Figure 1. Rescue of HRR in HCC1937 cells with the expression of BRCA1 from a helper-dependent adenoviral (HD-Ad) vector. (A) Schematic representation of the HD-Ad vector co-expressing a combined N-terminal influenza-hemagglutinin (HA) and triple-FLAG (3XFLAG) epitope tagged BRCA1 and the β-galactosidase (LacZ) reporter (ITR, inverted terminal repeat). (B) LacZ staining for β-galactosidase expression after infection with HD-Ad vector control or wild-type BRCA1 (BRCA1wt) or with uninfected HCC1937 cells. (C) Western blot analysis of lysates from HCC1937 cells infected as in B probed with FLAG (HD-Ad BRCA1) and BRCA1 (HD-Ad BRCA1 + endogenous 5382insC BRCA1) antibodies. Arrows indicate protein bands related to endogenous 5382insC BRCA1. (D) HCC1937/DR-GFP cells were infected with the indicated HD-Ad vectors or left uninfected followed by infection with Ad-SceI and HRR/GFP events were analyzed by fluorescence-activated cell sorting (FACS). Error bars show SEM from three independent experiments (**, P < 0.01). P = 0.0017 when wild-type BRCA1 was compared to vector control.