Fig. 4.
Expression levels of apoptosis-related molecules in human glioma cell lines. (A) DR5 cell-surface expression determined by flow cytometry analysis. Cultured cells were washed and reacted with PE-labeled anti-DR5 antibody, followed by flow cytometry analysis. Glioma cells with high sensitivity to anti-DR5 mAbs tended to have high cell-surface expression of DR5, whereas those with low sensitivity were associated with low expression. (B and C) Western blot analyses showing expression levels of various apoptosis-related molecules. Human glioma cells were harvested for whole cell lysates, which were then subjected to Western blotting. Expression levels of c-FLIPL, Akt, and cyclin D1 significantly correlated with sensitivity of these cell lines to treatment with anti-DR5 mAbs. Intrinsic expression of c-FLIPs was undetectable in all cell lines tested, whereas exogenous expression of c-FLIPs was identified in T98G.FLIPs cells (indicated as *). The molecules and their molecular sizes are shown on the left and right sides on each panel, respectively.