FIGURE 4.

Functional loss of ATM makes nuclei more deformable. (A) Representative time-lapse image sequence of MDA-MB-231 cells treated with ATM inhibitor KU-55933 (n = 95 cells) or vehicle control (DMSO, n = 45 cells) undergoing nuclear deformation in micropipette aspiration device with channels of 3 × 5 μm² in size. Arrowheads indicate the leading edge of nuclear protrusion. Scale bar: 5 µm (B) Quantification of the nuclear protrusion length inside the micropipette aspiration channels as shown in (A) based on the means of three independent experiments. *, p < 0.05; based on paired t-test, N = 3. (C) Representative image panel of Atm-Null MEFs (n = 117 cells total) and Atm wild-type (WT) controls (n = 130 cells total) undergoing nuclear deformation in micropipette aspiration device with channels of 3 × 5 μm² in size. Arrowheads indicate the leading edge of nuclear protrusion. Scale bar: 5 µm (D) Quantification of the nuclear protrusion length inside the micropipette aspiration channels as shown in (C), based on the means of three independent experiments. *, p < 0.05; **, p < 0.01; based on paired t-test, N = 3. Error bars in this figure represent mean ± s. e.m. of the mean values of each experiment.