borderline tumors, and 36% of patients with ovarian carcinomas when compared with healthy controls. Interestingly, KLK5 antibodies were also found in patients with undetectable sKLK5 levels.

CONCLUSIONS

In conclusion, our results showed that KLK5 is a potential new biomarker to be used in combination with other biomarkers for ovarian cancer detection. Moreover, the existence of KLK5 antibodies suggests that KLK5 might represent a possible target for immune-based therapies.

Mammaglobin B is an independent prognostic marker in epithelial ovarian cancer and its expression is associated with reduced risk of disease recurrence

Background

Traditional prognostic factors in epithelial ovarian cancer (EOC) are inadequate in predicting recurrence and long-term prognosis, but genome-wide cancer research has recently provided multiple potentially useful biomarkers. The gene codifying for Mammaglobin B (MGB-2) has been selected from our previous microarray analysis performed on 19 serous papillary epithelial ovarian cancers and its expression has been further investigated on multiple histological subtypes, both at mRNA and protein level. Since, to date, there is no information available on the prognostic significance of MGB-2 expression in cancer, the aim of this study was to determine its prognostic potential on survival in a large cohort of well-characterized EOC patients.

Methods

MGB-2 expression was evaluated by quantitative real time-PCR in fresh-frozen tissue biopsies and was validated by immunohistochemistry in matched formalin fixed-paraffin embedded tissue samples derived from a total of 106 EOC patients and 27 controls. MGB-2 expression was then associated with the clinicopathologic features of the tumors and was correlated with clinical outcome.

Results

MGB-2 expression was found significantly elevated in EOC compared to normal ovarian controls, both at mRNA and protein level. A good correlation was detected between MGB-2 expression data obtained by the two different techniques. MGB-2 expressing tumors were significantly associated with several clinicopathologic characteristics defining a less aggressive tumor behavior. Univariate survival analysis revealed a decreased risk for cancer-related death, recurrence and disease progression in MGB-2-expressing patients (p < 0.05). Moreover, multivariate analysis indicated that high expression levels of MGB-2 transcript (HR = 0.25, 95%, 0.08–0.75, p = 0.014) as well as positive immunostaining for the protein (HR = 0.41, 95%CI, 0.17–0.99, p = 0.048) had an independent prognostic value for disease-free survival.

Conclusion

This is the first report documenting that MGB-2 expression characterizes less aggressive forms of EOC and is correlated with a favorable outcome. These findings suggest that the determination of MGB-2, especially at molecular level, in EOC tissue obtained after primary surgery can provide additional prognostic information about the risk of recurrence.

Human Kallikrein 5: An Interesting Novel Biomarker in Ovarian Cancer Patients that Elicits a Humoral Response

Background and aim

Epithelial ovarian cancer (EOC) is characterized by few early symptoms, presentation at an advanced stage and poor survival. As a result, it is the most frequent cause of death from gynecological cancer. Recently, not only tumor antigens but also antibodies produced in response to the disease have been considered as biomarkers for early detection of EOC. Kallikrein-related peptidases (KLK) are secreted serine proteases implicated in tumor progression. A recent study has demonstrated that the serum KLK5 (sKLK5) concentration is elevated in patients with EOC, but the existence of a humoral immune response to KLK5 has not been studied. Moreover, the presence of sKLK5 in other ovarian diseases has not been clearly determined. The aim of this study was to examine the serological existence of anti-KLK5 antibodies, bound to KLK5 into circulating immune complexes (KLK5-lgM and KLK5-lgG ICs) or free antibodies (IgM and IgG), in healthy women and in patients with benign ovarian masses, borderline tumors and EOC. In the same patients we also assessed the levels of sKLK5.

