Metastatic Epithelial Ovarian Carcinoma Research Articles

HDAC1/2 control mesothelium/ovarian cancer adhesive interactions impacting on Talin-1-α5β1-integrin-mediated actin cytoskeleton and extracellular matrix protein remodeling

BackgroundPeritoneal metastasis, which accounts for 85% of all epithelial ovarian carcinoma (EOC) metastases, is a multistep process that requires the establishment of adhesive interactions between cancer cells and the peritoneal membrane. Interrelations between EOC and the mesothelial stroma are critical to facilitate the metastatic process. No data is available so far on the impact of histone acetylation/deacetylation, a potentially relevant mechanism governing EOC metastasis, on mesothelial cells (MCs)-mediated adhesion.MethodsStatic adhesion and peritoneal clearance experiments were performed pretreating mesenchymal-like MCs and platinum—sensitive/resistant EOC cell lines with MS-275—a Histone deacetylase (HDAC)1–3 pharmacological inhibitor currently used in combination trials. Results were acquired by confocal microscopy and were analyzed with an automated Opera software.The role of HDAC1/2 was validated by genetic silencing. The role of α4-, α5-α1 Integrins and Fibronectin-1 was validated using specific monoclonal antibodies.Quantitative proteomic analysis was performed on primary MCs pretreated with MS-275. Decellularized matrices were generated from either MS-275-exposed or untreated cells to study Fibronectin-1 extracellular secretion. The effect of MS-275 on β1 integrin activity was assessed using specific monoclonal antibodies. The role of Talin-1 in MCs/EOC adhesion was analyzed by genetic silencing. Talin-1 ectopic expression was validated as a rescue tool from MS-275-induced phenotype. The in vivo effect of MS-275-induced MC remodeling was validated in a mouse model of peritoneal EOC dissemination.ResultsTreatment of MCs with non-cytotoxic concentrations of MS-275 caused a consistent reduction of EOC adhesion. Proteomic analysis revealed several pathways altered upon MC treatment with MS-275, including ECM deposition/remodeling, adhesion receptors and actin cytoskeleton regulators. HDAC1/2 inhibition hampered actin cytoskeleton polymerization by downregulating actin regulators including Talin-1, impairing β1 integrin activation, and leading to abnormal extracellular secretion and distribution of Fibronectin-1. Talin-1 ectopic expression rescued EOC adhesion to MS-275-treated MCs. In an experimental mouse model of metastatic EOC, MS-275 limited tumor invasion, Fibronectin-1 secretion and the sub-mesothelial accumulation of MC-derived carcinoma-associated fibroblasts.ConclusionOur study unveils a direct impact of HDAC-1/2 in the regulation of MC/EOC adhesion and highlights the regulation of MC plasticity by epigenetic inhibition as a potential target for therapeutic intervention in EOC peritoneal metastasis.

Efficacy and safety of nanosomal docetaxel lipid suspension based chemotherapy in metastatic ovarian carcinoma: A retrospective study.

The aim of the current study was to assess the efficacy and safety of nanosomal docetaxel lipid suspension (NDLS) based chemotherapy in patients with metastatic epithelial ovarian carcinoma. In the present multicenter study, the medical records of patients who received NDLS (60-75 mg/m2; 3-weekly cycles) based chemotherapy for metastatic epithelial ovarian cancer in routine clinical care were retrospectively evaluated. Patients were followed-up from September 2014 until September 2018. The efficacy endpoints were the overall response rate (ORR) and disease control rate measured in accordance with the Response Evaluation Criteria in Solid Tumours 1.1. Overall survival (OS) and safety were also evaluated. Of the 13 patients evaluated, 46.2% (6/13) received NDLS-based first-line chemotherapy and 53.8% (7/13) patients received second-line chemotherapy [platinum-sensitive, 57.1% (4/7); platinum-resistant, 42.9% (3/7)]. The ORRs were 60.0% (3/5) and 57.1% (4/7) for patients receiving first- and second-line chemotherapy, respectively. The estimated median OS for patients receiving NDLS-based first-line chemotherapy was 17.4 months (follow-up duration, 4.3-49.4 months). The estimated median OS was 26.1 months (follow-up duration, 5.1-37.5 months) in patients with platinum-sensitive disease, whereas the OS was 14.8 months (follow-up duration, 3.5-14.8 months) in patients with platinum-resistant disease. No grade III/IV adverse events (AEs) were observed; ≥1 AE in grade I-II was reported in 84.6% (11/13) of patients. Overall, NDLS-based chemotherapy was efficacious and well-tolerated in the management of metastatic epithelial ovarian carcinoma.

