Investigation of novel nimesulide derivatives against breast cancer

This study focused on the synthesis of novel nimesulide semicarbazone derivatives and the evaluation of their cytotoxic potential against luminal-A (MCF-7) and triple-negative (MDA-MB-231) breast cancer cell lines. Additionally, their effects on mitochondrial membrane potential (MMP), apoptosis, and mitogen-activated protein kinase (MAPK) pathway modulation were investigated. Breast cancer remains the most prevalent malignancy among women, with luminal-A and triple-negative subtypes posing significant therapeutic challenges due to drug resistance and the lack of effective targeted treatments. The MAPK pathway plays a crucial role in breast cancer progression, making its inhibition a promising therapeutic approach. Non-steroidal anti-inflammatory drugs (NSAIDs), particularly nimesulide, have demonstrated anticancer potential beyond their well-established anti-inflammatory properties. Accordingly, the semicarbazone moiety was incorporated into the molecular scaffold to enhance the antiproliferative efficacy of nimesulide derivatives, as it has been reported to exhibit cytotoxic and apoptosis-inducing effects across various cancer cell lines. A series of nimesulide semicarbazone derivatives (5a-m) were synthesized through multi-step reactions and characterized using elemental analysis, FT-IR, ¹H NMR, ¹³C NMR and Mass spectroscopy (5e). In silico studies were performed to predict their binding affinities to MAPK12. The cytotoxic effects of the synthesized compounds were assessed by determining IC₅₀ values in MCF-7 and MDA-MB-231 cell lines (CCK8 test). Compounds exhibiting strong cytotoxic activity were further examined for their impact on MMP depolarization (JC-1 assay), apoptosis induction (Annexin V-FITC/PI staining), and MAPK pathway modulation (Western blotting of p-ERK and ERK protein). Molecular docking results indicated that the synthesized compounds exhibited favorable interactions with MAPK12, with compound 5e showing one of the highest binding affinity (-9.29 kcal/mol, Ki = 0.154 μM). Cytotoxicity assays revealed that compound 5e had the lowest IC₅₀ values (11.77 ± 0.26 μM in MCF-7; 20.72 ± 0.25 μM in MDA-MB-231), demonstrating significantly higher cytotoxicity than nimesulide. JC-1 assays confirmed that compound 5e induced MMP depolarization at higher concentrations, suggesting apoptosis activation. Flow cytometry analysis further validated a substantial increase in apoptotic cell populations following treatment with compound 5e. Western blot results showed a dose-dependent decrease in p-ERK levels in both MCF-7 and MDA-MB-231 cells, confirming MAPK pathway inhibition. These findings support that nimesulide-based semicarbazones, particularly compound 5e, exhibit potent antiproliferative and pro-apoptotic activity via MAPK pathway modulation, offering a promising avenue for the development of targeted breast cancer therapies.