title: ZM-66, a new podophyllotoxin derivative inhibits proliferation and induces apoptosis in K562/ADM cells.
abstract: OBJECTIVE
  To investigate the anti-tumor effect of ZM-66 on multidrug-resistant leukemic cell line K562/ADM.
  
  
  METHODS
  The K562/ADM cells were treated with varying concentrations (0, 1, 2, 4 × 10⁻³ mmol/L) of ZM-66 or etoposide for 24 hours. The proliferation was detected by Sulforhodamine B Sodium Salt (SRB) assay and apoptosis was detected by flow cytometry analysis and fluorescent staining. In addition, the expression levels of p53 and bax genes in K562/ADM cells were detected by RT-PCR analysis. The level of P-glycoprotein (P-gp), P53 and Bax protein in K562/ADM cells were detected by Western blot assay.
  
  
  RESULTS
  SRB assay demonstrated that etoposide had little inhibitory effect on K562/ADM cells, whereas ZM-66 (1, 2, 4 × 10⁻³ mmol/L) had significantly inhibitory effect on K562/ADM cells (all P<0.01). The acridine orange/propidium iodide dual staining showed that there were typical condensation of chromatin and nuclear fragmentation nuclei with red color in ZM-66 treated cells. Flow cytometric analysis showed that there was a significantly increase of apoptotic cells in K562/ADM cells after treated with ZM-66. RT-PCR showed that the p53 and bax mRNA expression levels in K562/ADM cells treated with ZM-66 at 1, 2, 4 × 10⁻³ mmol/L were higher than those in the cell without treatment. Western blot showed that the P53 and Bax protein expression levels in K562/ADM cells treated with ZM-66 at 2, 4 × 10⁻³ mmol/L were higher than those in the cell without treatment. But the P-gp protein expression level in K562/ADM cells treated with ZM-66 at 2, 4 × 10⁻³ mmol/L was gradually lower than those in the cell without treatment.
  
  
  CONCLUSIONS
  ZM-66 is able to induce cell death by apoptosis in vitro, as a result of the reverse of the apoptosis resistance in drug-resistant K562/ADM cells by modulating expression of key factors associated with apoptosis induction.
authors.affiliation: Department of Pharmacology, Logistics University of Chinese People's Armed Police Forces, Tianjin 300309, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Oral Pathology, Stomatological Hospital, Tianjin Medical University, Tianjin 300309, China.
authors.forename: Hong-jie
authors.initials: HJ
authors.lastname: Li
authors.affiliation: Department of Anatomy, Tianjin Medical University, Tianjin 300309, China.
authors.forename: Jian-sheng
authors.initials: JS
authors.lastname: Zhi
authors.affiliation: Department of Anatomy, Tianjin Medical University, Tianjin 300309, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
authors.affiliation: 1. Department of Pharmacology, Logistics University of Chinese People'
authors.forename: Wen-li
authors.initials: WL
authors.lastname: Xie
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D049109:Cell Proliferation / Q000187:drug effects*; D005434:Flow Cytometry; D006801:Humans; D020014:K562 Cells; D011034:Podophyllotoxin / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D012333:RNA, Messenger; C000593067:ZM-66 compound; D011034:Podophyllotoxin