Fig 1: Stemness of 5FU-resistant cell lines derived from two CRC cell lines. 5FU-resistant HT29R and CT26R cell lines were established from HT29 and CT26 cells, respectively, by continuous treatment with low-dose 5FU (IC5) for 50 passages. (A) Apoptosis. (B) 5FU (5 μg/mL for 48 h). (C) Mitophagy. Scale bar: 50 μm. Right panel: semi-quantification of fluorescence images. (D) Expression of stemness-associated genes HIF1α and ME1. Right panel: semi-quantification of RT-PCR signals. (E) Sphere areas. (F) Expression of the naïve/prime transition-associated genes PRODH and LIN28a. Right panel: semi-quantification of RT-PCR signals. Error bars: standard deviation of three independent trials. Asterisk, p < 0.05. Statistical differences were calculated using ordinary ANOVA with Bonferroni correction. CRC, colorectal cancer; 5FU, 5-fluorouracil; ACTB, β-actin; RT-PCR, reverse transcription polymerase chain reaction; PRODH, proline dehydrogenase; HIF1A, hypoxia-inducible 1α; ME1, cytosolic NADPH dehydrogenase 1 (malic enzyme 1); ANOVA, analysis of variance.