Oridonin and ponicidin induce GSDME-mediated pyroptosis in pancreatic ductal adenocarcinoma.

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive digestive malignancy with poor prognosis. Although apoptosis has been regarded as a principal mechanism through which chemotherapeutic agents exert their anti-tumor effects, PDAC cells exhibit marked resistance to apoptotic cell death, highlighting an urgent need for developing alternative therapeutic strategies. Emerging evidence suggests that pyroptosis can provoke anti-tumor immunity and suppress tumor growth. Gasdermin E (GSDME) is critical in pyroptosis by converting caspase 3 (CASP3)-mediated apoptosis into pyroptosis, thereby eliciting robust anti-tumor immunity.

METHODS

We applied a hGLuc-hGSDME-PCA system for high-throughput screening of compounds that induce GSDME-mediated pyroptosis, aiming to develop novel therapeutic strategies for PDAC. Cell migration was evaluated by wound healing and Transwell assays, and colony formation assay was used to assess cell proliferative. Pyroptosis was detected by flow cytometry and Hoechst 33342/PI staining, while the activation and expression of CASP3 and GSDME were analyzed by western blotting.

RESULTS

Based on this system, we screened 12 traditional Chinese herbal medicines and identified that Rabdosiae Rubescentis Herba (RRH) significantly induced pyroptosis. Notably, we demonstrated for the first time that oridonin and ponicidin, the primary active constituents of RRH, potentially triggered pyropotosis in PANC-1 cells. Further mechanistic investigation demonstrated that oridonin and ponicidin induced pyroptotic cell death via CASP3/GSDME signaling pathway.

CONCLUSION

Collectively, our study validated the reliability of hGLuc-hGSDME-PCA screening system and provided the first experimental evidence that oridonin and ponicidin could induce pyroptotic cell death. These findings suggested their potential as novel therapeutic agents for the treatment of PDAC.