The photocytotoxicity effect of cationic sulfonated corrole towards lung cancer cells: in vitro and in vivo study.

Corrole is a kind of new and promising photosensitizer (PS) in cancer photodynamic therapy (PDT). However, the protein molecular mechanism of PDT activity for corrole under light irradiation is still not clear. In this paper, water-soluble cationic sulfonated corrole (1) and its metal complexes (1-Fe, 1-Mn, and 1-Cu) were prepared, and the photodynamic anti-cancer activity against various tumor cells was investigated by MTT assay. The potential molecular mechanism of PDT activity was elucidated by fluorescence microscope, flow cytometry, molecular docking, and western blotting analysis. Besides, the potential PDT anti-tumor effect of 1 in vivo was assessed in human tumor xenografts in mice. Quantitative analysis revealed that 1's phototoxicity triggered a significant generation of reactive oxygen species, causing disruption of mitochondrial membrane potential. The results of western blotting (WB) assay shown in 1's phototoxicity could induce cell apoptosis via ROS-mediated mitochondrial caspase apoptosis pathway, in which SIRT1 protein degradation played a key role. PTD activity in vivo shown in 1 could significantly reduce the growth of A549 xenografted tumor, without obvious loss of mice body weight. We clearly found that cationic sulfonated corrole is a potential candidate of PS in vitro and in vivo. The phototoxicity of 1 could induce A549 cell apoptosis by inducing ROS production increase, further to activate the mitochondrial apoptosis pathway. We concluded that SIRT1 protein is a more appropriate target in this progress.