Proteins in total cell lysates or nuclear fractions were separated with 7–15% SDS-polyacrylamide gel electrophoresis (PAGE) (Choi et al. 2019) and then transferred onto a PVDF membrane. To reduce non-specific antibody reactions, the PVDF membrane was first blocked with BSA. After washing twice with Tris-buffered saline including Tween 20 (TBST), the membrane was incubated overnight with primary antibody in BSA. After three washing steps with TBST, the membrane was probed with a secondary antibody conjugated with horseradish peroxidase in BSA for 1 h. Immunoreactive bands were detected using an enhanced chemiluminescence kit (Pierce ECL Western blotting substrate, Thermo Scientific, Waltham, MA). Two different blots were obtained from two independent Western blotting analyses. Band intensity was measured and quantified using ImageJ (Bethesda, MD).