Ascites from ovarian cancer patients stimulates MUC16 mucin expression and secretion in human peritoneal mesothelial cells through an Akt-dependent pathway.

Background: CA125 is a well-established ovarian cancer (OC) serum biomarker. The CA125 heavily glycosylated epitope is carried by the MUC16 mucin, a high molecular weight transmembrane mucin. Upon proteolytic cleavage, the extracellular domain of MUC16 is released from the cell surface into malignant ascites and blood vessels.

Serum CA125 and ascites leptin level ratio predicts baseline clinical resistance to first-line platinum-based treatment and poor prognosis in patients with high grade serous ovarian cancer.

About 20% of patients with high grade serous epithelial ovarian carcinoma (HGSOC) are intrinsically resistant to standard first-line platinum-based combination therapy. There is no marker yet available to identify these patients. In that context, all patients with HGSOC initially receive the same standard first-line platinum-based therapy, and those with intrinsically resistant diseases can only be identified retrospectively after they experienced early relapse to therapy.

Ascites IL-10 Promotes Ovarian Cancer Cell Migration.

Ovarian cancer (OC) ascites is an inflammatory and immunosuppressive tumor environment characterized by the presence of various cytokines, chemokines and growth factors. The presence of high concentrations of these cytokines/chemokines in ascites is associated with a more aggressive tumor phenotype. IL-10 is an immunosuppressive cytokine for which high expression has been associated with poor prognosis in some cancers.

CCL18 from ascites promotes ovarian cancer cell migration through proline-rich tyrosine kinase 2 signaling.

Background: Ovarian cancer (OC) ascites consist in a proinflammatory tumor environment that is characterized by the presence of various cytokines, chemokines and growth factors. The presence of these inflammatory-related factors in ascites is associated with a more aggressive tumor phenotype. CCL18 is a member of CCL chemokines and its expression has been associated with poor prognosis in some cancers.

Mesothelial cells interact with tumor cells for the formation of ovarian cancer multicellular spheroids in peritoneal effusions.

Epithelial ovarian cancer (EOC) dissemination is primarily mediated by the shedding of tumor cells from the primary site into ascites where they form multicellular spheroids that rapidly lead to peritoneal carcinomatosis. While the clinical importance and fundamental role of multicellular spheroids in EOC is increasingly appreciated, the mechanisms that regulate their formation and dictate their cellular composition remain poorly characterized. To investigate these important questions, we characterized spheroids isolated from ascites of women with EOC.

Inflammation-regulating factors in ascites as predictive biomarkers of drug resistance and progression-free survival in serous epithelial ovarian cancers.

Background: Platinum-based combination therapy is the standard first-line treatment for women with advanced serous epithelial ovarian carcinoma (EOC). However, about 20 % will not respond and are considered clinically resistant. The availability of biomarkers to predict responses to the initial therapy would provide a practical approach to identify women who would benefit from a more appropriate first-line treatment.

MUC16 mucin (CA125) regulates the formation of multicellular aggregates by altering β-catenin signaling.

After shedding from the primary tumor site, ovarian cancer cells form three-dimensional multicellular aggregates that serve as vehicle for cancer cell dissemination in the peritoneal cavity. MUC16 mucin (CA125) is aberrantly expressed by most advanced serous ovarian cancers and can promote proliferation, migration and metastasis. MUC16 associates with E-cadherin and β-catenin, two proteins involved in regulation of cell adhesion and the formation of multicellular aggregates.

Ovarian cancer ascites enhance the migration of patient-derived peritoneal mesothelial cells via cMet pathway through HGF-dependent and -independent mechanisms.

Ovarian cancer ascites consist of a proinflammatory environment that is characterized by the presence of abundant human peritoneal mesothelial cells (HPMCs). Cytokines and growth factors in ascites modulate cell activities of tumor cells. The expression of proinflammatory cytokines in ascites is associated with a more aggressive tumor phenotype.

Transformation of NIH3T3 mouse fibroblast cells by MUC16 mucin (CA125) is driven by its cytoplasmic tail.

MUC16 (CA125) is a transmembrane mucin that contributes to the progression of epithelial ovarian cancer (EOC). Expression of MUC16 is not detectable in the epithelial surface of normal ovaries. MUC16 expression is, however, common in serous EOC as well as in metastatic and recurrent tumors.

Specimen quality evaluation in Canadian biobanks participating in the COEUR repository.

Human biological specimens are important for translational research programs such as the Canadian Ovarian Experimental Unified Resource (COEUR) funded by the Terry Fox Research Institute. Sample quality is an important consideration, as it directly impacts the quality of ensuing research. The aim of the present study was to determine the quality of tissues collected from different sites contributing to the COEUR cohort.

Role of malignant ascites on human mesothelial cells and their gene expression profiles.

