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Constitutive production of inflammatory cytokines is a characteristic of many human malignant cell lines; however, the in vitro and in vivo interdependence of these cytokines, and their significance to the human cancer microenvironment, are both poorly understood. Here, we describe for the first time how three key cytokine/chemokine mediators of cancer-related inflammation, TNF, CXCL12, and interleukin 6, are involved in an autocrine cytokine network, the "TNF network," in human ovarian cancer. We show that this network has paracrine actions on angiogenesis, infiltration of myeloid cells, and NOTCH signaling in both murine xenografts and human ovarian tumor biopsies. Neutralizing antibodies or siRNA to individual members of this TNF network reduced angiogenesis, myeloid cell infiltration, and experimental peritoneal ovarian tumor growth. The dependency of network genes on TNF was shown by their downregulation in tumor cells from patients with advanced ovarian cancer following the infusion of anti-TNF antibodies. Together, the findings define a network of inflammatory cytokine interactions that are crucial to tumor growth and validate this network as a key therapeutic target in ovarian cancer., (©2011 AACR.)

WWOX is a bona fide tumour suppressor, with hypomorphic and knockout mouse models exhibiting increased tumour susceptibility. In ovarian cancer cells WWOX transfection abolishes tumourigenicity, suppresses tumour cell adhesion to extracellular matrix and induces apoptosis in non-adherent cells. One-third of ovarian tumours show loss of WWOX expression, and this loss significantly associates with clear cell and mucinous histology, advanced stage, low progesterone receptor expression and poor survival, suggesting that WWOX status affects ovarian cancer progression and prognosis. Genetic variation in other tumour suppressors (e.g. p53 and XPD) is reported to modify cancer progression/outcome, and single nucleotide polymorphisms (SNPs) within the WWOX gene are reported to associate with prostate cancer risk. We previously identified polymorphic variants within WWOX, some of which have potential to affect its expression. We therefore examined a cancer modifier role for these WWOX variants. Eight SNPs, based upon location, frequency and potential to affect WWOX expression, were genotyped in 554 ovarian cancer patients (CGP samples), and associations with pathological and survival data were examined. The CGP samples demonstrated significant associations after Bonferroni correction between Isnp1 and both tumour grade (p(corr)=0.033) and histology (p(corr)=0.046), Isnp8 and tumour grade (p(corr)=0.032) and T1497G and progression-free survival (p(corr)=0.037). None of these positive associations were confirmed in an independent ovarian cancer population (Scotroc1 samples, n=863). While these results may suggest that the associations are false positives, differences between the two populations cannot be excluded, and thus highlight the challenges in validation studies., (Copyright 2009 Elsevier Ltd. All rights reserved.)

Cytokines orchestrate the tumor-promoting interplay between malignant cells and the immune system. In many experimental and human cancers, the cytokine TNF-alpha is an important component of this interplay, but its effects are pleiotropic and therefore remain to be completely defined. Using a mouse model of ovarian cancer in which either TNF receptor 1 (TNFR1) signaling was manipulated in different leukocyte populations or TNF-alpha was neutralized by antibody treatment, we found that this inflammatory cytokine maintained TNFR1-dependent IL-17 production by CD4+ cells and that this led to myeloid cell recruitment into the tumor microenvironment and enhanced tumor growth. Consistent with this, in patients with advanced cancer, treatment with the TNF-alpha-specific antibody infliximab substantially reduced plasma IL-17 levels. Furthermore, expression of IL-1R and IL-23R was downregulated in CD4+CD25- cells isolated from ascites of ovarian cancer patients treated with infliximab. We have also shown that genes ascribed to the Th17 pathway map closely with the TNF-alpha signaling pathway in ovarian cancer biopsy samples, showing particularly high levels of expression of genes encoding IL-23, components of the NF-kappaB system, TGF-beta1, and proteins involved in neutrophil activation. We conclude that chronic production of TNF-alpha in the tumor microenvironment increases myeloid cell recruitment in an IL-17-dependent manner that contributes to the tumor-promoting action of this proinflammatory cytokine.

