Fig. 1.

Nicotinamide treatment impairs resection and HR. (A) U2OS cells were untreated (Con) or pre-treated with NA and/or NaB, then exposed to CPT. Cell extracts were analyzed by western blotting (WB). (B) U2OS cells were treated and examined by immunofluorescence (IF). ssDNA was detected with anti-BrdU antibody. (C) HR (gene conversion) was measured (Ref 12; also see methods) and data from three experiments are presented as mean +/− S.D. (D) U2OS survival upon CPT treatment in the presence or absence of NA. Results represent three experiments; error bars, S.D. (E) U2OS cells were treated as (A) with 1μM etoposide.