title: Down-regulation of Bcl-XL by RNA interference suppresses cell growth and induces apoptosis in human esophageal cancer cells.
abstract: OBJECTIVE
  To determine the inhibitory effect of the vector-generated small interfering RNAs (siRNAs) on the expression of the Bcl-X(L) gene in established human esophageal cancer cells, and to investigate the effect of the Bcl-X(L) siRNAs on cell growth and apoptosis in esophageal cancer cells.
  
  
  METHODS
  Three siRNA-expressing vectors targeting different sites of the Bcl-X(L) gene were constructed from pTZ-U6+1 vector. Cultured esophageal cancer cells were transfected with the siRNA-expressing vector (or the control vector) using lipofectamine 2000. Bcl-X(L) gene expression was determined with semiquantitative RT-PCR assay and Western blotting. Among the three siRNA-expressing vectors, the most highly functional vector and its effect on cell growth and apoptosis in esophageal cancer cells was further analyzed.
  
  
  RESULTS
  Of the three siRNA-expressing vectors, siRNA-expressing vector No.1 was the most potent one which suppressed Bcl-X(L) mRNA production to 32.5% of that in the untreated esophageal cancer cells. Western blotting analysis showed that siRNA-expressing vector No.1 markedly down-regulated the expression of Bcl-X(L) in human esophageal cancer cells. Treatment of esophageal cancer cells with siRNA-expressing vector No.1 resulted in inhibition of cell growth and induction of apoptosis.
  
  
  CONCLUSIONS
  Down-regulation of Bcl-X(L) by vector-generated small interfering RNAs can suppress cell growth and induce apoptosis in human esophageal cancer cells.
authors.affiliation: The Institute of Immunology and Molecular Biology, North Sichuan Medical College, No.234, Fujiang Road, Nanchong 637007, Sichuan Province, China. xyongen@sina.com
authors.forename: Yong-En
authors.initials: YE
authors.lastname: Xie
authors.forename: En-Jie
authors.initials: EJ
authors.lastname: Tang
authors.forename: Da-Rong
authors.initials: DR
authors.lastname: Zhang
authors.forename: Bi-Xuan
authors.initials: BX
authors.lastname: Ren
mesh_terms: D017209:Apoptosis; D001483:Base Sequence; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015536:Down-Regulation; D004938:Esophageal Neoplasms / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D006801:Humans; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics / Q000627:therapeutic use; D051020:bcl-X Protein / Q000037:antagonists & inhibitors* / Q000235:genetics
chemical_list: C494811:BCL2L1 protein, human; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D034741:RNA, Small Interfering; D051020:bcl-X Protein