Fig. 1

SERT inhibition promotes Trp uptake and catabolism in vitro. a An RT-PCR for SERT, SLC1A5, SLC7A5, TDO2, AFMID and TPHI mRNA expression in SW480 cells transfected with siSERT or negative control (48 h). The mRNA expressions were normalized to GAPDH. b An RT-PCR for SLC1A5, SLC7A5, TDO2, AFMID and TPHI mRNA expression in SW480 cells treated with sertraline (15 μM, 12 h) or DMSO. The mRNA expressions were normalized to GAPDH. c, d WB for SERT, SLC1A5, SLC7A5 in SW480 and HCT116 cells transfected with siSERT or negative control for 72 h, or treated with increasing concentrations of sertraline (5–15 μM) for 12 h. e WB for SLC1A5, SLC7A5 in SW480 and HCT116 cells treated with increasing concentrations (5–15 μM) of sertraline for increasing hours (0-48 h). f SW480 cells were harvested 12 h after sertraline treatment for metabolite extraction. Intracellular concentrations of Trp, Kyn, and serotonin were quantified by LCMS/MS. Cell numbers were determined and metabolite concentrations were normalized to cell counts from the same sample. *p < 0.05; ** p < 0.05; ***p < 0.001 using the Student’s t test (two-tailed)