Apatinib combined with paclitaxel suppresses synergistically TNBC progression through enhancing ferroptosis susceptibility regulated SLC7A11/GPX4/ACSL4 axis

Triple-negative breast cancer (TNBC) is highly heterogeneous, often leading to resistance to chemotherapy agents like paclitaxel (PTX) and resulting in suboptimal outcomes. The anti-angiogenic agent apatinib not only enhances chemotherapy sensitivity but also involves in regulating ferroptosis. However, the potential of combining apatinib with PTX to improve treatment efficacy in refractory TNBC by increasing tumor cell susceptibility to ferroptosis remains elusive. This study aims to elucidate whether inducing ferroptosis participates in the beneficial effects of apatinib combined with PTX to synergistically suppress TNBC. Herein, we demonstrated that the coadministration of apatinib and PTX exerted significant inhibitory effects on both primary tumor progression and distant metastases to pulmonary and hepatic tissues in TNBC-bearing murine models. Transcriptomic and proteomic analyses indicated that ferroptosis induction is a key mechanism by which the drug combination suppresses TNBC, as evidenced by a marked downregulation of SLC7A11, GPX4, NRF2, and FTH1, and a significant upregulation of ACSL4. In vitro, the combination of 5 μM apatinib and 8 nM PTX synergistically inhibited tumor cell proliferation, migration, and invasion. Notably, the combination therapy markedly augmented ferroptosis in tumor cells through the regulation of the SLC7A11/GPX4/ACSL4 axis, leading to increased intracellular iron accumulation and lipid peroxide generation, concomitant with a reduction in GSH levels. The effect of apatinib combined with PTX on enhancing ferroptosis susceptibility could be exploited as a combination treatment regimen for future TNBC therapy.