Figure 4. CTCF induces 5-FU-based chemoresistance in CRC. (A, B) Cell growth inhibition rate was measured via CCK8 analysis and compared between different groups with different treatment concentration at indicated time (48 hours). (C) The apoptosis rate of different transfected groups with 5-FU treatment were measured by flow cytometry. (D) Western blot analysis of CTCF in HCT116 and RKO cell lines after 5-FU (10 μM) treatment for 48 hours. (E, F) Western blot analyses of cleaved-PARP, cleaved Capase-3 and ABCG2 in HCT116 and SW480 cell lines. (G) Spearman correlation analyses between relative CTCF and ABCG2 mRNA expression in 13 fresh human CRC specimens. The above data are presented as mean ± SEM. * P<0.05, **P<0.01, and ***P<0.001.