Figure 4

Suppression of Topo IIβ recruitment to DSB sites by inhibitors for PARP-1 and HDAC. (A) Recruitment of EGFP-Topo IIβ to DSB sites in the presence of ABT-888. HeLa cells expressing EGFP-Topo IIβ were pretreated with 2 µM ABT-888 or vehicle (DMSO) for 1 h and subsequently subjected to laser microirradiation. (B) Recruitment of EGFP-Topo IIβ to DSB sites in the presence of TSA. HeLa cells expressing EGFP-Topo IIβ were pretreated with 1 µM TSA or vehicle (ethanol) for 16 h and subsequently subjected to laser microirradiation. (C) Quantification of EGFP-Topo IIβ recruitment to DSB sites in the presence of ABT-888. A single shot of pulsed UVA laser was applied to the nucleus. Fluorescent images were captured at the indicated time points after laser microirradiation. EGFP signals in the DSB sites of 10 cells were quantified, and average values with SD were calculated. (D) Quantification of EGFP-Topo IIβ recruitment to damage sites in the presence of TSA. A single shot of pulsed UVA laser was applied to the nucleus. Fluorescent images were captured at the indicated time points after laser microirradiation. EGFP signals in the damaged sites of 10 cells were quantified, and average values with SD were calculated.