The WW domain-containing oxidoreductase (WWOX) gene is located at FRA16D, a common fragile site involved in human cancer. Targeted deletion of Wwox in mice causes increased spontaneous tumor incidence, confirming that WWOX is a bona fide tumor suppressor gene. We show that stable transfection of WWOX into human PEO1 ovarian cancer cells, containing homozygous WWOX deletion, abolishes in vivo tumorigenicity, but this does not correlate with alteration of in vitro growth. Rather, WWOX restoration in PEO1, or WWOX overexpression in SKOV3 ovarian cancer cells, results in reduced attachment and migration on fibronectin, an extracellular matrix component linked to peritoneal metastasis. Conversely, siRNA-mediated knockdown of endogenous WWOX in A2780 ovarian cancer cells increases adhesion to fibronectin. In addition, whereas there is no WWOX-dependent difference in cell death in adherent cells, WWOX-transfected cells in suspension culture display a proapoptotic phenotype. We further show that WWOX expression reduces membranous integrin alpha(3) protein but not integrin alpha(3) mRNA levels, and that adhesion of PEO1 cells to fibronectin is predominantly mediated through integrin alpha(3). We therefore propose that WWOX acts as an ovarian tumor suppressor by modulating the interaction between tumor cells and the extracellular matrix and by inducing apoptosis in detached cells. Consistent with this, the suppression of PEO1 tumorigenicity by WWOX can be partially overcome by implanting these tumor cells in Matrigel. These data suggest a possible role for the loss of WWOX in the peritoneal dissemination of human ovarian cancer cells.

Purpose of Review: Hormonal therapy has been used erratically to treat epithelial ovarian cancer since the mid 1960s; however, there has been little progress until recently in our understanding of which patients might benefit from treatment. Some clarity in the field is now beginning to emerge from recent studies, which have started to define biomarkers within epithelial ovarian cancers that link with hormonal response and thereby indicate which cohort of patients might be amenable to hormonal treatment., Recent Findings: Oestrogen-deprivation therapy in the form of the aromatase inhibitor letrozole has demonstrated activity in three clinical studies. As only a minority of patients will benefit from hormonal approaches, recent efforts have focussed on the use of molecular markers to help identify which subgroup of patients might respond to treatment. Parallel laboratory studies using primary cancer material for which endocrine response is known and model-based findings have identified components of oestrogen signalling pathways that may help predict outcome., Summary: Use of the antioestrogen letrozole in ovarian cancer has consistently demonstrated a significant level of activity and the larger clinical studies have linked response with oestrogen receptor alpha expression and other biomarkers.

Background: Clinicopathological features and outcome of women with endometrioid and serous ovarian adenocarcinoma were compared., Methods: Between 1984 and 2004, baseline and follow-up data were prospectively recorded on 1545 patients with ovarian cancer. Of these, 270 had pure endometrioid tumors; 659 had pure serous adenocarcinoma of the ovary. Response to platinum-based chemotherapy (PBC) overall survival, stage-for-stage median progression-free survival (PFS), and cause-specific median survival were compared. Independent predictors of survival were examined by using multivariate analyses., Results: Median age of diagnosis for patients with endometrioid tumors was younger than those with serous adenocarcinoma of the ovary (60 years vs 62 years; P = .013). They presented more often with early disease (stage I and II; 50% vs 17%; P < .001), had less ascites, and had better performance status both overall and for stage II and III disease. More endometrioid tumors were optimally debulked overall (71% vs 45%; P < .001), but there was no difference according to stage. Objective and CA125 PBC response rates were not significantly different, but median PFS was better for patients with endometrioid tumors (24 months vs 13 months; P < .0001) as was overall median survival (48 months vs 22 months; P < .0001). This relation remained for stage II and III disease and for moderately and poorly differentiated tumors. Patients with concurrent endometrioid ovarian and endometrial malignancies had a survival advantage compared with those with ovarian malignancies alone. Independent predictors of survival after PBC were histological type, debulking status, and disease stage., Conclusions: Despite similar PBC response rates, endometrioid histology is associated with better survival compared with serous adenocarcinoma of the ovary, even with stage III or poorly differentiated tumors., ((c) 2008 American Cancer Society.)

