Figure 6.

CD24 downregulation has no impact on ROS scavengers but decreases mitochondrial mass and membrane potential. (A) Analysis by reverse transcription-quantitative PCR of the relative expression of mRNAs encoding stress-associated factors involved in ROS metabolism in E_CD24-, E_CD24-c and M compared with E cells. For each gene, expression in E cells was normalized to 1 and ratio of relative mRNA level of E to E_CD24-, E_CD24-c and M cells is presented. Data are presented as the mean ± SD of 3 independent experiments. Significant differences (compared with E cells) were analyzed by one-way ANOVA followed by Dunnett's multiple comparisons correction test. *P<0.05, **P<0.01, ***P<0.001 and ****P<0.0001. ns: not significant. Mitochondrial (B) mass was assessed by Mitotracker Green probe and (C) membrane potential was assessed using TMRE staining. Mitochondrial mass and membrane potential were studied in untreated cells and at three days following 10 Gy irradiation and exposure to 400 µM 5FU. Data are presented as the mean ± SD of 4–10 independent experiments. Significant differences were analyzed by one-way ANOVA with Kruskal-Wallis followed by Dunn's multiple comparisons correction test. *P<0.05, **P<0.01, ***P<0.001. ns, non-significant. SOD, superoxide dismutase 2; HMOX1, heme oxygenase 1; GSR, glutathione-sulfide reductase; TXNDR1, thioredoxin reductase 1; TMRE, tetramethylrhodamine, ethyl ester; E, epithelial; M, mesenchymal; 5FU, 5-fluorouracil; ROS, reactive oxygen species.