Abstract 1415: Stromal and epithelial interactions in three dimensional models of epithelial ovarian cancer

Abstract

Abstract In vitro cell biology models of disease are a fundamental tool for the understanding of disease development in vivo. For cancer, two dimensional (2D) monolayer cell cultures have been used to establish in vitro models. However, it has become increasingly evident that these models fail to address important characteristics of tumours in vivo. The three dimensional (3D) architecture and the resulting interactions with the tumour microenvironment cannot be recreated in standard 2D cultures. We have shown that homotypic 3D models of normal ovarian surface epithelial (OSE) cells and epithelial ovarian cancers (EOCs) represent good models of tissues in vivo. However, heterotypic models including two or more cell types are likely to be even more relevant. Therefore we have created 3D models of ovarian stromal and epithelial cell interactions for EOC and the normal ovary. We established an immortalised ovarian fibroblast cell line from a normal ovary to represent the microenvironment in normal ovarian tissues. To recreate the stroma of a normal ovary in a postmenopausal woman we induced senescence in the normal ovarian fibroblasts (NOFs). Morphological and histocytochemical examination of spheroids with senescent ovarian fibroblasts (SOFs) showed increased numbers of mitosis and staining for Mib-1, suggesting that SOFs can promote epithelial cell proliferation. To model the stroma of a malignant tumour we used mesenchymal stem cells (MSC) which can differentiate into cancer associated fibroblasts (CAFs) after being recruited into the tumour stroma. We induced differentiation of MSC into a ‘CAF -like’ phenotype using conditioned medium from EOC cell line cultures. Differentiation of MSCs was evident one week after conditioning and was verified by staining for the CAF markers aSMA, FSP, Vimentin and FAP. Stromal and epithelial cells were labelled using eGFP and the far red fluorescent protein mKate2 respectively, to enable discrimination between both cell types. Heterotypic 3D cultures were set-up by co-culturing the stromal cells with transformed ovarian epithelial cells using polyHEMA coated tissue culture plastics. Fluorescent labelling has enabled us to study the 3D invasive properties and the influence of the changing microenvironment on the invasive ability of transformed epithelial cells. In conclusion, we have established 3D spheroid models of stromal and epithelial interactions representing both normal ovarian tissues and EOCs. These models will serve as valuable reagents in our understanding of stromal-epithelial interactions and the development of ovarian cancer. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1415.