A, Representative IF images of H9c2 cells treated with control or Snrk siRNA alone, or combination of Snrk and Dstn siRNA and stained with Phalloidin-iFluor 488 to assess cell surface area. B, Summary of results in Panel A (n=20 cells for each condition, one-way ANOVA with Tukey’s test). C, Representative IF images of 8-OHdG stain of H9c2 cells treated with control, Snrk, Dstn, or Snrk+Dstn siRNA. Scale bar = 50 μM. D, Results of the 8-OHdG fluorescence from Panel C (n=20 cells measured for each condition, two-way ANOVA with Tukey’s test). E, Western blot of SNRK, DSTN, pH2AX, and H2AX in H9c2 cells treated with control siRNA, Snrk siRNA, Dstn siRNA, or Snrk+Dstn siRNA. F, Summary of results in Panel E (n=3, one-way ANOVA with Tukey’s test). G, Western blot of p-ATM and total ATM in H9c2 cells treated with control, Snrk, Dstn, or Snrk+Dstn siRNA. H, Summary bar graph of Panel G (n=4-6, two-way ANOVA with Tukey’s test). I, Representative IF images of H9c2 cells treated with DAPI staining and with control, Snrk, or Snrk+Dstn siRNA. Scale bar = 10 μm. J-K, Nuclear volume (J) and nuclear flatness (K) in H9c2 cells treated with control, Snrk, or Snrk+Dstn siRNA. Nuclear flatness reflects the ratio of the length of the intermediate axis of the cell to length of the shortest axis. (n=10, one-way ANOVA with Tukey’s multiple comparisons test). *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001.