title: [Effects of PLK1 gene silence on apoptosis of K562 cells].
abstract: OBJECTIVE
  To investigate the effects of PLK1 gene silence by short hairpin RNA (shRNA) on PLK1 expression and apoptosis in K562 cells, and explore the role of PLK1 in the pathogenesis of leukemia.
  
  
  METHODS
  The shRNA fragment targeting at 1416-1436 bp of PLK1 mRNA was synthesized and cloned into pEGFP-H1 vector, named as pEGFP-H1/PLK1. The empty control, pEGFP-H1 and pEGFP-H1/PLK1 were transfected into K562 cells respectively via electroporation. 24 h or 48 h after transfection, gene and protein expression of PLK1 in the cells were assayed by RT-PCR and Western blot analysis respectively, cells viability by MTT assay, caspase-3 activity by colorimetry, cell cycle and apoptosis by FACS.
  
  
  RESULTS
  24 and 48 h after transfection, PLK1 expression in K562 cells was 1.25 +/- 0.07 for control group, 0.52 +/- 0.04 and 0.25 +/- 0.02 for pEGFP-H1/PLK1 group, and 1.24 +/- 0.08 and 1.23 +/- 0.09 for pEGFP-H1 group respectively. The alteration status of PLK1 protein levels were similar to that of PLK mRNA levels. The apoptosis rate was (8.3 +/- 0.6)% in control group, (8.7 +/- 0.7)% in pEGFP-H1 group and (49.7 +/- 3.8)% and (82.3 +/- 6.9)% in pEGFP-H1/PKLK1 group at 24 and 48 h, respectively. In addition, cell fraction at G(2)/M phase was increased obviously compared with control and pEGFP-H1-transfected group.
  
  
  CONCLUSIONS
  The constructed shRNA can remarkably inhibit PLK1 expression and transfected K562 cell proliferation, increase apoptosis and block cell-cycle, suggesting that PLK1 play important roles in apoptosis and cell-cycle control of leukemia cells.
authors.affiliation: Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan 430022, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Zhi-chao
authors.initials: ZC
authors.lastname: Chen
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.forename: Yong
authors.initials: Y
authors.lastname: You
authors.forename: Zhong-ping
authors.initials: ZP
authors.lastname: Liu
authors.forename: Ping
authors.initials: P
authors.lastname: Zou
mesh_terms: D017209:Apoptosis / Q000235:genetics*; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism; D049109:Cell Proliferation; D005822:Genetic Vectors; D006801:Humans; D020014:K562 Cells; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics; D014162:Transfection; D000097869:Polo-Like Kinase 1
chemical_list: D018797:Cell Cycle Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D000097869:Polo-Like Kinase 1