Metallic- nanoparticles mediated programmed cell death in cancer cells: mechanisms and therapeutic implications
摘要
The advent of nanotechnology/nanomedicine, today offers new paradigms in cancer diagnosis and therapy. Nanoparticles, due to their unique properties viz. sub micron size, high surface: volume ratio, dissimilarity, enhanced permeability, retention effect and precise targeting can enter the cancer cells and manifest cell death through different mechanisms/pathways. Under physiological conditions, they can pass TME, RES, BBB and renal infiltration. They can be administered through several routes viz. oral, nasal, parenteral and intraocular etc. While reaching the target, they can damage or kill the cell through intrinsic and/or extrinsic pathways of apoptosis and modulate death receptor signaling. While Intrinsic apoptosis is characterized by mitochondrial injury, ER stress and DNA damage; extrinsic pathway involves signals that activate plasma membrane associated death receptors. An inter play between extrinsic and intrinsic pathways does contribute to cell death. Secondly, NPs can activate inflammasome, a multiprotein complex within the cell and lead to pyroptosis. When activated, inflammasome triggers the release of inflammatory cytokines that induce cell death. Ferroptosis has also been implicated in the cytotoxicity of NPs. It is characterized by an iron dependent accumulation of lipid peroxides that cause membrane damage and cancer cell death. NPs can direct cancer cells to autophagy, a process wherein unnecessary cell components are removed or recycled. Briefly, NPs induced cuproptosis facilitates targeted delivery of copper to cancer cells; introduces stimuli responsive release of Cu2+ions within the tumor environment; promotes protein aggregation and destabilize Fe-S clusters halting TCA cycle. Intriguingly, a cross talk amongst different cell death signaling pathways has also been reported. Recent research shows that NPs can be engineered to target specific cancer cells or to enhance therapeutic effects of drugs. Despite these promising effects of nanoparticles on cancer cells, application of individual NPs faces specific challenges in their clinical translation. Healthy cells may suffer from their toxicity through ROS and oxidative stress. Most studies revolve around cells and animal models that may not provide yet comprehensible results in human subjects. Present review especially discusses the effects of silver, titanium and zinc oxide nanoparticles on dominant modes of cell death viz. apoptosis, pyroptosis, ferroptosis, cuproptosis and autophagy with especial reference to cancer cells.
Graphical Abstract