Culturing cell lines for drug screening

All cell lines except for HepG2 except and the gene-edited MEFs^{43 (link)} were obtained from ATCC (Manassas, VA, USA). HepG2 cell identity was estimated to be 100% by the Centre for Translational Research and Diagnostics of the National University of Singapore. All cell lines were cultured in high glucose DMEM (Nacalai, Kyoto, Japan) supplemented with 10% FBS, 2 mM glutamine, 100 U/ml penicillin and 100 μg/ml streptomycin (Thermo Fisher Scientific, Waltham, MA, USA). Primary renal proximal tubule epithelial cells (PRETEC) (ATCC, PCS-400-010) were cultured in the recommended media (ATCC, PCS-400-030 and PCS-400-040) and used within tenfold expansion in cell number. GSK-J4 (12073) and CPI-455 (22127) were obtained from Cayman Chemical (Ann Arbor, MI, USA). Tunicamycin (T-7765) was from Sigma-Aldrich (St Louis, MO, USA). Cycloheximide and actinomycin D were from FUJIFILM Wako (Osaka, Japan). The final DMSO concentration was adjusted to 0.2% in all experiments with inhibitor treatment.