Photocatalytic Superoxide Radical Generator that Induces Pyroptosis in Cancer Cells.

Area of Science:

• Biochemistry
• Materials Science
• Cancer Research

Background:

• Pyroptosis is an emerging immunogenic cell death pathway with significant potential in cancer immunotherapy.
• Current biocompatible strategies for activating pyroptosis are limited.
• Developing novel agents to selectively trigger pyroptosis is crucial for advancing cancer treatment.

Purpose of the Study:

• To investigate the potential of a novel photocatalytic superoxide radical generator, NI-TA, to induce pyroptosis in cancer cells.
• To elucidate the molecular mechanisms underlying NI-TA-mediated pyroptosis.
• To evaluate the efficacy of NI-TA in inhibiting cancer cell growth, including under hypoxic conditions.

Main Methods:

• Design and synthesis of NI-TA, a photocatalytic superoxide radical generator.
• In vitro studies using cancer cell lines to assess pyroptosis induction upon photoexcitation.
• Mechanistic investigations involving caspase and gasdermin pathway analysis.
• Evaluation of NI-TA's efficacy in 3D multicellular spheroids, including under hypoxic conditions.

Main Results:

• NI-TA effectively generates superoxide radicals upon photoexcitation, triggering pyroptosis in cancer cells.
• The pyroptosis pathway activated by NI-TA involves caspase-3 and gasdermin E (GSDME), distinct from canonical caspase-1/GSDMD pathways.
• NI-TA demonstrates potent cancer cell ablation and antitumor efficiency, even under hypoxic conditions (≤2% O2).
• NI-TA treatment of T47D 3D multicellular spheroids resulted in significant antitumor effects and inhibition of stemness.

Conclusions:

• NI-TA serves as an effective biocompatible agent for inducing pyroptosis via photocatalysis.
• The caspase-3/GSDME pathway is a viable target for NI-TA-mediated pyroptosis.
• Photocatalytic chemistry offers a promising avenue for developing novel pyroptosis-inducing cancer therapeutics, particularly effective in hypoxic tumor microenvironments.