Protein expression levels of the OCTs and MATE transporters in lung cancer cell lines. The protein expression levels of OCT1, OCT2, OCT3, OCT6, MATE1, and MATE2 in the PC-14, PC-6/L-OHP, SBC-3, and SBC-3/L-OHP cells were assessed using western blotting. The levels of OCT6 protein in the PC-14/LOHP and SBC-3/L-OHP cells were downregulated compared with the parental cells, PC-14 and SBC-3, respectively. OCTs, organic cation transporters; MATE, anti-multidrug and toxin extrusion; PC-14, parental lung adenocarcinoma cell line; L-OHP, oxaliplatin; SBC-3, human small cell lung cancer cell line.