Repurposed Antidepressant Imipramine Inhibits Caco-2 Cancer Cell Proliferation via Semaphorin and Ferroptosis Pathways

This study demonstrated the potential effects of imipramine in Caco-2 cell line via semaphorin signaling pathways. The impact of imipramine (0–120 μg/mL concentration range) on cellular viability was evaluated utilizing the MTT test. Furthermore, SEMA3E levels were quantified in imipramine-treated Caco-2 cells to investigate semaphorin-mediated processes. The results indicated that treatment of Caco-2 cells to imipramine at concentrations of 15, 60, and 90 μg/mL for 24 hours led to notable, dose-dependent decrease on cell proliferation (p<0.01). SEMA3E and PLXND1 concentrations were quantified utilizing ELISA, RT-qPCR, and Western blot techniques. Imipramine administration markedly decreased the mRNA and protein levels of several genes in a dose-dependent impact (p<0.01). Imipramine treatment decreased GSH levels while significantly increasing MDA and total ROS levels, indicating disruption of oxidative balance and membrane damage. Analysis of ferroptosis-related protein and gene levels revealed dose-dependent changes in SOX10, GPx4, ACSL4, and TFR expression. GPx4 expression was markedly suppressed, while Fe²⁺ accumulation and increased ACSL4 and TFR protein levels were observed (p<0.01). This study demonstrates that imipramine exhibits dose-dependent cytotoxic effects on Caco-2 cells via the SEMA3E/PLXND1 pathway and also triggers oxidative stress and ferroptosis-related processes.