Expression profiles of epithelial-mesenchymal transition-associated proteins in epithelial ovarian carcinoma

Epithelial-mesenchymal transition (EMT) has been suggested to contribute to tumor progression and acquisition of therapeutic resistance. To assess the clinical significance of EMT-associated proteins, we evaluated the expression of Snail and Slug, the key regulators of EMT, in the primary ovarian cancer samples (n = 103) by immunohistochemistry. Snail was differentially expressed according to the histologic subtype (P = 0.001) and was predominantly expressed in serous and endometrioid types. In the serous and endometrioid adenocarcinomas, the expression of Snail remained high across the stage and grade, suggesting its role in the early phase of carcinogenesis. However, the expression of Snail and Slug was not related to chemoresistance and poor prognosis and did not serve as independent predictive or prognostic marker.

An mDia2/ROCK signaling axis regulates invasive egress from epithelial ovarian cancer spheroids

Multi-cellular spheroids are enriched in ascites of epithelial ovarian cancer (OvCa) patients. They represent an invasive and chemoresistant cellular population fundamental to metastatic dissemination. The molecular mechanisms triggering single cell invasive egress from spheroids remain enigmatic. mDia formins are Rho GTPase effectors that are key regulators of F-actin cytoskeletal dynamics. We hypothesized that mDia2-driven F-actin dynamics promote single cell invasive transitions in clinically relevant three-dimensional (3D) OvCa spheroids. The current study is a dissection of the contribution of the F-actin assembly factor mDia2 formin in invasive transitions and using a clinically relevant ovarian cancer spheroid model. We show that RhoA-directed mDia2 activity is required for tight spheroid organization, and enrichment of mDia2 in the invasive cellular protrusions of collagen-embedded OVCA429 spheroids. Depleting mDia2 in ES-2 spheroids enhanced invasive dissemination of single amoeboid-shaped cells. This contrasts with spheroids treated with control siRNA, where a mesenchymal invasion program predominated. Inhibition of another RhoA effector, ROCK, had no impact on ES-2 spheroid formation but dramatically inhibited spheroid invasion through induction of a highly elongated morphology. Concurrent inhibition of ROCK and mDia2 blocked single cell invasion from ES-2 spheroids more effectively than inhibition of either protein alone, indicating that invasive egress of amoeboid cells from mDia2-depleted spheroids is ROCK-dependent. Our findings indicate that multiple GTPase effectors must be suppressed in order to fully block invasive egress from ovarian cancer spheroids. Furthermore, tightly regulated interplay between ROCK and mDia2 signaling pathways dictates the invasive capacities and the type of invasion program utilized by motile spheroid-derived ovarian cancer cells. As loss of the gene encoding mDia2, DRF3, has been linked to cancer progression and metastasis, our results set the stage for understanding molecular mechanisms involved in mDia2-dependent egress of invasive cells from primary epithelial tumors.

Pathway modulations and epigenetic alterations in ovarian tumorbiogenesis

Cellular pathways are numerous and are highly integrated in function in the control of cellular systems. They collectively regulate cell division, proliferation, survival and apoptosis of cells and mutagenesis of key genes that control these pathways can initiate neoplastic transformations. Understanding these pathways is crucial to future therapeutic and preventive strategies of the disease. Ovarian cancers are of three major types; epithelial, germ-cell, and stromal. However, ovarian cancers of epithelial origin, arising from the mesothelium, are the predominant form. Of the subtypes of ovarian cancer, the high-grade serous tumors are fatal, with low survival rate due to late detection and poor response to treatments. Close examination of preserved ovarian tissues and in vitro studies have provided insights into the mechanistic changes occurring in cells mediated by a few key genes. This review will focus on pathways and key genes of the pathways that are mutated or have aberrant functions in the pathology of ovarian cancer. Non-genetic mechanisms that are gaining prominence in the pathology of ovarian cancer, miRNAs and epigenetics, will also be discussed in the review.

ZNF300P1 encodes a lincRNA that regulates cell polarity and is epigenetically silenced in type II epithelial ovarian cancer

Background

We previously identified that the CpG island-associated promoter of the novel lincRNA ZNF300P1 (also known as LOC134466) is frequently hypermethylated and silenced in ovarian cancer tissues. However, the function of ZNF300P1 was unknown. In this report we demonstrate that ZNF300P1 is involved in the regulation of key cell cycle and cell motility networks in human ovarian surface epithelial cells, and may play a role in promoting metastasis in ovarian cancer cells.

Methods

We applied methylated DNA immunoprecipitation on whole genome promoter tiling arrays and Sequenom assays to examine methylation status of ZNF300P1 in multiple ovarian cancer cell lines, as well as in normal ovarian and ovarian tumor tissues. Transcript profiling was used to investigate the effects of ZNF300P1 suppression in ovarian cancer cells. We utilized siRNA knockdown in normal ovarian surface epithelial cells and performed cellular proliferation, migration and adhesion assays to validate and explore the profiling results.

Results

We demonstrate that ZNF300P1 is methylated in multiple ovarian cancer cell lines. Loss of ZNF300P1 results in decreased cell proliferation and colony formation. In addition, knockdown of the ZNF300P1 transcript results in aberrant and less persistent migration in wound healing assays due to a loss of cellular polarity. Using an ex vivo peritoneal adhesion assay, we also reveal a role for ZNF300P1 in the attachment of ovarian cancer cells to peritoneal membranes, indicating a potential function of ZNF300P1 expression in metastasis of ovarian cancer cells to sites within the peritoneal cavity.

Conclusion

Our findings further support ZNF300P1 as frequently methylated in ovarian cancer and reveal a novel function for ZNF300P1 lincRNA expression in regulating cell polarity, motility, and adhesion and loss of expression may contribute to the metastatic potential of ovarian cancer cells.

Borderline tumours of the ovary, current controversies regarding their diagnosis and treatment

Borderline ovarian tumours generally affect women of reproductive age. The positive prognosis is related to the fact that over 80% of cases are diagnosed at an early stage of the disease. Although radical surgery is the standard of care for this disease, fertility-sparing surgery can be performed in selected cases. Since it was first described in 1929, the knowledge of the molecular and histologic characteristics has been significantly improved. In this review, advances in the clinical behaviour, pathologic characteristics, prognostics factors, and different strategies of treatment are discussed.

Disarming mutant p53 oncogenic function

In the last decade intensive research has confirmed the long standing hypothesis that some p53 point mutants acquire novel activities able to cooperate with oncogenic mechanisms. Particular attention has attracted the ability of several such mutants to actively promote the development of aggressive and metastatic tumors in vivo. This knowledge opens a new dimension on rational therapy design, suggesting novel strategies based on pharmacological manipulation of those neomorphic activities. P53 point mutants have several characteristics that make them attractive targets for anti-cancer therapies. Remarkably, mutant p53 has been found predominantly in tumor cells and may act pleiotropically by interfering with a variety of cellular processes. Therefore, drugs targeting mutant p53 may selectively affect tumor cells, inactivating simultaneously several mechanisms of tumor promotion. Moreover, the high frequency of missense mutations on the p53 gene suggests that interfering with mutant p53 function may provide a valuable approach for the development of efficient therapies able to target a wide range of tumor types.

