Pyrrole-Tethered Bisbenzoxazole Derivatives: Apoptosis-Inducing Agents Targeting Breast Cancer Cells

This study presents the design, synthesis, and biological evaluation of a series of novel pyrrole-tethered bisbenzoxazole (PTB) derivatives as potential apoptosis-inducing agents targeting the MCF-7 human breast cancer cell line. The anticancer activity of these compounds was evaluated in vitro using the MTT assay, with tamoxifen serving as the reference therapeutic agent. Compounds B8, B14, and B18 demonstrated remarkable cytotoxicity against MCF-7 cells, exhibiting approximately 8-fold lower IC50 values compared to tamoxifen, while showing minimal effects on healthy fibroblasts. Further investigations revealed that these compounds effectively induced early-stage apoptosis and selectively arrested the cell cycle at the G1 phase in cancer cells. Gene expression analysis confirmed selective activation of the caspase-9-mediated apoptotic pathway in MCF-7 cells, providing insights into their underlying molecular mechanisms. These findings highlight the promising potential of PTB derivatives as potent anticancer agents, laying the groundwork for the development of targeted therapies for breast cancer that leverage apoptosis induction for improved therapeutic outcomes. © 2025 The Author(s). Chemical Biology & Drug Design published by John Wiley & Sons Ltd.