Characterisation of Extracellular Vesicles (EVs) released by 4T1 breast cancer cells (360G-Wellcome-211459_Z_18_Z)

Extracellular vesicles(EVs) are tiny vesicles that shuttle genetic information between cells, and throughout the circulation. MicroRNAs(miRNAs) are small non-coding RNAs that regulate gene expression. This study will focus on EV- encapsulated microRNAs(EVmiRs). The host group recently published work showing a potent tumor suppressor role for miRNA-379 in breast cancer. Tumour-targeted delivery of the miR was achieved by harnessing the natural homing capacity of Mesenchymal Stem Cells(MSCs) engineered to over-express miR-379. The MSCs were found to release miR-379 in EVs, and the miR-379 enriched EVs were shown to reduce breast cancer growth in vivo. This study was performed in immunocompromised animals and must be expanded to take the host immune system into account. This will be achieved using murine 4T1 breast cancer cells in immune competent animals. It is necessary to first establish the characteristics of EVs released from these cells. The aim of this study is to define the EV-miR profile of 4T1 cells in vitro. The data generated will inform a subsequent In Vivo study, where EVmiRs detected in vitro will be compared to those detected in the bloodstream of mice bearing 4T1 tumours. This will provide a potential biomarker of disease progression or response to MSC-EV therapy.