Brain metastasis from ovarian carcinoma: Analysis of eight cases from a single radiotherapy center

ObjectiveBrain metastasis from epithelial ovarian carcinoma (EOC) is rarely seen having rate of 1–3% with very poor prognosis. Studies on brain metastatic EOC is limited with low number of participants. An increasing trend in EOC related to brain metastasis has been reported recently confronting managing clinicians with new challenges. Therefore, more information on this issue is needed. We aimed to analyze a single radiotherapy center experience on EOC related brain metastases. Materials and methodsData of all patients treated between January 1998 and December 2016 at a radiation center of a university hospital were reviewed retrospectively. Clinicopathological characteristics, treatment details and outcome were analyzed. ResultsWe identified only ten cases with EOC related brain metastasis in our department during 18-year period. Two patients were excluded because of data unavailability and therefore our study was performed among 8 patients. The median time between EOC diagnosis and detection of brain metastasis was 19.8 months. Brain metastasis was multiple in majority (75%). Extracranial metastasis at the time of brain metastasis was 62.5%. All patients died in the follow-up. The median survival time after the diagnosis of brain metastasis was 4.5 months. The median overall survival (OS) after the diagnosis of EOC was 28.9 months. The interval between the initial diagnosis and brain metastasis was negatively correlated with survival after brain metastasis (B-OS) occurred as time interval (p = 0.047). Presence of extracranial metastasis at time of occurrence of brain metastasis and application of multimodal treatment after brain metastasis were positively correlated with B-OS time (p = 0.007, p = 0.046, respectively). ConclusionPrognosis of brain metastasis from EOC remains poor. The factors associated with better B-OS were the longer time between initial diagnosis and brain metastasis, absence of extracranial disease at time of brain metastasis, and application of the multimodal treatment.

Abstract GMM-023: PATIENT DERIVED XENOGRAFTS (PDXS) AND PDX DERIVED TUMOR CELLS (PDTC) ALLOW THE IDENTIFICATION OF ACTIONABLE CANCER GENES AND TREATMENT OPTIONS FOR PLATINUM REFRACTORY/RESISTANT OVARIAN CARCINOMAS

Abstract Patients with advanced ovarian cancers have experienced little improvement in overall survival with standard treatments even after the incorporation of anti-angiogenic therapies. Besides anti-PARP inhibitors, matching individual critical genomic alterations with the best available drugs has not advanced as in other cancers, likely because a handful of cancer-related genes are mutated at high frequency, while many more are found mutated at much lower frequencies. This so called “mutation tail” is not only long but also mostly unexplored. We used Patient Derived Xenografts (PDXs) to identify actionable cancer genes and PDX Derived Tumor Cells (PDTCs) to accelerate the discovery of treatment options. We envisioned that the alleged weakness of PDX models, i.e. lack of human stromal and immune cells, might be instrumental to identify mutations in cancer and to test approved or experimental targeted drugs as monotherapy or in different combinations to link biomarkers to treatments. Forty-nine PDX lines from metastatic epithelial ovarian carcinomas have been propagated and fully characterized as far as histology, immunohistochemistry of epithelial and high-grade serous-specific markers and presence of TP53 and BRCA1/2 mutations. Copy number variations (CNV) analysis and Whole Exome Sequencing (WES) were carried out PDX lines derived from naïve metastatic high-grade epithelial ovarian carcinomas, which came out to be refractory/resistant to platinum drugs. We studied non-synonymous mutations with allele frequencies ≥0.1. Only mutations in cancer genes listed in databases were further analyzed. SNPdb allowed ruling out polymorphisms. SIFT and PROVEAN softwares predicted deleterious or damaging effects onto the protein sequences. DGIdb helped selecting actionable genes. We identified in one PDX line, a possibly loss-of-function mutation of the PIK3R1 gene (encoding the p85alpha regulatory subunit of PI3K) had an allele frequency=0.9 in early and late passages. Moreover, in two micro-dissected FFPE samples of the source tumor this mutation had an allele frequency nearly identical to that of the mutated TP53. Hence, PIK3R1W624R could be a trunk mutation in the PDX line and possibly in the human counterpart. Treatment options were assayed ex-vivo, on short-term cultures of PDTCs of the PIK3R1W624R PDX line. Buparlisib, a pan-class I PI3K inhibitor, showed the ability to block proliferation of PDTCs and the growth in vivo of PDXs in regression preclinical trial. These data proofed-the-concept that a PDX-based pipeline is able to unveil actionable pathways for the treatment of advanced/metastatic ovarian cancer. Citation Format: Martina Olivero, Jessica Erriquez, Maddalena Arigoni, Sonia Capellero, Concetta D'Ambrosio, Gloria Mittica, Fulvio Borella, Dionyssios Katsaros, Silvana Privitera, Enrico Berrino, Tiziana Venesio, Giorgio Valabrega, Raffaele Calogero and Maria Flavia Di Renzo. PATIENT DERIVED XENOGRAFTS (PDXS) AND PDX DERIVED TUMOR CELLS (PDTC) ALLOW THE IDENTIFICATION OF ACTIONABLE CANCER GENES AND TREATMENT OPTIONS FOR PLATINUM REFRACTORY/RESISTANT OVARIAN CARCINOMAS [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr GMM-023.