The role of the fallopian tube in the origin of ovarian cancer

Advanced cases of epithelial ovarian, primary peritoneal, and primary tubal malignancies have a relatively poor prognosis and collectively remain the most deadly of all gynecologic malignancies. Although traditionally thought of as one disease process, ongoing research suggests that there is not 1 single site or cell type from which these cancers arise. A majority of the serous tumors appear to originate from dysplastic lesions in the distal fallopian tube. Therefore, what we have traditionally considered "ovarian" cancer may in fact be tubal in origin. In this article, we will review epithelial ovarian cancer classification and genetics, theories regarding cells of origin with a focus on tubal intraepithelial carcinoma, and implications for prevention and screening.

Expression and purification of the extracellular domain of the human follicle-stimulating hormone receptor using Escherichia coli

AIM

Although much is known about the structure and biological functions of follicle-stimulating hormone (FSH) receptor (FSHR), the interaction of FSHR and FSH has been challenging to characterize due to the limited quantity of active FSHR protein produced by simple methods. The goal of this study was to express and purify the extracellular domain (ECD) of human FSHR (hFSHR).

METHODS

Total RNA was isolated from normal human ovary tissue. cDNA for hFSHR ECD were amplified and subsequently ligated into the pET32a(+) vector. The plasmid vector construct was confirmed by polymerase chain reaction and sequencing. Expression in Escherichia coli Rosetta (DE3) pLysS strain was induced by isopropyl-thio-β-D-thiogalactoside, and the recombinant products were purified by immuno-affinity chromatography using an Ni-NTA and High-Q column. The recombinant protein was confirmed by western blotting.

RESULTS

Following induction, E. coli expressed a recombinant protein of approximately 65 kDa in size, whereas the non-induced E. coli did not express the recombinant protein. The recombinant fragments purified using a High-Q column demonstrated a single band and an abundant yield. The recombinant protein was soluble and specifically recognized by an antibody for hFSHR. Additionally, four mutation sites were detected that resulted in amino acid shifts at position 112 Asn/Thr, 197 Glu/Ala, 198 Leu/Val and 307 Ala/Thr.

CONCLUSION

The recombinant hFSHR ECD protein was expressed and purified. This method could be easily scaled for increased production and may facilitate additional applications utilizing FSHR in assisted reproductive technology, a contraceptive FSH vaccine and FSHR-targeted therapeutic agents used to treat ovarian cancer.

Aspirin Blocks EGF-stimulated Cell Viability in a COX-1 Dependent Manner in Ovarian Cancer Cells

Objective: Although aspirin has been associated with a reduction of the risk of cancer when used as a nonsteroidal anti-inflammatory drug, its use to reduce the risk of ovarian cancer is controversial. Ovarian cancer cells usually express high levels of cyclooxygenase-1 (COX)-1. Because aspirin is a rather selective inhibitor of COX-1, the ability of aspirin to reduce the risk of ovarian cancer may be dependent on the level of COX-1 expression in those cells. Furthermore, epidermal growth factor receptor (EGFR) is frequently overexpressed in the malignant phenotype of ovarian cancer leading to increased cell proliferation and survival. Here we investigated if aspirin attenuates EGFR-activated ovarian cancer cell growth in a COX-1 dependent manner.

Methods: Cell viability assays and Western blot analyses were used to determine the effect of aspirin on EGF-stimulated cell proliferation. Gene silencing and gene expression techniques were employed to knockdown or to express COX-1, respectively.

Results: Aspirin inhibited cell viability induced by EGF in a dose dependent manner in COX-1 positive ovarian cancer cells. On the other hand, aspirin had no effect on cell viability in COX-1 negative ovarian cancer cells. In particular, aspirin decreased phosphorylated Akt and Erk activated by EGF. COX-1 silencing in COX-1 positive cells attenuated the inhibitory effect of aspirin on EGF-stimulated cell viability. Furthermore, we developed a COX-1 expressing cell line (SKCOX-1) by stably transfecting COX-1 expression vector into COX-1 negative SKOV-3 cells. SKCOX-1 cells were more responsive to aspirin when compared to cells transfected with empty vector, and decreased EGF-activated Akt and Erk as well as cell viability.

Conclusions: Taken together, aspirin inhibits viability of ovarian cancer cells by blocking phosphorylation of Akt and Erk activated by EGF. Thus it may potentiate the therapeutic efficacy of drugs used to treat COX-1 positive ovarian cancer subsets.

Tracking NF-κB activity in tumor cells during ovarian cancer progression in a syngeneic mouse model

Background

Nuclear factor-kappa B (NF-kappaB) signaling is an important link between inflammation and peritoneal carcinomatosis in human ovarian cancer. Our objective was to track NF-kappaB signaling during ovarian cancer progression in a syngeneic mouse model using tumor cells stably expressing an NF-kappaB reporter.

Methods

ID8 mouse ovarian cancer cells stably expressing an NF-kappaB-dependent GFP/luciferase (NGL) fusion reporter transgene (ID8-NGL) were generated, and injected intra-peritoneally into C57BL/6 mice. NGL reporter activity in tumors was non-invasively monitored by bioluminescence imaging and measured in luciferase assays in harvested tumors. Ascites fluid or peritoneal lavages were analyzed for inflammatory cell and macrophage content, and for mRNA expression of M1 and M2 macrophage markers by quantitative real-time RT-PCR. 2-tailed Mann-Whitney tests were used for measuring differences between groups in in vivo experiments.

Results

In ID8-NGL cells, responsiveness of the reporter to NF-kappaB activators and inhibitors was confirmed in vitro and in vivo. ID8-NGL tumors in C57BL/6 mice bore histopathological resemblance to human high-grade serous ovarian cancer and exhibited similar peritoneal disease spread. Tumor NF-kappaB activity, measured by the NGL reporter and by western blot of nuclear p65 expression, was markedly elevated at late stages of ovarian cancer progression. In ascites fluid, macrophages were the predominant inflammatory cell population. There were elevated levels of the M2-like pro-tumor macrophage marker, mannose-receptor, during tumor progression, and reduced levels following NF-kappaB inhibition with thymoquinone.

Conclusions

Our ID8-NGL reporter syngeneic model is suitable for investigating changes in tumor NF-kappaB activity during ovarian cancer progression, how NF-kappaB activity influences immune cells in the tumor microenvironment, and effects of NF-kappaB-targeted treatments in future studies.

