towards improved death receptor targeted therapy for ... - TI Pharma

Combination study: TRAIL and TFT
and A549 cells, exposure to TRAIL slightly increased the phosphorylation of Chk1, whereas
Chk2 and Cdc25c phosphorylation levels remained similar (Fig. 2B) reflecting an increase
of cells in the G1 phase (Fig. 2A).
A
B
Figure 2. Effect of TRAIL, TFT and combined treatment on the cell cycle progression. (A) The
percentages of cells in G1, S and G2/M phase are depicted after the indicated treatments in H460
and A549 cells. Values are means of three independent experiments ± SEM. After 24 h or 48 h
incubation with TRAIL, medium was refreshed with drug free medium. (B) Western blots showing
the expression and phosphorylation of cell cycle regulatory proteins Chk‐1, Chk‐2 and Cdc25c. Cells
were exposed to 5 µM TFT, and 10 ng/ml TRAIL in H460, and 5 µM TFT, 150 ng/ml TRAIL in A549 or
the combinations for 72 h.
Cell death activation by TFT and TRAIL
TFT triggered cell death in a time‐dependent manner in H460 and A549 cells, whereas
TRAIL killed H460 and not A549 cells as expected (Fig. 3A). In TRAIL resistant A549 cells
the combination of TFT and TRAIL resulted in more cell death activation within 24 h that
further increased in time. Since TFT alone induced cell death at exposure times longer
than 24 h, the early cell killing effect in the combination was likely attributed to sensitized
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