Abstract 3102: Identification of actionable cancer genes and treatment options for metastatic ovarian carcinomas using patient-derived xenografts and PDX-derived tumor cells

Abstract Patients with advanced ovarian cancers have experienced little improvement in overall survival with standard treatments even after the incorporation of anti-angiogenic therapies. Besides anti-PARP inhibitors, matching individual critical genomic alterations with the best available drugs has not advanced as in other cancers, likely because a handful of cancer-related genes are mutated at high frequency, while many more are found mutated at much lower frequencies. This so called “mutation tail” is not only long but also mostly unexplored. We used Patient Derived Xenografts (PDXs) to identify actionable cancer genes and PDX Derived Tumor Cells (PDTCs) to accelerate the discovery of treatment options. We envisioned that the alleged weakness of PDX models, i.e. lack of human stromal and immune cells, might be instrumental to identify mutations in cancer and to test approved or experimental targeted drugs as monotherapy or in different combinations to link biomarkers to treatments. Fourty-nine PDX lines from metastatic epithelial ovarian carcinomas have been propagated and fully characterized as far as histology, immunohistochemistry of epithelial and high-grade serous-specific markers and presence of TP53 and BRCA1/2 mutations. Copy number variations (CNV) analysis and Whole Exome Sequencing (WES) were carried out of 12 PDX lines derived from naïve metastatic high-grade serous epithelial ovarian carcinomas. We studied non-synonymous mutations with allele frequencies ≥0.1. Only mutations in cancer genes listed in databases were further analyzed. SNPdb allowed ruling out polymorphisms. SIFT and PROVEAN softwares predicted deleterious or damaging effects onto the protein sequences. DGIdb helped selecting actionable genes. We identified mutations in 1-4 cancer genes in 8/12 PDX lines. In one PDX line, a possibly loss-of-function mutation of the PIK3R1 gene (encoding the p85alpha regulatory subunit of PI3K) had an allele frequency=0.9 in early and late passages. Moreover, in two micro-dissected FFPE samples of the source tumor this mutation had an allele frequency nearly identical to that of the mutated TP53. Hence, PIK3R1W624R could be a trunk mutation in the PDX line and possibly in the human counterpart. Treatment options were assayed ex-vivo, on short-term cultures of PDTCs of the PIK3R1W624R PDX line. Buparlisib, a pan-class I PI3K inhibitor, showed the ability to block proliferation of PDTCs and the growth in vivo of PDXs in regression preclinical trial. These data proofed-the-concept that a PDX-based pipeline is able to unveil actionable pathways for the treatment of advanced/metastatic ovarian cancer. Citation Format: Martina Olivero, Jessica Erriquez, Maddalena Arigoni, Sonia Capellero, Concetta D'Ambrosio, Gloria Mittica, Fulvio Borella, Dionyssios Katsaros, Silvana Privitera, Enrico Berrino, Tiziana Venesio, Giorgio Valabrega, Raffaele Calogero, Maria Flavia Di Renzo. Identification of actionable cancer genes and treatment options for metastatic ovarian carcinomas using patient-derived xenografts and PDX-derived tumor cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3102.

