Figure 4: FHL1 regulates cancer radioresistance and is a radioresistance marker.

(a) HeLa cells infected with FHL1 shRNA or FHL1 shRNA plus FHL1-R were irradiated (8 Gy) and analysed for the proportion of mitotic cells by FACS using phosphorylated histone H3 (Ser 10)-PI staining. Phospho-histone H3 (Ser10) is the mitosis marker. Representative FACS and immunoblot with the indicated antibodies are shown. (b) HeLa cells stably infected with FHL1 shRNA or control shRNA were transfected with CDC25C siRNAs, irradiated and analysed as in a. Data shown are mean±s.d. of three independent experiments. *P<0.05 versus control shRNA without IR, ^#P<0.05, ^##P<0.01 versus control shRNA with IR (a,b). (c) Clonogenic survival assays of HeLa cells infected with FHL1 shRNA or FHL1 shRNA plus FHL1-R and irradiated at the indicated doses. (d) Clonogenic survival assays of FHL1 shRNA-expressing HeLa cells transfected with CDC25C siRNAs and irradiated at the indicated doses. Data shown are mean±s.d. of three independent experiments. *P<0.05, **P<0.01 versus corresponding control shRNA (c,d). The P values were generated using two-tailed Student’s t-test (b–d). (e) Kaplan–Meier estimates of radiosensitivity of FHL1 KO mice treated with or without IR (10 Gy). (f) Kaplan–Meier estimates of DFS and OS of breast cancer patients with (upper panel) or without (lower panel) radiotherapy. (g) Kaplan–Meier estimates of DFS of cervical cancer patients with (upper panel) or without (lower panel) radiotherapy. Marks on graph lines represent censored samples (f,g). Representative immunohistochemical staining of FHL1 is shown at the bottom (f,g). Scale bars, 100 μm.