title: Telomere length, telomerase activity, and expressions of human telomerase mRNA component (hTERC) and human telomerase reverse transcriptase (hTERT) mRNA in pulmonary neuroendocrine tumors.
abstract: BACKGROUND
  Telomeres are important for chromosome structure and function, protecting them against degradation. However, few studies have examined telomeres in pulmonary neuroendocrine (NE) tumors.
  
  
  METHODS
  We investigated deparaffinized sections obtained from 70 primary NE lung tumors [34 typical carcinoids (TCs), 10 atypical carcinoids (ACs), 16 large cell neuroendocrine carcinoma (LCNECs) and 10 small cell lung carcinomas (SCLCs)].
  
  
  RESULTS
  Positive expressions of human telomerase mRNA component (hTERC) and human telomerase reverse transcriptase (hTERT) mRNA were recognized, respectively, in 58% and 74% of TCs, and in 100% and 100% of ACs, LCNECs and SCLCs. Alteration of telomere length was greater in both LCNECs and SCLCs than in TCs. Telomerase activity was detected in LCNECs, but not in TCs. By the reverse-transcriptase polymerase chain reaction (RT-PCR), hTERC mRNA was detected in 100% of LCNECs and TCs examined, while hTERT mRNA was detected in 67% of LCNECs, but not at all in TCs.
  
  
  CONCLUSIONS
  These results suggest that alterations in telomere length, telomerase activity, and the expression of hTERT mRNA may (i) play roles in pathogenesis in pulmonary neuroendocrine tumors, and (ii) be a useful tool for differential diagnosis between TCs and LCNECs.
authors.affiliation: Department of Pathology and Laboratory Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Nishio
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Nakanishi
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ozeki
authors.forename: Shi-Xu
authors.initials: SX
authors.lastname: Jiang
authors.forename: Toru
authors.initials: T
authors.lastname: Kameya
authors.forename: Akira
authors.initials: A
authors.lastname: Hebisawa
authors.forename: Makio
authors.initials: M
authors.lastname: Mukai
authors.forename: William D
authors.initials: WD
authors.lastname: Travis
authors.forename: Teri J
authors.initials: TJ
authors.lastname: Franks
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Kawai
mesh_terms: D018278:Carcinoma, Neuroendocrine / Q000201:enzymology* / Q000235:genetics* / Q000473:pathology; D006801:Humans; D017403:In Situ Hybridization; D008175:Lung Neoplasms / Q000201:enzymology* / Q000235:genetics* / Q000473:pathology; D012313:RNA / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019098:Telomerase / Q000096:biosynthesis / Q000378:metabolism*; D016615:Telomere / Q000648:ultrastructure*
chemical_list: D012333:RNA, Messenger; C422952:telomerase RNA; D012313:RNA; C509186:TERT protein, human; D019098:Telomerase