Study On The Anti-tumor Effect And Mechanism Of Nitrogen Heterocyclic Carbene Iridium (Ⅲ) Complex

Cancer is one of the leading causes of death in the world,and the development of anti-cancer drugs has become an epidemic trend.In recent years,metal complexes have attracted the attention of scientists because of their anti-tumor activity and promoting apoptosis.At present,many metallic anticancer drugs are based on platinum,but the toxic side effects of platinum drugs seriously limit their actual efficacy and the scope of application.Researches have found that the metal iridium complexes have better therapeutic efficacy than the cisplatin,and the design and development of the metal iridium antitumor drugs have aroused widespread interest.Our laboratory had been designed and developed iridium（Ⅲ） anticancer complex[（η⁵-C₅MeC₆H₄C₆H₅）Ir（C^C）Cl]PF₆,which could selectively kill and inhibite tumor cell,but its internal mechanism was not fully clear.The anti-tumor mechanism and anti-metastasis of iridium（Ⅲ）complex were studied in this paper.1.First,the metal iridium（Ⅲ）complex was synthesized in this study,and the structure of the complex was identified by ¹H NMR,¹³C NMR et al.2.The toxicity of cells,including non-small cell lung cancer cells（A549）,human lung squamous cells（L78）,human cervical cancer cells（Hela）and human bronchial epithelial cells（BEAS-2B）,were determined by MTT,it found that A549 cells has higher antitumor activity.This study analyzed the cell localization of the metal iridium（Ⅲ）complex using confocal microscopy,and it found that the complex targeted lysosomes and entered the cancer cells through an energy-dependent pathway.The complex analyzed by flow cytometry,the results showed that after effecting,the apoptosis rate was increased significantly,the cell cycle was inhibited in the G₀/G₁phase.Moreover,mitochondrial membrane potential was studied and it found that the complex induced intracellular reactive oxygen species（ROS）,along with the relative expression of caspase-3 raising.Finally,the expression of proteins,which were related to promoting the apoptosis of A549 cells,were analyzed by western blot.The results showed that the lysosomal membrane protein（LAMP-1）was destroyed,and cathepsin（CB）was released into the cytoplasm,inducing mitochondrial dysfunction,which was led to the release of cytochrome C（Cyt C）and activated the amplification downstream pathway to promote cell apoptosis.On this basis,we inferred that the anti-tumor mechanism of metal iridium（Ⅲ）complex may promote cell apoptosis through the lysosome-mitochondrial pathways.3.In this study,cell scratch method,migration and invasion experiments were used to investigate the anti-metastasis ability of the metal iridium（Ⅲ）complex to A549 cells.The expression levels of NEDD9 andβ-catenin were analyzed by immunohistochemistry and western blot.The results of this study showed that the metal iridium（Ⅲ）complex has obvious anti-metastasis ability to A549 cells and may reduce the proliferation and metastasis of lung cancer cells by acting on NEDD9.And the metal iridium（Ⅲ）complex also induced the expression ofβ-catenin protein,increased the membrane surface viscosity,and reduced the transfer capacity of A549 cells.