Materials and methods

Serum samples were obtained from 50 healthy women, 50 patients with benign ovarian masses, 1 7 patients with borderline ovarian tumors, and 50 patients with EOC, before any surgical or chemotherapeutic treatment. Patients with a past or concomitant history of malignancy were excluded from the study. KLK5-lgM and KLK5-lgG ICs were detected with a sandwich ELISA using a polyclonal anti-KLK5 antibody (R&D Systems, Minneapolis, MN, USA) in capture and an anti-hlgM-HRP antibody (Sigma Aldrich Inc, St Louis, MO, USA) or anti-hlgG-HRP antibody (Sigma) in detection. Free anti-KLK5 IgM and IgG were detected with an indirect ELISA using recombinant human kallikrein 5 (R&D) in coating and anti-hlgM-HRP or anti-hlgG-HRP antibodies in detection. Finally, sKLK5 was detected with a sandwich ELISA, using a polyclonal anti-KLK5 antibody in capture and a biotinylated poyclonal anti-hK5 antibody (R&D) in detection.

Results

Elevated levels of KLK5-lgM and KLK5-lgG ICs were detected in 11% of patients with borderline tumors and 8% of patients with EOC, whereas elevated levels of free anti-KLK5 IgM and IgG were found in 1 7% of patients with borderline tumors and 8% of patients with EOC, resulting in a 100% specificity both in healthy women and patients with benign ovarian disease. Patients with EOC showed higher levels of sKLK5, whereas the protein was almost undetectable in women with other ovarian tumors (Kruskal-Wallis test: p<0.001). In particular, at 95% specificity in healthy controls, 52% of patients with EOC showed high sKLK5 levels. Interestingly, both the immune complexes and the free antibodies were elevated in patients with undetectable sKLK5 levels and borderline tumors with intraepithelial carcinoma.

Conclusion

Our results showed that sKLK5 is a potential new biomarker to be used in combination with other biomarkers for EOC detection. Moreover, the combination of sKLK5 and antibodies reactive to KLK5 might improve the sensitivity in EOC detection since these antibodies may be found in patients without detectable sKLK5 levels. In conclusion, the identification of an immune response that generally precedes the presence of high levels of circulating antigens may represent a novel useful tool for early EOC detection.

Development and characterization of a human single-chain antibody fragment against claudin-3: a novel therapeutic target in ovarian and uterine carcinomas

OBJECTIVE

The purpose of this study was to develop and characterize a human antibody in a single-chain antibody fragment format (scFv) that is directed specifically against claudin-3 (CLDN3).

STUDY DESIGN

The synthetic ETH-2 Gold human antibody phage display library was used to select scFv specific against CLDN3. scFv binding properties were analyzed by surface plasmon resonance; specificity was confirmed with enzyme-linked immunosorbent assay, immunofluorescence, and flow cytometry on a panel of ovarian and uterine serous carcinoma cell lines.

RESULTS

Surface plasmon resonance studies indicated scFv H6 to be the clone with the highest affinity against CLDN3 (K(D) of 23.60 nmol/L). scFv H6 efficiently stained CLDN3-expressing cells and recognized its epitope in enzyme-linked immunosorbent assay that was performed with uterine serous papillary carcinoma native protein extract, which suggested that a conformational epitope is recognized by this antibody. Cell surface immunofluorescence with laser scanning confocal microscopy confirmed the specific binding to the native membrane CLDN3.

CONCLUSION

scFv H6 may represent a novel antitumor agent against chemotherapy-resistant ovarian and serous papillary carcinomas and other human malignancies that overexpress CLDN3.

Trefoil factor 3: a novel serum marker identified by gene expression profiling in high-grade endometrial carcinomas

