Shear stress induces not only platelet aggregation but also platelet-tumor cell interaction.
To investigate the interaction between platelets and tumor cells under well-defined flow conditions, the effect of tumor cells on platelet aggregation induced by shear stress was studied using a cone and plate viscometer adapted for measuring transmitted light intensity. Aggregation was markedly enhanced by HMV-1 cells in a cell number-dependent fashion under shear stress of 12 dyne/cm2. Enhancement was not observed at a high shear stress of 108 dyne/cm2. A monoclonal antibody against GPIIb/IIIa, 7E3 completely abolished enhancement of aggregation by HMV-1. Apyrase had similar inhibitory effects. Scanning electronmicroscopy showed that direct contacts of platelets with HMV-1 cells could be demonstrated when platelet-platelet interaction was inhibited by 7E3 or apyrase. These results may indicate that, at a shear stress of 12 dyne/cm2, direct contacts of platelets and HMV-1 cells may trigger enhancement of platelet aggregation.
Fukuyama
M
M
Department of Chemical Engineering, Waseda University, Japan.
Kawakami
K
K
Sakai
K
K
Itagaki
I
I
Kawano
K
K
Handa
M
M
Ikeda
Y
Y
D001783:Blood Flow Velocity / Q000502:physiology*; D002460:Cell Line; D005260:Female; D006801:Humans; D008545:Melanoma; D008855:Microscopy, Electron, Scanning; D009360:Neoplastic Cells, Circulating / Q000648:ultrastructure; D010973:Platelet Adhesiveness / Q000502:physiology; D010974:Platelet Aggregation / Q000502:physiology*; D014407:Tumor Cells, Cultured / Q000502:physiology*; D014625:Vaginal Neoplasms