Flaxseed enriched diet-mediated reduction in ovarian cancer severity is correlated to the reduction of prostaglandin E(2) in laying hen ovaries

Prevention of ovarian cancer is the best approach for reducing the impact of this deadly disease. The laying hen is a robust model of spontaneous ovarian cancer that recapitulates the human disease. Dietary intervention with flaxseed, the richest vegetable source of omega-3 fatty acids (OM-3FAs) and phytoestrogen lignans, demonstrate the potential for effective prevention and amelioration of ovarian cancer by targeting inflammatory prostaglandin pathways. Prostaglandin E2 (PGE2) is the most pro-inflammatory ecoisanoid and one of the downstream products of two isoforms of cyclooxygenase (COX) enzymes: COX-1 and COX-2. Our objective was to investigate the effect of flaxseed supplementation for one year on ovarian cancer and correlate its effects to expression of COX enzymes and concentrations of prostaglandins. White Leghorn hens were fed 10% flaxseed-enriched or standard diet for one year. The severity of ovarian cancer was determined by gross pathology and histology. COX-1 and COX-2 localization and protein and mRNA expression and PGE2 and PGE3 concentrations in ovaries were measured by IHC, western blot, quantitative real-time PCR and LC-MS-MS, respectively. The results demonstrated a significant reduction in late stage ovarian tumors in the flaxseed-fed hens compared with the control diet-fed hens. In correlation with decreased ovarian cancer severity, concentrations of PGE2 and expression of COX-2 were diminished in ovaries of flaxseed-fed hens. PGE3 concentrations were below the level of detection. The results demonstrated that in normal ovaries, COX-1 was localized to the granulosa cell layer surrounding the follicles and ovarian surface epithelium (OSE) whereas COX-2 protein was localized to the granulosa cell layer in the follicle. Extensive COX-1 and COX-2 protein expression was found throughout the ovarian carcinoma. Our findings suggest that the flaxseed-mediated reduction in the severity of ovarian cancer in hens is correlated to the reduction in PGE2 in the ovaries of flaxseed-fed hens. These findings may provide the basis for clinical trials of dietary intervention targeting prostaglandin biosynthesis for the prevention and treatment of ovarian cancer.

Modeling High-Grade Serous Carcinoma: How Converging Insights into Pathogenesis and Genetics are Driving Better Experimental Platforms

Recent developments in the study of epithelial ovarian cancer have called into question the traditional views regarding the site of tumor initiation. Histopathologic studies and genomic analyses suggest that extra-ovarian sites, like the fallopian tube, may harbor the coveted cell of origin and could therefore contribute significantly to the development of high-grade serous ovarian carcinoma (HG-SOC). Our ability to validate these emerging genomic and pathologic observations and characterize the early transformation events of HG-SOC hinges on the development of novel model systems. Currently, there are only a handful of new model systems that are addressing these concerns. This review will chronicle the convergent evolution of these ovarian cancer model systems in the context of the changing pathologic and genomic understanding of HG-SOC.

Epithelial ovarian cancer experimental models

Epithelial ovarian cancer (OvCa) is associated with high mortality and, as the majority (>75%) of women with OvCa have metastatic disease at the time of diagnosis, rates of survival have not changed appreciably over 30 years. A mechanistic understanding of OvCa initiation and progression is hindered by the complexity of genetic and/or environmental initiating events and lack of clarity regarding the cell(s) or tissue(s) of origin. Metastasis of OvCa involves direct extension or exfoliation of cells and cellular aggregates into the peritoneal cavity, survival of matrix-detached cells in a complex ascites fluid phase and subsequent adhesion to the mesothelium lining covering abdominal organs to establish secondary lesions containing host stromal and inflammatory components. Development of experimental models to recapitulate this unique mechanism of metastasis presents a remarkable scientific challenge, and many approaches used to study other solid tumors (for example, lung, colon and breast) are not transferable to OvCa research given the distinct metastasis pattern and unique tumor microenvironment (TME). This review will discuss recent progress in the development and refinement of experimental models to study OvCa. Novel cellular, three-dimensional organotypic, and ex vivo models are considered and the current in vivo models summarized. The review critically evaluates currently available genetic mouse models of OvCa, the emergence of xenopatients and the utility of the hen model to study OvCa prevention, tumorigenesis, metastasis and chemoresistance. As these new approaches more accurately recapitulate the complex TME, it is predicted that new opportunities for enhanced understanding of disease progression, metastasis and therapeutic response will emerge.

Endoglin is necessary for angiogenesis in human ovarian carcinoma-derived primary endothelial cells

Endoglin (CD105, END) is upregulated in proliferating endothelial cells, suggesting potential therapeutic properties. However, it is not clear whether endoglin mediates an enhanced proliferative rate or may be upregulated as part of a negative feedback loop. To gain insights into context-dependent and cell type-dependent regulatory effects of endoglin, we studied its role properties in human ovarian carcinoma-derived endothelial cells (ODMECs). We isolated and cultured primary ODMECs from epithelial ovarian carcinoma tissue. ODMECs had higher expression of endoglin and VEGFR-2, and also exhibited enhanced spontaneous formation of vessel-like structures in vitro. Transfection of siRNA targeting endoglin in ODMECs cells resulted in the reduction of the proliferation and tube formation. These results indicate that a subset of ODMECs display abnormal angiogenic properties and this phenotype was blocked by decreasing endoglin levels, suggesting endoglin is essential for stimulating angiogenesis, and targeting it may be an attractive approach to anti-angiogenesis therapy for ovarian carcinoma.

Utility of progranulin and serum leukocyte protease inhibitor as diagnostic and prognostic biomarkers in ovarian cancer

BACKGROUND

Epithelial ovarian cancer (EOC) is the fifth leading cause of cancer-related death in females and leading gynecologic cause of cancer-related death. Despite the identification of a number of serum biomarkers, methods to identify early-stage disease and predict prognosis remain scarce. We have evaluated two biologically connected serum biomarkers, serum leukocyte protease inhibitor (SLPI) and progranulin (PGRN).

METHODS

Two-hundred frozen plasma samples were acquired from the Mayo Clinic Biospecimen Repository for Ovarian Cancer Research. Samples were obtained from 50 patients with benign conditions, 50 with American Joint Committee on Cancer (AJCC) stage I and II EOC, and 100 with AJCC stage III and IV EOC. Samples were obtained before surgical resection of a mass and were analyzed for absolute levels of SLPI and PGRN using ELISA assays. Receiver-operator characteristic curves were generated for SLPI and PGRN. Median follow-up was 48 months.

RESULTS

Absolute levels of SLPI were significantly elevated in patients with EOC compared with benign disease and predicted the presence of EOC (AUC of 0.812; P = 0.04); SLPI remained elevated in the subset of patients with normal CA-125. PGRN levels were not significantly increased in patients with early-stage or late-stage EOC as a whole, but an increase in PGRN levels was associated with decreased overall survival in advanced EOC.

CONCLUSIONS

SLPI levels are elevated in EOC, and SLPI shows promise as a diagnostic biomarker for patients with both elevated and normal CA-125 levels. An increase in PGRN is associated with decreased overall survival.

IMPACT

SLPI is elevated in EOC and warrants investigation in a screening study in women at risk for EOC.

