Targeting the MDM2/Caspase-3/GSDME axis: apatinib and cinobufagin synergistically induce pyroptosis to suppress gastric cancer progression.

Abstract

Gastric cancer (GC) is a highly heterogeneous and aggressive malignancy with a poor prognosis, especially in advanced stages. Apatinib and cinobufagin (CS-1) have shown promising antitumor potential. However, the therapeutic efficacy and underlying mechanisms of their combined use in GC remain unclear. GC cell lines (AGS and GPM-1) were treated with apatinib, CS-1, or both. Cell viability, proliferation, migration, apoptosis, stemness, and pyroptosis-related protein expression were evaluated using cell counting kit-8 (CCK-8), colony formation, wound healing assays, flow cytometry, tumorsphere assays, and western blotting. The role of mouse double minute 2 homolog (MDM2) in modulating treatment response was investigated via overexpression experiments. Antitumor efficacy in vivo was assessed using a subcutaneous xenograft mouse model, and tumor apoptosis and proliferation were analyzed by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and immunohistochemistry. Combined treatment with apatinib and CS-1 significantly inhibited GC cell viability, proliferation, migration, and stemness, while inducing apoptosis and pyroptosis more effectively than either agent alone. Mechanistically, the combination therapy downregulated MDM2 expression and upregulated cleaved caspase-3 (C-caspase-3) and gasdermin E-N (GSDME-N). Overexpression of MDM2 partially reversed these effects both in vitro and in vivo, leading to reduced apoptosis, pyroptosis, and antitumor efficacy. Apatinib combined with CS-1 synergistically suppresses GC progression by inducing MDM2/C-caspase-3/GSDME-regulated pyroptosis. These findings highlight MDM2 as a critical therapeutic target and provide novel insights into the molecular mechanisms underlying the combined use of targeted agents and natural compounds in GC therapy.