This study identifies the genetic fingerprint of poorly differentiated endometrioid endometrial carcinomas (G3-EEC) and analyses the potential utility of trefoil factor 3 (TFF3) as novel serum marker in G3-EEC. Affymetrix microarrays were used to identify the gene expression patterns of 19 snap-frozen G3-EEC and 15 normal endometrium (NE) biopsies. Quantitative real-time PCR (qRT-PCR) and immunohistochemistry were used to validate TFF3 expression. Finally, TFF3 serum levels were determined by ELISA in 25 G3-EEC patients, 42 healthy controls, and in 13 endometrial hyperplasia patients. Hierarchical cluster analysis showed TFF3 as the top differentially expressed gene between 363 upregulated genes in G3-EEC, when compared with NE. Trefoil factor 3 gene expression levels analysed by qRT-PCR significantly correlated with Affymetrix results (P<0.001; rs=0.85). By immunohistochemistry, TFF3 protein was significatively more expressed in EEC compared with NE (P<0.01), with cytoplasmatic positivity in 79% G3-EEC and 18% NE. Patients harbouring G3-EECs had significantly higher TFF3 serum concentration by ELISA when compared with healthy patients (P<0.001) or patients harbouring endometrial hyperplasia (P=0.012). In conclusion, TFF3 is highly expressed at gene and protein level in G3-EEC. Further investigations on a wider set of samples are warranted to validate TFF3 as a novel serum marker for early detection and/or monitoring of G3-EEC patients.

Mammaglobin B expression in human endometrial cancer

Mammaglobin B (MGB-2) is an uteroglobin gene family member recently found highly differentially expressed in ovarian cancer by gene expression profiling. To evaluate its potential as a novel endometrial cancer biomarker, in this study we quantified and compared MGB-2 expression at messenger RNA and protein levels in endometrial tumors (endometrioid endometrial cancer [EEC]) with different grades of differentiation. MGB-2 expression was evaluated by real-time polymerase chain reaction (PCR) and immunohistochemistry (IHC) in fresh frozen biopsies and paraffin-embedded tissues derived from a total of 70 patients including 50 primary EEC and 20 normal endometria (NECs). High levels of MGB-2 gene expression were detected in 10 of 11 EEC G1 cases (91%), 16 of 17 EEC G2 cases (94%), and 6 of 22 EEC G3 cases (27%) by real-time PCR. In contrast, normal endometrial cells expressed low to negligible levels of MGB-2 by real-time PCR (P= 0.002 EEC vs NEC). Well- and moderately differentiated EECs overexpressed MGB-2 gene at significant higher levels when compared to NECs (P< 0.01). Pairwise differences between both G2 and G1 vs G3 cases for MGB-2 relative gene expression values were also statistically significant (G2 vs G3 P< 0.001, G1 vs G3 P= 0.016). MGB-2 protein expression was detected in 31 (86%) of 36 EEC and 0 of 5 atrophic NEC controls, while seven of eight (88%) of the proliferative/secretory/hyperplastic NECs focally expressed MGB-2 by IHC. MGB-2 is highly expressed in EEC, particularly in well- and moderately differentiated tumors, and may represent a novel molecular marker for EEC.

Claudin-7 expression in human epithelial ovarian cancer

Claudin-7 (CLDN-7) is a tight junction protein recently found highly differentially expressed in ovarian carcinoma. To evaluate its potential as a novel biomarker, in this study, we quantified and compared claudin-7 expression at messenger RNA and protein level in 110 patients harboring various histologic types of epithelial ovarian carcinomas (EOC). CLDN-7 transcript was found significantly overexpressed in both primary and metastatic EOCs compared to normal human ovarian surface epithelium cell lines (fold change = 111.4, P < 0.001) by reverse transcription-polymerase chain reaction. At the protein level, CLDN-7 expression was found significantly higher in tumors of primary and metastatic origin when compared to normal ovaries (P < 0.001), regardless of the histologic type, the grade of differentiation, and the pathologic stage of the disease (P = 0.12). Moreover, a strong immunoreactivity for CLDN-7 was detected in EOC cells present in ascites fluids, whereas ascites-derived inflammatory cells, histiocytes, and reactive mesothelial cells were negative. Finally, immunohistochemical expression of CLDN-7 was observed in several human normal epithelial control tissues analyzed. CLDN-7 is significantly overexpressed in all main histologic types of EOC and in single neoplastic cells disseminated in peritoneal cavity and pleural effusions, suggesting its potential role as novel diagnostic marker in ovarian cancer. Despite widespread expression of CLDN-7 in several human normal tissues, the high density of CLDN-7 molecules, their membranous localization on EOC cells, and their lack of expression on the celomic epithelium in the peritoneal cavity suggest that this target could be potentially suitable for antibody-mediated localized therapies of ovarian adenocarcinoma.

