Fig. 3.

The BER pathway, but not the mismatch repair pathway, protects cells from FdUrd and F+A. OVCAR-8 cells were transfected with control luciferase (Luc) and XRCC1 (A) or MSH2 (B) siRNAs and plated as single cells, allowed to adhere, exposed to the indicated concentrations of FdUrd with or without 3 μM ABT-888 for 24 h, and washed. Then 3 μM ABT-888 was readded to the cultures that initially contained ABT-888, and the plates were cultured until colonies formed. For cells exposed only to ABT-888 (right), the exposure was continuous.