Chemokines and cellular plasticity of ovarian cancer stem cells.

The diversity of cancer is generated through genetic alterations as well as by epigenetic events regulated by the tumor microenvironment. At the apex of this hierarchy are cancer stem cells (CSCs) which are characterized by their ability to self-renew, as well as to generate the cells constituting the tumor bulk. CSCs contribute to cancer metastasis and therapeutic resistance [1]. It is now clear that cellular interactions within the tumor microenvironment regulate both the cancer stem cell and bulk cell components which play an important role in tumor progression and metastasis. Deconvoluting the role of various components in the human cancer microenvironment and elucidating the mechanism of interaction has proved to be a great challenge. Recent studies have demonstrated that different immune components including Th22 cells [2] and myeloid derived suppressor cells (MDSCs) [3] are involved in the control of cancer stemness. Chemokines are important players in the immune responses. For some time it has been known that chemokines are able to target and recruit specific immune subsets into the microenvironment. For example, CXCL12 [4] and CXCL20 [5] mediate tumor trafficking of plasmacytoid dendritc cells (4) and regulatory T cells [5], respectively. These immune cell subsets can mediate immunosuppression and consequently promote cancer progression. Interestingly, chemokines may directly target tumor cells and affect tumorigenesis. CXCL8 (IL-8) [6] has been demonstrated to be involved in cancer stem cell biology and cancer cell metastasis. Furthering this work, Zhu et al, in this issue of Oncoscience, describe a new role for cancer stem cell-derived CCL5 in ovarian cancer metastasis. Ovarian cancer stem cells are enriched in cell fractions expressing CD133+ and ALDH-1+ [3, 7]. In an attempt to examine the role of CCL5 in cancer metastasis, Dr. Zhu and colleagues employed several complementary approaches to test the hypothesis that cancer stem cell-derived CCL5 played a role in endowing CSCs with invasive properties. They found that in the presence of CD133+ CSCs, CD133− cancer cells undergo an epithelial-mesenchymal transition (EMT)-like process and display enhanced metastatic capacity in in vitro assays as well as in vivo xenografts. They demonstrated that CD133+, but not CD133− cancer cells, expressed CCL5, with CCL5 signaling blockade abrogating and recombinant CCL5 mimicking these effects. In further support of the potential clinical significance of CCL5 and its receptors in tumorigenesis, they detected elevated expression of CCL5 and its receptors CCR1, CCR3 and CCR5 in human and murine metastatic epithelial ovarian carcinomas. To gain mechanistic insight into this process, they observed that paracrine CCL5 from CD133+ ovarian cancer stem cells activated the NF-κB signaling pathway in CD133− cells via binding CCR1, CCR3 and CCR5, thereby inducing EMT and tumor invasion. Therefore, it is reasonable to conclude that at least in this experimental setting, CCL5 and/or CCL5 expressing CSCs promote ovarian cancer EMT and potential metastasis. Although this manuscript represents a significant advance, many questions remain to be answered. The authors propose that CCL5 converts non-CSCs into CSCs through an EMT. However, they do not exclude the possibility that there are more than one form of CSCs in ovarian cancer since previous studies have suggested that CSCs can exist in alternative EMT- and MET-like states [8]. Thus, induction of EMT may represent transition in CSC state, rather than true induction of CSCs. In addition, the authors do not examine the role of other cell types in the tumor microenvironment which are capable of CCL5 expression. To what extent CD133+ cell-derived CCL5 is important in ovarian cancer metastasis in patients is not known. In addition, since these studies utilize established cell lines, it is unclear whether primary ovarian cells show similar cytokine expression patterns. Despite these limitations, this work adds to increasing evidence for the importance of CSCs and their regulation by cell-cell interactions in the tumor microenvironment. Furthermore, these studies suggest the possibility of inhibiting ovarian CSCs by blocking CCL5 signaling.

