BORIS resists DDP-induced tumor cell suppression. (A) Cell proliferation study of H1299 cells transfected by NC (negative siRNA control) or siBORIS (BORIS siRNA-1) for 24 h and subsequently treated by DDP at different doses (0, 1, 2 and 4 µg/ml) for 72 h. (B) Cell proliferation study of H1299 cells transfected by the vector (empty plasmid) or pBORIS (BORIS overexpression plasmid) for 24 h and subsequently treated by DDP (0, 1, 2 and 4 µg/ml) for 72 h. (C) Cell apoptosis of H1299 cells with overexpression of BORIS after treatment using 2 µg/ml DDP for 24 h. BORIS overexpression suppressed DDP-induced apoptosis in H1299 cells. **P<0.01; ***P<0.001. BORIS, Brother of Regulator of Imprinted Sites; NSCLC, non-small cell lung cancer; OD, optical density; si, small interfering; PI, propidium iodide; DDP, cisplatin.