Every year, breast cancer kills more Irish women than any other type of cancer. Other cells that surround cancer cells, called ‘stromal cells’ (SC) are receiving increased attention for their role in causing and maintaining breast tumour growth and metastasis1. SC also release factors that create an immune-suppressive niche within the tumour microenvironment (TME). Therefore discovering a regimen to safely target SC or SC-derived factors is a key goal in breast cancer medicine. We have developed a process that allows us to specifically isolate and grow SC from breast cancer tissue and tumour-associated normal tissue from the same patient. Our work indicates that these SC are of mesenchymal origin as they express CD90, CD105, and CD73 and are negative for CD45, CD34, CD14, CD11b and MHC-II. Additionally these SC possess immune-suppressive properties as they are capable of inhibiting CD4+ T cell proliferation in vitro. At present we have isolated tumour-derived SC from 11 different patients. In these studies we will further characterize these SC populations by measuring the expression of genes and proteins known to be activated in tumour SC compared to normal SC. These studies are significant as they will help us identify markers to verify isolation of tumour-activated SC and allow us to design essential experiments to test these SC in animal breast cancer models. Findings from this study will be of great significance to breast cancer patients as in future experiments these tumour-derived SC populations can be used to identify unknown patient-specific SC therapeutic targets.
