A KRAS variant is a biomarker of poor outcome, platinum chemotherapy resistance and a potential target for therapy in ovarian cancer.

Germline variants in the 3' untranslated region (3'UTR) of cancer genes disrupting microRNA (miRNA) regulation have recently been associated with cancer risk. A variant in the 3'UTR of the KRAS oncogene, referred to as the KRAS variant, is associated with both cancer risk and altered tumor biology. Here, we test the hypothesis that the KRAS variant can act as a biomarker of outcome in epithelial ovarian cancer (EOC), and investigate the cause of altered outcome in KRAS variant-positive EOC patients. As this variant seems to be associated with tumor biology, we additionally test the hypothesis that this variant can be directly targeted to impact cell survival. EOC patients with complete clinical data were genotyped for the KRAS variant and analyzed for outcome (n=536), response to neoadjuvant chemotherapy (n=125) and platinum resistance (n=306). Outcome was separately analyzed for women with known BRCA mutations (n=79). Gene expression was analyzed on a subset of tumors with available tissue. Cell lines were used to confirm altered sensitivity to chemotherapy associated with the KRAS variant. Finally, the KRAS variant was directly targeted through small-interfering RNA/miRNA oligonucleotides in cell lines and survival was measured. Postmenopausal EOC patients with the KRAS variant were significantly more likely to die of ovarian cancer by multivariate analysis (hazard ratio=1.67, 95% confidence interval: 1.09-2.57, P=0.019, n=279). Perhaps explaining this finding, EOC patients with the KRAS variant were significantly more likely to be platinum resistant (odds ratio=3.18, confidence interval: 1.31-7.72, P=0.0106, n=291). In addition, direct targeting of the KRAS variant led to a significant reduction in EOC cell growth and survival in vitro. These findings confirm the importance of the KRAS variant in EOC, and indicate that the KRAS variant is a biomarker of poor outcome in EOC likely due to platinum resistance. In addition, this study supports the hypothesis that these tumors have continued dependence on such 3'UTR lesions, and that direct targeting may be a viable future treatment approach.

Diagnostic and prognostic impact of serum HE4 detection in endometrial carcinoma patients.

BACKGROUND: To date, no good marker for screening or disease monitoring of endometrial cancer (EC) is available. The aims of this study were to investigate HE4 gene, protein expression and serum HE4 (sHE4) levels in a panel of ECs and normal endometria (NEs) and to correlate sHE4 with patient clinicopathological characteristics and prognosis. METHODS: Using quantitative real-time PCR we tested 46 ECs and 20 NEs for HE4 gene expression. Protein expression was analysed by immunohistochemistry on tissue microarrays in 153 ECs and 33 NEs. Pre-operative serum samples from 138 EC and 76 NE patients were analysed with HE4-EIA assay. Association between sHE4 and patient clinicopathological characteristics or outcome was evaluated. RESULTS: Protein and HE4 gene were significantly upregulated in EC tissues and sera, compared with controls. High sHE4 levels were significantly associated with worse EC clinical characteristics. By univariate survival analysis, high sHE4 levels significantly correlated with decreased overall survival, progression-free survival and disease-free survival, retaining their independent prognostic value on the poorly differentiated EC cohort. CONCLUSION: We demonstrate, for the first time, that high sHE4 levels correlates with an aggressive EC phenotype and may constitute an independent prognostic factor for poorly differentiated-ECs. Determination of sHE4 could be clinically useful in identifying high-risk EC patients for a more aggressive adjuvant therapy.

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.

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.

HER-2/neu overexpression and amplification in uterine serous papillary carcinoma: comparative analysis of immunohistochemistry, real-time reverse transcription-polymerase chain reaction, and fluorescence in situ hybridization.

Uterine serous papillary carcinoma (USPC) is a rare and highly malignant form of endometrial cancer (EC) characterized by early metastasis, chemoresistance, and high mortality rate. Little is known about USPC tumorigenesis even if recently a HER-2/neu role has been suggested in its development and progression. The aim of the present study was to evaluate HER-2 expression by immunohistochemistry (IHC) in 12 USPC formalin-fixed, paraffin-embedded (FFPE) samples. Moreover, we looked at the correlation between HER-2 protein expression and HER-2/neu gene amplification by fluorescence in situ hybridization (FISH), other than HER-2/neu messenger RNA expression by quantitative real-time reverse transcription (RT)-polymerase chain reaction (PCR). Finally, these results have been compared with commonly evaluated clinical features in EC patients, in order to define the potential prognostic value of HER-2/neu overexpression in USPCs. A high expression of HER-2 protein by IHC was noted in 2 of 12 patients (16.6%), and the same cases showed specific HER-2/neu gene amplification by FISH. All the samples investigated displayed a perfect concordance between IHC and FISH data. Five (41.6%) of 12 tumors demonstrated polysomy of chromosome 17 and, focusing on the 2 USPCs that showed HER-2/neu overexpression, one of them (50%) was polysomic for chromosome 17. All the other USPC cases (58.4%) showed to be disomic for chromosome 17. Quantitative RT real-time PCR performed on complementary DNA obtained from all FFPE USPC samples showed a complete correlation with FISH and IHC data. Moreover, HER-2/neu overexpression was associated with a poorer overall survival and a very low relapse-free survival time, thus being considered a candidate marker of worse overall prognosis in USPC. The use of trastuzumab (Herceptin), a monoclonal antibody directed against HER-2/neu, for the therapy of patients with HER-2/neu-positive USPCs should be further investigated in clinical trials.

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.

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.