In vivo and in vitro studies on apoptosis in OSE cells and inclusion cysts of pregnant heifers

Elevated progesterone concentration during pregnancy and use of progesterone-like contraceptives are known to reduce ovarian cancers. This study was undertaken to decipher whether or not there is any relationship between progesterone (also oestrogen)-mediated ovarian surface epithelium (OSE) apoptosis and expression of p53, a cell-cycle arresting protein and potential tumour suppressor. Immunohistochemical staining with cytokeratin confirmed epithelial nature of the cells in the OSE layer and inclusion cysts that invaginate inside stroma after ovulation takes place. The in situ apoptosis index was determined during oestrus, and at mid and late-pregnancy stages in heifers. Epithelia of both tissues exhibited significantly high nuclear staining, suggesting that these cells are aiming to apoptotic destruction. To further establish a role of progesterone, the OSE cells were exposed in vitro to two concentrations of oestrogen and progesterone. It was revealed that progesterone at both concentrations and oestrogen only at high concentration converted a large proportion of these cells apoptotic. The stimulatory effect of progesterone (and to some extent oestrogen) was also seen on p53 expression in the same cultivated OSE cells. The steroid dosage dependence for apoptosis and p53 expression was also somewhat similar. Assuming that progesterone action is mediated through p53-caused apoptosis as a mechanism to evade malignant transformation of OSE cells, p53 expression at mRNA and protein level was investigated in the OSE layer in proximity to stroma, antrum and corpus luteum (CL). In cycling animals CL produces a large amount of progesterone and also oestrogen to maintain the post-ovulatory cycle and to suppress the gonadotropin production. Hence, cells undergoing re-epithelialization and which are in contact with CL were expected to undergo maximum apoptotic modification. Indeed we got the maximum p53/p53 gene expression in these cells. We conclude that progesterone during cycling and pregnancy may reduce the risk of developing ovarian cancer by ceasing cell cycle and diverting damaged and mutagenized OSE cells for apoptosis, and the process may be mediated through elevated p53 synthesis. However, it is also possible that progesterone and p53-induced apoptosis may be entirely different cancer suppressive actions but coincidently happening together.

Targeted paclitaxel nanoparticles modified with follicle-stimulating hormone β 81-95 peptide show effective antitumor activity against ovarian carcinoma

The majority of patients with advanced ovarian cancer will experience a relapse and ultimately die from refractory diseases. Targeted therapy shows promise for these patients. Novel therapeutic strategies should be developed on the basis of the molecular mechanisms involved in ovarian cancer and the steroid hormone environment of ovaries. The ovary is the main target organ of follicle-stimulating hormone (FSH), which bind to its receptor with high affinity. In this study a FSH receptor-targeting ligand, FSH β 81-95 peptide, was used as a targeting moiety to synthesize an FSH receptor-mediated drug delivery system. FSH β 81-95 peptide-conjugated nanoparticles (FSH81-NPs) and paclitaxel-loaded FSH81-NPs (FSH81-NP-PTXs) were synthesized. In vitro studies showed that FSH β 81-95 peptide enabled the specific uptake of cytotoxic drugs and increased the intracellular paclitaxel concentration in FSH receptor-expressing cancer cells, resulting in enhanced cytotoxic effects. In vivo studies showed that FSH81-NP-PTXs possessed higher antitumor efficacy against FSH receptor-expressing tumors without any clinical signs of adverse side effects or body weight loss due to modification with FSH β 81-95 peptide. Therefore, FSH binding peptide-targeted drug delivery system exhibited high potential in the treatment of ovarian cancer, and tumor targeting via reproductive hormone receptors might improve the outcome of diseases.

Characteristics of chemokine signatures elicited by EGF and TNF in ovarian cancer cells

Background

Ovarian cancer, an inflammation-associated cancer, is the fifth leading cause of cancer deaths in women. The malignancy produces a large amount of tumor necrosis factor (TNF) which promotes a proinflammatory tumor microenvironment. In addition, the epidermal growth factor receptor (EGFR) is frequently overexpressed in high-grade ovarian cancer, which likely aggravates cancer progression. Since ovarian cancer progression is closely associated with chemokine networks driven by inflammation or EGFR activation, we investigated the chemokine signatures elicited by EGF and TNF in ovarian cancer cells to determine their individual profiles and if there was in fact some kind of synergy between their actions on the chemokine network.

Methods

We used a PCR array for the chemokine network to examine the signature of chemokines and their receptors elicited by EGF and TNF in four ovarian cancer cell lines (OVCAR-3, SKOV-3, CaOV-3 and TOV-21G).

Results

The chemokine network revealed that ovarian cancer cells commonly expressed high levels of proinflammatory chemokines such as CCL20, CXCL1-3 and CXCL8 in response to EGF or TNF. However, the responsiveness to EGF or TNF displayed a cell line specific pattern. Although OVCAR-3 and SKOV-3 cells were responsive to either EGF or TNF, their TNF responsiveness was dominant. On the other hand, CaOV-3 and TOV-21G cells were responsive to EGF but less to TNF, probably due to the high levels of non-canonical nuclear factor (NF)-κB components such as IKKα and p52 in these cell lines compared to OVCAR-3 and SKOV-3 cells. Among chemokine receptors, only CXCR5 was responsive to EGF or TNF in CaOV-3 cells. Finally, CCL20 and CXCL8 responded synergistically in response to EGF and TNF in OVCAR-3 and SKOV-3 cells.

Conclusion

Our results indicate that CCL20, CXCL1-3 and CXCL8 are the primary chemokines induced by EGF or TNF and are elicited in these ovarian cancer cells via NF-κB, Akt and Erk signaling pathways. Of interest, there was a syngergistic response in terms of CCL20 and CXCL8 levels, when OVCAR-3 and SKOV-3 cells were exposed to EGF plus TNF. Targeting these proinflammatory chemokines may be a promising therapeutic strategy for ovarian cancer with abundant TNF and EGFR activation patterns.

Inhibition of focal adhesion kinase (FAK) activity prevents anchorage-independent ovarian carcinoma cell growth and tumor progression

Recurrence and spread of ovarian cancer is the 5th leading cause of death for women in the United States. Focal adhesion kinase (FAK) is a cytoplasmic protein-tyrosine kinase located on chromosome 8q24.3 (gene is Ptk2), a site commonly amplified in serous ovarian cancer. Elevated FAK mRNA levels in serous ovarian carcinoma are associated with decreased (logrank P = 0.0007, hazard ratio 1.43) patient overall survival, but how FAK functions in tumor progression remains undefined. We have isolated aggressive ovarian carcinoma cells termed ID8-IP after intraperitoneal (IP) growth of murine ID8 cells in C57Bl6 mice. Upon orthotopic implantation within the peri-ovarian bursa space, ID8-IP cells exhibit greater tumor growth, local and distant metastasis, and elevated numbers of ascites-associated cells compared to parental ID8 cells. ID8-IP cells exhibit enhanced growth under non-adherent conditions with elevated FAK and c-Src tyrosine kinase activation compared to parental ID8 cells. In vitro, the small molecule FAK inhibitor (Pfizer, PF562,271, PF-271) at 0.1 uM selectively prevented anchorage-independent ID8-IP cell growth with the inhibition of FAK tyrosine (Y)397 but not c-Src Y416 phosphorylation. Oral PF-271 administration (30 mg/kg, twice daily) blocked FAK but not c-Src tyrosine phosphorylation in ID8-IP tumors. This was associated with decreased tumor size, prevention of peritoneal metastasis, reduced tumor-associated endothelial cell number, and increased tumor cell-associated apoptosis. FAK knockdown and re-expression assays showed that FAK activity selectively promoted anchorage-independent ID8-IP cell survival. These results support the continued evaluation of FAK inhibitors as a promising clinical treatment for ovarian cancer.