Overexpression of epidermal growth factor type-1 receptor (EGF-R1) in cervical cancer: Implications for Cetuximab-mediated therapy in recurrent/metastatic disease

OBJECTIVES

To evaluate and compare epidermal growth factor type-1 receptor (EGF-R1) expression in short term and established cervical cancer cell lines generated from primary and metastatic/recurrent sites of disease. To evaluate the sensitivity of cervical cancer cell lines to treatment with a chimeric MAb against EGFR-1 (Cetuximab).

METHODS

EGFR-1 expression was evaluated by flow cytometry on 22 cervical cancer cell lines including 14 primary cervical cancer cell lines obtained from cervical biopsies (11 patients) and recurrent sites of disease (three patients) as well as eight established cell lines. Tumor cell lines were tested for sensitivity to Cetuximab-mediated complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC) in 51Cr release assays. Finally, Cetuximab-mediated inhibition of cell proliferation was also tested.

RESULTS

Fourteen out of fourteen (100%) primary tumors and seven out of eight (87.5%) established cervical cancer cell lines expressed EGFR-1 by flow cytometry. Cell lines from recurrent/metastatic sites of disease expressed higher levels of EGFR-1 when compared to those obtained from primary sites (p>0.05). Minimal CDC was detected in the majority of cervical cancer cell lines exposed to complement+/-Cetuximab in the absence of peripheral blood lymphocytes (PBL). In contrast, cervical tumor cell lines were found highly sensitive to Cetuximab-mediated ADCC when challenged with PBL from either healthy donors or cervical cancer patients. Importantly, ADCC was further increased in the presence of complement. Finally, tumor proliferation was significantly inhibited by Cetuximab in all cervical tumors tested.

CONCLUSIONS

EGFR-1 is highly expressed in primary and recurrent cervical tumors. Cetuximab might be a novel and attractive therapeutic strategy in patients harboring chemotherapy-resistant, recurrent, or metastatic cervical cancer.

Overexpression of mammaglobin B in epithelial ovarian carcinomas

OBJECTIVE

Mammaglobin B is a uteroglobin gene family member recently found highly differentially expressed in serous papillary ovarian cancer by gene expression profiling. In order to evaluate its potential as a novel ovarian cancer biomarker, in this study we quantified and compared Mammaglobin B expression in various histologic types of epithelial ovarian carcinomas (EOC).

METHODS

Mammaglobin B expression was evaluated by real-time PCR and/or immunohistochemistry in fresh-frozen biopsies and paraffin-embedded tissues derived from a total of 137 patients including 69 primary EOC with different histologies, 28 serous papillary omental metastasis, 8 borderline tumors, 26 benign cystadenomas and 14 normal ovaries.

RESULTS

High levels of Mammaglobin B gene expression were detected in 100% (68 out of 68) of the ovarian cancer biopsies tested by real-time PCR. In contrast, normal human ovarian surface epithelium (HOSE) expressed negligible levels of Mammaglobin B mRNA (EOC versus HOSE, p<0.01). Although Mammaglobin B gene expression levels were higher in endometrioid, mucinous and undifferentiated tumors when compared to serous papillary tumors, clear cell tumors and those with mixed histology, these differences were not statistically significant. In agreement with real-time PCR results, EOC were found to express significantly higher levels of Mammaglobin B protein when compared to normal ovaries and benign cystadenomas (p<0.01). However, only 29 out of 68 (42%) of the EOC samples found positive for Mammaglobin B by real-time PCR showed immunoreactivity by IHC.

