title: Investigation the mechanism of the apoptosis induced by lactacystin in gastric cancer cells.
abstract: The study aims to investigate the relationship between nuclear factor (nuclear factor kappa B (NF-κB)) viability and lactacystin-mediated cell apoptosis in gastric cancer cells. Two gastric cancer cell lines (MKN28 and SGC7901) were treated with lactacystin-a proteasome inhibitor for 24 h. The cell viability, toxicity, and death were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. DNA binding viability of NF-κB and caspase-3 viability were analyzed by ELISA; the expression of p65 NF-κB nuclear protein was detected by immunocytochemistry and Western blot. Lactacystin reduced DNA binding viability of NF-κB (t = 3.0,P = 0.013) and the NF-κB viability (compared to the 5, 10 μmol/L MKN28 cell (p53 mutant) line, P < 0.001) and the expression of p65 NF-κB nuclear protein decreased parallelled to concentrations of lactacystin in MKN28 cell line, while without obvious effects on NF-κB viability in SGC7901 cell line (P = 0.381), while the viability of caspase-3 increased also along with the raising of lactacystin concentrations (compared to control, 5 μmol/L: SGC7901 cell line P = 0.029, MKN28 cell line P < 0.001; 10 μmol/L: SGC7901 cell line, P < 0.001, MKN28 cell line, P < 0.001). It was concluded that lactacystin had diversified killing effects on gastric cancer cells. The mechanism may be related to induce the apoptosis by downregulation of nuclear factor kappa B viability. There may be additional cell survival/death pathway in SGC7901 gastric cancer cells.
authors.affiliation: Department of Oncology, The Second Affiliated Hospital of Dalian Medical University, 467 Zhongshan Road, Dalian, China, lianyingli_dr@163.com.
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Li
authors.forename: Haifeng
authors.initials: H
authors.lastname: Gao
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Chaoyang
authors.initials: C
authors.lastname: Dai
mesh_terms: D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004247:DNA / Q000378:metabolism; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000473:pathology
chemical_list: D016328:NF-kappa B; C067713:lactacystin; D004247:DNA; D053148:Caspase 3; D000111:Acetylcysteine