Objective: To explore the predictive value of estrogen-regulated gene changes as indicators of sensitivity in ovarian cancer patients treated with the aromatase inhibitor Letrozole., Methods: Expression of a range of proteins was assessed by semi-quantitative immunohistochemistry in tissue sections from the tumors of patients treated with Letrozole. Expression was correlated with clinical response to Letrozole. Corresponding mRNA in ovarian cancer cell lines treated with 17beta-estradiol (E2) was measured by quantitative RT-PCR., Results: In an estrogen receptor (ER)-positive ovarian cancer cell line, quantitative RT-PCR analysis demonstrated that PLAU, VIM, BIGH3, CDH6, FN1, CASP4, KRT4, KRT7, KRT13, TRAM and NGAL were down-regulated and TFF1, TFF3, TRAP1, TFAP4, MYC, CTSD, IL17BR, TOP2A, CCNB1, CCNB2, PDZK1 and UBE2C were up-regulated by E2. The E2 modulation of these genes was reversed by the anti-estrogen tamoxifen and was ERalpha-dependent. For ovarian cancer patients treated with Letrozole, we tested the predictive value of the majority of these genes in paraffin sections from their primary tumors by semi-quantitative immunohistochemistry. Significant differences in expression levels of TFF1, TFF3, BIGH3, TRAP1, VIM, TOP2A, PLAU and UBE2C were observed between tumors from CA125 responsive/stable patients as opposed to tumors from patients whose disease progressed, using serum levels of CA125 as an indicator of response. Aromatase expression in the ovarian cancers also differed between these 2 groups of patients., Conclusion: These results suggest that expression levels of certain proteins in ovarian cancers are estrogen-regulated and could help identify patients who would benefit from endocrine therapy.

Purpose: To evaluate the efficacy of the aromatase inhibitor letrozole in preselected estrogen receptor (ER)-positive relapsed epithelial ovarian cancer patients and to identify markers that predict endocrine-sensitive disease., Experimental Design: This was a phase II study of letrozole 2.5 mg daily until clinical or marker evidence of disease progression in previously treated ER-positive ovarian cancer patients with a rising CA125 that had progressed according to Rustin's criteria. The primary end point was response according to CA125 and response evaluation criteria in solid tumors (RECIST) criteria. Marker expression was measured by semiquantitative immunohistochemistry in sections from the primary tumor., Results: Of 42 patients evaluable for CA125 response, 7 (17%) had a response (decrease of >50%), and 11 (26%) patients had not progressed (doubling of CA125) following 6 months on treatment. The median time taken to achieve the CA125 nadir was 13 weeks (range 10-36). Of 33 patients evaluable for radiological response, 3 (9%) had a partial remission, and 14 (42%) had stable disease at 12 weeks. Eleven patients (26%) had a PFS of >6 months. Subgroup analysis according to ER revealed CA125 response rates of 0% (immunoscore, 150-199), 12% (200-249), and 33% (250-300); P = 0.028, chi(2) for trend. Expression levels of HER2, insulin-like growth factor binding protein 5, trefoil factor 1, and vimentin were associated with CA125 changes on treatment., Conclusions: This is the first study of a hormonal agent in a preselected group of ER-positive ovarian cancer patients. A signature of predictive markers, including low HER2 expression, predicts response.

Purpose: This study sought to explore the predictive value of the insulin-like growth factor (IGF) binding proteins (IGFBP) as markers of response in ovarian cancer patients treated with the aromatase inhibitor letrozole., Experimental Design: IGFBP mRNA expression in cell lines was measured by quantitative reverse transcription-PCR and IGFBP protein expression measured in sections from primary tumors of patients treated with letrozole by semiquantitative immunohistochemistry., Results: Quantitative reverse transcription-PCR analysis showed that IGFBP3 and IGFBP5 were down-regulated and IGFBP4 was up-regulated by 17beta-estradiol (E(2)) in an estrogen receptor (ER)-positive ovarian cancer cell line. Expressions of IGFBP1, IGFBP2, and IGFBP6 were unaffected by E(2). The E(2) modulation of these genes was reversed by tamoxifen. Using ERalpha-specific (propyl pyrazole triol) and ERbeta-specific (diarylpropionitrile) agonists, the gene expression modulations produced by E(2) could be replicated by propyl pyrazole triol but not by diarylpropionitrile. For ovarian cancer patients being treated with letrozole, we tested the predictive value of the IGFBPs in paraffin-fixed sections from their primary tumors by semiquantitative immunohistochemistry. Using serum CA125 as an indicator of progression/response, significant differences in expression levels of IGFBPs were observed between tumors from CA125 responding/stable patients compared with tumors from progressing patients. Mean immunoscores for IGFBP3 and IGFBP5 were significantly lower, and mean expression of IGFBP4 was significantly higher in tumors from patients demonstrating CA125 response or stabilization compared with CA125 progression., Conclusion: These results indicate that expression levels of certain IGFBP family members in ovarian cancers are estrogen regulated and can, thus, help identify patients who could benefit from endocrine therapy.

