title: Cyclin E1 knockdown induces apoptosis in cancer cells.
abstract: OBJECTIVE
  Cyclin E1 is expressed during the late G1 phase of the cell cycle and mediates the initiation of DNA synthesis by activating cyclin-dependent kinases 2 (CDK2). Abnormally high levels of cyclin E1 expression have frequently been found in cancer cells. Here, we investigate the effect of cyclin E1 knockdown on cancer cells.
  
  
  METHODS
  RNA interference, expressed from a DNA-based retroviral vector, was used to knockdown cyclin E1 in adenocarcinoma (HeLa), breast (MDA-MB-31) and glioblastoma (U-373-MG) cell lines and an explant from one glioma patient (GB-LP-2).
  
  
  RESULTS
  We have obtained very efficient depletion of cyclin E1 protein (over 80%) and considerable apoptotic induction (50-70%) after 96 hours post-infection. The ability of U-373-MG cells to induce tumor growth in nude mice was also abolished after cyclin E1 knockdown.
  
  
  CONCLUSIONS
  Our results indicate that retrovirus carrying the DNA to be transcribed into a short hairpin RNA (shRNA) against cyclin E1 could be used as a therapeutic agent for cancer therapy.
authors.affiliation: Departament of Molecular Biology, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Facultad de Ciencias, Cantoblanco, Madrid 28049, Spain.
authors.forename: Esteban N
authors.initials: EN
authors.lastname: Gurzov
authors.forename: Marta
authors.initials: M
authors.lastname: Izquierdo
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D015153:Blotting, Western; D002453:Cell Cycle / Q000502:physiology; D049109:Cell Proliferation; D019927:Cyclin E / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005455:Fluorescent Antibody Technique; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009374:Neoplasms, Experimental / Q000235:genetics / Q000628:therapy*; D015513:Oncogene Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D012190:Retroviridae; D014162:Transfection
chemical_list: C475820:CCNE1 protein, human; D019927:Cyclin E; D015513:Oncogene Proteins