NQO1 Enzyme Activity Assay Protocol

NQO1 enzyme activity was performed as previously described [23 (link)]. Briefly, 2 × 10⁷ cells of each cell line were collected, and pellets were solubilized in extraction buffer for 20 min, after which they were centrifuged at 18,000× g for 20 min at 4 °C. Supernatants were collected into Eppendorf tubes and stored at −80 °C. Samples were run according to the manufacturer’s protocol for the NQO1 activity assay kit (Abcam). Results were read at an absorbance of 440 nm every 20 s for 5 min, utilizing the Synergy-H1 Hybrid microplate reader. Plates were shaken both before and after each reading.