Pertuzumab (Omnitarg, rhuMab 2C4) is a humanized monoclonal antibody, which inhibits HER2 dimerization. Because it has shown some clinical activity in ovarian cancer, this study sought to identify predictors of response to this agent in a model of ovarian cancer. A panel of 13 ovarian cancer cell lines was treated with heregulin beta1 (HRGbeta1) or transforming growth factor-alpha, and cell proliferation was assessed. Both agents increased cell number in the majority of cell lines studied, the response to both being similar (r = 0.83; P = 0.0004, Pearson test). HRGbeta1 stimulation could be partially reversed by pertuzumab in 6 of 13 cell lines, with complete reversal in PE04 and PE06 cells. Addition of pertuzumab to transforming growth factor-alpha-stimulated cells produced growth inhibition in 3 of 13 cell lines (PE01, PE04, and PE06). The magnitude of HRGbeta1-driven growth stimulation correlated significantly with an increase in extracellular signal-regulated kinase 2 (P = 0.037) but not Akt (P = 0.99) phosphorylation. Such HRGbeta1-driven phosphorylation of extracellular signal-regulated kinase 1/2 and Akt could be reduced with pertuzumab, accompanied by changes in cell cycle distribution. In cell lines responsive to pertuzumab, HRGbeta1-enhanced phosphorylation of HER2 (Tyr(877)) was reduced. Estrogen-stimulated changes in growth, cell cycle distribution, and signaling were reversed by pertuzumab, indicating cross-talk between HER2 and estrogen signaling. These data indicate that there is a subset of ovarian cancer cell lines sensitive to pertuzumab and suggest possible predictors of response to identify patients who could benefit from this therapy. Furthermore, we have identified an interaction between HER2 and estrogen signaling in this disease.

There is currently much interest in the role of the Raf family in cancer, particularly since mutated B-Raf has been shown to be oncogenic in certain disease types. In this study we have explored the expression, signaling and function of the three known Raf isoforms (Raf-1, A-Raf and B-Raf) in patients with ovarian cancer. While increased expression of Raf-1 was associated with poor survival, increased expression of B-Raf was associated with improved survival. Using a panel of ovarian cancer cell lines, all three isoforms were shown to be involved in growth factor initiated signaling. Antisense inhibition of function in ovarian cancer cell lines indicated that both Raf-1 and A-Raf, but not B-Raf, were linked to cell proliferation. Raf-1 (but not A-Raf or B-Raf) was also associated with reduced apoptosis. While individual Raf reduction by isoform-targeted antisense oligonucleotides (ODNs) produced growth inhibition in some cell lines, similar use of the MEK inhibitor UO126 produced growth inhibition in all cell lines tested. These data suggest that Raf-1 is the predominant Raf isoform responsible for regulating cellular growth in ovarian cancer cells and may be particularly important in high grade serous ovarian cancers.

