Synthesis and biological evaluation of terminal functionalized thiourea-containing dipeptides as antitumor agents

Abstract

A series of antitumor agents based on terminal functionalized dipeptide derivatives containing the thiourea moiety were synthesized and evaluated for antiproliferative activity using a panel of cancer cell lines, and the effects and mechanism of apoptosis induction were determined. These compounds exhibited significant selectivity to different cancer cell lines with IC₅₀ values at micromolar concentrations. In particular, compound I-11 appeared to be the most potent compound, with an IC₅₀ = 4.85 ± 1.44 μM against the NCI-H460 cell line, at least partly, by the induction of apoptosis. Mechanistically, compound I-11 induced the activation of caspase-12 and CHOP, which triggered apoptotic signalling via the ROS-dependent endoplasmic reticulum pathway and arrested the cell cycle at the S phase. Thus, we concluded that dipeptide derivatives containing the thiourea moiety terminally functionalized by electron-withdrawing substituents may be potential antitumor agents for further investigation.