Résumé
Epithelial-to-mesenchymal transition (EMT) has been described as a critical step in the metastatic process. Recent studies have detected circulating tumor cells (CTCs) in hybrid EMT-states in the blood of cancer patients, however fully epithelial CTC states were also detected, challenging the EMT dogma. Besides invasion through EMT, the amoeboid migration mode has been proposed as an alternative migration mechanism for CTCs, but functional evidence is lacking. In this study, we aimed to investigate the migration mode retained in established CTC lines using in vitro and in vivo assays as well as patient samples. We found that established CTCs are strictly epithelial and yet develop blebbing-amoeboid movement in 3D environments, including individual as well as amoeboid-collective migration modes. Thus, clinically isolated CTCs from epithelial cancer patients retain a range of invasion strategies during metastasis, including amoeboid dissemination.