Clonogenic survival curves.

(A) Human UT-7 cells: UT-7, open squares; UT-7/E8-1, open circles; UT-7/E8-2, closed triangles; UT-7/9, closed squares. Both UT-7/E8-2 and UT-7/9 expressing high levels of BCR-ABL exhibited lower clonogenic survival (ie, increased radiosensitivity) than low BCR-ABL expressing UT-7/E8-1 and the parental UT-7 cells after 2, 4 and 6 Gy. (B) Murine BaF3 cells: Ba/F3 NT, open squares; Ba/F3 p210C3, closed triangles; Ba/F3 p210 inducible with doxycycline, open circle; Ba/F3 p210 inducible without doxycycline, closed square. The tet-inducible BCR-ABL SIN-p210 cells were grown in the presence of IL-3 (10% WEHI) with or without doxycycline (1 μg/mL). Cells were irradiated in exponential phase and plated in methylcellulose as described above, in the presence of 10% WEHI. The clonogenic survival of Ba/F3 cells decreased in the presence of BCR-ABL expression, both in stable and inducible BCR-ABL transfectants.