MTS proliferation assay following prolonged cilengitide treatment in combination with ionizing radiation . Cells were treated in the same manner as in Figure 3, with the addition that for the radiation groups, cells were treated with the indicated dose of IR following 1 hr of cilengitide treatment. All four cell lines show a combination effect where cilengitide in combination with radiation has an enhanced growth delay effect when compared to IR alone treated cells. A) T-47D cells show this combination effect at lower doses of cilengitide than other cells lines. B) MCF-7 cells show an improvement over radiation alone with cilengitide combination. C) MDA-MB-231 cells show a trend toward an enhanced effect of cilengitide in combination with IR treatment. D) MDA-MB-468 cells also show only a trend toward increased growth delay in the combination groups versus the radiation alone group. Figures show Mean ± SEM and represent the average of three experiments. * = ≤ 0.05.