Estrogens play a significant role in the development, growth, invasion and metastasis of ovarian tumors. The transcriptional program regulated by 17beta-estradiol (E(2)) in human ovarian cancer cell lines was analyzed using cDNA microarrays containing 1200 cancer-related genes. Twenty-eight transcripts had at least a threefold change in expression in E(2)-treated PEO1 ovarian carcinoma cells compared with controls. These differences were confirmed by real-time quantitative PCR and shown to be dependent upon the expression of functional estrogen receptor-alpha (ERalpha). Consistent with this, these gene expression changes were blocked by the anti-estrogen tamoxifen. The use of ERalpha- and ERbeta-specific ligands allowed molecular dissection of the E(2) response and showed that ERalpha activation was responsible for the observed changes in gene expression, whereas ERbeta played no significant role. Inhibition of de novo protein synthesis by cycloheximide was used to distinguish between primary and secondary target genes regulated by E(2). Actinomycin D was used to show that changes in gene expression levels induced by E(2) were a result of changes in transcription and not due to changes in mRNA stability. The results presented here demonstrate that estrogen-driven growth of epithelial ovarian carcinoma is mediated by activation of ERalpha-mediated, and not ERbeta-mediated, transcription.

Purpose: The IgLON family of cell adhesion molecules, comprising OPCML, HNT, LSAMP, and NEGR1, has recently been linked to cancer, through two of its members being proposed as tumor suppressors. We examined the expression profile of the family in human sporadic epithelial ovarian cancer and the normal ovary., Experimental Design: We determined the expression level of each IgLON in a panel comprising 57 tumor and 11 normal ovarian samples by quantitative real-time reverse transcription-PCR. The results were statistically tested for associations with clinicopathologic variables., Results: OPCML, LSAMP and NEGR1 exhibited reduced expression in the tumor samples relative to the normal samples, whereas HNT expression was elevated. Statistically significant changes were specific to histologic type. The expression levels of individual IgLONs were correlated, the most significant finding being a positive correlation between LSAMP and NEGR1. LSAMP expression was also negatively correlated with overall survival and was found to be a negative predictor of outcome., Conclusions: The expression of the IgLON family is altered in sporadic epithelial ovarian tumors in comparison to the normal ovary. In our small but representative cohort of patients, we have found significant correlations and associations in expression and clinicopathology that suggest a wider role of the family in ovarian cancer.

The majority of ovarian cancer patients are treated with platinum-based chemotherapy, but the emergence of resistance to such chemotherapy severely limits its overall effectiveness. We have shown that development of resistance to this treatment can modify cell signaling responses in a model system wherein cisplatin treatment has altered cell responsiveness to ligands of the erbB receptor family. A cisplatin-resistant ovarian carcinoma cell line PE01CDDP was derived from the parent PE01 line by exposure to increasing concentrations of cisplatin, eventually obtaining a 20-fold level of resistance. Whereas PE01 cells were growth stimulated by the erbB receptor-activating ligands, such as transforming growth factor-alpha (TGFalpha), NRG1alpha, and NRG1beta, the PE01CDDP line was growth inhibited by TGFalpha and NRG1beta but unaffected by NRG1alpha. TGFalpha increased apoptosis in PE01CDDP cells but decreased apoptosis in PE01 cells. Differences in extracellular signal-regulated kinase and phosphatidylinositol 3-kinase signaling were also found, which may be implicated in the altered cell response to ligands. Microarray analysis revealed 51 genes whose mRNA increased by at least 2-fold in PE01CDDP cells relative to PE01 (including FRA1, ETV4, MCM2, AXL, MT3, TRAP1, and FANCG), whereas 36 genes (including IGFBP3, TRAM1, and KRT4 and KRT19) decreased by a similar amount. Differential display reverse transcriptase-PCR identified altered mRNA expression for TCP1, SLP1, proliferating cell nuclear antigen, and ZXDA. Small interfering RNA inhibition of FRA1, TCP1, and MCM2 expression was associated with reduced growth and FRA1 inhibition with enhanced cisplatin sensitivity. Altered expression of these genes by cytotoxic exposure may provide survival advantages to cells including deregulation of signaling pathways, which may be critical in the development of drug resistance.

