title: Zinc induces apoptosis on cervical carcinoma cells by p53-dependent and -independent pathway.
abstract: There is evidence that the mineral zinc is involved in the apoptotic cell death of various carcinoma cells. In this study, we aim to determine whether zinc in the form of CIZAR induces apoptosis in cervical carcinoma cells by increasing intracellular zinc concentration.
  
  
  
  CaSki and HeLa cervical carcinoma cells and HPV-16 DNA-transformed keratinocyte (CRL2404) were treated with different concentrations of CIZAR. The cell viability test was carried out, the intracellular level of zinc was determined, and apoptosis was confirmed by flow cytometry after propidium iodide (PI) staining and fluorescence microscopy under DAPI staining. The expression of cell-cycle regulators was analyzed by Western blot, including the knock down of p53 and expression of HPV E6 and E7 genes by RT-PCR.
  
  
  
  Intracellular zinc accumulation induced the down-regulation of E6/E7 proteins through targeting of the specific transcriptional factors in the upstream regulatory region. p53 was induced after CIZAR treatment and p53-dependent apoptosis did not occur after knock down by p53 siRNA. In cervical carcinoma cells, regardless of HPV-infection, CIZAR induces apoptosis by the activation of the p53-independent pathways through the up-regulation of p21waf1, the down-regulation of c-Myc, and by decreasing the Bcl-2/Bax ratio.
  
  
  
  CIZAR induces apoptosis not only through the restoration of p53/Rb-dependent pathways in HPV-positive cells, but also through the activation of p53/Rb-independent pathways and the mitochondrial death-signal pathway in cervical carcinoma cells regardless of HPV-infection.
authors.affiliation: Department of Obstetrics and Gynecology, Seoul St. Mary's Hospital, The Catholic University of Korea, Republic of Korea.
authors.forename: Seog Nyeon
authors.initials: SN
authors.lastname: Bae
authors.affiliation: Department of Obstetrics and Gynecology, Seoul St. Mary's Hospital, The Catholic University of Korea, Republic of Korea. Electronic address: hohoho@catholic.ac.kr.
authors.forename: Keun Ho
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Department of Obstetrics and Gynecology, Seoul St. Mary's Hospital, The Catholic University of Korea, Republic of Korea.
authors.forename: Jin Hwi
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Obstetrics and Gynecology, Seoul St. Mary's Hospital, The Catholic University of Korea, Republic of Korea.
authors.forename: Sung Jong
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Obstetrics and Gynecology, Seoul St. Mary's Hospital, The Catholic University of Korea, Republic of Korea.
authors.forename: Lae Ok
authors.initials: LO
authors.lastname: Park
mesh_terms: D052685:Alphapapillomavirus / Q000235:genetics; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D015536:Down-Regulation; D005260:Female; D005814:Genes, Viral; D016259:Genes, myc; D006801:Humans; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D015854:Up-Regulation; D002583:Uterine Cervical Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000821:virology; D015032:Zinc / Q000494:pharmacology*
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016159:Tumor Suppressor Protein p53; D015032:Zinc
keywords: CIZAR; Human papilloma virus; Mitochondrial death-signal pathway; Telomerase; Zinc