Highlights of This Issue

Brunquell and colleagues found that the Groucho-related TLE1 corepressor protein is a novel survival pathway that is activated by breast cancer cells in the absence of cell-substrate attachment. Importantly, the nuclear TLE1 protein is channelled to cytoplasm and targeted for degradation by the caspase-independent apoptotic effector Bit1 protein during anoikis (detachment-induced apoptosis). These observed molecular events provided mechanistic insight underlying the Bit1 anoikis pathway, which the authors have previously shown to be uniquely regulated by integrin-mediated cell attachment. Given the role of TLE1 in the anoikis resistance of breast cancer cells, inhibition of the TLE1 pathway may serve as a novel therapeutic strategy in combating breast cancer aggressiveness and metastatic disease through restoration of tumor cell anoikis sensitivity. The data also suggest a novel mechanism by which breast cancer cells evade anoikis via TLE1 expression, which is regulated downstream of matrix attachment.Mechanisms underlying metastatic epithelial ovarian carcinoma (MEOC) are not well understood. Expression and function of the lymphotactin receptor (XCR1), a potentially drug-targetable protein of the G protein-coupled receptor family, was investigated to validate it as a future target against MEOC. It was found that XCR1 is expressed in the majority of primary and metastatic EOCs. Activated lymphotactin axis was able to support EOC cell proliferation and migration. Reduction of XCR1 expression in EOC cells prevented metastasis on common sites, such as diaphragm and peritoneal wall. These results indicate that XCR1 may be a potential target against MEOC.Zebrafish standstill mutant embryos exhibit developmental defects and cell-cycle abnormalities. Verduzco and colleagues used positional cloning to show that standstill encodes zebrafish cdc25a, a key cell-cycle regulator. Unexpectedly, they found that genetic or pharmacologic inhibition of ATM kinase can rescue the cell-cycle effects of cdc25a deficiency. The DNA damage response pathway is critically important in cancer biology and treatment, but there has been little exploration of its functions in early embryogenesis. This work establishes a new role of cdc25a to balance constitutive activity of the ATM-mediated DNA damage response pathway during vertebrate development.Hedgehog signaling is involved in cancer development and metastasis. The receptor Patched is a Hedgehog target gene that is overexpressed in many tumors that develop drug resistance and disease recurrence. Bidet and colleagues demonstrate a link between Patched and resistance to chemotherapy and provide new insight into Patched function. Data show that the expression of human Patched in yeast conferred resistance to several chemotherapeutic agents such as doxorubicin and that inhibition of Patched expression increased doxorubicin accumulation in different cancer cell lines. Patched targeting therapy should be a promising strategy to overcome the resistance of cancer to chemotherapeutic treatment.

TRAIL-R3-related apoptosis: Epigenetic and expression analyses in women with ovarian neoplasia

ObjectiveTo assess the expression of TRAIL-R3 and the methylation of a CpG island within the TRAIL-R3 promoter both in cystadenoma tumors and primary and metastatic epithelial ovarian carcinoma (EOC). MethodsRNA was obtained from women with normal ovarian (NO) tissues (n=18), ovarian serous cystadenoma tumors (n=11) and EOC (n=16) using Trizol®. Quantitative PCR (qRT-PCR) was performed to quantify the relative levels of TRAIL-R3. The methylation frequency of the CpG island in the TRAIL-R3 promoter was assessed using the methylation-specific PCR (MSP) assay after DNA bisulfite conversion. The differences between the groups were evaluated using the chi-square, Student's t, ANOVA, Mann–Whitney U, Wilcoxon or Kruskal–Wallis tests as indicated. The survival rates were calculated using the Kaplan–Meier method. ResultsCystadenoma and metastatic EOC tumors expressed significantly more TRAIL-R3 mRNA than primary EOC tumors. Methylation of the TRAIL-R3 promoter was absent in NO tissues, while hemimethylation of the TRAIL-R3 promoter was frequently found in the neoplasia samples with 45.4% of the cystadenoma tumors, 8.3% of the primary EOC samples and 11.1% of the metastatic EOC samples showing at least partial methylation (p=0.018). Neither the expression of TRAIL-R3 nor alterations in the methylation profile were associated to cumulative progression-free survival or the overall survival in EOC patients. ConclusionsPrimary EOC is associated to a lower TRAIL-R3 expression, which leads to a better understanding of the complex disease and highlighting potential therapeutic targets. Promoter DNA methylation was not related to this finding, suggesting the presence of other mechanisms to transcriptional control.

