Suspension state promotes metastasis of breast cancer cells by up-regulating cyclooxygenase-2

Hematogenous metastasis requires tumor cells to detach from primary tumor into blood/lymphatic circulation and extravasate. Tumor cells in the blood circulation system, named circulating tumor cells (CTCs), are in a suspension state, with unique cytoskeletal structure and molecular phenotype different from primary tumor cells. The aim of this study is to assess the impact of suspension state on the metastatic potential of breast cancer cells (BCCs) and study its underlying mechanism.