title: [Inhibition of PDK1 gene expression in esophageal cancer EC9706 cells by RNA interference and its effect on their malignant biological behavior].
abstract: OBJECTIVE
  To explore the silencing effects of RNA interference on the expression of 3-phosphoinositide-dependent protein kinase 1 (PDK1) gene, and the effects on malignant phenotypes of esophageal carcinoma EC9706 cells.
  
  
  METHODS
  PDK1 siRNAs was transfected into the EC9706 cells. The expression of PDK1 mRNA was detected by reverse transcriptase polymerase chain reaction (RT-PCR). At the same time, expressions of PDK1, Akt and phosphorylated Akt proteins were detected by Western blot. Methyl thiazolyl tetrazolium assay (MTT) was used to examine the cell proliferation after transfection. Flow cytometry was used to determine the percentage of apoptosis cells, and Transwell chambers were used to detect the invasion ability of the cells. Tumor formation in nude mice was used to assess the tumorigenic characteristics in vivo.
  
  
  RESULTS
  Compared with the non-transfected group, PDK1 siRNA effectively inhibited the expression of PDK1 mRNA in EC9706 cells, with an inhibition rate of (28.5 ± 4.2)% at 24 h, (51.1 ± 5.7)% at 48 h and (60.6 ± 4.1)% at 72 h after transfection. The expressions of PDK1 and phosphorylated Akt protein were also knocked down by PDK1 siRNA (P < 0.05). PDK1 siRNA significantly inhibited the cell proliferation and invasion, promoted the cell apoptosis, and inhibited the EC9706 cells proliferation in vivo and the expression of PDK1 protein in the transplanted tumors (P < 0.05).
  
  
  CONCLUSIONS
  PDK1 may play an important role in esophageal cancer cell proliferation, invasion and apoptosis, and may serve as an effective target for cancer gene therapy.
authors.affiliation: Department of Pathology, The First Affiliated Hospital, Zhengzhou University, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yu
authors.forename: Kui-sheng
authors.initials: KS
authors.lastname: Chen
authors.forename: Ya-nan
authors.initials: YN
authors.lastname: Li
authors.forename: Juan
authors.initials: J
authors.lastname: Yang
authors.forename: Lu
authors.initials: L
authors.lastname: Zhao
mesh_terms: D064413:3-Phosphoinositide-Dependent Protein Kinases; D000818:Animals; D017209:Apoptosis; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004938:Esophageal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D009368:Neoplasm Transplantation; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics*; D014162:Transfection; D047368:Tumor Burden
chemical_list: D012333:RNA, Messenger; D034741:RNA, Small Interfering; D064413:3-Phosphoinositide-Dependent Protein Kinases; C578562:PDPK1 protein, human; C578564:Pdpk1 protein, mouse; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt