Abstract
Mitochondrial activity is central to tissue homeostasis. Mitochondria dysfunction constitutes a hallmark ofmany genetic diseases and plays a key role in tumor progression. The essential role of mitochondria, addedto their recently documented capacity to transfer from cell to cell, obviously contributes to their currentinterest. However, determining the proper role of mitochondria in defined biological contexts washampered by the lack of suitable experimental tools. We designed a protocol (MitoCeption) to directly andquantitatively transfer mitochondria, isolated from cell type A, to recipient cell type B. We validated andquantified the effective mitochondria transfer by imaging, fluorescence-activated cell sorting (FACS) andmitochondrial DNA analysis. We show that the transfer of minute amounts of mesenchymal stem/stromalcell (MSC) mitochondria to cancer cells, a process otherwise occurring naturally in coculture, results incancer cell enhanced oxidative phosphorylation (OXPHOS) activity and favors cancer cell proliferation andinvasion. The MitoCeption technique, which can be applied to different cell systems, will therefore be amethod of choice to analyze the metabolic modifications induced by exogenous mitochondria in host cells.