Abstract:Objective: To investigate the effect of cell apoptosis on the vasculogenic mimicry in human breast cancer cells(MDA-MB-231). Methods:The tube formation ability was assessed using a matrigel basement membrane model, and the structures of the tubular networks were observed under the inverted microscope. Apoptosis cells were stained with Annexin-FITC and PI,and then quantified by fluorescent microscope. Using the broad range caspase inhibitor Z-VAD-FMK and the caspase-3 inhibitor Ac-DEVD-CHO,we further explored the influence of cell apoptosis on forming capillary like structures. Results:MDA-MB-231 cells linked to each other to form wreaths and network structures after 24 h based on three dimensional culture. Capillary-like structures of MDA-MB-231 cells were stained positively with PAS. Apoptosis occurred before capillary-like structure formation but not after capillary-like structures had assembled. Both Z-VAD-FMK and Ac-DEVD-CHO blocked capillary-like structure formation. Conclusion:Breast cancer cells can adopt a capillary-like structure and engage in vasculogenic mimicry. Capillary-like structure formation requires apoptotic cell death through activation of a caspase-dependent mechanism.