TR3 modulates platinum resistance in ovarian cancer

In metastatic ovarian cancer, resistance to platinum chemotherapy is common. Although the orphan nuclear receptor TR3 (nur77/NR4A1) is implicated in mediating chemotherapy-induced apoptosis in cancer cells, its role in ovarian cancer has not been determined. In an ovarian cancer tissue microarray, TR3 protein expression was elevated in stage I tumors, but downregulated in a significant subset of metastatic tumors. Moreover, TR3 expression was significantly lower in platinum-resistant tumors in patients with metastatic disease, and low TR3 staining was associated with poorer overall and progression-free survival. We have identified a direct role for TR3 in cisplatin-induced apoptosis in ovarian cancer cells. Nucleus-to-cytoplasm translocation of TR3 was observed in cisplatin-sensitive (OVCAR8, OVCAR3, and A2780PAR) but not cisplatin-resistant (NCI/ADR-RES and A2780CP20) ovarian cancer cells. Immunofluorescent analyses showed clear overlap between TR3 and mitochondrial Hsp60 in cisplatin-treated cells, which was associated with cytochrome c release. Ovarian cancer cells with stable shRNA- or transient siRNA-mediated TR3 downregulation displayed substantial reduction in cisplatin effects on apoptotic markers and cell growth in vitro and in vivo. Mechanistic studies showed that the cisplatin-induced cytoplasmic TR3 translocation required for apoptosis induction was regulated by JNK activation and inhibition of Akt. Finally, cisplatin resistance was partially overcome by ectopic TR3 overexpression and by treatment with the JNK activator anisomycin and Akt pathway inhibitor, wortmannin. Our results suggest that disruption of TR3 activity, via downregulation or nuclear sequestration, likely contributes to platinum resistance in ovarian cancer. Moreover, we have described a treatment strategy aimed at overcoming platinum resistance by targeting TR3.

Long term consumption of flaxseed enriched diet decreased ovarian cancer incidence and prostaglandin E₂in hens

OBJECTIVE

Ovarian cancer is the most lethal gynecological malignancy. Prevention may be the best approach to reduce ovarian cancer. Flaxseed is the richest vegetable source of omega-3 fatty acids which may be effective in the prevention of ovarian cancer. Prostaglandin E₂ (PGE₂) is the most pro-inflammatory ecoisanoid and one of the downstream products of two isoforms of cyclooxygenase (COX) enzymes: COX-1 and COX-2. Our objective was to determine if long-term consumption of a flaxseed enriched diet decreased ovarian cancer severity and incidence in the laying hen and to investigate its potential correlation with the expression of COX enzymes and PGE₂ concentration.

METHODS

White Leghorn hens were fed 10% flaxseed-enriched or standard diet for 4years. The severity and incidence of ovarian cancer were determined by gross pathology and histology. COX-1 and COX-2 protein and mRNA expression and PGE₂ concentrations in ovaries were measured by Western blot, quantitative real-time PCR and ELISA, respectively.

RESULTS

The results demonstrated that there was a reduction in ovarian cancer severity and incidence in hens fed flaxseed diet. In correlation with decreased ovarian cancer severity and incidence, concentration of PGE₂ and expression of COX-2 were diminished in ovaries of hens fed flaxseed.

CONCLUSIONS

Our findings suggest that the lower levels of COX-2 and PGE₂ are the main contributing factors in the chemo-suppressive role of long-term flaxseed consumption in ovarian cancer in laying hens. These findings may provide the basis for clinical trials of dietary intervention targeting prostaglandin biosynthesis for the prevention and treatment of ovarian cancer.

Primary fallopian tube carcinoma

Primary fallopian tube carcinoma (PFTC) is a rare gynaecological tumour that accounts for 0.14-1.8% of genital malignancies. The most common age of occurrence is between 40 and 65 years, and the mean age is 55 years. The factors that contribute to its appearance are not well known. Population studies show that the mean incidence of PFTC is 3.6 per million women per annum. Overall survival percentages for patients with PFTC are generally low, in the range of 22-57%. Pre-operative diagnosis is rare and PFTC is usually confirmed by a pathologist, but earlier diagnosis with early clinical manifestation and prompt investigation improves the prognosis. Both PFTC and epithelial ovarian cancer (EOC) are treated with similar surgical and chemotherapy methods. Studies have shown that the prognosis for PFTC is worse than that for EOC or other primary gynaecological tumours. This article reviews and presents the current updates of this rare gynaecological malignancy.

Stathmin regulates mutant p53 stability and transcriptional activity in ovarian cancer

Stathmin is a p53-target gene, frequently overexpressed in late stages of human cancer progression. Type II High Grade Epithelial Ovarian Carcinomas (HG-EOC) represents the only clear exception to this observation. Here, we show that stathmin expression is necessary for the survival of HG-EOC cells carrying a p53 mutant (p53^MUT) gene. At molecular level, stathmin favours the binding and the phosphorylation of p53^MUT by DNA-PK_CS, eventually modulating p53^MUT stability and transcriptional activity. Inhibition of stathmin or DNA-PK_CS impaired p53^MUT–dependent transcription of several M phase regulators, resulting in M phase failure and EOC cell death, both in vitro and in vivo. In primary human EOC a strong correlation exists between stathmin, DNA-PK_CS, p53^MUT overexpression and its transcriptional targets, further strengthening the relevance of the new pathway here described. Overall our data support the hypothesis that the expression of stathmin and p53 could be useful for the identification of high risk patients that will benefit from a therapy specifically acting on mitotic cancer cells.

Inhibition of tumor growth and metastasis by a self-therapeutic nanoparticle

Although biomedical applications of nanotechnology, which typically involve functionalized nanoparticles, have taken significant strides, biological characterization of unmodified nanoparticles remains underinvestigated. Herein we demonstrate that unmodified gold nanoparticles (AuNPs) inhibit the proliferation of cancer cells in a size- and concentration-dependent manner by abrogating MAPK-signaling. In addition, these AuNPs reverse epithelial-mesenchymal transition (EMT) in cancer cells by reducing secretion of a number of proteins involved in EMT, up-regulating E-Cadherin, and down-regulating Snail, N-Cadherin, and Vimentin. Inhibition of MAPK signaling and reversal of EMT upon AuNP treatment inhibits tumor growth and metastasis in two separate orthotopic models of ovarian cancer. Western blot analyses of tumor tissues reveal up-regulation of E-Cadherin and down-regulation of Snail and phospho-MAPK, confirming the reversal of EMT and inhibition of MAPK signaling upon AuNP treatment. The ability of a single self-therapeutic nanoparticle to abrogate signaling cascades of multiple growth factors is distinctive and purports possible medical applications as potential antitumor and antimetastatic agent.

