title: Telomere length is shorter in affected members of families with familial nonmedullary thyroid cancer.
abstract: BACKGROUND
  The theory that short telomere length and genetic defects in maintaining telomere length are associated with familial nonmedullary thyroid cancer (FNMTC) is controversial. Thus, the aim of this study was to determine whether telomere length and genes involved in maintaining telomere length are altered in FNMTC.
  
  
  METHODS
  Blood samples were collected from 44 members (13 affected and 31 unaffected) of six families with FNMTC and from 60 controls. Quantitative polymerase chain reaction (Q-PCR) and reverse transcription PCR were performed to analyze relative telomere length (RTL), gene copy number, and mRNA expression of telomerase reverse transcriptase (hTERT), telomere repeat binding factor 1 (TRF1), telomere repeat binding factor 2 (TRF2), repressor activator protein 1 (RAP1), TRF1 interacting nuclear factor 2 (TIN2), tripeptidyl peptidase 1 (TPP1), and protection of telomere 1 (POT1).
  
  
  RESULTS
  Affected members had shorter RTL, as compared with unaffected members (0.98 vs. 1.23, p<0.01). There was no significant difference in hTERT, TRF1, TRF2, RAP1, TIN2, TPP1, and POT1 gene copy number or mRNA expression between affected and unaffected members.
  
  
  CONCLUSIONS
  RTL is shorter in affected members with FNMTC but is not associated with altered copy number or expression in hTERT, TRF1, TRF2, RAP1, TIN2, TPP1, and POT1. The small differences in RTL preclude the utility of RTL as a marker for FNMTC in at-risk individuals.
authors.affiliation: Endocrine Oncology Branch, National Cancer Institute, Bethesda, Maryland 20892, USA.
authors.forename: Mei
authors.initials: M
authors.lastname: He
authors.forename: Brent
authors.initials: B
authors.lastname: Bian
authors.forename: Krisana
authors.initials: K
authors.lastname: Gesuwan
authors.forename: Neelam
authors.initials: N
authors.lastname: Gulati
authors.forename: Lisa
authors.initials: L
authors.lastname: Zhang
authors.forename: Naris
authors.initials: N
authors.lastname: Nilubol
authors.forename: Electron
authors.initials: E
authors.lastname: Kebebew
mesh_terms: D000328:Adult; D002277:Carcinoma / Q000235:genetics* / Q000378:metabolism; D002291:Carcinoma, Papillary; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D018628:Gene Dosage; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D000089804:Shelterin Complex; D011795:Surveys and Questionnaires; D019098:Telomerase / Q000235:genetics; D016615:Telomere / Q000648:ultrastructure*; D034501:Telomere-Binding Proteins / Q000235:genetics; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000378:metabolism; D013965:Thyroidectomy; D000091346:Tripeptidyl-Peptidase 1
chemical_list: D012333:RNA, Messenger; D000089804:Shelterin Complex; D034501:Telomere-Binding Proteins; D000091346:Tripeptidyl-Peptidase 1; D019098:Telomerase; C000717267:TPP1 protein, human