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Virchows Archiv

, Volume 434, Issue 6, pp 483–487 | Cite as

Overexpression of human telomerase RNA is an early event in oesophageal carcinogenesis

  • Toru Hiyama
  • Hiroshi Yokozaki
  • Yasuhiko Kitadai
  • K. Haruma
  • Wataru Yasui
  • Goro Kajiyama
  • E. Tahara
ORIGINAL ARTICLE

Abstract

 Telomerase, the ribonucleoprotein enzyme that elongates telomeres, is repressed in normal human somatic cells but is reactivated during tumour progression. The purpose of this study was to investigate the localization of human telomerase RNA (hTR) expression in human oesophageal dysplasia and cancer by using in situ mRNA hybridization (ISH) with avidin–biotin staining. Ki-67 immunoreactivity was also examined. We analysed 51 squamous cell carcinomas, 9 dysplasias and 60 normal mucosae. The integrity of the mRNA in each sample was verified by using a poly d(T)20 probe. Seventy-six samples (63%) showed no mRNA degradation; these included 30 carcinomas, 7 dysplasias and 39 normal mucosae. At the single-cell level, high levels of hTR expression were found in the cytoplasm and especially in the nucleus. Most (>90%) cancer cells demonstrated high levels of hTR expression in 29 (97%) of the 30 tumours. Most dysplastic cells also showed high levels of hTR in all 7 dysplastic cases. In all 39 normal mucosae, most basal cells indicated high levels of hTR expression, which were also seen in infiltrating lymphocytes. The distribution of hTR-expressing cells was similar to that of Ki-67-positive cells. These data suggest that overexpression of hTR may be correlated with the proliferative activity that defined by Ki-67 immunoreactivity and is an early event in carcinogenesis of the oesophagus.

Key words Human telomerase RNA In situ mRNA hybridization Oesophageal carcinoma Oesophageal dysplasia 

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Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • Toru Hiyama
    • 1
  • Hiroshi Yokozaki
    • 1
  • Yasuhiko Kitadai
    • 2
  • K. Haruma
    • 2
  • Wataru Yasui
    • 1
  • Goro Kajiyama
    • 2
  • E. Tahara
    • 1
  1. 1.First Department of Pathology, Hiroshima University School of Medicine, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-8551, Japan e-mail: etahara@mcai.med.hiroshima-u.ac.jp Tel.: +81-82-257-5145, Fax: +81-82-257-5149JP
  2. 2.First Department of Internal Medicine, Hiroshima University School of Medicine, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-8551, JapanJP

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