CONCLUSIONS

Mammaglobin B gene is highly expressed in EOC and may represent a novel molecular marker for multiple histological types of ovarian cancer. Additional studies to evaluate the clinical utility of Mammaglobin B as a diagnostic and/or therapeutic target in ovarian cancer are warranted.

Overexpression of Clostridium perfringens Enterotoxin Receptors Claudin-3 and Claudin-4 in Uterine Carcinosarcomas

PURPOSE

To evaluate the expression levels of claudin-3 and claudin-4, the low- and high-affinity receptors, respectively, for the cytotoxic Clostridium perfringens enterotoxin (CPE) in uterine carcinosarcomas and explore the potential for targeting these receptors in the treatment of this aggressive uterine tumor.

EXPERIMENTAL DESIGN

We analyzed claudin-3 and claudin-4 receptor expression at mRNA and protein levels in flash frozen and formalin-fixed, paraffin-embedded carcinosarcoma specimens. Recombinant CPE was used as a novel therapy against chemotherapy-resistant carcinosarcoma cell lines in vitro. The therapeutic effect of sublethal doses of CPE was studied in severe combined immunodeficient mouse xenografts harboring large s.c. carcinosarcomas.

RESULTS

All flash-frozen carcinosarcoma biopsies (12 of 12) and short-term carcinosarcoma cell lines evaluated overexpressed claudin-3 and claudin-4 by quantitative reverse transcription-PCR. Membranous immunoreactivity for claudin-4 protein expression was documented in 80% (20 of 25) of primary tumors and 100% (6 of 6) of the metastatic carcinosarcomas, whereas negligible staining was found in normal endometrial cells. Regardless of their resistance to chemotherapeutic agents, all short-term carcinosarcoma cell lines tested died within 1 h of exposure to 3.3 microg/mL of CPE in vitro. Intratumoral injections of well-tolerated doses of CPE in large s.c. carcinosarcoma xenografts led to large areas of tumor cell necrosis and tumor disappearance in all treated animals.

CONCLUSIONS

Claudin-3 and claudin-4 receptors are highly overexpressed in carcinosarcoma. These proteins may offer promising targets for the use of CPE as a novel type-specific therapy against this biologically aggressive variant of endometrial cancer.

Overexpression of claudin-3 and claudin-4 receptors in uterine serous papillary carcinoma: novel targets for a type-specific therapy using Clostridium perfringens enterotoxin (CPE)

BACKGROUND

Uterine serous papillary carcinoma (USPC) represents a highly aggressive variant of endometrial cancer. Using gene expression profiling, we recently identified high expression of the claudin-3 and claudin-4 receptors in a limited set of USPC. These tight junction proteins represent the low- and high-affinity receptors, respectively, for the cytotoxic Clostridium perfringens enterotoxin (CPE) and are sufficient to mediate CPE binding and trigger subsequent toxin-mediated cytolysis. The potential for targeting this pathway in the treatment of USPC was explored.

METHODS

Claudin-3 and claudin-4 receptor expression was analyzed at the mRNA and protein levels in flash-frozen and formalin-fixed, paraffin-embedded tissue from 20 consecutive USPC patients. The potential of recombinant CPE as a novel therapy against primary, metastatic, and chemotherapy-resistant USPC cell lines was also investigated in vitro. Finally, the in vivo therapeutic effect of sublethal doses of CPE was studied in SCID mouse xenografts harboring subcutaneous and intraperitoneal USPC that expressed claudin-3 and claudin-4.

RESULTS

In all, 100% (20 out of 20) of the primary flash-frozen USPC tested overexpressed 1 or both CPE receptors by quantitative reverse-transcriptase polymerase chain reaction (RT-PCR). Membranous immunoreactivity for claudin-4 protein expression was documented in the majority of USPC specimens tested by immunohistochemistry, whereas only a low level of membranous staining was found in normal endometrial control tissue samples. When primary and metastatic short-term USPC cell lines were incubated with different concentrations of CPE in vitro, a dose-dependent cytotoxic effect was demonstrated. In vivo, intratumoral injections of well-tolerated doses of CPE in large subcutaneous USPC xenografts led to large areas of tumor cell necrosis and tumor disappearance in all the treated animals, whereas sublethal intraperitoneal injections of CPE had a significant inhibitory effect on tumor progression, with extended survival of animals harboring chemotherapy-resistant intra-abdominal USPC carcinomatosis.

