| Expression of hTERT mRNA in a mortal liver cell line during S phase without detectable telomerase activity. | |
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MedLine Citation:
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PMID: 15754032 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Normal human liver cells have a limited capacity for proliferation due to telomere shortening, whereas immortalized cells prevent shortening of the 3' single strand telomeric repeat by expressing telomerases, including human telomerase reverse transcriptase (hTERT). The hTERT transcript contains three deletion sites that give rise to alternatively spliced variants (ASVs). Recently, hTERT expression was observed in cycling primary presenescent human fibroblasts, which were believed to lack hTERT expression and telomerase activity. hTERT mRNA was expressed in the synthesis (S) phase of the cell cycle. Although hTERT mRNA has eight isoforms, it is not known which of the hTERT ASVs are expressed in S phase. In order to determine the possible relationships between the cell cycle and ASV expressions, we measured the full-length isoform and ASVs of hTERT mRNA in a mortal liver cell line and immortal cell lines that were synchronized in S phase of the cell cycle. Using RT nested-PCR analysis, the full-length isoform and alpha-deletion ASV of hTERT were detected in the LI90 mortal liver cell line at points when cells in S phase represented >48% of the cell population without detectable telomerase activity. hTERT was always expressed in the HLE and Huh-7 hepatocellular carcinoma cell lines, regardless of the cell cycle. Our results suggest the possibility that telomerase is regulated in a cell cycle-dependent manner in normal liver cells. |
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Authors:
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Kumi Nagao; Junko H Ohyashiki; Kazuma Ohyashiki; Keiko Tabata; Kenji Takai; Kazuhisa Kameyama; Soichi Kitano; Katsumi Kawano; Nozomu Hibi; Taichi Kanamaru; Hisashi Hisatomi |
Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: International journal of molecular medicine Volume: 15 ISSN: 1107-3756 ISO Abbreviation: Int. J. Mol. Med. Publication Date: 2005 Apr |
Date Detail:
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Created Date: 2005-03-08 Completed Date: 2005-08-04 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 9810955 Medline TA: Int J Mol Med Country: Greece |
Other Details:
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Languages: eng Pagination: 683-8 Citation Subset: IM |
Affiliation:
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Center for Molecular Biology and Cytogenetics, SRL, Inc., Hachioiji, Tokyo 192-0031, Japan. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Alternative Splicing
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genetics Carcinoma, Hepatocellular / enzymology, genetics DNA-Binding Proteins Humans Liver / metabolism* Reverse Transcriptase Polymerase Chain Reaction S Phase / genetics, physiology* Telomerase / biosynthesis, genetics* Telomere / genetics, metabolism |
| Chemical | |
Reg. No./Substance:
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0/DNA-Binding Proteins; EC 2.7.7.49/Telomerase |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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