A prognostic regulatory pathway in stage I epithelial ovarian cancer: new hints for the poor prognosis assessment

BACKGROUND

Clinical and pathological parameters of patients with epithelial ovarian cancer (EOC) do not thoroughly predict patients' outcome. Despite the good outcome of stage I EOC compared with that of stages III and IV, the risk assessment and treatments are almost the same. However, only 20% of stage I EOC cases relapse and die, meaning that only a proportion of patients need intensive treatment and closer follow-up. Thus, the identification of cell mechanisms that could improve outcome prediction and rationalize therapeutic options is an urgent need in the clinical practice.

PATIENTS AND METHODS

We have gathered together 203 patients with stage I EOC diagnosis, from whom snap-frozen tumor biopsies were available at the time of primary surgery before any treatment. Patients, with a median follow-up of 7 years, were stratified into a training set and a validation set.

RESULTS AND CONCLUSIONS

Integrated analysis of miRNA and gene expression profiles allowed to identify a prognostic cell pathway, composed of 16 miRNAs and 10 genes, wiring the cell cycle, 'Activins/Inhibins' and 'Hedgehog' signaling pathways. Once validated by an independent technique, all the elements of the circuit resulted associated with overall survival (OS) and progression-free survival (PFS), in both univariate and multivariate models. For each patient, the circuit expressions have been translated into an activation state index (integrated signature classifier, ISC), used to stratify patients into classes of risk. This prediction reaches the 89.7% of sensitivity and 96.6% of specificity for the detection of PFS events. The prognostic value was then confirmed in the external independent validation set in which the PFS events are predicted with 75% sensitivity and 94.7% specificity. Moreover, the ISC shows higher classification performance than conventional clinical classifiers. Thus, the identified circuit enhances the understanding of the molecular mechanisms lagging behind stage I EOC and the ISC improves our capabilities to assess, at the time of diagnosis, the patient risk of relapse.

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.

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

Germ-line 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 appears 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 employed to confirm altered sensitivity to chemotherapy with the KRAS-variant. The KRAS-variant was directly targeted through siRNA/miRNA oligonucleotides in cell lines and survival was measured.

Post-menopausal EOC patients with the KRAS-variant were significantly more likely to die of ovarian cancer by multivariate analysis (HR=1.67, 95% CI=1.09–2.57, p=0.019, n=279). Possibly explaining this finding, EOC patients with the KRAS-variant were significantly more likely to be platinum resistant (OR=3.18, CI=1.31–7.72, p=0.0106, n=291). Additionally, 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 work 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.

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.

HER-2/neuoverexpression and amplification in uterine serous papillary carcinoma: comparative analysis of immunohistochemistry, real-time reverse transcription-polymerase chain reaction, and fluorescencein situhybridization

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.

Genistein affects adipose tissue deposition in a dose-dependent and gender-specific manner

The soy isoflavone genistein targets adipose tissue and elicits physiological effects that may vary based on dietary intake. We hypothesized that the adipose effects of genistein are dose and gender dependent. Four-week-old C57BL/6 male and female mice received daily oral doses of genistein (50-200,000 microg/kg.d) or 17beta-estradiol (E2) (5 microg/kg.d) for 15 d or a diet containing 800 ppm genistein. Genistein increased epididymal and renal fat pad and adipocyte size at doses up to 50,000 microg/kg.d or at 800 ppm in the diet in males but not in females. The alteration in adipocity correlated with changes in peripheral insulin resistance. These treatments increased genistein serum concentrations from 35+/-6 to 103+/-26 nM 12 h after treatment and lowered plasma triglycerides and cholesterol levels. The 200,000 microg/kg.d genistein dose decreased adipose tissue weight similarly to E2. This genistein dose down-regulated estrogen receptor (beta more than alpha) and progesterone receptor expression and induced estrogen-dependent adipose differentiation factors; it did not change expression of the minimal consensus estrogen-responsive element in ERE-tK-LUC mice, which was positively modulated in other tissues (e.g. the lung). E2 down-regulated almost all examined adipogenic factors. Gene microarray analysis identified factors in fat metabolism and obesity-related phenotypes differentially regulated by low and high doses of genistein, uncovering its adipogenic and antiadipogenic actions. The lower dose induced the phospholipase A2 group 7 and the phospholipid transfer protein genes; the 200,000 microg/kg.d dose inhibited them. The antiadipogenic action of genistein and down-regulation of adipogenic genes required the expression of ERbeta. In conclusion, nutritional doses of genistein are adipogenic in a gender-specific manner, whereas pharmacological doses inhibited adipose deposition.

