Enhancing GSDME-induced pyroptosis through low-dose doxorubicin/biflavonoid derivative co-loaded nanodisc in hepatocellular carcinoma

The chemotherapeutic drug doxorubicin (DOX) has been demonstrated to trigger pyroptosis in tumor cells at exceptionally high concentrations. Nevertheless, the administration of DOX at suprapharmacological doses could cause acute off-target cytotoxicity and severe adverse effects. Herein, a biflavonoid derivative, F24, was found to improve the sensitivity of hepatocellular carcinoma (HCC) cells to low-dose DOX and reduce the adverse effects of DOX. We demonstrated that F24 synergized with low-dose DOX to increase pyroptosis and autophagy in HCC cells through dual-target CDK6 inhibition/p53 activation at a proper ratio. To achieve this synergistic effect, nanodiscs with large hydrophobic cavities were selected to codeliver the low-dose hydrophobic drugs DOX and F24 (DOX-F24@Nanodisc, DF@N), which improved the tumor accumulation of the two drugs and ensured precise drug ratio integrity within the tumor cells. DF@N can trigger gasdermin-E (GSDME)-based pyroptosis in tumor cells, accompanied by the cleavage of caspase-3. Strikingly, knocking out GSDME or caspase-3 redirected DF@N-driven cellular death from the pyroptosis pathway to the apoptotic pathway. Furthermore, DF@N administration suppressed tumor growth and activated pyroptosis in a Huh7 mouse xenograft tumor model. Overall, F24 was found to induce autophagy by targeting CDK6 and had a synergistic effect on DOX-induced pyroptosis. These results indicate that the pyroptosis-induced DF@N nanodisc system provides an effective and secure therapeutic strategy for treating HCC.