Metastatik Over Karsinomlarında Metastazla İlişkili NM23-H1, KAI1 ve MKK4 Genlerinin Ekspresyon Analizleri

Objective: Cytoreductive surgery as a basis of therapy in epithelial ovarian carcinomas (EOC) provides the primary tumor and metastatic tumor samples from a same patient. This gives an excellent opportunity for evaluation of metastatic factors by excluding inter-individual differences. Therefore, we aimed to define changes at mRNA levels of NM23-H1, KAI1 and MKK4 metastasis-related genes in the paired normal tissue, primary tumor and omental metastatic tumor samples obtained from a same patient. Material and Methods: mRNA levels were quantified by quantitative reverse transcription polymerase chain reaction (Q-RT-PCR) following total RNA extraction in normal tissues, primary malign tissues of EOC, and its metastatic lesions on omentum for 41 patients with stage III-C (FIGO) EOC. Results: We found that mRNA level of NM23-H1 was significantly higher in metastatic samples compared to primary tumors (p=0.009). On the other hand, MKK4 was found to be significantly lower in primary tumor samples compared to normal tissues (p=0.024). There was no significant change at mRNA level of KAI1 among normal tissues, primary tumors and omental metastatic tumor samples. Conclusion: We suppose that in detailed functional studies, approaches that suppress NM23-H1 gene and restore MKK4 gene would make these genes important molecular targets for treatment of metastatic EOC in the future.

Cisplatin treatment of primary and metastatic epithelial ovarian carcinomas generates residual cells with mesenchymal stem cell-like profile

Epithelial mesenchymal transition (EMT) and cancer stem cells (CSC) have been associated with resistance to chemotherapy. Eighty percent of ovarian cancer patients initially respond to platinum-based combination therapy but most return with recurrence and ultimate demise. To better understand such chemoresistance we have assessed the potential role of EMT in tumor cells collected from advanced-stage ovarian cancer patients and the ovarian cancer cell line OVCA 433 in response to cisplatin in vitro. We demonstrate that cisplatin-induced transition from epithelial to mesenchymal morphology in residual cancer cells correlated with reduced E-cadherin, and increased N-cadherin and vimentin expression. The mRNA expression of Snail, Slug, Twist, and MMP-2 were significantly enhanced in response to cisplatin and correlated with increased migration. This coincided with increased cell surface expression of CSC-like markers such as CD44, α2 integrin subunit, CD117, CD133, EpCAM, and the expression of stem cell factors Nanog and Oct-4. EMT and CSC-like changes in response to cisplatin correlated with enhanced activation of extracellular signal-regulated kinase (ERK)1/2. The selective MEK inhibitor U0126 inhibited ERK2 activation and partially suppressed cisplatin-induced EMT and CSC markers. In vivo xenotransplantation of cisplatin-treated OVCA 433 cells in zebrafish embryos demonstrated significantly enhanced migration of cells compared to control untreated cells. U0126 inhibited cisplatin-induced migration of cells in vivo, suggesting that ERK2 signaling is critical to cisplatin-induced EMT and CSC phenotypes, and that targeting ERK2 in the presence of cisplatin may reduce the burden of residual tumor, the ultimate cause of recurrence in ovarian cancer patients.

Microenvironmental Regulation of Chemokine (C-X-C-Motif) Receptor 4 in Ovarian Carcinoma

The majority of women diagnosed with epithelial ovarian carcinoma (EOC) succumb due to complications of metastatic disease, suggesting that antimetastatic therapies may improve patient survival. EOC metastasis involves intraperitoneal shedding of cells from the primary tumor, followed by adhesion and localized penetration of the submesothelial matrix to anchor metastatic implants. Accumulation of malignant ascites is also common. Thus, a unique microenvironmental niche is established, which includes malignant cells and a plethora of soluble factors secreted by-or in response to-tumor cells. As cells penetrating the submesothelial surface encounter an interstitial collagen-rich extracellular matrix, we have used three-dimensional type I collagen gels to model early events resulting from intraperitoneal anchoring. In this study, we show a novel pathway of CXCR4 upregulation through beta1 integrin - and NFkappaB-dependent signaling pathways in response to three-dimensional type I collagen. We also show the involvement of CXCR4-SDF1 axis in collagen invasion and proliferation, relevant to the metastatic EOC. Our data show that CXCR4 expression in human EOCs, as well as SDF1 presence in the ascites, is correlated with disease progression and metastasis. These data emphasize the importance of the CXCR4-SDF1 axis in EOC metastasis and suggest that this mechanism should be accounted for when targeting EOC metastasis.

