Figure 1. The establishment of the different cell lines.

(A) Strategy for construction of the different cell lines. The red circles indicated the potentially transformed cells. KO, knock out. (B) IF-FISH was carried out to detect co-localization of γH2A.X (red) and telomeric (5′-TTAGGG-3′)₃ probes (green) in the TPP1^ΔOBRD overexpressing cells with 100 ng/ml of doxycyclin. We used DAPI staining (blue) to indicate the cell nuclei. The white arrowheads showed the co-localization of γH2A.X and telomeres. (C) The knockdown efficiency of ATRX shRNAs were measured using anti-ATRX antibody for western blotting. GAPDH was used as the loading control. shATRX-1, ATRX shRNA1; shATRX-2, ATRX shRNA2. (D) The knockdown efficiency of ATRX and DAXX in three ΔT + shA + D-KO cell lines was detected using anti-ATRX antibody and anti-DAXX antibody for western blotting. GAPDH was used as the loading control. ΔT, TPP1^ΔOBRD; shA, ATRX shRNA2; D-KO 1, D-KO 2 and D-KO 3 indicated the three DAXX knock out clones.