title: Resistance to apoptosis of harringtonine-resistant HL60 cells induced by tetrandrine.
abstract: OBJECTIVE
  To study the mechanism of resistance to apoptosis in the harringtonine (Har)-resistant HL60 cells with tetrandrine (Tet).
  
  
  METHODS
  Growth inhibition, flow cytometry, DNA agarose gel electrophoresis, protein phosphorylation, and RNA dot hybridization.
  
  
  RESULTS
  The resistant cells had no cross resistance to Tet. Tet induced the sensitive but not the Har-resistant HL60 cells to apoptosis. The high phosphorylation of protein < 30 kDa occurred when the resistant cells were treated with Tet. Tet and Har increased the expression of c-myc mRNA in the sensitive HL60 cells. The expression of c-myc mRNA in the resistant cells was obviously decreased and almost not changed in treatment with Tet and Har.
  
  
  CONCLUSIONS
  Tet induced the sensitive but not the Har-resistant HL60 cells to apoptosis, and the resistance to apoptosis induced by Tet was associated with the high protein phosphorylation and reduction of the expression of c-myc mRNA.
authors.affiliation: Department of Biology, Beijing Normal University, China.
authors.forename: Q Y
authors.initials: QY
authors.lastname: He
authors.forename: H Q
authors.initials: HQ
authors.lastname: Zhang
authors.forename: D B
authors.initials: DB
authors.lastname: Pang
authors.forename: X S
authors.initials: XS
authors.lastname: Chi
authors.forename: S B
authors.initials: SB
authors.lastname: Xue
mesh_terms: D000470:Alkaloids / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D044182:Benzylisoquinolines; D019008:Drug Resistance, Neoplasm; D016259:Genes, myc; D018922:HL-60 Cells / Q000187:drug effects; D006248:Harringtonines / Q000494:pharmacology*; D006801:Humans; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D000470:Alkaloids; D000972:Antineoplastic Agents, Phytogenic; D044182:Benzylisoquinolines; D006248:Harringtonines; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; C009438:tetrandrine