KRAS 抑制诱导的 GSDME 介导的细胞焦亡及其在 KRAS 突变肺癌中通过 LAT1 抑制的增强

Introduction: KRAS mutations are the most common oncogenic alterations in non-small cell lung cancer (NSCLC) globally. Although KRAS inhibitors (KRASi) show clinical benefit, their efficacy remains limited. This underscores the need to better understand KRASi-induced cell death mechanisms and to identify rational combination strategies that enhance antitumor activity. Pyroptosis, an inflammatory form of programmed cell death mediated by gasdermin (GSDM) pore-forming proteins, has emerged as a potential key mechanism to enhance therapeutic response and antitumor immunity. Whether KRASi induces pyroptosis in KRAS-mutant NSCLC has not been established. Here, we identify KRASi-induced pyroptosis, define its molecular mechanisms, and explore approaches to potentiate this process. Methods: Murine and human KRAS G12C or G12D mutant NSCLC cell lines (H23, A427, KXP885, 2695L and others) were treated with mutation-specific KRASi. Pyroptosis and associated mechanisms were evaluated by LDH release, live-cell microscopy, Western blotting, and various siRNA knockdowns. LAT1 involvement was assessed using the LAT1 inhibitor JPH203 and rescue with spermidine. Results: Mutation-specific KRASi induced pyroptosis in KRAS G12C and G12D mutant NSCLC cell lines, as evidenced by LDH release, characteristic pyroptotic morphology, and GSDM cleavage. This process required GSDME, but not GSDMD, as confirmed by GSDME knockdown. Mechanistically, KRASi activated two complementary GSDME-dependent pathways. First, KRASi triggered mitochondrial apoptosis, resulting in caspase-9 and caspase-3 activation and cleavage of GSDME into its pore-forming active N-terminal fragment (GSDME-NT). Second, KRASi stabilized GSDME-NT by suppressing its degradation. Previous research has shown that LAT1-mediated methionine uptake promotes GSDME-NT degradation. Consistent with this, we found that KRASi reduced c-MYC expression and downregulated its transcriptional target LAT1, the major transporter of methionine, thereby decreasing methionine-dependent GSDME-NT turnover and stabilizing the active fragment. Pharmacologic LAT1 inhibition with JPH203 further enhanced KRASi-induced pyroptosis, and this augmentation was reversed by the methionine-derived metabolite spermidine. Conclusions: We identify GSDME-mediated pyroptosis as a previously unrecognized mechanism of KRASi-induced cell death in KRAS-mutant NSCLC. KRASi promotes both the generation and stabilization of GSDME-NT, while LAT1 inhibition amplifies this process by increasing metabolic stress and reducing GSDME-NT degradation. These findings support metabolic modulation, specifically LAT1 inhibition, as a promising combination strategy to enhance KRAS-targeted therapy and potentially improve immunogenic tumor cell death in KRAS-mutant NSCLC.