Fig 2: Close association of epigenetic status with Ets1 level.a ChIP-seq analysis of H3K27Ac and H3K27me3 at Ets1 promoter locus in MCF-7 (blue line) and MDA-MB-231 (red line) cells. b ChIP analysis of active marker (H3Ac) and inactive markers (H3K9me3 and H3K27me3) at Ets1 promoter locus under unstimulated or P/I stimulation conditions. The data from each replicate were normalized to the input control and the graphs represent fold enrichment of the indicated proteins to control antibody at the designated locus. Data are presented as mean ± SD. Two-way ANOVA with Bonferroni post-tests showed a significant difference of binding efficiency of H3Ac, H3K9me3, and H3K27me3 between MCF-7 and MDA-MB-231 cells. c DNA methylation status in the nine CpG sites (−375 or −534) was analyzed by bisulfite sequencing under unstimulated or stimulated (P/I) condition. Closed and open circles indicate methylated and unmethylated CpG sites, respectively. Bar graphs represent percentage methylation. Data are presented as mean ± SD. Two-way ANOVA with Bonferroni post-tests showed a significant difference of DNA methylation status. d Heatmap of RNA-sequencing data showing relative expression of DNA methylation-related and demethylation-related factors. e Analysis of relative expression levels in transcripts normalized against Hprt and proteins by qRT-PCR and Immuno-blots, respectively. Data are presented as mean ± SD. One-way ANOVA with Bonferroni correction indicated a significant difference of expression. f Scatterplots and nonparametric Spearman’s rank correlation (ρ) analysis with corresponding p-values correlation analysis from CCLE. Correlation between Ets1 and DNA methylation-related genes (Dnmt3a, Dnmt3b, and Apobec3c) in mRNA. Each symbol represents an individual human breast cancer cell line. Green circle: MCF-7 cells; Red circle: MDA-MB-231 cells. b, c, e Data shown are representative of more than two independent experiments with similar results. *p < 0.05, **p < 0.01, and ***p < 0.001 (unpaired t-test)

Fig 3: L1-EGFP retrotransposition after knockdown of APOBEC3 genes. (a) Images of MM231 cells co-cultured with L1-EGFP cells after siRNA-mediated knockdown of APOBEC3 genes. (b) EGFP expression in A3C-1 and A3F-3 siRNA transfected cells co-cultured with L1-EGFP cells for 21 days. All scale bars represent 100 µm. N = 3 wells in 6-well plate.