Discovery and Evaluation of Novel Sulfonamide Derivatives Targeting Aromatase in ER+ Breast Cancer

Background: Third-generation aromatase inhibitors (CYP19A1) are the mainstay of treatment for estrogen-receptor-positive breast cancer. This is because estrogen is required for cancer growth in approximately 70% of patients with this condition. Although potent and effective, aromatase inhibitors induce resistance and secondary effects, requiring treatment to be discontinued. This clinical limitation highlights the need to search for new molecules. Previous studies have led to the identification of a set of indole sulfonamide molecules that exhibit interesting activity against aromatase. Methods: Phenyl and benzyl sulfonamide derivatives with alkylated heterocycles linked by short methylene bridges were designed and synthesized. The aromatase inhibition and cytotoxicity were tested through in vitro assays. Molecular docking and dynamic simulations evaluated the interactions with the aromatase enzyme, while a target fishing strategy linked to gene associations relevant to breast cancer helped to uncover other targets. Results: All of the non-steroidal inhibitors synthesized showed significant activity. Compounds 3 and 9 demonstrated IC50 values in the low micromolar range and selective action against MCF7 breast cancer cells over healthy lines. Computational studies confirmed stable and favorable aromatase binding. Target fishing identified EGFR and PTK2B as additional potential targets for a multi-target therapeutic strategy. Conclusions: Compounds 3 and 9 outperform indole-based inhibitors in their potency and selectivity, revealing strong therapeutic potential. Their binding affinity and specificity support further development. EGFR and PTK2B may enable a broader, multi-target approach.