Japanese Journal of Clinical Oncology Advance Access originally published online on October 23, 2006
Japanese Journal of Clinical Oncology 2007 37(1):16-22; doi:10.1093/jjco/hyl118
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© 2006 Foundation for Promotion of Cancer Research
Telomere Length, Telomerase Activity, and Expressions of Human Telomerase mRNA Component (hTERC) and Human Telomerase Reverse Transcriptase (hTERT) mRNA in Pulmonary Neuroendocrine Tumors
1 Department of Pathology and Laboratory Medicine
2 Department of Surgery, National Defense Medical College, Tokorozawa, Saitama
3 Department of Pathology, Kitasato University, Sagamihara, Kanagawa
4 Pathology Division, Shizuoka Cancer Center Hospital and Research Institute, Sunto-gun, Shizuoka
5 Department of Pathology, National Tokyo Hospital, Kiyose, Tokyo
6 Division of Diagnostic Pathology, Keio University School of Medicine, Tokyo, Japan
7 Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY
8 Armed Forces Institute of Pathology, Washington DC, USA
For reprints and all correspondence: Kuniaki Nakanishi, Department of Pathology and Laboratory Medicine, National Defense Medical College, Tokorozawa 359-8513, Japan. E-mail: nknsknak{at}ndmc.ac.jp
Received May 15, 2006; accepted August 18, 2006
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.
Key Words: Telomere telomerase human telomerase mRNA component (hTERC) telomerase reverse transcriptase (hTERT) neuroendocrine tumors