DA-5: A novel azaindole-based GPX4 inhibitor inducing ferroptosis for targeted therapy of triple-negative breast cancer.

BACKGROUND

Triple-negative breast cancer (TNBC) is an aggressive subtype lacking the ER, PR, and HER2 receptors, with limited treatment options and poor prognosis. Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, has emerged as a promising therapeutic strategy for TNBC. Glutathione peroxidase 4 (GPX4) is a key ferroptosis suppressor, and its inhibition sensitizes TNBC cells to oxidative damage.

PURPOSE: To discover and characterize DA-5, a novel 3,5-disubstituted azaindole derivative inspired by compounds from the traditional Chinese medicine Shuganning injection (SGNI), as a potent GPX4 inhibitor to induce ferroptosis in TNBC cells.

METHODS

Molecular docking and structural optimization were used to design DA-5. Its binding affinity (Kd) and enzymatic inhibitory activity (IC50) against GPX4 were evaluated. In vitro assays assessed DA-5's ability to induce ferroptosis in TNBC cells through lipid peroxidation while sparing normal mammary epithelial cells. In vivo studies evaluated the efficacy and safety of DA-5 in TNBC xenograft models via oral administration. Pharmacokinetic profiles were also analyzed.

RESULTS

DA-5 demonstrated high-affinity binding to GPX4 (Kd = 10.04 μM) and effectively suppressed its enzymatic activity (IC50 = 10.90 μM). In TNBC cells, DA-5 promoted lipid peroxidation and induced ferroptosis, which was rescued by ferroptosis inhibitors and by iron chelators. Oral administration of DA-5 significantly inhibited TNBC xenograft growth in vivo without systemic toxicity, supported by favorable pharmacokinetic and safety profiles.

CONCLUSION

These findings identify DA-5 as a novel azaindole-based GPX4 inhibitor capable of inducing ferroptosis through GPX4-targeted lipid peroxidation. This breakthrough offers a promising targeted therapy for TNBC.