title: Telomere length and telomerase expression in pituitary tumors.
abstract: OBJECTIVE
  Telomere dysfunction and telomerase activation underlie cancer transformation. This study aims to investigate the contribution of telomere biology to pituitary tumor behavior.
  
  
  METHODS
  Samples from 50 patients with pituitary tumors (11 ACTH-secreting, 18 GH-secreting, and 21 non-secreting tumors) and 7 subjects without pituitary lesions were collected. The expressions of telomerase essential components TERT and TERC and tumor telomere content were measured by quantitative PCR techniques.
  
  
  RESULTS
  Telomerase (TERT) expression was detected in 36% of tumors. No correlation was observed between TERT and TERC expression level and tumor size in any tumor type. There was no association between gene expression and clinical findings. Telomere content (T/S ratio) was similar between pituitary adenomas (0.39 ± 0.16) and normal pituitaries (0.47 ± 0.12; p = 0.24) and also was between the different adenoma types: ACTH-secreting (0.43 ± 0.08), GH-secreting (0.31 ± 0.12), and non-secreting (0.42 ± 0.20; p = 0.10) tumors.
  
  
  CONCLUSIONS
  The telomere content and expression of telomerase components are comparable between normal pituitary glands and tumor tissues, suggesting that telomere biology does not play an important role in pituitary tumor development.
authors.affiliation: Department of Internal Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Av Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil. cla_martins@yahoo.com.br.
authors.forename: C S
authors.initials: CS
authors.lastname: Martins
authors.affiliation: Department of Internal Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Av Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil.|Center for Cell-based Therapy, São Paulo Research Foundation (FAPESP), Ribeirao Preto, SP, Brazil.
authors.forename: B A
authors.initials: BA
authors.lastname: Santana-Lemos
authors.affiliation: Department of Pathology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
authors.forename: F P
authors.initials: FP
authors.lastname: Saggioro
authors.affiliation: Department of Pathology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
authors.forename: L
authors.initials: L
authors.lastname: Neder
authors.affiliation: Department of Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
authors.forename: H R
authors.initials: HR
authors.lastname: Machado
authors.affiliation: Department of Internal Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Av Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil.
authors.forename: A C
authors.initials: AC
authors.lastname: Moreira
authors.affiliation: Department of Internal Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Av Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil.|Center for Cell-based Therapy, São Paulo Research Foundation (FAPESP), Ribeirao Preto, SP, Brazil.
authors.forename: R T
authors.initials: RT
authors.lastname: Calado
authors.affiliation: Department of Internal Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Av Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil. castrom@fmrp.usp.br.
authors.forename: M
authors.initials: M
authors.lastname: de Castro
mesh_terms: D000328:Adult; D015870:Gene Expression / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000201:enzymology / Q000378:metabolism*; D012313:RNA / Q000378:metabolism; D019098:Telomerase / Q000378:metabolism*; D016615:Telomere / Q000378:metabolism*
chemical_list: C422952:telomerase RNA; D012313:RNA; C509186:TERT protein, human; D019098:Telomerase
keywords: Pituitary; Telomerase; Telomere; Tumor