Background: Malignant ascites is often present at diagnostic in women with advanced ovarian cancer (OC) and its presence is associated with a worse outcome. Human peritoneal mesothelial cells (HPMCs) are key components of malignant ascites. Although the interplay between HPMCs and OC cells is believed to be critical for tumor progression, it has not been well characterized.

MUC16 mucin (CA125) attenuates TRAIL-induced apoptosis by decreasing TRAIL receptor R2 expression and increasing c-FLIP expression.

Background: MUC16 (CA125) is a large transmembrane mucin protein (> 200 kDa) aberrantly expressed in approximately 80% of human epithelial ovarian cancers (EOC). MUC16 expression in EOC cells is associated with increased tumorigenesis and inhibiton of genotoxic drug-induced apoptosis. However, the mechanism by which MUC16 mediates these effects is unknown.

Osteoprotegerin (OPG) activates integrin, focal adhesion kinase (FAK), and Akt signaling in ovarian cancer cells to attenuate TRAIL-induced apoptosis.

Background: Resistance to apoptosis is a major problem in ovarian cancer (OC) and correlates with poor prognosis. Osteoprotegerin (OPG) is a soluble secreted factor that acts as a decoy receptor for receptor activator of NF-κB ligand (RANKL) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). OPG has been reported to attenuate TRAIL-induced apoptosis in a variety of cancer cells, including OC cells.

Ovarian cancer ascites increase Mcl-1 expression in tumor cells through ERK1/2-Elk-1 signaling to attenuate TRAIL-induced apoptosis.

Background: Ascites may affect the progression of ovarian cancer (OC). In particular, soluble factors present in OC ascites can create a protective environment for tumor cells that promote de novo resistance to drug- and death receptor-induced apoptosis. However, the underlying molecular mechanisms responsible for ascites-induced drug resistance are not well characterized.

Osteoprotegerin (OPG) protects ovarian cancer cells from TRAIL-induced apoptosis but does not contribute to malignant ascites-mediated attenuation of TRAIL-induced apoptosis.

Background: Resistance to apoptosis is a major problem in ovarian cancer and correlates with poor prognosis. Osteoprotegerin (OPG) is a secreted factor in malignant ascites and acts as a decoy receptor for receptor activator of NF-κB ligand (RANKL) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). TRAIL promotes apoptosis in ovarian cancer cells.

Profiling of cytokines in human epithelial ovarian cancer ascites.

Background: The behavior of tumor cells is influenced by the composition of the surrounding tumor environment. The importance of ascites in ovarian cancer (OC) progression is being increasingly recognized. The characterization of soluble factors in ascites is essential to understand how this environment affects OC progression.

Targeted ovarian cancer treatment: the TRAILs of resistance.

Ovarian cancer (OC) is the leading cause of death from gynecological malignancies. Although most patients respond to the initial therapy when presenting with advanced disease, only 10-15% maintain a complete response following first-line therapy. Recurrence defines incurable disease in most cases.

Prognostic significance of IL-6 and IL-8 ascites levels in ovarian cancer patients.

Background: The acellular fraction of epithelial ovarian cancer (EOC) ascites promotes de novo resistance of tumor cells and thus supports the idea that tumor cells may survive in the surrounding protective microenvironment contributing to disease recurrence. Levels of the pro-inflammatory cytokines IL-6 and IL-8 are elevated in EOC ascites suggesting that they could play a role in tumor progression.

Methods: We measured IL-6 and IL-8 levels in the ascites of 39 patients with newly diagnosed EOC.

MUC16 (CA125) regulates epithelial ovarian cancer cell growth, tumorigenesis and metastasis.

Objectives: MUC16 (CA125) protein is a high molecular weight mucin overexpressed in the majority of epithelial ovarian cancers (EOC) but not in the epithelium of normal ovaries suggesting that it might play a role in EOC pathogenesis. Here, we explored the phenotypic consequences of MUC16 knockdown and expression of its C-terminal domain with the aim of establishing a role for MUC16 in tumorigenesis.

Methods: MUC16 was down-regulated by stably expressing an anti-MUC16 endoplasmic reticulum-targeted single-chain antibody which prevented MUC16 cell surface localization in NIH:OVCAR3 cells.

The prosurvival activity of ascites against TRAIL is associated with a shorter disease-free interval in patients with ovarian cancer.

Background: The production of ascites is a common complication of ovarian cancer. Ascites constitute a unique tumor microenvironment that may affect disease progression. In this context, we recently showed that ovarian cancer ascites may protect tumor cells from TRAIL-induced apoptosis.

Antiapoptotic proteins Bcl-2 and Bcl-XL inhibit Clostridium difficile toxin A-induced cell death in human epithelial cells.

It has been well established that Clostridium difficile toxin A (TcdA) induces cell death in human epithelial cells. However, the mechanism of TcdA-induced cell death remains to be fully characterized. Here, we show that TcdA induces dose-dependent cell death in ovarian carcinoma and colonic carcinoma cell lines.