The Epidermal Growth Factor Receptor (EGFR) and its structural relative erbB2 are frequently over-expressed in ovarian cancers and both are strongly associated with poor patient survival. To investigate the relative roles of these receptors in the regulation of cell growth and migration, a panel of ovarian carcinoma cell lines were stimulated with TGF alpha and NRG1beta. TGF alpha had a much greater influence on cell migration than NRG1beta where growth effects were equivalent. The extent of TGF alpha-stimulated migration on collagen in these assays could be associated with erbB2 expression levels. In addition, TGF alpha was found to stimulate activation of the ERK, PI3 kinase and PLC gamma pathways. Direct blockade of the TGF alpha-interacting receptor EGFR inhibited both cell growth and migration, as well as downstream signaling induced by the growth factor. Specific blockade of the downstream proteins MEK and PI3 kinase significantly affected TGF alpha-induced mitogenesis in the cell lines tested but had less impact upon migration. Conversely, inhibition of the PLC gamma pathway had little effect on cell growth but significantly decreased TGF alpha-driven migration. These results corroborate the likely importance of migration as well as growth in erbB receptor over-expressing ovarian cancers and directly implicate the roles of ERK and PI3 kinase in growth control, and PLC gamma in the regulation of migration in this disease.

Purpose: We sought to identify determinants of growth response to the Raf-1-targeted antisense oligonucleotide (ASO; ISIS 5132) using a large panel of ovarian cancer cell lines., Experimental Design: First-(ISIS 5132) and second-generation (ISIS 13650) anti-Raf 1 ASOs were compared with control oligonucleotides. Growth was assessed by cell counts; apoptosis was assessed by poly(ADP-ribose) polymerase cleavage; and cell cycle analysis was assessed by flow cytometry. Protein expression was detected by Western blot analysis, and mRNA expression was detected by quantitative reverse transcription-PCR. Raf-1 kinase activity was detected by anti-Raf-1 immunoprecipitation, followed by myelin basic protein phosphorylation., Results: A panel of 15 ovarian cancer cell lines was used to model a range of growth responses to ASOs targeting Raf-1 mRNA. Growth inhibition varied from 10% to >90% inhibition. Growth inhibition was associated with increased apoptosis and accumulation of cells in the G(2)-M and S phases of the cell cycle. Growth response was not related to level of Raf-1 protein expression, Raf-1 kinase activity, intracellular ASO uptake, or degree of Raf-1 protein inhibition. However, ASO growth response was associated with a high proportion of Raf-1 mRNA [relative to total (i.e., Raf-1 + A-Raf + B-Raf) Raf mRNA] and significantly higher Raf-1 kinase activity induction following growth factor (transforming growth factor alpha) stimulation in the cell lines consistent with dependency of these cell lines on Raf-1., Conclusions: These data indicate that ovarian cancers demonstrate differential sensitivity to ASOs targeted against Raf-1, and target expression levels and degree of utilization of Raf-1 signaling are implicated. Clinically sensitive tumors could feasibly be identified.

Microcell-mediated transfer of normal chromosome 11 (chr 11) to a clonal derivative of the ovarian cancer cell line, OVCAR3, was performed and generated independent hybrids with a common set of phenotypes: inhibition of cell growth and of cellular migration in vitro; and inhibition of tumor growth in vivo. Differential display reverse transcriptase-PCR (RT-PCR), cDNA-representational difference analysis, and hybridization of cDNA high-density filter arrays identified altered mRNAs associated with these phenotypic alterations. Quantitative RT-PCR-based validation of each altered mRNA eliminated false positives to identify a reduced set of expression differences. Twelve products were confirmed as up-regulated and 4 as down-regulated upon introduction of chr 11. Strikingly, 4 of the 12 up-regulated genes were located on chr 11. Expression analysis of selected products by quantitative RT-PCR in a series of 18 human primary ovarian tumors revealed several associations with clinicopathological features. Importantly, low expression of two products, the lysosomal protease CTSD and the lens crystallin CRYAB, was significantly associated with adverse patient survival. Immunohistochemical analysis of CTSD in a larger independent panel of 58 primary ovarian tumors confirmed that low CTSD was associated with poor survival. Furthermore, low CTSD was significantly associated with serous histology and advanced tumor stage. The combined approach of microcell-mediated chromosome transfer and expression difference analysis has identified several altered mRNAs in a model of chr 11-mediated ovarian tumor suppression. The detailed contextual characterization of these genes will determine the extent of their involvement in neoplastic development.

