Chromatin immunoprecipitation assays

Based on the predicted results from JASPAR (http://jaspar.genereg.net/), ChIP assay was used to confirm the binding region of NRF2 on the NPC1L1 promoter. In brief, 1 × 10⁷ Du145^TXR or MCF‐7^ADR cells were treated with drugs and cross‐linked with 1% formaldehyde. Next, the samples were sonicated at 30% of the maximum power for ~8 min/10 s each pulse (XINYI‐IID). Supernatants were obtained by centrifugation at 15,000 × g for 10 min and immunoprecipitated with 1 μg of NRF2 antibody or IgG antibody using a ChIP kit (Millipore Corp.). The products were analyzed by RT‐qPCR to detect any DNA binding by NRF2. The primers used are shown in Table 5.

List of primers of NPC1L1 promoter region used for ChIP assays.