Socioeconomic factors may contribute to neoadjuvant chemotherapy use in metastatic epithelial ovarian carcinoma

Objective. To identify patient characteristics which predict receipt of neoadjuvant chemotherapy (NCT) versus standard therapy (ST) in metastatic ovarian cancer. Methods. A retrospective matched case control study was conducted of 52 women treated with NCT compared to 104 women who received standard treatment from 1996 to 2007. The t test was used for comparison of means between the groups, and the χ 2 test was used for categorical data. Multivariable analysis was performed with logistic regression models and only two-tailed analyses with a P value < 0.05 were considered statistically significant. Results. Age, employment and marital status, and insurance alone did not affect treatment allocation ( P = NS). However, non-Hispanic White (NHW) patients were more as likely to receive ST ( P < 0.05). When insurance was stratified by ethnicity, NHW patients were twice as likely to have private insurance (OR = 2.29, CI = 1.16–4.53). Furthermore, medically compromised (MC) patients who were NHW were almost three times more likely to receive ST (OR = 2.72, CI = 1.02–5.00). In multivariate analysis, only MC and publically funded women were more likely to receive NCT (OR 3.83 CI = 1.35–11.11); P = 0.01). During surgery, patients receiving NCT were found to have smaller tumors and less ascites, and were more likely to be optimally debulked with lower estimated blood loss and shorter hospital stays. The median survival for ST was 55.8 months versus 26 months for NCT ( P < 0.001). Conclusions. Non-clinical factors such as publically funded status and non-Hispanic White race may influence the allocation of NCT for women with metastatic ovarian cancer.

Overexpression of Epithelial Cell Adhesion Molecule in Primary, Metastatic, and Recurrent/Chemotherapy-Resistant Epithelial Ovarian Cancer

To evaluate the potential of epithelial cell adhesion molecule (Ep-CAM/TROP-1)-specific immunotherapy against epithelial ovarian carcinomas (EOCs), we have analyzed the expression of Ep-CAM at RNA and protein level in patients harboring primary, metastatic, and chemotherapy-resistant/recurrent EOC. Epithelial cell adhesion molecule expression was evaluated by real-time polymerase chain reaction and immunohistochemistry in 168 fresh-frozen biopsies and paraffin-embedded tissues. In addition, Ep-CAM surface expression was evaluated by flow cytometry in several freshly established ovarian carcinoma cell lines derived from patients harboring tumors resistant to chemotherapy in vivo as well as in vitro. Epithelial cell adhesion molecule transcript was found significantly overexpressed in primary, metastatic, and recurrent EOC when compared with normal human ovarian surface epithelium cell lines and fresh-frozen normal ovarian tissue (P < 0.001). Similarly, by immunohistochemistry, Ep-CAM protein expression was found significantly higher in primary, metastatic, and recurrent EOC when compared with normal ovarian tissues. Of interest, metastatic/recurrent tumors were found to express significantly higher levels of Ep-CAM protein when compared with primary ovarian carcinomas (P < 0.001). Finally, a high surface expression of Ep-CAM was found in 100% (5/5) of the chemotherapy-resistant ovarian carcinoma cell lines studied by flow cytometry. These results demonstrate high Ep-CAM overexpression in ovarian carcinoma, especially in metastatic and recurrent/chemotherapy-resistant ovarian disease. The lack of Ep-CAM expression on the chelomic epithelium in the peritoneal cavity, combined with the recent development of fully human monoclonal antibodies against this surface molecule, suggest Ep-CAM as a promising target for antibody-mediated therapies in ovarian carcinoma patients harboring tumors refractory to standard treatment modalities.

