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Ahmed N.,Womens Cancer Research Center | Ahmed N.,University of Melbourne | Ahmed N.,Prince Henrys Institute for Medical Research | Stenvers K.L.,Prince Henrys Institute for Medical Research | Stenvers K.L.,Monash University
Frontiers in Oncology | Year: 2013

More than one third of ovarian cancer patients present with ascites at diagnosis, and almost all have ascites at recurrence. The presence of ascites correlates with the peritoneal spread of ovarian cancer and is associated with poor disease prognosis. Malignant ascites acts as a reservoir of a complex mixture of soluble factors and cellular components which provide a pro-inflammatory and tumor-promoting microenvironment for the tumor cells. Subpopulations of these tumor cells exhibit cancer stem-like phenotypes, possess enhanced resistance to therapies and the capacity for distal metastatic spread and recurrent disease. Thus, ascites-derived malignant cells and the ascites microenvironment represent a major source of morbidity and mortality for ovarian cancer patients. This review focuses on recent advances in our understanding of the molecular, cellular, and functional characteristics of the cellular populations within ascites and discusses their contributions to ovarian cancer metastasis, chemoresistance, and recurrence. We highlight in particular recent translational findings which have used primary ascites-derived tumor cells as a tool to understand the pathogenesis of the disease, yielding new insights and targets for therapeutic manipulation. © 2013 Ahmed and Stenvers.

Kumar J.,Deakin University | Fraser F.W.,Deakin University | Riley C.,Womens Cancer Research Center | Ahmed N.,Womens Cancer Research Center | And 3 more authors.
British Journal of Cancer | Year: 2014

Background:Ovarian cancer remains a major cause of cancer mortality in women, with only limited understanding of disease aetiology at the molecular level. Granulocyte colony-stimulating factor (G-CSF) is a key regulator of both normal and emergency haematopoiesis, and is used clinically to aid haematopoietic recovery following ablative therapies for a variety of solid tumours including ovarian cancer.Methods:The expression of G-CSF and its receptor, G-CSFR, was examined in primary ovarian cancer samples and a panel of ovarian cancer cell lines, and the effects of G-CSF treatment on proliferation, migration and survival were determined.Results:G-CSFR was predominantly expressed in high-grade serous ovarian epithelial tumour samples and a subset of ovarian cancer cell lines. Stimulation of G-CSFR-expressing ovarian epithelial cancer cells with G-CSF led to increased migration and survival, including against chemotherapy-induced apoptosis. The effects of G-CSF were mediated by signalling via the downstream JAK2/STAT3 pathway.Conclusion:This study suggests that G-CSF has the potential to impact on ovarian cancer pathogenesis, and that G-CSFR expression status should be considered in determining appropriate therapy. © 2014 Cancer Research UK.

Brennan D.J.,Queensland Center for Gynaecological Oncology | Hackethal A.,Queensland Center for Gynaecological Oncology | Metcalf A.M.,Queensland Institute of Medical Research | Coward J.,Materials Medical Research Institute | And 9 more authors.
Gynecologic Oncology | Year: 2014

Objective HE4 has emerged as a promising biomarker in gynaecological oncology. The purpose of this study was to evaluate serum HE4 as a biomarker for high-risk phenotypes in a population-based endometrial cancer cohort. Methods Peri-operative serum HE4 and CA125 were measured in 373 patients identified from the prospective Australian National Endometrial Cancer Study (ANECS). HE4 and CA125 were quantified on the ARCHITECT instrument in a clinically accredited laboratory. Receiver operator curves (ROC), Spearman rank correlation coefficient, and chi-squared and Mann-Whitney tests were used for statistical analysis. Survival analysis was performed using Kaplan-Meier and Cox multivariate regression analyses. Results Median CA125 and HE4 levels were higher in stage III and IV tumours (p < 0.001) and in tumours with outer-half myometrial invasion (p < 0.001). ROC analysis demonstrated that HE4 (area under the curve (AUC) = 0.76) was a better predictor of outer-half myometrial invasion than CA125 (AUC = 0.65), particularly in patients with low-grade endometrioid tumours (AUC 0.77 vs 0.64 for CA125). Cox multivariate analysis demonstrated that elevated HE4 was an independent predictor of recurrence-free survival (HR = 2.40, 95% CI 1.19-4.83, p = 0.014) after adjusting for stage and grade of disease, particularly in the endometrioid subtype (HR = 2.86, 95% CI 1.25-6.51, p = 0.012). Conclusion These findings demonstrate the utility of serum HE4 as a prognostic biomarker in endometrial cancer in a large, population-based study. In particular they highlight the utility of HE4 for pre-operative risk stratification to identify high-risk patients within low-grade endometrioid endometrial cancer patients who might benefit from lymphadenectomy. © 2013 Elsevier Inc.

