Discovery of indole analogue Tc3 as a potent pyroptosis inducer and identification of its combination strategy against hepatic carcinoma

<b>Rationale:</b> Hepatic carcinoma, one of the most malignant cancers in the world, has limited success with immunotherapy and a poor prognosis in patients. While pyroptosis is considered as a promising immunotherapy strategy for tumors, it still suffers from a lack of effective inducers. <b>Methods:</b> We designed, synthesized and screened an indole analogue, <b>Tc3</b>, featuring a 2, 4-thiazolidinedione substituted indole scaffold. Western blotting, qPCR and immunofluorescence were employed to detect the levels of pyroptosis pathway induced by <b>Tc3</b>. RNA sequencing was used to identify the mechanisms of <b>Tc3</b> in hepatic carcinoma. To validate anti-tumor effect of <b>Tc3</b>, we used CDXs and PDXs mouse models <i>in vivo</i>. Then, the syngeneic effects of <b>Tc3</b> with cisplatin and anti-PD-1 antibody were verified via western blotting, immunofluorescence, flow cytometry and ELISA. <b>Results:</b> Treatment with <b>Tc3</b> notably inhibited the growth of hepatic carcinoma both <i>in vitro</i> and <i>in vivo</i>. Mechanistically, <b>Tc3</b> inhibited the function of PRDX1 and up-regulated excessive ROS. Then, <b>Tc3</b> induced gasderminE-mediated pyroptosis by activating the endoplasmic reticulum stress. Tumor cells with high expression of GSDME achieved better responses to <b>Tc3</b>-therapy. <b>Tc3</b> also improved the efficacy of cisplatin against hepatic carcinoma. Additionally, superior synergistic treatment was observed when <b>Tc3</b> was combined with anti-PD-1 antibody. Notably, <b>Tc3</b> activated the tumor immune microenvironment (TIME) and enhanced CD8⁺ T cell infiltration in hepatic carcinoma. <b>Conclusions:</b> Collectively, we identified <b>Tc3</b> as a promising and effective compound for treating hepatic carcinoma and established its synergistic therapeutic strategy as a pyroptosis inducer.