A Metal-Phenolic Nanocoordinator Launches Radiotherapeutic Cancer Pyroptosis Through an Epigenetic Mechanism

Radiotherapy, although clinically effective in immunoactivation, still cannot radio-functionalize tumor as a potent immunogenetic center. Given that newly found pyroptosis efficiently releases immunogenic damage-associated molecular patterns, initiating radiotherapeutic pyroptosis may turn a vision of radiotherapy-induced immunity into reality. However, a precondition is that the absent gasdermin E (GSDME), which essentiates in caspase-3-mediated pyroptosis, can be well translated in cancer cells. Here, an epigenetic strategy to launch cancer pyroptosis in radiotherapy is introduced. The nanocoordinator (PWE) is constructed via a metal-phenolic coordination between polyphenolic DNA methyltransferase inhibitor (epigallocatechin-3-gallate, EGCG), high-Z radiosensitizer (W6+), and polyphenol-modified block copolymer. While recovering GSDME expression by EGCG, PWE cleaves GSDME into fragmented GSDME N-terminal (pyroptotic key protein) via radiotherapeutic caspase-3. To examine anti-tumor immune activities, PWE amplifies immunological effects of traditional radiotherapy and decreases radiotherapy-upregulated regulatory T cells, providing new insight into tumor radiotherapy.

Automated summary

Radiotherapy is effective in immunoactivation but lacks the ability to turn tumor into an immunogenetic center. This study introduces an epigenetic strategy to induce cancer pyroptosis in radiotherapy by constructing a nanocoordinator (PWE) that comprises a polyphenolic DNA methyltransferase inhibitor, a high-Z radiosensitizer, and a polyphenol-modified block copolymer. PWE recovers GSDME expression and cleaves it into fragmented GSDME N-terminal, amplifying the immunological effects of traditional radiotherapy and decreasing regulatory T cells upregulated by radiotherapy.