Fig. 7
USP9X reshapes the amino acid metabolic microenvironment by stabilizing REV1 expression, thereby promoting lung cancer radioresistance. A A549 cells were transfected with siRNA or SFB-REV1 plasmids, and Western blotting was used to detect the expression levels of the corresponding proteins (n = 3). B Left panel: typical representative images of the comet assay; scale bar, 10 μm. Right panel: Olive tail moment statistics, **P < 0.01, ***P < 0.001 (n = 3). C Left panel: A549 cells transfected with SFB-REV1 and/or siUSP9X 4 h after receiving 6 Gy of 1 irradiation and immunostaining to detect Rad51 focus formation. Right panel: statistical analysis of the proportion of Rad51 focus-positive cells, **P < 0.01, ***P < 0.001 (n = 3). D A549 cells transfected with SFB-REV1 and/or SiUSP9X, 2 weeks after receiving the corresponding dose of X-ray irradiation, number of dose clones, and plotted cell survival curves. E LC-MS to detect intracellular levels of Gly/Ser/Thr. *P < 0.05, **P < 0.01, (n = 3). F LC-MS to detect cell supernatant Gly/Ser/Thr levels. n.s. P > 0.05, *P < 0.05, **P < 0.01, ***P < 0.001 (n = 3). G The data from GEPIA showed that the expression of USP9X was positively correlated with that of REV1. H Representative immunohistochemical staining for USP9X and REV1 in lung cancer tissues. Scale bar, 400 μm. I Positive correlation between USP9X and REV1 protein levels in lung cancer tissues (P < 0.001, chi-square test)