title: [Reversal of multidrug resistance of K562/A02 cell line by mdr1 and GSTpi gene silence].
abstract: OBJECTIVE
  To investigate the effect of short hairpin RNA (shRNA) on mdr1 and GSTpi expression of human multidrug resistant leukemia cell line K562/A02.
  
  
  METHODS
  shRNAs were synthesized according to the sequence targeting mdr1 and GSTpi coding region of 79-99nt and 308 approximately 327nt, and cloned into pSilencer 2.1-U6 neo vector. The cloned products, pSilence-mdr1 and pSilence-GSTpi, were transfected into K562/A02 cell line. Expression of mdr1 and GSTpi mRNA was assayed by real time PCR. 50% inhibition concentration (IC(50)) of doxorubicin (ADM) for K562/A02 cell line was determined by MTT method.
  
  
  RESULTS
  After transfected with pSilence mdr1, the expression of mdr1 mRNA in K562/A02 cells was reduced by 71.5%, from (2.80 +/- 1.65) x 10(8) copy/microg RNA to (3.90 +/- 2.37) x 10(7) copy/microg RNA(P < 0.01). While the expression of GSTpi mRNA in pSilence-GSTpi transfected K562/A02 cells reduced by 39.8%, from (2.30 +/- 1.14) x 10(5) copy/microg RNA to (5.40 +/- 2.45) x 10(4) copy/microg RNA (P < 0.01). The resistance indexes after transfection were decreased to 8 and 10 respectively as compared to 23 of the mock transfection (P < 0.01).
  
  
  CONCLUSIONS
  The shRNA could effectively reverse the multidrug resistance of K562/A02 cell line.
authors.affiliation: Department of Hematology, Central Laboratory, Hua-shan Hospital, Fudan University, Shanghai 200040, China.
authors.forename: Jing-wen
authors.initials: JW
authors.lastname: Gu
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.forename: Bo-bing
authors.initials: BB
authors.lastname: Chen
authors.forename: Yuan
authors.initials: Y
authors.lastname: Lu
authors.forename: Guo-wei
authors.initials: GW
authors.lastname: Lin
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics*; D018432:Drug Resistance, Multiple / Q000235:genetics*; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D019450:Genes, MDR / Q000235:genetics; D005822:Genetic Vectors; D051549:Glutathione S-Transferase pi / Q000235:genetics*; D006801:Humans; D020014:K562 Cells; D034622:RNA Interference; D034741:RNA, Small Interfering; D014162:Transfection
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D034741:RNA, Small Interfering; D051549:Glutathione S-Transferase pi