Epithelial ovarian cancer (EOC), the leading cause of death from gynecological malignancy, is a poorly understood disease. The typically advanced presentation of EOC with loco-regional dissemination in the peritoneal cavity and the rare incidence of visceral metastases are hallmarks of the disease. These features relate to the biology of the disease, which is a principal determinant of outcome. EOC arises as a result of genetic alterations sustained by the ovarian surface epithelium (OSE; ref. 3). The causes of these changes are unknown but are manifest by activation of oncogenes and inactivation of tumor-suppressor genes (TSGs). Our analysis of loss of heterozygosity at 11q25 identified OPCML (also called OBCAM), a member of the IgLON family of immunoglobulin (Ig) domain-containing glycosylphosphatidylinositol (GPI)-anchored cell adhesion molecules, as a candidate TSG in EOC. OPCML is frequently somatically inactivated in EOC by allele loss and by CpG island methylation. OPCML has functional characteristics consistent with TSG properties both in vitro and in vivo. A somatic missense mutation from an individual with EOC shows clear evidence of loss of function. These findings suggest that OPCML is an excellent candidate for the 11q25 ovarian cancer TSG. This is the first description to our knowledge of the involvement of the IgLON family in cancer.

Purpose: To investigate the expression and function of neuregulin (NRG) isoforms in ovarian cancer cell lines and tumor samples., Experimental Design: Expression of NRG-1alpha and NRG-1beta proteins were detected by immunohistochemistry and mRNA by RT-PCR. erbB receptor levels and downstream signaling proteins were measured by Western blot analysis., Results: Expression of NRG-1alpha and NRG-1beta proteins were detected by immunohistochemistry in 46 of 53 (87%) and 41 of 53 (77%) ovarian carcinomas, respectively. Serous carcinomas express higher levels of NRG-1alpha than endometrioid carcinomas (P = 0.017). NRG mRNA was detected by RT-PCR in 20 of 24 (83%) of ovarian carcinomas and eight of nine (89%) ovarian cancer cell lines. NRG-1alpha stimulated the growth of 5 of 14 cell lines whereas NRG-1beta stimulated 7 of 14 cell lines. The magnitude of NRG growth response was significantly associated with erbB2 expression levels. NRG-1alpha and -1beta (1 nM) growth-stimulated cell lines PE01 and PE06 demonstrated increased tyrosine phosphorylation of erbB2 and elevated tyrosine phosphorylation of ERK1 and ERK2. In contrast, the SKOV-3 cell line, the growth of which was unaffected, did not show these downstream responses. An anti-erbB3 receptor antibody (clone H3.105.5) blocked NRG-1beta growth changes and signaling in these cell lines. Conversely, the anti-erbB4 antibody (clone H4.72.8) enhanced NRG-beta1 growth stimulation. Herceptin also inhibited growth., Conclusions: With NRG expression in the majority of ovarian carcinomas and cell lines, there is the potential for autocrine regulation of cell growth. Interfering with ligand-receptor interactions by receptor blocking antibodies suggests erbB3 is primarily involved in NRG-1beta-induced proliferation, with erbB4 having a more complex role.

Epithelial ovarian cancer (EOC) is the most common cause of death from gynaecological malignancy. Resistance to platinum chemotherapy is a major reason for treatment failure and poor prognosis. The human homeobox gene BARX2 is located within a minimal region at 11q25 that is associated with frequent loss of heterozygosity (LOH) and adverse survival in EOC. BARX2 is a transcription factor known to regulate transcription of specific cell adhesion molecules in the mouse. We have previously shown that BARX2 expression is low in clear cell/endometrioid and high in serous adenocarcinomas of the ovary, histologic variants that are less and more sensitive, respectively to platinum chemotherapy. The aim of this study was to define whether BARX2 could modulate sensitivity to cisplatin in human epithelial ovarian cancer. In two cell line series sequentially derived from ovarian cancer patients pre- and post-cisplatin chemotherapy, BARX2 expression was downregulated in the cell lines established upon tumor recurrence after platinum therapy. Transfection of BARX2 into a platinum resistant cell line significantly reversed cisplatin resistance compared with its isogenic platinum sensitive parent, in both growth inhibition and clonogenic assays. Taken together, our data demonstrate that the homeobox gene BARX2 may be a biological factor involved in determining sensitivity or resistance to the cytotoxic effects of cisplatin.

