Figure 3.

Lovastatin has no influence on initial DNA double-strand break (DSB) formation following fractionated irradiation. However, it lowers the amount of residual DNA DSBs and impacts mechanisms of the DDR in primary human lung cells. Non-growing HMVEC-L, HPF and HSAEpC were treated as described before (Figure 1a). The number of nuclear γH2AX foci was analyzed by immunocytochemical staining. (a) Representative images. green, γH2AX foci; blue, DAPI. (b–g) Number of γH2AX foci detectable 1 h (b, d, f) and 24 h (c,e,g) after the last irradiation. Shown are the mean±S.D. from n=2–3 independent experiments. Two-way ANOVA with Bonferroni post hoc test. *P≤0.05 IR versus IR+Lova. (h) One hour after the last irradiation the activation status of a subset of key proteins of the DNA damage response was investigated by Western blot analysis. Shown are the protein levels of Ser1981 phosphorylated ATM (pATM), Thr68 phosphorylated checkpoint kinase-2 (pChk2), Ser15 phosphorylated protein 53 (pp53), Ser824 phosphorylated KRAB-associated protein-1 (pKap1). Expression of β-actin and Talin-1 were used as loading controls