Fig. 2

p52 promotes cellular senescence. a Quantification of β-gal staining of MEFs expressing empty vector (EV), HA-tagged p50 or p52 at indicated passage. Inset: Immunoblot (IB) with anti-HA. b Quantification of γ-H2AX foci staining in MEFs expressing indicated construct. c Growth curves of MEFs from experiment a at indicated passage following derivation (set as time 0). d Quantification of β-gal staining of MEFs expressing p52, p100 or EV. Inset: IB using lysate from cells expressing indicated construct at time of initial infection, probed with anti-p52. e Quantification of β-gal positive WI-38 cells expressing EV, wildtype p52 or p52-R54A/Y55A (p52-mut). f Representative immunofluorescence (IF) of endogenous p52/100 (green) in WI-38 cells on Day 0 (D0) and day 5 (D5) following treatment with vehicle, SN52 or SN52-mut. Counterstain with DAPI (blue). Scale bar, 10 μm. g Quantification of β-gal positive WI-38 cells on Day 0 and 5 following prolonged culture treated with vehicle (CNTL), SN52 or SN52-mut. Representative image shown (right); Scale bar, 100 μm. β-gal staining data represent mean value from at least 200 cells per sample from three biological repeats, ± SEM. * P < 0.05, ** P < 0.01 (two-tailed t test)