FIGURE 4.

KLF2 affects BIRC5 expression by binding to the promoter region of BIRC5. (A) Correlation analysis of KLF2 and BIRC5 in lung adenocarcinoma. (B) Box plot of BIRC5 expression in lung adenocarcinoma tissue samples. (C) BIRC5 expression in lung adenocarcinoma tissues and adjacent normal tissues determined by RT‐qPCR (n = 78). (D) BIRC5 protein level in lung adenocarcinoma tissue and adjacent normal tissues determined by immunohistochemical staining (n = 78, Scale bar = 100 μm). (E) BIRC5 expression in five lung adenocarcinoma cell lines and human embryonic lung fibroblast cell lines determined by RT‐qPCR. (F) The possible binding site of KLF2 and BIRC5 promoter predicted by JASPAR website. (G) The degree of KLF2 enrichment in BIRC5 gene promoter region detected by ChIP‐PCR. (H) The binding site of KLF2 and BIRC5 promoter region verified using the dual‐luciferase reporter gene assay. A549 and H1650 cells were transduced with oe‐KLF2 after irradiation. (I) The transfection efficiency of KLF2 overexpression in A549 and H1650 cells detected by RT‐qPCR. (J) Protein levels of KLF2 and BIRC5 in A549 and H1650 cells measured by Western blot analysis. Data are shown as the mean ± standard deviation of three technical replicates. Data comparisons between two groups were analysed by unpaired t‐test. Data comparisons among multiple groups were analysed by the one‐way ANOVA with Tukey's post hoc test. *p < 0.05; **p < 0.01; ***p < 0.001