Fig. 6: Cells with enhanced radioresistance acquire radiosensitivity by inhibiting NRBF2.

a qRT‒PCR analysis of nrbf2 mRNA levels after IR (3 Gy) or additional treatment with lidoflazine (1 µM) in RR cells or untreated U-87 MG cells. b Western blot analysis of NRBF2 protein expression levels after IR (3 Gy), lidoflazine (1 µM), or both in RR cells or untreated U-87 MG cells. c Autophagic flux analysis using the mCherry-EGFP reporter. U-87 MG and RR cells transfected with mCherry-GFP-LC3B were treated with IR (3 Gy), lidoflazine (1 μM), or both for 24 h. The mean numbers of autophagosomes and autolysosomes are represented by yellow and red dots, respectively, in the merged images. The images were quantified using ImageJ (n = 5). Scale bars, 10 µm. d Percentage of GBM cells stained positively for the Ki67 proliferation marker undergoing different treatments. e Cell reproductive death after treatment with ionizing radiation (3 Gy), lidoflazine (1 µM), or both was determined using crystal violet staining. f IC₅₀ of lidoflazine with or without IR in U-87 MG RR cells was measured by CellTiter-Glo® Luminescent Cell Viability Assay. Cells were treated with increasing concentrations of lidoflazine and/or IR (3 Gy) for 48 h. g Transwell migration and invasion assays were performed to analyze cell movement. Scale bars, 200 µm. h Control and RR cells in a three-dimensional culture system were stained with α-tubulin (green) and DAPI (blue). Scale bars, 100 µm. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001 using an unpaired t test.