Niclosamide: Drug Repurposing For Human Chondrosarcoma Treatment Via The Caspase-dependent Mitochondrial Apoptotic Pathway

Background:Chondrosarcoma is a lethal ossature malignancy that threatens human lives.Poor sensitivity to chemotherapy drugs and the high rate of recrudescence are the bottlenecks of chondrosarcoma treatment.Drug repurposing is a safe,economical and timesaving way to explore new chemotherapy for diseases.Niclosamide,as an approved anthelmintic drug,has been identified as a potential anticancer agent.However,few studies have reported the effect of niclosamide in the treatment of human chondrosarcoma,the mechanisms of niclosamide in chondrosarcoma remains unknown.Objective:To investigate the effect and mechanism of niclosamide in human chondrosarcoma.Methods:PartⅠ:To examine the inhibitory effect of niclosamide on the cell growth and proliferation of SW1353 and CAL78 cell lines,the crystal violet cell viability assay,CCK-8 assay and colony forming assay were performed at following concentrations for 24 h.PartⅡ:To determine the effect of niclosamide on the cell migratory and invasive capacities of SW1353 and CAL78 cells,the wound-healing assay and cell transwell invasive assay were performed at following concentrations for 24 h.PartⅢ:To investigate whether niclosamide could induce the cell apoptosis of SW1353 and CAL78 cells,Annexin V-FITC/PI flow cytometry assay and TUNEL assay were performed after the treatment of niclosamide at indicated concentrations.PartⅣ:To determine the effect of niclosamide on the cell apoptosis and related mechanisms,JC-1 cell mitochondrial membrane potential assay,Seahorse XFp cell mito stress test and western blotting were performed.The effect of niclosamide on mitochondria including mitochondrial membrane potential,oxygen consumption rate was determined by JC-1 and Seahorse cell mito stress assay,respectively.The expression of caspase-3,cleaved caspase-3,caspase-9,cleaved caspase-9,andβ-tubulin levels examined by western blotting.Results:PartⅠ:Niclosamide could inhibit the cell growth and proliferation of SW1353 and CAL78 cell lines.Niclosamide was found to be highly active with IC₅₀ values of 0.5072 and 0.9472μM in SW1353 and CAL78 cells,respectively.PartⅡ:Niclosamide could attenuate the migratory and invasive capacities of SW1353 and CAL78 cell lines.PartⅢ:Niclosamide could induce the cell apoptosis of SW1353 and CAL 78 cells.PartⅣ:Niclosamide could decrease cell mitochondrial membrane potential,inhibit cell mitochondrial respiration and induce the activation of caspase-dependent mitochondrial apoptosis in SW1353 and CAL78 cells.Conclusions:Niclosamide served as a potent tumor inhibitor in chondrosarcoma via the activation of caspase-dependent mitochondrial apoptotic pathway in vitro,which might be an approach to the therapeutic strategy of chondrosarcoma.