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.

Restoration of tumor specific human leukocyte antigens class I-restricted cytotoxicity by dendritic cell stimulation of tumor infiltrating lymphocytes in patients with advanced ovarian cancer

Despite the large number of potentially cytotoxic tumor-infiltrating (TIL) and tumor-associated (TAL) lymphocytes accumulated in the peritoneal cavity ascitic fluid and tumor tissue, advanced ovarian cancer is a progressive disease, suggesting that TIL and TAL populations eventually become functionally suppressed in vivo. Dendritic cells (DC) are the most powerful professional antigen presenting cells known in humans and recently, ovarian tumor antigen pulsed DC have been shown to elicit tumor specific human leukocyte antigens (HLA)-class I-restricted cytotoxicity from the peripheral blood of advanced ovarian cancer patients. In this study, we have evaluated the potential of tumor antigen-pulsed fully mature DC stimulation in restoring tumor-specific cytotoxicity in anergic TIL populations from advanced ovarian cancer patients. In addition, we have compared tumor-specific T-cell responses induced by tumor antigen-loaded DC in TIL to those induced in TAL and peripheral blood lymphocytes (PBL). DC stimulation induced powerful cytotoxicity against autologous tumor target cells in TIL-derived CD8+ T-cells from all patients tested, while autologous Epstein–Barr virus (EBV)-transformed lymphoblastoid cell lines (LCL) were not lysed. Killing of autologous tumor cells was higher by CD8+ T-cells from TIL compared to PBL and TAL (P < 0.01) and was more strongly inhibited by anti-HLA class I MAb (P < 0.05 compared to PBL and TAL). Phenotypically, all cytotoxic T lymphocyte (CTL) populations were CD3+/CD8+, with variable levels of CD56 expression. Finally, although a marked Type 1 cytokine bias [ie, interferon-gamma/interleukin-4 (IFN-γhigh/IL-4low)] was observable in all DC-stimulated CD8+ T-cell populations, TIL derived CD8+ T-cells showed a higher percentage of IFN-γ positive cells compared to TAL and PBL. Taken together, these data show that tumor lysate-pulsed DC can consistently restore strong CD8+ CTL responses from TIL against autologous ovarian cancer cells. DC-stimulated TIL may represent a superior source of tumor-specific CTL for adoptive T-cell immunotherapy for advanced ovarian cancer.

Restoration of tumor specific human leukocyte antigens class I-restricted cytotoxicity by dendritic cell stimulation of tumor infiltrating lymphocytes in patients with advanced ovarian cancer

