The relationship between coagulation cascade activation and
glioma cell proliferation was examined. The human
glioma cell lines T98G,
TM-1 and normal human astrocyte cell strain (NHA) were examined. Using anti-
tissue factor (TF) antibody, immunocytochemical detection of
TF antigen was obtained in both cell lines and cell strain.
TF antigen in cell lysates was also measured by
enzyme linked
immunosorbent assay (ELISA). In a one-stage clotting assay, T98G,
TM-1 and NHA revealed procoagulant activity (PCA) in normal human plasma and
factor VII deficient plasma. PCA in normal human plasma was significantly inhibited by both inhibitory anti-TF antibody and
cysteine protease inhibitor HgCl2. This result indicates that T98G,
TM-1 and NHA cells express not only TF but also
cancer procoagulant (CP) at the same time. In a cell proliferation assay,
thrombin induced proliferation in T98G and
TM-1 cells in a dose-dependent fashion and in NHA cell in a bell-shaped fashion. This mitogenic stimulant was inhibited by the specific
thrombin inhibitor
hirudin. The combinations of
coagulation factors II, V, and X with or without
factor VII induced proliferation in T98G,
TM-1, and NHA cells. The maximal mitogenic stimulatory effects were larger in
glioma cells than in NHA. These mitogenic stimulatory effects were also inhibited by
hirudin. Each
coagulation factor on its own or in any other combination of
coagulation factors had no proliferative effect. Thus, these mitogenic stimulatory effects were considered to be the effect of
thrombin. In conclusion, T98G and
TM-1 human
glioma cells express two different types of procoagulants TF and CP. In the presence of
coagulation factors, these
glioma cells can generate
thrombin and this
thrombin generation is capable of inducing
glioma cell proliferation in vitro.