Fig. 3.

ATM depletion or inhibition rescues growth of MT-hTer-47A-treated cells. LOX (A) and UM-UC-3 (B) cells were infected with lentivirus expressing scramble #1 (closed symbols) or ATM #2 (open symbols) shRNAs at day -2, followed by infection with lentivirus expressing WT-hTER (squares) or MT-TER-47A (triangles) at day 0. Cells were harvested and counted by hemocytometer at indicated time points. C. LOX melanoma cells were infected with lentivirus expressing scramble #1 (black bars), scramble #2 (white bars), ATM #1 (grey bars), or ATM #2 (stippled bars) shRNAs at day -2, followed by lentivirus expressing WT-hTER or MT-hTer-47A at day 0. Cells were harvested and counted by hemocytometer at indicated time points. The graph depicts the percent cell proliferation of MT-hTer-47A-treated samples relative to matched WT-hTER-treated samples. Error bars indicate standard deviation for three separate hTER infections. Analysis of day 6 data from at least three independent experiments indicates that the increased proliferation in MT-hTer-47A-treated cells seen with the ATM #1 and ATM #2 shRNAs compared to the scramble controls is statistically significant (p < 0.01 and 0.0001 respectively). The difference in the growth of MT-hTer-47A-treated cells between the ATM #1 and ATM #2 shRNA samples is also statistically significant (p < 0.02). D. LOX cells were infected with lentivirus expression WT-hTER or MT-hTer-47A, and KU-55933 was added at the indicated concentrations 8 hours later. Cells were harvested and counted 7 days after infection. Proliferation of each sample is shown relative to the WT-hTER, no-drug control. The growth of MT-hTer-47A cells is significantly increased by KU-55933 at 1 μM and 3 μM (p < 0.005). The inset shows the growth of MT-hTer-47A-treated cells relative to the WT-hTer-treated cells at each drug concentration.