Purpose: This study was an open-label Phase II trial of the aromatase inhibitor letrozole (Femara) in patients with relapsed ovarian cancer with evaluation of possible biological markers for response., Experimental Design: 60 patients were treated with letrozole (2.5 mg daily) at the time of CA125 relapse. Disease response was assessed by Union International Contre Cancer (UICC) criteria and by CA125 measurement. Estrogen receptor (ER), progesterone receptor, epidermal growth factor receptor, erbB2, and HSP27 were measured by immunohistochemistry in paraffin-fixed material obtained from the primary tumors at initial surgery., Results: 50 patients were evaluable by UICC criteria, and although no complete or partial responses were obtained, 10 patients had stable disease on scan for at least 12 weeks. CA125 responses were evaluable in 54 patients. A partial marker response (>50% decrease) was seen in 5, and the marker remained stable in an additional 14 patients (25% increase). Tumors from the UICC stable disease group had significantly higher ER (P = 0.027) and progesterone receptor (P = 0.0066) values than the progressive disease group, and a combination of these was strongly associated with stable disease (P < 0.0001). Using CA125 criteria, comparison of the CA125 stable/responding disease with progressive disease indicated that tumors with higher ER (P = 0.013), lower erbB2 (P = 0.026), and higher epidermal growth factor receptor (P = 0.009) were associated with CA125 stable/responsive disease., Conclusions: These results imply that letrozole treatment can produce disease stabilization and CA125 responses that in turn are linked to higher levels of ER expression. These data suggest the presence of an endocrine-sensitive group that could be targeted in future studies.

Purpose: Matriptase is a type II transmembrane serine protease expressed by cells of surface epithelial origin, including epithelial ovarian tumor cells. Matriptase cleaves and activates proteins implicated in the progression of ovarian cancer and represents a potential prognostic and therapeutic target. The aim of this study was to examine the expression of matriptase, and its inhibitor, hepatocyte growth factor activator inhibitor-1 (HAI-1), in epithelial ovarian cancer and to assign clinicopathological correlations., Experimental Design: We have determined by immunohistochemistry the expression of matriptase and HAI-1 in 54 epithelial ovarian cancers. Statistical analyses of immunohistochemistry expression data with clinical outcome and clinicopathological parameters were then performed., Results: Of 54 tumors tested, 39 (72%) and 11 (20%) were positive for matriptase and for HAI-1, respectively. All HAI-1-positive tumors were also matriptase positive. Analysis of clinicopathological parameters demonstrated a loss of matriptase associated with stage III/IV tumors as compared with stage I/II tumors (P = 0.030). There was also a loss of HAI-1 expression associated with stage III/IV tumors (P = 0.039). Of 34 stage I/II tumors, 28 (82%) stained positive for matriptase, and 10 (29%) stained positive for HAI-1; 10 (29%) tumors showed coexpression. Of 20 stage III/IV tumors, however, 11 stained positive for matriptase (55%), only 1 of which coexpressed HAI-1 (P = 0.039)., Conclusions: Advanced-stage ovarian tumors that express matriptase are more likely to do so in the absence of its inhibitor, HAI-1, indicating that an imbalance in the matriptase:HAI-1 ratio could be important in the development of advanced disease. Such an imbalance could promote the proteolytic activity of matriptase and, consequently, a more invasive phenotype.

The incidence and management of bowel obstruction in a series of 105 patients with ovarian adenocarcinoma presenting to this unit were studied retrospectively. Forty-three of these patients developed bowel obstruction during the course of their illness. Patients with more advanced disease at presentation developed obstruction more rapidly. Small bowel obstruction was more common than large bowel obstruction. Surgical intervention at the time of obstruction appeared to produce more favourable responses and longer survival times. Patients treated surgically were less likely to reobstruct. No patient showed any response to chemotherapy given following resolution of the obstruction. Early surgical intervention should be considered in the management of patients with bowel obstruction secondary to ovarian adenocarcinoma. [ABSTRACT FROM PUBLISHER]