Fig. 5

TOPOIIα is critical for mediating TG2 promoted DNA damage repair. A, B: Representative immunofluorescence of TOPOIIα and 53BP1 at DSB sites, in the HT1080 cells with 53BP1 expression after laser micro-irradiation. Colocalization analysis was also performed by using Image Pro Plus 6.0 software. C: Whole cell lysates were harvested from the A549 cells transfected with TG2 construct/TG2 siRNA/TG2 siRNA + TOPOIIα at the indicated time points of IR (8 Gy) treatments. Whole cell lysates were blotted with pDNA-PKcs, DNA-PKcs, pATM and ATM antibodies. D: Whole cell lysates were harvested from the A549 cells transfected with TOPOIIα siRNA/ TOPOIIα siRNA + TG2 construct at the indicated time points of IR (8 Gy) treatments. Whole cell lysates were analyzed with indicated antibodies. E: representative images of comet assay in cells with TG2 and /or TOPOII α knockdown after irradiation. F: Quantitate analysis of comet assay showed the tail moment of A549 cells transfected with TOPOII α siRNA and siTG2 after treatment of ionizing radiation (IR). G: Immunoblot of γ-H2AX in original A549 cells, and the A549 cells with either TG2 knockdown or TOPOIIα knockdown after IR. H: colony formation assay of cells with TG2 and /or TOPOII α knockdown after 0, 2, 4, 6 Gy irradiation. *P < 0.05