CONCLUSIONS

Claudin-3 and claudin-4 receptors may offer promising targets for the use of CPE as a novel type-specific therapy against this highly aggressive and chemotherapy-resistant variant of endometrial cancer.

Gene expression profile of ovarian serous papillary carcinomas: identification of metastasis-associated genes

OBJECTIVE

The purpose of this study was to identify genes that are highly differentially expressed in metastatic serous papillary ovarian tumors (MET) when compared with primary ovarian serous carcinomas (OSPC).

STUDY DESIGN

An oligonucleotide microarray with probe sets complementary to >14,500 human genes was used to determine whether patterns of gene expression may differentiate OSPC from MET in 31 snap-frozen serous papillary ovarian carcinomas (ie, 14 primary OSPC and 17 omental metastasis [MET]).

RESULTS

Hierarchic cluster analysis of gene expression in OSPC and MET identified 156 genes that exhibited > 2-fold differences (P < .05) and that distinguished OSPC from MET. A number of invasion and metastasis predictive genes (including plasminogen activator; matrix metalloproteinase; matrix structural constituent genes encoding products with collagen, heparin, and hyaluronic acid binding activity; genes encoding receptors for insulin-like growth factors; vascular endothelial growth factor; endothelin type A; fibroblast growth factor; thrombospondin 1 and 2; type A and B integrins, and chemokines [stromal cell-derived factor 1 (CXCL12)]) were found among the 120 genes that were highly differentially overexpressed in MET, when compared with OSPC. Down-regulated genes in MET compared with OSPC included hepsin and testisin. Overexpression of CXCL12, matrix metalloproteinase, plasminogen activator, type A and B integrins, and hepsin genes was validated by quantitative real-time polymerase chain reaction in all samples. Finally, overexpression of CXCL12 in MET, when compared with OSPC, was validated at the protein level by immunohistochemistry.

CONCLUSION

Gene expression profiling may differentiate metastatic ovarian cancer from primary OSPC. The identification of metastasis-associated genes may provide a foundation for the development of new type-specific diagnostic strategies and treatment for metastatic ovarian cancer.

Correlation between serological immune response analyzed by a new ELISA for HPV-16/18 E7 oncoprotein and clinical characteristics of cervical cancer patients

Human papillomaviruses (HPVs), particularly HPV-16/18, are linked to cervical cancer development. Full-length, recombinant HPV-16/18 E7 oncoproteins were used in a new streptavidin-biotin capture ELISA method to investigate anti-HPV E7 antibody prevalence in serum. Sera from 99 healthy women, 70 cervical cancer patients, and 30 patients with cervical pre-invasive neoplasia were analyzed. Anti-HPV-16/18 E7 positivity was found in 53% of cervical cancer patients, in 40% with cervical pre-invasive neoplasia, and in 8% of healthy women. Serum samples from 12 cervical cancer patients were obtained at different time intervals during the treatment. Eleven out of 12 showed a correspondence between HPV-E7 antibody levels (decreasing versus increasing) and the type of response (clinically complete or partial response versus progression or stable disease) at each serological evaluation. Five patients with recurrent HPV-16/18-positive cervical carcinoma were analyzed before and after vaccination with HPV-16/18 E7-pulsed autologous dendritic cells; anti-HPV-16/18 E7 positivity was found in 3 out of 5 women. In conclusion, this assay could potentially be used as an adjunctive tool to monitor the type of response to treatment and possibly to detect antibody induction in cervical cancer patients after vaccination, as a potential marker to evaluate its efficacy.

