Targeting AIF to trigger RIPKs/MLKL necroptosis: a disulfiram-based strategy to reverse paclitaxel resistance in...

Paclitaxel is a cornerstone first-line therapy for ovarian cancer, but its efficacy is limited by chemoresistance. Disulfiram (DSF), an FDA-approved alcohol-aversion drug, shows promising antitumor activity. However, its impact on paclitaxel sensitivity in ovarian cancer and the underlying mechanism remain unclear.

This study identified DSF as a reversal agent of paclitaxel resistance. In vitro, DSF's chemosensitizing effect was tested on paclitaxel-resistant and parent ovarian cancer cells. Mechanistic investigations involved examining the triggering of RIPK1/RIPK3/MLKL-regulated necroptosis versus caspase-dependent apoptosis, depending on cellular context. RIPK1 was inhibited with Nec-1, and the direct binding to Apoptosis-inducing factor (AIF) was studied, with AIF knockdown used for validation. In vivo studies were conducted using resistant xenograft models to confirm the anticancer efficacy and observe necroptosis markers.

DSF significantly improved paclitaxel chemosensitivity in vitro. Mechanistically, it selectively triggered necroptosis in paclitaxel-resistant cells with higher caspase-8 expression, while promoting apoptosis in cells with lower caspase-8 expression. RIPK1 inhibition impaired DSF-induced necroptosis and chemosensitization. Furthermore, DSF directly bound to AIF, enhancing RIPK1/RIPK3/MLKL phosphorylation and necroptosis activation; this effect was suppressed by AIF knockdown. Crucially, in vivo studies confirmed that DSF boosted the anticancer efficacy of paclitaxel in resistant models, which was accompanied by upregulation of the necroptosis executor p-MLKL and no observable toxicity.

Our findings not only unveiled a novel mechanistic basis for the repurposing of DSF but also highlighted AIF-mediated necroptosis as a promising therapeutic strategy to overcome chemoresistance in ovarian cancer.