Fig. 3.

Polθ is important for cell survival upon replicative stress. (A) Validation of Polθ expression and knockdown in RKO cells. RKO were transfected with siRNA pools directed against Polθ and protein levels were estimated by western blot after 72 h. (B,C) Polθ deficiency leads to sensitisation of cancer cells to hydroxyurea (HU) (B) and Ara-C (C) treatments. RKO cells were transfected with siRNA targeting Luciferase and Polθ. On the following day, cells were treated with the indicated doses of drug for 4 h. Cell viability was assessed 48 h after treatment. (D) Polθ overexpression leads to resistance of cells to hydroxyurea treatment. MRC5-SV or MRC5-Q cells were treated with the indicated doses of drug for 4 h. Cell viability was assessed 48 h after treatment. Error bars represent standard deviation from three independent experiments.