Figure 3

The CTCF binding site mutant at the Rb promoter is differentially reactivated. A, Flow cytometry profiles of four K562 stable cell lines expressing the transgene described in 2A after 0, 30 and 100 days of continuous cell culture. These lines were isolated and selected from two independent experiments; sc, single-copy integrant, and mc, multi-copy integrants. B, Reactivation experiments of the corresponding cell lines performed at 30 days and 100 days of continuous cell culture. Reactivation assays were performed using 5-aza-2'-deoxycytidine (AZA), trichostatin-A (TSA) and mock cells (STx). The plot represents the average of fluorescent cells, where the black bar corresponds to the inactive cell population and the white bar to the fluorescent cell population. The results correspond to the average of three independent reactivation experiments for each cell line, and the standard error is shown.