title: [Inhibition of polo like kinase gene expression induces apoptosis in gastric cancer cells].
abstract: OBJECTIVE
  To observe the effect of inhibition of polo like kinase1 (plk1) gene expression on apoptosis induction in gastric cancer cell line-MKN45 and discuss the vital role of plk1 proliferation and viability of gastric cancer cells.
  
  
  METHODS
  The plk1 expression was inhibited by chemically synthesized siRNA. The plk1 mRNA and protein level were respectively measured by real-time quantitative PCR and Western blotting. The spindle morphological change was observed by immunofluorescence staining and confocal microscopy. The change of cell cycle distribution and apoptosis rate was detected by flow-cytometry. Pro caspase3 level was also detected by western blotting.
  
  
  RESULTS
  After treatment by siRNA targeting plk1, plk1 mRNA and protein level decreased obviously, the cell mitotic spindle became obscure and lost cohesiveness, more MKN45 cells accumulated at G(2)/M phase (P< 0.05), apoptosis rate of plk1 siRNA treated MKN45 cells was higher than that of control cells at 48 h and 72 h (P< 0.05) with pro-caspase3 level decreasing at 72 h.
  
  
  CONCLUSIONS
  Inhibition of plk1 gene expression induces apoptosis in MKN45 cells through the pathway of caspase3. Plk1 gene play a key role in viability of MKN45 cells.
authors.affiliation: Department of Surgery, Ruijin Hospital, Shanghai Second Medical University, Shanghai 200025, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Lan
authors.forename: Bin-ya
authors.initials: BY
authors.lastname: Liu
authors.forename: Xue-hua
authors.initials: XH
authors.lastname: Cheng
authors.forename: Ying
authors.initials: Y
authors.lastname: Qu
authors.forename: Xiao-qing
authors.initials: XQ
authors.lastname: Zhang
authors.forename: Qu
authors.initials: Q
authors.lastname: Cai
authors.forename: Zheng-gang
authors.initials: ZG
authors.lastname: Zhu
mesh_terms: D017209:Apoptosis; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000235:genetics*; D045744:Cell Line, Tumor; D015870:Gene Expression; D006801:Humans; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D034741:RNA, Small Interfering / Q000235:genetics*; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000097869:Polo-Like Kinase 1
chemical_list: D018797:Cell Cycle Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering; D000097869:Polo-Like Kinase 1