Purpose: With the development of nanomedicine, microwave ablation enhanced by multifunctional nanoplatforms has been widely studied for synergistic cancer therapy. Though scientists have got a lot of significant achievements in this field, the detailed molecular mechanisms and potential targets of microwave ablation enhanced by multifunctional nanoplatforms still need further exploration. In this study, we found that a kind of magnetite Fe₃O₄ nanoparticles (Fe₃O₄ NPs) could induce severe endoplasmic reticulum stress and activate cancer apoptosis under the irradiation of mild microwave.
Methods: In this study, plenty of studies including cell immunofluorescence, mitochondrial membrane potential, electron microscopy, atomic force microscopy and microwave ablation in vivo were conducted to explore the molecular mechanisms and potential targets of microwave ablation enhanced by the Fe₃O₄ NPs.
Results: The IRE1-ASK1-JNK pathway was strongly activated in A375 cells treated with both Fe₃O₄ NPs and mild microwave. The endoplasmic reticulum of the A375 cells was significantly dilated and exhibited ballooning degeneration. By investigating the mitochondrial membrane potential (ΔΨm), we found that the mitochondria of cancer cells had been significantly damaged under microwave treatment coupled with Fe₃O₄ NPs. In addition, melanoma of B16F10-bearing mice had also been effectively inhibited after being treated with Fe₃O₄ NPs and microwave.
Conclusion: In this study, we found that a kind of magnetite Fe₃O₄ nanoparticles could induce severe ER stress and activate cancer apoptosis under mild microwave irradiation. Apparent apoptosis had been observed in the A375 cells under a scanning electron microscope and transmission electron microscope. Moreover, melanoma had also been inhibited effectively in vivo. As a result, the endoplasmic reticulum stress is a promising target with clinical potential in nanomedicine and cancer therapy.
Keywords: microwave ablation, ER stress, apoptosis, magnetite Fe₃O₄ nanoparticles