Expression and hydroxyurea-triggered induction of EGFP upon CRISPR/Cas9-mediated integration into the γ-globin gene of K562 cells.

To knock-in an EGFP cassette into the γ-globin genes of K562 cells via CRISPR/Cas9, and to assess expression and hydroxyurea (HU)-mediated induction of the targeted EGFP transgene. The EGFP cassettes were specifically knocked into the Gγ gene. EGFP expression was detected in the targeted cell population and isolated clones. Furthermore, EGFP transcript and fluorescence levels were significantly induced following HU-treatment. This system is readily utilizable for genome scale studies of cis-acting regulatory elements which are implicated in γ-globin expression or HU-mediated induction.