title: Riccardin D-N induces lysosomal membrane permeabilization by inhibiting acid sphingomyelinase and interfering with sphingomyelin metabolism in vivo.
abstract: Lysosomes are important targets for anticancer drug discovery. Our previous study showed that Riccardin D-N (RD-N), a natural macrocylic bisbibenzyl derivative produced by Mannich reaction, induced cell death by accumulating in lysosomes. Experiments were performed on human lung squamous cell carcinoma tissue from left inferior lobar bronchus of patient xenografts and H460 cells. RD-N was administrated for 25days. The specimens of xenografts in Balb/c athymic (nu+/nu+) male mice were removed for immunohistochemistry, subcellular fractionation, enzyme activities and Western blotting analysis. mRFP-GFP-LC3 reporter was used to examine autophagy in H460 cells. Sphingomyelin assay was evaluated by thin-layer chromatography and assay kit. Lysosomal membrane permeabilization (LMP) caused by acid sphingomyelinase (ASM) inhibition and subsequent changes of sphingomyelin (SM) metabolism selectively destabilized the cancer cell lysosomes in RD-N-treated H460 cells in vitro and tumor xenograft model in vivo. The destabilized lysosomes induced the release of cathepsins from the lysosomes into the cytosol and further triggered cell death. These results explain the underlying mechanism of RD-N induced LMP. It can be concluded that a more lysosomotropic derivative was synthesized by introduction of an amine group, which could have more potential applications in cancer therapy.
authors.affiliation: Department of Natural Product Chemistry, Key Lab of Chemical Biology of MOE (Ministry of Education), Shandong University, Jinan 250012, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Jinan 250012, China.
authors.forename: Huanmin
authors.initials: H
authors.lastname: Niu
authors.affiliation: Department of Natural Product Chemistry, Key Lab of Chemical Biology of MOE (Ministry of Education), Shandong University, Jinan 250012, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Sun
authors.affiliation: School of Pharmaceutical Science, Shandong University, Jinan 250012, China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: Department of Natural Product Chemistry, Key Lab of Chemical Biology of MOE (Ministry of Education), Shandong University, Jinan 250012, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Jinan 250012, China.
authors.forename: Huiqing
authors.initials: H
authors.lastname: Yuan
authors.affiliation: Department of Natural Product Chemistry, Key Lab of Chemical Biology of MOE (Ministry of Education), Shandong University, Jinan 250012, China. Electronic address: louhongxiang@sdu.edu.cn.
authors.forename: Hongxiang
authors.initials: H
authors.lastname: Lou
mesh_terms: D000818:Animals; D002463:Cell Membrane Permeability / Q000187:drug effects*; D007425:Intracellular Membranes / Q000187:drug effects*; D008247:Lysosomes / Q000187:drug effects*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D010647:Phenyl Ethers / Q000633:toxicity*; D013108:Sphingomyelin Phosphodiesterase / Q000378:metabolism*; D013109:Sphingomyelins / Q000378:metabolism*; D013267:Stilbenes / Q000633:toxicity*
chemical_list: D010647:Phenyl Ethers; D013109:Sphingomyelins; D013267:Stilbenes; C578790:riccardin D-N; D013108:Sphingomyelin Phosphodiesterase
keywords: Acid sphingomyelinase; Cathepsin; Lysosome; Sphingomyelin