Metal-DNA Nanocomplexes Enhance Chemo-dynamic Therapy by Inhibiting Autophagy-Mediated Resistance

Chemo-dynamic therapy (CDT) based on the Fenton or Fenton-like reaction has emerged as a promising approach for cancer treatment. However, autophagy-mediated self-protection mechanisms of cancer cells pose a significant challenge to the efficacy of CDT. Herein, we developed metal-DNA nanocomplexes (DACs-Mn) to enhance CDT via DNAzyme inhibition of autophagy. Specifically, Mn-based catalyst in DACs-Mn was used to generate highly hydroxyl radicals (⋅OH) that kill cancer cells, while the ATG5 DNAzyme incorporated into DACs-Mn inhibited the expression of autophagy-associated proteins, thereby improving the efficacy of CDT. By disrupting the self-protective pathway of cells under severe oxidative stress, this novel approach of DACs-Mn was found to synergistically enhance CDT in both in vitro and in vivo models, effectively amplifying tumor-specific oxidative damage. Notably, the Metal-DNA nanocomplexes can also induce immunogenic cell death (ICD), thereby inhibiting tumor metastasis. Specifically, in a bilateral tumor model in mice, the combined approach of CDT and autophagy inhibition followed by immune checkpoint blockade therapy shown significant potential as a novel and effective treatment modality for primary and metastatic tumors.