*4.6. Preparation of the Cell Nuclear Protein Extract*

Cells were lysed with 1% NP-40 (Sigma-Aldrich, St. Louis, MO, USA) in the presence of a proteinase inhibitor cocktail (Sigma-Aldrich, St. Louis, MO, USA) and a phosphatase inhibitor cocktail (Thermo Fisher Scientific, Waltham, MA, USA). A nuclear extract was prepared using a Nuclear Extract Kit (Active Motif, Carlsbad, CA, USA) according to the manufacturer's protocol. The protein concentrations of these samples were measured using the Bradford method. The culture supernatants were collected and stored at −80 ◦C for further analysis.