Claudin-7 expression in human epithelial ovarian cancer

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

Primary chemotherapy and adjuvant tumor debulking in the management of advanced-stage epithelial ovarian cancer

The aim of this article was to review the experience with neoadjuvant chemotherapy and interval surgical debulking in patients with metastatic epithelial ovarian cancer. A retrospective chart review was carried out to identify patients treated with neoadjuvant platinum/Taxol chemotherapy and interval debulking. Cox regression modeling was used to identify significant predictors of progression-free interval. The Kaplan-Meier method was used to estimate the survival statistic for the study group. Sixty-one patients were identified after being treated with neoadjuvant chemotherapy and interval debulking surgeries. All surgeries were performed after three cycles of platinum/Taxol combination chemotherapy. Eighty percent of patients had a residual disease status of 2 cm or less after surgery. Suboptimal debulking was statistically associated with tumor involvement of the upper abdominal organs (P < 0.001) and non-normalization of CA125 before surgery (P= 0.03). The perioperative complication rate was 7%. At a mean follow-up time of 19 months, 77% of patients were still alive. Cox regression modeling identified the microscopic tumor residual status as the only significant predictor of progression-free interval. The estimated median survival for the group was 41.70 months (95% confidence interval = 13.84-69.56 months). Neoadjuvant chemotherapy with interval debulking surgery appeared to be safe and feasible in patients with metastatic epithelial ovarian carcinoma.

Granulin-epithelin precursor is a novel prognostic marker in epithelial ovarian carcinoma.

The granulin-epithelin precursor (GEP) was preferentially expressed in invasive ovarian tumor epithelium specimens compared with specimens of borderline ovarian tumors. The objective of the current study was to evaluate the anatomic site-related and cellular expression of GEP and its association with clinicopathologic parameters and survival in patients with advanced-stage ovarian carcinoma. Effusions (n = 190), corresponding primary tumor specimens (n = 64), and specimens of metastatic lesions (n = 125) were analyzed using immunohistochemistry with a specific polyclonal antipeptide antibody. In addition, 36 effusions were analyzed using immunoblotting. GEP was detected in tumor cells in 171 of 190 (90%) effusions and demonstrated both focal membrane and cytoplasmic localization. Mesothelial cells were often GEP positive (81%). GEP was found in carcinoma cells in 180 of 189 (95%) tumor biopsy specimens, with stromal and endothelial cell expression in 93 of 180 (52%) and 124 of 185 (67%) specimens, respectively. Lower GEP expression in stromal cells was observed in metastases sampled during or after chemotherapy (P = 0.034). The presence of GEP-positive stromal cells in untreated primary tumor specimens correlated with worse overall survival (P = 0.014). Significantly more frequent GEP expression was observed in tumor cells of both primary (P = 0.002) and metastatic (P < 0.001) tissue specimens compared with malignant effusions. GEP expression was observed in primary and metastatic epithelial ovarian carcinoma specimens, with down-regulated expression in tumor cells of malignant effusions. The poor outcome associated with stromal GEP expression suggests a prognostic role for this growth factor in ovarian carcinoma.

Angiogenesis in primary and metastatic epithelial ovarian carcinoma

Objective: Our goal was to evaluate angiogenesis in the ovaries and omental metastases as a prognostic indicator in patients with epithelial ovarian carcinoma. Study design: Ovarian specimens of 42 consecutive patients with primary epithelial ovarian carcinoma (stages I to IV) and omental metastases of 19 of these patients with stage IIIB or stage IIIC disease were stained immunohistochemically for factor VIII–related antigen. Microvessel counts were tested for correlation with patient age, stage of disease, type of tumor, preoperative serum CA 125 level, tumor size, tumor resectability, patient survival, and omental microvessel counts. Statistical analysis included parametric (factorial analysis of variance) and nonparametric (Mann-Whitney and Kruskal-Wallis) group comparison tests, parametric (Pearson) and nonparametric (Spearman) correlation tests, and parametric (Cox proportional hazards) and nonparametric (Kaplan-Meier) survival analysis with p < 0.05 considered significant throughout. Results: Microvessel counts of omental metastases in patients with stage IIIB or stage IIIC ovarian carcinoma were significantly correlated with preoperative serum CA 125 level ( p = 0.028) and patient survival ( p = 0.019). Microvessel counts of the ovaries examined were not correlated with patient age, stage of disease, type of tumor, preoperative serum CA 125 level, tumor size, tumor resectability, patient survival, or microvessel count of the corresponding omental metastases. Conclusion: Microvessel count of omental metastases is an independent prognostic indicator of survival in patients with advanced epithelial ovarian carcinoma and correlates with preoperative serum CA 125 level.