Figure 1.

VX-970 selectively attenuates ATR-CHK1 signaling axis elicited by DNA damaging agents in multiple myeloma cells. Exponentially growing MM1.S, H929, KMS20 and OPM2 cells were either left untreated (NT) or treated with increasing concentrations of VX-970 (0.15 and 0.3 µM). Treatment with VX-970 was initiated 1 hour (h) before the addition of hydroxyurea (HU, 2 mM) or melphalan (50 μM). After 3 h cells were harvested and analyzed by immunoblotting for the expression of the indicated proteins. Vinculin for MM1.S and GAPDH for the other cell lines, were used as loading controls. The asterisks indicate unspecific bands.