title: Differential p53 protein expression level in human cancer-derived cell lines after estradiol treatment.
abstract: BACKGROUND
  p53 has a remarkable number of biological activities, including a central role in cell cycle checkpoints, apoptosis, senescence, and maintenance of genomic integrity. Its expression is modified by estradiol in some epithelial cancer-derived cell lines from the reproductive tract. The aim of this study was to evaluate the effect of low and high doses of estradiol in p53 gene expression in epithelial cancer-derived cell lines from the reproductive tract.
  
  
  METHODS
  p53 gene expression was assessed by Northern and Western blot methods in three human epithelial cancer-derived cell lines after estradiol treatment.
  
  
  RESULTS
  These indicated that no changes in p53 mRNA content occurred after estradiol treatment at both low (10 nM) and high (1 micro M) doses of estradiol in HeLa, CaLo, and C-33 cell lines. p53 protein content was nearly constant in HeLa and C-33 cell lines at administration of 10 nM of estradiol. However, when estradiol was administered at a higher dose (1 micro M), an increase in p53 protein was observed over time in HeLa and CaLo cell lines. In contrast, estradiol was without variations in C-33.
  
  
  CONCLUSIONS
  Overall results indicate that estradiol induces variations of p53 protein levels in epithelial cancer-derived cell lines from the reproductive tract in vitro and that this effect may be related with status p53 and/or presence of E6/E7 from human papillomavirus.
authors.affiliation: Unidad de Investigación Médica en Enfermedades Oncológicas, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social (IMSS), Mexico City, Mexico.
authors.forename: Irene
authors.initials: I
authors.lastname: Correa
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Cerbón
authors.forename: Ana Ma
authors.initials: AM
authors.lastname: Salazar
authors.forename: José Dolores
authors.initials: JD
authors.lastname: Solano
authors.forename: Alejandro
authors.initials: A
authors.lastname: García-Carrancá
authors.forename: Angelina
authors.initials: A
authors.lastname: Quintero
mesh_terms: D015152:Blotting, Northern; D015153:Blotting, Western; D002453:Cell Cycle / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D005833:Genital Neoplasms, Female / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D027383:Papillomaviridae / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; D004958:Estradiol