Induction of apoptosis in HMC1.1 but not in HMC1.2 cells by KIT inhibitors.

DNA fragmentation assay shows that the HMC1.1 clone expressing only the Val560Gly juxtamembrane RT mutation undergoes apoptosis, as indicated by formation of DNA “ladders” in the presence of the inhibitors at 0.1 to 1 μM (lanes 2-3). In contrast, the HMC1.2 clone expressing both the Val560Gly mutation and the Asp816Val EST mutation does not show any significant DNA “ladder” in the presence of the inhibitors at 1 to 10 μM (lanes 5-6).