title: [P21(WAF1) inhibits the growth of leukemia cell line K562 and decreases its sensitivity to Vp16].
abstract: OBJECTIVE
  To explore the effect of p21(WAF1) on the proliferation and the sensitivity to Vp16 of leukemia cell line K562.
  
  
  METHODS
  A p21(WAF1) retroviral expression vector pLXSN-p21(WAF1) was constructed by FuGENE 6, pLXSN-p21(WAF1) and pLXSN-neo, and transfected into p21(WAF1) defect leukemia cell line K562. After selected with G418, K562-p21(WAF1) cell clones that stably expressed p21(WAF1) were isolated. The ectopic expressions of p21(WAF1) mRNA and protein in K562-p21(WAF1) were identified by RT-PCR and Western b1ot. The cell growth rate was tested by trypan blue dye, the cell cycle by FCM and the sensitivity to Vpl6 by cell count and MTT assay.
  
  
  RESULTS
  The expression of p21(WAF1) protein and mRNA could be detected in K562-p21(WAF1) cells. A strong inhibition of cell proliferation was observed in K562-p21(WAF1) cell as compared with that of the control. The cell number in G(0)/G(1) phase was remarkably increased. The sensitivity to Vpl6 decreased, the IC (50) of K562-neo cells was (56.4 +/- 6.5) microgram/ml, and that of K562-p21(WAF1) cells was (131.0 +/- 8.7) microgram/ml (P < 0.01).
  
  
  CONCLUSIONS
  p21(WAF1) can inhibit the proliferation of leukemia cell and decrease its sensitivity to Vp16.
authors.affiliation: Department of Pediatrics, People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Yang
authors.forename: Shenwu
authors.initials: S
authors.lastname: Wang
authors.forename: Huijun
authors.initials: H
authors.lastname: Yin
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D015153:Blotting, Western; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005047:Etoposide / Q000494:pharmacology*; D016193:G1 Phase / Q000187:drug effects; D015870:Gene Expression; D006801:Humans; D020014:K562 Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016192:Resting Phase, Cell Cycle / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
chemical_list: D000972:Antineoplastic Agents, Phytogenic; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D012333:RNA, Messenger; D005047:Etoposide