title: Effects and mechanism of downregulation of survivin expression by RNA             interference on proliferation and apoptosis of lung cancer cells.
abstract: The survivin protein, a member of the inhibitors of apoptosis (IAP) family,             has gained popularity as a therapeutic target for cancer due to its selective             expression in tumor cells and its significant involvement in tumor cell viability.             The aim of this study was to investigate the effect of the survivin-small interfering             RNA (siRNA) plasmid on survivin expression in the human lung cancer cell line,             A549, and to observe its effects on apoptosis and proliferation of A549 cells.             A549 human lung cancer cells were transfected with survivin-targeting siRNA. The             downregulation of survivin expression was determined by real-time polymerase chain             reaction and western blotting. The proliferation of A549 cells was determined             by MTT assay. The apoptotic rate and cell cycle distribution were analyzed by             flow cytometry (FCM). Caspase-9 activity was also detected to study the apoptosis             of lung cancer cells induced by siRNA against survivin. The sequence-specific             siRNA efficiently and specifically downregulated the expression of survivin at             both the mRNA and protein levels. Downregulation of survivin expression dramatically             suppressed the proliferation of A549 cells and arrested the cells at the G (1)/G             (0) phase. Caspase-9 activity was significantly increased in A549 cells transfected             with siRNA against survivin. In this study, we found that survivin-specific siRNA             can efficiently suppress the expression of survivin, increase apoptosis and inhibit             A549 cell proliferation. Our findings further indicate the possibility that the             antitumor effects of survivin-siRNA are mediated through the activation of caspase-9.
authors.affiliation: Department of Respiratory Medicine, The Union Hospital of FuJian Medical University, Fuzhou 350001, PR China.
authors.forename: Xiang-Qi
authors.initials: XQ
authors.lastname: Chen
authors.forename: Sheng
authors.initials: S
authors.lastname: Yang
authors.forename: Zhi-Ying
authors.initials: ZY
authors.lastname: Li
authors.forename: Hui-Shan
authors.initials: HS
authors.lastname: Lu
authors.forename: Ming-Qiang
authors.initials: MQ
authors.lastname: Kang
authors.forename: Ting-Yan
authors.initials: TY
authors.lastname: Lin
mesh_terms: D017209:Apoptosis; D053453:Caspase 9 / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015536:Down-Regulation; D059585:G1 Phase Cell Cycle Checkpoints; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism*; D000077022:Survivin
chemical_list: C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D034741:RNA, Small Interfering; D000077022:Survivin; D053453:Caspase 9