KRAS/ABHD17C/ALOX15B Axis Promotes Pancreatic Cancer Progression via Ferroptosis Evasion

Understanding the mechanisms underlying Kirsten rat sarcoma (KRAS) mutation-driven development and progression of pancreatic ductal adenocarcinoma (PDAC) may facilitate the discovery of novel strategies for KRAS-mutant PDAC (KRAS^mut-PDAC) treatment. Here, it is reported that downregulation of arachidonate 15-lipoxygenase (ALOX15B) significantly correlated with poor outcomes in patients with KRAS^mut-PDAC. Mechanistically, KRAS^mut/ERK1-elicited phosphorylation of ABHD17C promotes depalmitoylation and membrane-to-cytoplasm translocation of ALOX15B, facilitating proteasome-dependent degradation of ALOX15B via interaction with the E3 ligase complex CUL4/DDB1/DCAF10. Notably, treatment with methyl protodioscin (MPD), a steroid saponin primarily purified from polygonatum sibiricum rhizome, restored the S-palmitoylation and membrane location of ALOX15B via disruption of the ABHD17C/ALOX15B interaction, consequently resulting in significant inhibition of growth rate of patient-derived KRAS^mut-PDAC organoids in vitro and KRAS^mut-PDAC-formed tumor in vivo via induction of ferroptosis. Therefore, these findings unveil a prominent role of ferroptosis evasion in KRAS^mut-PDAC progression and highlight the potential of targeting KRAS/ERK1/ABHD17C/ALOX15B axis in KRAS^mut-PDAC treatment.