Characterization and Classification of Ovarian Cancer Patient Derived Cells

A cancer cell’s ability to migrate and invade other tissues is a hallmark for metastatic disease. To invade, cells must undergo a process called epithelial-mesenchymal transition (EMT). In this process epithelial genes such as E-cadherin are downregulated and genes associated with a mesenchymal phenotype are upregulated, leading to migratory and invasive properties in cells. The action of transcription factors including SNAI1 causes the changes observed in EMT. Cancer cells that express both epithelial and mesenchymal markers are considered hybrid (E/M) cells, are associated with increased tumor-forming ability, and exhibit more cancer stem-cell (CSC) like characteristics. Previously, our lab characterized high grade serous ovarian cancer (HGSOC) cell lines by determining the level of SNAI1 expression relative to the expression level of E-cadherin (S/E index). Cell lines that exhibited more mesenchymal and stem-like characteristics scored a higher S/E index. Cell lines, although useful, have undergone many passages and can often acquire mutations that may not accurately emulate the disease from which they were originally derived. In this study I use patient derived HGSOC cells, obtained from de-bulking surgery, to characterize and analyze E vs. M and CSC status. In addition to SNAI1 & E-cadherin, expression levels of several EMT markers such as occludin, claudin (E), twist and vimentin (M) are analyzed to determine a gene expression signature indicative of the invasive phenotype