title: Synthetic Bichalcone TSWU-BR23 Induces Apoptosis of Human Colon Cancer HT-29 Cells by p53-Mediated Mitochondrial Oligomerization of BAX/BAK and Lipid Raft Localization of CD95/FADD.
abstract: A synthetic bichalcone analog, (E)-1-(3-((4-(4-acetylphenyl)piperazin-1-yl)methyl)-4-hydroxy-5-methoxyphenyl)-3-(pyridin-3-yl)prop-2-en-1-one (TSWU-BR23), has been shown to induce apoptosis in human colon cancer HT-29 cells involving the induction of CD95 and FAS-associated protein death domain (FADD), but its precise mechanism of action has not been fully elucidated. Using cell-surface biotinylation and sucrose density-gradient-based membrane flotation techniques, we showed that the disruption of TSWU-BR23-induced lipid raft localization of CD95/FADD by cholesterol-depleting agent (methyl-β-cyclodextrin) was reversed by cholesterol replenishment. Blockade of p53 expression by short-hairpin RNA (shRNA) suppressed oligomeric Bcl-2-associated x protein (BAX)/Bcl-2 antagonist killer 1 (BAK)-mediated mitochondrial apoptosis but did not inhibit lipid raft localization of CD95/FADD and pro-caspase-8 cleavage induced by TSWU-BR23. Co-expression of p53 shRNA and dominant-negative mutant of FADD completely inhibited TSWU-BR32-induced mitochondrial apoptotic cell death. Collectively, these data demonstrate that TSWU-BR23 leads to HT-29 cell apoptosis by inducing p53-mediated mitochondrial oligomerization of BAX/BAK and the localization of CD95/FADD with lipid rafts at the cell surface.
authors.affiliation: Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung, Taiwan, R.O.C. mllinsally@yahoo.com.tw.
authors.forename: Meng-Liang
authors.initials: ML
authors.lastname: Lin
authors.affiliation: Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung, Taiwan, R.O.C.
authors.forename: Shih-Shun
authors.initials: SS
authors.lastname: Chen
authors.affiliation: Department of Chemistry, National Cheng Kung University, Tainan, Taiwan, R.O.C.
authors.forename: Tian-Shung
authors.initials: TS
authors.lastname: Wu
mesh_terms: D017209:Apoptosis; D047188:Chalcones / Q000138:chemical synthesis* / Q000494:pharmacology*; D053200:Fas-Associated Death Domain Protein / Q000378:metabolism; D019073:HT29 Cells / Q000187:drug effects* / Q000378:metabolism*; D006801:Humans; D021962:Membrane Microdomains / Q000187:drug effects; D008928:Mitochondria / Q000378:metabolism; D011725:Pyridines / Q000138:chemical synthesis* / Q000494:pharmacology*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D050998:bcl-2 Homologous Antagonist-Killer Protein / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000378:metabolism; D019014:fas Receptor / Q000378:metabolism
chemical_list: C559076:1-(3-((4-(4-acetylphenyl)piperazin-1-yl)methyl)-4-hydroxy-5-methoxyphenyl)-3-(pyridin-3-yl)prop-2-en-1-one; C494772:BAK1 protein, human; C494826:BAX protein, human; D047188:Chalcones; C505533:FADD protein, human; C491901:FAS protein, human; D053200:Fas-Associated Death Domain Protein; D011725:Pyridines; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D050998:bcl-2 Homologous Antagonist-Killer Protein; D051028:bcl-2-Associated X Protein; D019014:fas Receptor
keywords: Apoptosis; BAX/BAK; CD95; FADD; bichalcone analog; human colon carcinoma HT-29 cells