<p>HepG2 or MHCC97L cells were treated with Ad5/F35-siAPE1 or Ad5/F35-EGFP; 48 h after infection, cells were irradiated (6 Gy), and apoptosis was determined at 24 h post irradiation by terminal dUTP nick end labeling (TUNEL) staining. (A) TUNEL staining of HepG2 xenograft. (B) TUNEL staining of MHCC97L xenograft. Data are expressed as percentage of apoptosis-positive cells examined with TUNEL. Bar graphs represent the mean values of triplicate determinations ± standard deviation. Lane 1, Ad5/F35-EGFP; lane 2, Ad5/F35-siAPE1; lane 3,Ad5/F35-EGFP+IR; lane 4, Ad5/F35-siAPE1+ IR.<sup> *</sup>P<0.01 vs Ad5/F35-EGFP; <sup>#</sup>P<0.01 vs Ad5/F35-siAPE1; <sup>$</sup>P<0.01 vs Ad5/F35-EGFP+IR.</p
