Artesunate triggers ferroptosis in ovarian cancer via GP130-mediated IL-6/STAT3/OTUB1/SLC711 axis disruption

Ovarian cancer (OC) is highly malignant with suboptimal current therapeutic outcomes. Ferroptosis is a novel cell death mode. Artesunate (ART) has demonstrated relatively broad-spectrum anticancer effects recently, yet whether it can suppress OC by inducing ferroptosis, along with the underlying mechanisms, warrants further exploration.

To clarify the anti-OC effect and mechanism of ART, focusing on ferroptosis induction and identify its therapeutic target.

ART's anti-OC effects were assessed in vitro via cell counting kit-8, live-cell staining, scratch, and transwell assays. In vivo efficacy and safety of ART were evaluated in OC-bearing mice. Ferroptosis markers were analyzed by enzyme linked immunosorbent assay, western blot, and reverse transcription quantitative polymerase chain reaction, especially OTU domain-containing ubiquitin aldehyde-binding protein 1 (OTUB1)-mediated solute carrier family 7 member 11 (SLC7A11) deubiquitination was measured by co-immunoprecipitation. RNA-seq profiled transcriptional changes, and signal transducer and activator of transcription 3 (STAT3) regulation of OTUB1 was confirmed by dual-luciferase reporter and chromatin immunoprecipitation quantitative polymerase chain reaction assays. ART binding to the interleukin-6 (IL-6)/interleukin-6 receptor (IL-6R)/glycoprotein 130 (GP130) complex was determined by bioluminescence resonance energy transfer, cellular thermal shift assay, molecular docking, and dynamics simulations. GP130 point mutations validated the functional binding site.

ART induced ferroptosis in OC cells by targeting GP130, inhibiting cell viability and hindering cell invasion/metastasis. In vivo, ART significantly suppressed the tumor growth of OC-bearing mice, and the tumor volume inhibitory rate and weight inhibitory rate of ART (5 mg/kg) was (82.34±4.97 %) and (78.27±4.74 %), respectively, and no side effects were observed. Mechanistically, ART bond to lysine 250 (Lys250) of GP130 (GP130^Lys250), disrupting IL-6/IL-6R/GP130 complex formation. This suppressed the IL-6/STAT3 pathway, inhibiting STAT3-mediated OTUB1 transcription and subsequent OTUB1-mediated SLC7A11 deubiquitination. The resulting antioxidant dysfunction led to reactive oxygen species accumulation and ferroptosis.

ART exerted potent anti-OC effects by targeting GP130^Lys250, disrupting IL-6/STAT3 signaling, downregulating OTUB1, promoting SLC7A11 degradation, and triggering ferroptosis. The identification of GP130^Lys250 as ART's precise binding site and the novel IL-6/STAT3/OTUB1/SLC7A11 axis represent significant mechanistic innovations. ART is a highly promising and safe candidate for OC therapy.