Identifying early events of gene expression in breast cancer with systems biology phylogenetics

Advanced omics technologies such as deep sequencing and spectral karyotyping are revealing more of cancer heterogeneity at the genetic, genomic, gene expression, epigenetic, proteomic, and metabolomic levels. With this increasing body of emerging data, the task of data analysis becomes critical for mining and modeling to better understand the relevant underlying biological processes. However, the multiple levels of heterogeneity evident within and among populations, healthy and diseased, complicate the mining and interpretation of biological data, especially when dealing with hundreds to tens of thousands of variables. Heterogeneity occurs in many diseases, such as cancers, autism, macular degeneration, and others. In cancer, heterogeneity has hampered the search for validated biomarkers for early detection, and it has complicated the task of finding clonal (driver) and nonclonal (nonexpanded or passenger) aberrations. We show that subtyping of cancer (classification of specimens) should be an a priori step to the identification of early events of cancers. Studying early events in oncogenesis can be done on histologically normal tissues from diseased individuals (HNTDI), since they most likely have been exposed to the same mutagenic insults that caused the cancer in their neighboring tissues. Polarity assessment of HNTDI data variables by using healthy specimens as outgroup(s), followed by the application of parsimony phylogenetic analysis, produces a hierarchical classification of specimens that reveals the early events of the disease ontogeny within its subtypes as shared derived changes (abnormal changes) or synapomorphies in phylogenetic terminology.

Decreased expression of Beclin 1 correlates closely with Bcl-xL expression and poor prognosis of ovarian carcinoma

Background

It has been suggested that autophagy-related Beclin 1 plays a critical role in the regulation of tumor development and/or progression, but its prognostic significance and relationship with Bcl-xL expression in ovarian carcinoma are unclear.

Methodology/Principal Findings

In the present study, the methods of Western blotting and immunohistochemistry (IHC) were utilized to investigate the expression status of Beclin 1 and Bcl-xL in fresh ovarian tissues and paraffin-embedded epithelial ovarian tumor tissues. Decreased expression of Beclin 1 was examined by IHC in 8.3% of normal ovaries, in 15.4% of cystadenomas, in 20.0% of borderline tumors, and in 55.6% of ovarian carcinomas, respectively. In ovarian carcinomas, decreased expression of Beclin 1 was correlated closely with ascending histological grade, later pT/pN/pM status and/or advanced clinical stage (P<0.05). In univariate survival analysis, a highly significant association between low-expressed Beclin 1 and shortened patient survival was evaluated in ovarian carcinoma patients (P<0.01), and Beclin 1 expression was an independent prognostic factor as evidenced by multivariate analysis (P = 0.013). In addition, decreased expression of Beclin 1 was inversely correlated with altered expression of Bcl-xL in ovarian carcinoma cohort, and combined analysis further showed that the low Beclin 1/high Bcl-xL group had the lowest survival rate.

Conclusions/Significance

Our findings suggest that Beclin 1 expression, as examined by IHC, could be served as an additional tool in identifying ovarian carcinoma patients at risk of tumor progression, and predicting patient survival in ovarian carcinomas with increased expression of Bcl-xL.

Global ovarian cancer health disparities

OBJECTIVE

The objective of this article is to broadly review the scientific literature and summarize the most up-to-date findings on ovarian cancer health disparities worldwide and in the United States (U.S.).

METHODS

The present literature on disparities in ovarian cancer was reviewed. Original research and relevant review articles were included.

RESULTS

Ovarian cancer health disparities exist worldwide and in the U.S. Ovarian cancer disproportionately affect African American women at all stages of the disease, from presentation through treatment, and ultimately increased mortality and decreased survival, compared to non-Hispanic White women. Increased mortality is likely to be explained by unequal access to care and non-standard treatment regimens frequently administered to African American women, but may also be attributed to genetic susceptibility, acquired co-morbid conditions and increased frequency of modifiable risk factors, albeit to substantially lesser extent. Unequal access to care is, in turn, largely a consequence of lower socioeconomic status and lack of private health insurance coverage among the African American population.

CONCLUSIONS

Our findings suggest the need for policy changes aimed at facilitating equal access to quality medical care. At the same time, further research is necessary to fully resolve racial disparities in ovarian cancer.

Tu-be or not tu-be: that is the question… about serous ovarian carcinogenesis

Our understanding of the early natural history of epithelial ovarian carcinoma is limited by the access to early lesions as the disease is very often diagnosed at advanced stages. The incessant ovulation theory from the last century that indicated the ovary as the site for the initiation of high-grade serous cancers is contrary to the newly emerging idea that ovarian cancer could arise from the distal fallopian tube. In view of the recent pathological and molecular studies, we propose to discuss the genesis of high-grade serous ovarian cancer.

Ovarian epithelial tumors and reproductive factors: a systematic review

PURPOSE

The aim of this systematic review is to summarize the current knowledge about the etiology and pathogenesis of borderline tumors ovarian cancer with special emphasis on the role of endocrine treatments and reproductive factors to establish a foundation for future studies.

METHODS

We performed a systematic review on the relation between ovarian epithelial tumors (OET) and reproductive factors using the keywords: ovarian cancer, ovarian tumor, ovarian borderline tumor, age at menarche, age at menopause, parity, infertility, PCO syndrome, oral contraception, menopausal hormone therapy, fertility treatment. Totally, 3,290 abstracts were scanned for their relevance in this publication and 127 were finally included.

RESULTS

The incidence of ovarian epithelial cancer and ovarian borderline tumors is influenced by certain reproductive factors. The strongest protective effects are conferred by parity and use of oral contraceptive pills. Recent molecular biologic and histopathologic studies prove that OET represent a diverse group of tumors, each histologic type with a different genetic background. This is at least partly reflected in epidemiologic and clinical studies showing different risk modulating effects of reproductive factors and endocrine therapies on OET.

CONCLUSIONS

The etiology and pathogenesis of ovarian cancer are still not fully understood. None of the so far proposed hypothesis on the development of OET can fully account for the epidemiologic and clinical findings in the context of reproductive factors and OET development. Further research approaches are warranted and need to put more weight on the clinical and genetical diversity of OET to yield a more detailed insight into their pathogenesis.

Clinicopathologic study of serous tubal intraepithelial carcinoma with invasive carcinoma: is serous tubal intraepithelial carcinoma a reliable feature for determining the organ of origin?

In the past several decades, the concept of serous ovarian carcinoma has been revised repeatedly. However, the exact pathogenesis remains controversial. The most popular current concept is origin from the epithelium of the fimbriated ends of the fallopian tubes. The objective of our study was to evaluate the characteristic clinical and morphologic features of serous tubal intraepithelial carcinoma (STIC) and associated invasive carcinomas. One hundred sixteen consecutive cases of STIC seen from 2007 to 2011 were included in this study. High-grade serous carcinoma (HGSC) with or without a mixed component was identified in 107 cases (92.2%), non-HGSC in 5 cases, and STICs without invasive carcinoma in 4 cases. Using conventional criteria, HGSCs were classified as fallopian tube in origin in 65 cases (60.7%), as ovarian in 30 (28.0%), as peritoneal in 9 (8.4%), and as endometrial in 3 (2.8%). Among the 107 cases with HGSCs, most STICs (86; 80%) were present unilaterally, whereas invasive tumors more commonly involved the ovaries bilaterally (79%; 84 cases). These findings support the hypothesis that STIC acts as a precursor lesion for most fallopian tube, ovarian, and peritoneal HGSCs, but not for endometrial HGSC.