Overexpression of kallikrein 10 (hK10) in uterine serous papillary carcinomas

OBJECTIVE

Kallikrein 10 is a secreted serine protease recently implicated in the growth and invasion of several human tumors. The goal of this study was to investigate the expression and secretion levels in vitro and in vivo of kallikrein 10 in uterine serous papillary carcinoma, a highly aggressive variant of endometrial tumor.

STUDY DESIGN

Human kallikrein 10 gene expression levels were evaluated in 11 snap-frozen uterine serous papillary carcinoma biopsies and 6 normal endometrial cell biopsies by real-time polymerase chain reaction. Secretion of kallikrein 10 protein by 10 primary tumor cultures including 3 uterine serous papillary carcinomas, 2 endometrioid carcinomas, and 5 ovarian serous papillary tumors was measured using a sensitive ELISA. Finally, kallikrein 10 concentration in 75 serum and plasma samples from 22 healthy women, 20 women with benign diseases, 21 women with endometrioid carcinomas, and 12 uterine serous papillary carcinoma patients was studied.

RESULTS

Kallikrein 10 gene expression levels were significantly higher in uterine serous papillary carcinoma when compared with normal endometrial cell biopsies (mean copy number by real time polymerase chain reaction = 743 versus 1.4; uterine serous papillary carcinoma versus endometrioid carcinoma: P < .02). In vitro kallikrein 10 secretion was detected in all primary uterine serous papillary carcinoma cell lines tested (mean = 2.7 microg/L), and the secretion levels were not significantly different to those found in primary ovarian serous papillary tumor cultures (mean 4.2 microg/L). In contrast, no kallikrein 10 secretion was detectable in primary endometrioid carcinomas. Kallikrein 10 serum and plasma concentrations (microg/L; mean +/- SEM) among normal healthy females (0.6 +/- 0.04), patients with benign diseases (0.6 +/- 0.06), and patients with endometrioid carcinomas (0.7 +/- 0.06) were not significantly different. In contrast, serum and plasma kallikrein 10 values in uterine serous papillary carcinoma patients (1.2 +/- 0.1) were significantly higher than those in the non-cancer group (P = .002), benign group (P = .002), and endometrioid carcinoma patients (P = .005).

CONCLUSION

Kallikrein 10 is highly expressed in uterine serous papillary carcinoma, and it is released in the plasma and serum of uterine serous papillary carcinoma patients. Kallikrein 10 may represent a novel biomarker for uterine serous papillary carcinoma.

Impaired natural and CD16-mediated NK cell cytotoxicity in patients with WAS and XLT: ability of IL-2 to correct NK cell functional defect

In this study we show that Wiskott-Aldrich syndrome protein (WASp), a critical regulator of actin cytoskeleton that belongs to the Scar/WAVE family, plays a crucial role in the control of natural killer (NK) cell cytotoxicity. Analysis of NK cell numbers and cytotoxic activity in patients carrying different mutations in the WASP coding gene indicated that although the percentage of NK cells was normal or increased, natural cytotoxicity and antibody-mediated NK cell cytotoxicity were inhibited in all patients with the classical WAS phenotype and in most patients carrying mutations associated with the X-linked thrombocytopenia (XLT) phenotype. The inhibition of NK cell-mediated cytotoxicity was associated with the reduced ability of WAS and XLT NK cells to form conjugates with susceptible target cells and to accumulate F-actin on binding. Treatment with interleukin-2 (IL-2) corrected the functional defects of NK cells by affecting their ability to bind to sensitive target cells and to accumulate F-actin. In addition, we provide information on the molecular mechanisms that control WASp function, demonstrating that binding of NK cells to sensitive targets or triggering through CD16 by means of reverse antibody-dependent cellular cytotoxicity (ADCC) rapidly activates Cdc42. We also found that WASp undergoes tyrosine phosphorylation upon CD16 or β2-integrin engagement on NK cells. (Blood. 2004;104:436-443)