Despite the large number of potentially cytotoxic tumor-infiltrating (TIL) and tumor-associated (TAL) lymphocytes accumulated in the peritoneal cavity ascitic fluid and tumor tissue, advanced ovarian cancer is a progressive disease, suggesting that TIL and TAL populations eventually become functionally suppressed in vivo. Dendritic cells (DC) are the most powerful professional antigen presenting cells known in humans and recently, ovarian tumor antigen pulsed DC have been shown to elicit tumor specific human leukocyte antigens (HLA)-class I-restricted cytotoxicity from the peripheral blood of advanced ovarian cancer patients. In this study, we have evaluated the potential of tumor antigen-pulsed fully mature DC stimulation in restoring tumor-specific cytotoxicity in anergic TIL populations from advanced ovarian cancer patients. In addition, we have compared tumor-specific T-cell responses induced by tumor antigen-loaded DC in TIL to those induced in TAL and peripheral blood lymphocytes (PBL). DC stimulation induced powerful cytotoxicity against autologous tumor target cells in TIL-derived CD8+ T-cells from all patients tested, while autologous Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCL) were not lysed. Killing of autologous tumor cells was higher by CD8+ T-cells from TIL compared to PBL and TAL (P < 0.01) and was more strongly inhibited by anti-HLA class I MAb (P < 0.05 compared to PBL and TAL). Phenotypically, all cytotoxic T lymphocyte (CTL) populations were CD3+/CD8+, with variable levels of CD56 expression. Finally, although a marked Type 1 cytokine bias [ie, interferon-gamma/interleukin-4 (IFN-gammahigh/IL-4low)] was observable in all DC-stimulated CD8+ T-cell populations, TIL derived CD8+ T-cells showed a higher percentage of IFN-gamma positive cells compared to TAL and PBL. Taken together, these data show that tumor lysate-pulsed DC can consistently restore strong CD8+ CTL responses from TIL against autologous ovarian cancer cells. DC-stimulated TIL may represent a superior source of tumor-specific CTL for adoptive T-cell immunotherapy for advanced ovarian cancer.

Molecular detection of cell line cross-contaminations using amplified fragment length polymorphism DNA fingerprinting technology

We have tested amplified fragment length polymorphism (AFLP) technology, in comparison with isoenzyme analysis, for the simultaneous detection of inter- and intraspecific cell line cross-contaminations (CCCs) in the cell line collection held at the Istituto Zooprofilattico della Lombardia e dell'Emilia Romagna. Isoenzyme analysis identified four cases of interspecific CCCs. In a single experiment, AFLP was able to identify the species of origin of all cell lines for which a reference genomic deoxyribonucleic acid was available and to detect five interspecific contaminations. Four CCCs confirmed data on isoenzymes, whereas the fifth CCC was detected in a species for which isoenzyme analysis was noninformative. In addition, AFLP was able to identify the putative source of the contaminations detected. The utility of the technology in the detection of intraspecific cell line contaminations depends on the number of cell lines that have to be distinguished in a specific species and on the availability of highly informative fingerprinting systems. In mice, a single AFLP primer pair produced 16 polymorphisms and distinguished all the 15 strains of mouse cell lines analyzed. In humans, 18 AFLPs identified 83 different profiles in the 159 cell lines analyzed. Amplified fragment length polymorphism can conveniently be applied for cell line fingerprinting in species for which hypervariable markers are not available. In species for which a highly informative multiplex of microsatellite markers is available, AFLP can still provide a useful and cheap tool for simultaneously testing inter- and intraspecific contaminations.

Establishment and characterization of two new pig cell lines for use in virological diagnostic laboratories

Two pig cell lines derived from kidney and trachea tissues and referred to as newborn swine kidney (NSK) and newborn pig trachea (NPTr) were established following serial culture of primary cells. They were characterized by an epithelial-like morphology, high capacity to replicate and stability of the cell monolayer for several days after seeding. Their modal chromosome number was modified in comparison to that of primary swine cells and they both displayed a transforming potential in vitro and displayed oncogenicity in nude mice. Infection with pig endogenous retroviruses was detected. Almost all the swine viruses tested, i.e., pseudorabies virus, pig parvovirus, hog cholera virus, transmissible gastroenteritis virus of swine, encephalomyocarditis virus, swine vesicular disease virus and the enteroviruses, except pig reproductive respiratory syndrome virus, were capable of replicating in the new cell lines with titres similar to the ones detected in the reference culture systems. Furthermore, all the selected influenza virus sub-types isolated from human, swine and avian species replicated with cytopathic effect in NSK and NPTr cells, whereas, of all the equine influenza viruses tested only the Miami and Suffolk sub-types replicated.