Epigenetic analysis of the Notch superfamily in high-grade serous ovarian cancer

OBJECTIVES

Gene methylation and other epigenetic modifications of gene regulation have been implicated in the growth of ovarian cancer, but the clinical significance of such modifications in the Notch pathway in high-grade serous ovarian cancer (HGS-OvCa) is not well understood. We used The Cancer Genome Atlas (TCGA) data to study the clinical relevance of epigenetic modifications of Notch superfamily genes.

METHODS

We analyzed the interaction of DNA methylation and miRNAs with gene expression data for Notch superfamily members with the Spearman rank correlation test and explored potential relationships with overall survival (OS) with the log-rank test. We downloaded clinical data, level 3 gene expression data, and level 3 DNA methylation data for 480 patients with stage II-IV HGS-OvCa from the TCGA data portal. Patients were randomly divided into training and validation cohorts for survival analyses. In each set, patients were grouped into percentiles according to methylation and microRNA (miRNA) or messenger RNA (mRNA) levels. We used several algorithms to predict miRNA-mRNA interaction.

RESULTS

There were significant inverse relationships between methylation status and mRNA expression for PPARG, CCND1, and RUNX1. For each of these genes, patients with a lower methylation level and higher expression level had significantly poorer OS than did patients with a higher methylation level and lower expression level. We also found a significant inverse relationship between miRNAs and mRNA expression for CCND1, PPARG, and RUNX1. By further analyzing the effect of miRNAs on gene expression and OS, we found that patients with higher levels of CCND1, PPARG, and RUNX1 expression and lower expression levels of their respective miRNAs (502-5p, 128, and 215/625) had significantly poorer OS.

CONCLUSIONS

Epigenetic alterations of multiple Notch target genes and pathway interacting genes (PPARG, CCND1, and RUNX1) may relate to activation of this pathway and poor survival of patients with HGS-OvCa.

Multiple genetic alterations within the PI3K pathway are responsible for AKT activation in patients with ovarian carcinoma

The phosphatidylinositol 3-kinase (PI3K)/AKT pathway is activated in multiple cancers including ovarian carcinoma (OC). However, the relative contribution of the single components within the PI3K pathway to AKT activation in OC is still unclear. We examined 98 tumor samples from Italian OC patients for alterations in the members of the PI3K pathway. We report that AKT is significantly hyperactive in OC compared to normal tissue (n = 93; p<0.0001) and that AKT activation is preferentially observed in the elderly (>58 years old; n = 93; p<0.05). The most frequent alteration is the overexpression of the p110α catalytic subunit of PI3K (63/93, ∼68%); less frequent alterations comprise the loss of PTEN (24/89, 27%) and the overexpression of AKT1 (18/96, 19%) or AKT2 (11/88,12.5%). Mutations in the PIK3CA or KRAS genes were detected at lower frequency (12% and 10%, respectively) whereas mutations in AKT1 or AKT2 genes were absent. Although many tumors presented a single lesion (28/93, of which 23 overexpressed PIK3CA, 1 overexpressed AKT and 4 had lost PTEN), many OC (35/93) presented multiple alterations within the PI3K pathway. Apparently, aberrant PI3K signalling was mediated by activation of the canonical downstream AKT-dependent mTOR/S6K1/4EBP1 pathway and by regulation of expression of oncogenic transcription factors that include HMGA1, JUN-B, FOS and MYC but not by AKT-independent activation of SGK3. FISH analysis indicated that gene amplification of PIK3CA, AKT1 and AKT2 (but not of PI3KR1) and the loss of PTEN are common and may account for changes in the expression of the corresponding proteins. In conclusion, our results indicate that p110α overexpression represents the most frequent alteration within the PI3K/AKT pathway in OC. However, p110α overexpression may not be sufficient to activate AKT signalling and drive ovarian tumorigenesis since many tumors overexpressing PI3K presented at least one additional alteration.

Agreement for tumor grade of ovarian carcinoma: analysis of archival tissues from the surveillance, epidemiology, and end results residual tissue repository

BACKGROUND

Emerging data suggest that ovarian cancers differ by tumor grade. However, the reliability of microscopic grade from paraffin tissue in the general medical community and as reflected in population-based cancer registries is unknown.

METHODS

We examined grade agreement between two gynecologic pathologists and the Surveillance Epidemiology and End Results Residual Tissue Repository (SEER). Grade agreement was assessed with percent observer agreement and kappa coefficients for 664 invasive ovarian carcinomas, using previously defined three-tier and two-tier grading systems. A random subset of ovarian carcinomas was selected to compare intra- and inter-pathologist agreement.

RESULTS

Five hundred and eighty-six of SEER's 664 tumors were confirmed invasive. Percent agreement was 49 % with fair kappa coefficient = 0.25 (95 % CI: 0.20-0.30) for the 664 tumors. Agreement improved slightly when restricted to the 586 confirmed invasive cancers; it was better for high grade than low grade tumors, for two-tier than three-tier grading systems, and within (66 %) than between study pathologists (43 %). Grade was not a robust independent predictor of ovarian cancer-specific survival.

CONCLUSIONS

Grade agreement was fair between SEER and study pathologists irrespective of grading system. Recorded grade in SEER should be used with caution and is probably not a reliable metric for ovarian cancer epidemiology.

Genomic complexity and AKT dependence in serous ovarian cancer

Effective oncoprotein-targeted therapies have not yet been developed for ovarian cancer. To explore the role of PI3 kinase/AKT signaling in this disease, we performed a genetic and functional analysis of ovarian cancer cell lines and tumors. PI3K pathway alterations were common in both, but the spectrum of mutational changes differed. Genetic activation of the pathway was necessary, but not sufficient, to confer sensitivity to selective inhibition of AKT and cells with RAS pathway alterations or RB1 loss were resistant to AKT inhibition, whether or not they had coexistent PI3K/AKT pathway activation. Inhibition of AKT1 caused growth arrest in a subset of ovarian cell lines, but not in those with AKT3 expression, which required pan-AKT inhibition. Thus, a subset of ovarian tumors are sensitive to AKT inhibition, but the genetic heterogeneity of the disease suggests that effective treatment with AKT pathway inhibitors will require a detailed molecular analysis of each patient's tumor.

SIGNIFICANCE

A subset of ovarian cancers exhibits AKT pathway activation and is sensitive to selective AKT inhibition. Ovarian tumors exhibit significant genetic heterogeneity and thus an individualized approach based on real-time, detailed genomic and proteomic characterization of individual tumors will be required for the successful application of PI3K/AKT pathway inhibitors in this disease.

PAX8 is a novel marker for differentiating between various types of tumor, particularly ovarian epithelial carcinomas

Paired-box gene 8 (PAX8) encodes a transcription factor associated with important roles in embryogenesis and disease, and is a member of the PAX gene family. PAX8 has been demonstrated to be crucial in determining cell fate during the development of the thyroid, kidney, brain, eyes and Müllerian system and regulates expression of the Wilms’ tumor suppressor gene (WT1). Several previous studies have reported that PAX8 is expressed at high levels in specific types of tumor, including thyroid and renal carcinomas and pancreatic neuroendocrine tumors. In addition, PAX8 has been reported to be useful for the detection and differential diagnosis of ovarian carcinoma. The consistency of PAX8 staining in epithelial ovarian carcinomas (EOCs) and the fallopian tube has provided morphological evidence that EOC may originate from the fallopian tube. The molecular mechanism of PAX8 in the carcinogenesis of these tumors remains unclear and requires further studies.

