(E) AsiSI endonuclease-integrated U2OS cells were transfected with siControl and siEWS. Cells were incubated with doxycycline for 4 hours to induce DSBs. With or without changing the Dox-added media to fresh media for 2 hours (for release samples), the amount of chromatin-associated PARP1 was measured using ChIP assay. (N.T: Non-treat, T: AsiSI treat, Release: Damage released samples). Data represented as mean ±SEMs, and technical repeats (n=3), significance determined by two-way ANOVA, ***P< 0.001. 