Fig. 3
Knockdown of THOC1 leads to increased DNA damage and R-loop formation and confers sensitivity to cisplatin. a Immunostaining with R-loop (red) and THOC1 (green) antibodies in PLC/PRF/5 and Hep3B cells transfected with siNC or siTHOC1. The median of the R-loop signal intensity per nucleus after nucleolar signal removal is shown (one-way ANOVA; **P < 0.01, ***P < 0.001, ****P < 0.0001). Scale bar, 20 μm. b Immunofluorescence of γH2AX (green) in PLC/PRF/5 and Hep3B cells transfected with siNC or siTHOC1. Percentage of cells that contain > 5 γH2AX foci is shown (one-way ANOVA; *P < 0.05, **P < 0.01, ***P < 0.001). Scale bar, 20 μm. PLC/PRF/5 and Hep3B cells were treated with different concentrations of cisplatin for 48 h, and their expression of THOC1 was detected by (c) RT-qPCR (one-way ANOVA; **P < 0.01, ***P < 0.001, ****P < 0.0001) and (d) Western blot assay. e PLC/PRF/5 and Hep3B cells transfected with siNC or siTHOC1 were treated with different concentrations of cisplatin for 48 h, and their cell viability was evaluated through the MTT assay. The effects of THOC1 knockdown on IC50 of cisplatin in PLC/PRF/5 and Hep3B cells were analyzed (Student’s t test; ****P < 0.0001)