Identification and molecular characterization of a new ovarian cancer susceptibility locus at 17q21.31

Epithelial ovarian cancer (EOC) has a heritable component that remains to be fully characterized. Most identified common susceptibility variants lie in non-protein-coding sequences. We hypothesized that variants in the 3' untranslated region at putative microRNA (miRNA)-binding sites represent functional targets that influence EOC susceptibility. Here, we evaluate the association between 767 miRNA-related single-nucleotide polymorphisms (miRSNPs) and EOC risk in 18,174 EOC cases and 26,134 controls from 43 studies genotyped through the Collaborative Oncological Gene-environment Study. We identify several miRSNPs associated with invasive serous EOC risk (odds ratio=1.12, P=10(-8)) mapping to an inversion polymorphism at 17q21.31. Additional genotyping of non-miRSNPs at 17q21.31 reveals stronger signals outside the inversion (P=10(-10)). Variation at 17q21.31 is associated with neurological diseases, and our collaboration is the first to report an association with EOC susceptibility. An integrated molecular analysis in this region provides evidence for ARHGAP27 and PLEKHM1 as candidate EOC susceptibility genes.

Early Detection of Ovarian Tumors Using Ultrasound

Ovarian cancer can be treated with a very good prognosis if detected in the early stages, but not after it has advanced. Transvaginal ultrasound is capable of identifying changes in ovarian size and structure, and thereby detects early ovarian malignancies. This view has generated four major trials on transvaginal ultrasound detection: the Kentucky, PLCO, UKCTOCS, and SCSOCS trials. Each is sufficiently different to warrant examination. The Kentucky, UKCTOCS and SCSOCS trials report a shift to early stage detection. The Kentucky trial reports a survival benefit, while follow-up survival analysis is pending in the UKCTOCS and SCSOCS trials. Details of these trials are presented including definitions, inclusions/exclusions, analytic structure (intention-to-treat vs per protocol), performance (sensitivity, specificity, positive predictive value and negative predictive value), extent of screening-related treatment, time from screening to treatment, length of follow-up and survival versus mortality analysis. Questions are answered here about effectiveness, application, prevalence, cost and the potential for harm.

Inhibitory effect of tumor suppressor p53 on proinflammatory chemokine expression in ovarian cancer cells by reducing proteasomal degradation of IκB

Ovarian cancer, one of inflammation-associated cancers, is the fifth leading cause of cancer deaths among women. Inflammation in the tumor microenvironment is associated with peritoneal tumor dissemination and massive ascites, which contribute to high mortality in ovarian cancer. Tumor suppressor p53 is frequently deleted or mutated in aggressive and high-grade ovarian cancer, probably aggravating cancer progression and increasing mortality. We therefore investigated the influence of p53 on proinflammatory chemokines in ovarian cancer cells. A PCR array of the chemokine network revealed that ovarian cancer cells with low or mutated p53 expression expressed high levels of proinflammatory chemokines such as CXCL1, 2, 3 and 8. Transient transfection of p53 into p53-null ovarian cancer cells downregulated proinflammatory chemokines induced by tumor necrosis factor-α (TNF), a proinflammatory cytokine abundantly expressed in ovarian cancer. Furthermore, p53 restoration or stabilization blocked TNF-induced NF-κB promoter activity and reduced TNF-activated IκB. Restoration of p53 increased ubiquitination of IκB, resulting from concurrently reduced proteasome activity followed by stability of IκB. A ubiquitination PCR array on restoration of p53 did not reveal any significant change in expression except for Mdm2, indicating that the balance between p53 and Mdm2 is more important in regulating NF-κB signaling rather than the direct effect of p53 on ubiquitin-related genes or IκB kinases. In addition, nutlin-3, a specific inducer of p53 stabilization, inhibited proinflammatory chemokines by reducing TNF-activated IκB through p53 stabilization. Taken together, these results suggest that p53 inhibits proinflammatory chemokines in ovarian cancer cells by reducing proteasomal degradation of IκB. Thus, frequent loss or mutation of p53 may promote tumor progression by enhancing inflammation in the tumor microenvironment.

Prognostic role of E-cadherin in patients with advanced serous ovarian cancer

PURPOSE

To analyse correlation between expression of E-cadherin and clinical and pathological features and overall survival in advanced-stage serous ovarian carcinoma.

METHODS

The expression of E-cadherin was analysed immunohistochemically in formalin-fixed, paraffin-embedded samples from 54 patients with advanced-stage serous ovarian cancer and related to clinicopathological characteristics and patients survival. The clinicopathological characteristics included the stage according to the International Federation of Gynecology and Obstetrics (FIGO), tumour differentiation, number of mitoses per 10 high-power fields (HPF), residual tumour size, and vascular invasion. Only patients with serous ovarian cancer FIGO stages III-IV were included. Overall survival (OS) was defined as time from surgery to the last follow-up date on 01.10.2010. OS was evaluated using Kaplan-Meier method, and log-rank test was used to asses the differences between the positive and E-cadherin negative group. Multivariate analysis was completed using the Cox proportional hazard regression model.

RESULTS

E-cadherin immunoreactivity was not associated with FIGO stage, tumour grade, number of mitotic figures per 10 HPF, residual tumour volume or vascular invasion. Negative E-cadherin expression significantly predicted shorter OS (p < 0.001). The multivariate analyses showed that negative E-cadherin (p < 0.001), FIGO stage (p = 0.012) and residual tumour size >1 cm after the initial cytoreductive surgery (p < 0.001) were predictors of shorter OS.

CONCLUSION

Negative E-cadherin expression like presence of residual tumour after primary cytoreductive surgery and higher FIGO stage seem to predict unfavourable clinical outcome in patients with advanced-stage serous ovarian cancer. Negative expression of E-cadherin was shown to be a significant independent predictor of poorer OS. E-cadherin as marker has prognostic value.

Low-grade and high-grade serous Mullerian carcinoma: review and analysis of publicly available gene expression profiles

OBJECTIVE

Mullerian low grade serous carcinoma (LGSC) and high grade serous carcinoma (HGSC) have distinct molecular profiles, clinical behavior and treatment response. Our objective was to study the biological profiles of these carcinomas.

METHODS

This study examines publicly available gene expression profiles of LGSC and HGSC to identify differentially expressed genes and key pathways involved in carcinogenesis and chemotherapy response.

RESULTS

Our analysis supports the hypothesis that serous mullerian carcinoma develop through two different pathways yielding two distinct malignancies, namely LGSC and HGSC. Furthermore, genes potentially involved in chemotherapeutic resistance of LGSC were identified. Suppressing the levels of these genes/proteins may increase clinical response to standard chemotherapy in patients with LGSC.

CONCLUSION

In summary, this review shows the molecular profile of LGSC and HGSC through multi-center analysis of gene expression profiles of these tumors. The gene signatures of these neoplasms may potentially be used to develop disease-specific, targeted therapy for LGSC and HGSC.