Figure 2.

TRAIL and radiation have a combined apoptotic effect in p53 wild-type breast carcinoma cells. (A) MCF7 cells (p53 wild-type) were treated with 8 Gy radiotherapy (RT) or TRAIL (1,000 ng/ml) alone or in combination. Apoptosis was assessed 42 hr posttreatment by morphology (DNA staining) or sub-G₁ DNA content (flow cytometry). UnRx, untreated control. (B) SUM44 cells (p53 wild-type) were treated with TRAIL and selected doses of RT alone or in combination for 42 hr, and cell death was assessed by MTS assay. Cell death was determined relative to the percent viable cells in the untreated control. (C) SUM 149 cells (p53 mutant) were treated with 8 Gy RT and selected doses of TRAIL alone or in combination, and cell death was assessed by MTS assay 42 hr posttreatment. (D) SUM 190 (p53 mutant) and SUM225 (p53 mutant) cells were treated with 8 Gy RT and TRAIL (1,000 ng/ml) alone or in combination, and cell death was assessed by MTS assay 42 hr posttreatment. The data shown (mean ± SD) is from at least three independent experiments.