title: EGCG induces lung cancer A549 cell apoptosis by regulating Ku70 acetylation.
abstract: Lung cancer is the leading cause of cancer-related death worldwide. (-)-Epigallocatechin-3-gallate (EGCG) is a potential chemopreventive and therapeutic agent for lung cancer. Induction of apoptosis was examined using Annexin V/PI double staining flow cytometry. Western blot analysis detected the protein expression of cleaved caspase-3, Bax and Bcl-xL. Co-immunoprecipitation was used to detect the interaction of Ku70-Bax and the acetylation status of Ku70. Treatment of A549 cells with EGCG-induced apoptosis via increased expression of cleaved caspase-3 and Bax, but decreased expression of Bcl-xL. EGCG upregulated the K70 acetylation status of A549 cells and downregulated the interaction of Bax-Ku70 in a concentration- and time-dependent manner. The apoptosis-promoting effect of EGCG on A549 cells was obviously weakened, along with strengthening of the Bax-Ku70 interaction, after pCDNA3.1(+)-Ku70 plasmid and pCDNA3.1(+)-Ku70539/542R plasmid transfection. Our results established a role of EGCG in inducing cell apoptosis by suppressing Bax activity. Regulating Ku70 acetylation by EGCG, that block the interaction between Ku70 and Bax, will result in lung cancer cell apoptosis.
authors.affiliation: Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Li
authors.affiliation: Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.
authors.forename: Qi-Hua
authors.initials: QH
authors.lastname: Gu
authors.affiliation: Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.
authors.forename: Jian
authors.initials: J
authors.lastname: An
authors.affiliation: Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Cao
authors.affiliation: Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.
authors.forename: Hua-Ping
authors.initials: HP
authors.lastname: Yang
authors.affiliation: Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.
authors.forename: Cheng-Ping
authors.initials: CP
authors.lastname: Hu
mesh_terms: D000072283:A549 Cells; D000107:Acetylation / Q000187:drug effects; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D000072200:Ku Autoantigen / Q000235:genetics / Q000378:metabolism*; D008175:Lung Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000378:metabolism; D051020:bcl-X Protein / Q000378:metabolism
chemical_list: D016588:Anticarcinogenic Agents; C494826:BAX protein, human; C494811:BCL2L1 protein, human; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein; D002392:Catechin; C045651:epigallocatechin gallate; C505407:CASP3 protein, human; D053148:Caspase 3; D000072200:Ku Autoantigen