Fen 1

Protein lysates were separated by SDS/PAGE and blotted onto a nitrocellulose membrane. Membranes were blocked for 1 h at room temperature (RT) with 5% milk in Tris‐buffered saline containing 0.1% Tween‐20 (TBST), pH 7.6, prior to probing with antibodies. Primary antibodies to HMGA2 (1 : 1000), HMGA1 (1 : 1000), γH2AX (1 : 1000), phospho‐STAT3 (pSTAT3^Tyr705; 1 : 1000), total STAT3 (1 : 2000), PARP1 (1 : 2000), XRCC1 (1 : 1000), PKCα (1 : 1000), p21 (1 : 1000), α‐tubulin, MGMT (1 : 1000; all rabbit polyclonal IgG, Cell Signaling, via New England Biolabs, Whitby, ON, Canada), lamin a/c 1 : 500 (goat polyclonal antibody) and p53 (1 : 2000; both from SantaCruz, CA, USA), FEN‐1 (1 : 1000, Bethyl Laboratories, Montgomery, TX, USA), MPG (1 : 3000), Ape‐1 (1 : 2000, both Abcam, Toronto, Canada), cathepsin B (1 : 100; gift from E. Weber, Germany), LIN28A (1 : 1000; rabbit polyclonal antibody; Cedarlane, Burlington, ON, Canada), and β‐actin (1 : 10,000; Sigma) were probed overnight at 4 °C followed by incubation for 1 h at RT with HRP‐conjugated anti‐rabbit (Cell Signaling), anti‐goat, and anti‐mouse (Sigma) secondary antibodies.