Hugo H.J.,St. Vincents Institute | Lebret S.,Deakin University | Tomaskovic-Crook E.,St. Vincents Institute | Ahmed N.,Womens Cancer Research Center | And 6 more authors.
Cancer Microenvironment | Year: 2012

Hyperactive inflammatory responses following cancer initiation have led to cancer being described as a 'wound that never heals'. These inflammatory responses elicit signals via NFκB leading to IL-6 production, and IL-6 in turn has been shown to induce epithelial to mesenchymal transition in breast cancer cells in vitro, implicating a role for this cytokine in cancer cell invasion. We previously have shown that conditioned medium derived from cancer-associated fibroblasts induced an Epithelial to Mesenchymal transition (EMT) in PMC42-LA breast cancer cells and we have now identify IL-6 as present in this medium. We further show that IL-6 is expressed approximately 100 fold higher in a cancer-associated fibroblast line compared to normal fibroblasts. Comparison of mouse-specific (stroma) and human-specific (tumor) IL-6 mRNA expression from MCF-7, MDA MB 468 and MDA MB 231 xenografts also indicated the stroma rather than tumor as a significantly higher source of IL-6 expression. Mast cells (MCs) feature in inflammatory cancer-associated stroma, and activated MCs secrete IL-6. We observed a higher MC index (average number of mast cells per xenograft section/average tumor size) in MDA MB 468 compared to MDA MB 231 xenografts, where all MC were observed to be active (degranulating). This higher MC index correlated with greater mouse-specific IL-6 expression in the MDA MB 468 xenografts, implicating MC as an important source of stromal IL-6. Furthermore, immunohistochemistry on these xenografts for pSTAT3, which lies downstream of the IL-6 receptor indicated frequent correlations between pSTAT3 and mast cell positive cells. Analysis of publically available databases for IL-6 expression in patient tissue revealed higher IL-6 in laser capture microdissected stroma compared to adjacent tissue epithelium from patients with inflammatory breast cancer (IBC) and invasive non-inflammatory breast cancer (non-IBC) and we show that IL-6 expression was significantly higher in Basal versus Luminal molecular/phenotypic groupings of breast cancer cell lines. Finally, we discuss how afferent and efferent IL-6 pathways may participate in a positive feedback cycle to dictate tumor progression. © 2012 Springer Science+Business Media B.V.

Ahmed N.,Womens Cancer Research Center | Ahmed N.,University of Melbourne | Ahmed N.,Prince Henrys Institute of Medical Research | Abubaker K.,Womens Cancer Research Center | And 2 more authors.
Current Cancer Drug Targets | Year: 2010

Overcoming intrinsic and acquired chemoresistance is the major challenge in treating ovarian cancer patients. Initially nearly 75% of ovarian cancer patients respond favourably to chemotherapy, but subsequently the majority gain acquired resistance resulting in recurrence, cancer dissemination and death. This review summarizes recent advances in our understanding of the cellular origin and the molecular mechanisms defining the basis of cancer initiation and malignant transformation with respect to epithelial-mesenchymal transition (EMT) of ovarian cancer cells. We discuss the critical role of EMT frequently encountered in different phases of ovarian cancer progression and its involvement in regulating cancer growth, survival, migration, invasion and drug resistance. Using a model ovarian cancer cell line we highlight the relationship between EMT and the 'migrating cancer stem (MCS) cell-like phenotype' in response to drug treatment, and relate how these processes can impact on chemoresistance and ultimately recurrence. We propose the molecular targeting of distinct 'EMT transformed cancer stem-like cells' and suggest ways that may improve the efficacy of current chemotherapeutic regimens much needed for the management of this disease. © 2010 Bentham Science Publishers Ltd.

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