hTERT gene copy number is not associated with hTERT RNA expression or telomerase activity in colorectal cancer
2005 (English)In: International Journal of Cancer, ISSN 0020-7136, E-ISSN 1097-0215, Vol. 116, no 3, 395-400 p.Article in journal (Refereed) Published
In a majority of malignant human tumors telomerase activity can be detected, suggesting an immortal phenotype. Expression of the reverse transcriptase subunit, hTERT, in the human telomerase complex is required for telomerase activity. The regulation of hTERT, from gene level to a fully functional protein, is still a poorly understood process. Increased copy number of the hTERT gene has been demonstrated in a significant portion of established cell lines and tumors of different origin but its relevance for telomerase activity levels is unclear. In the present study, we examined the hTERT gene copy number using fluorescence in situ hybridization (FISH) in samples from 64 colorectal carcinomas and an increased copy number (≥ 3 hTERT gene copies/nucleus) was observed in 31 cases (48%). No statistical association existed between hTERT gene copy number and hTERT RNA expression or telomerase activity. However, a significant relationship was found between an increase in hTERT gene copy number and p53 protein accumulation (p = 0.002) and aneuploidy (p = 0.036). Only 4 tumors showed microsatellite instability, 3 of which had a normal hTERT gene copy number. The data indicated that the increased copy number of the hTERT gene in colorectal carcinoma was a result of genomic instability with no obvious consequence for telomerase activity levels.
Place, publisher, year, edition, pages
Geneve: International union against cancer , 2005. Vol. 116, no 3, 395-400 p.
Aneuploidy, Colorectal Neoplasms/*enzymology/*genetics, DNA-Binding Proteins, Gene Dosage, Humans, In Situ Hybridization; Fluorescence, Microsatellite Repeats, RNA/biosynthesis, Telomerase/*biosynthesis/*genetics/*physiology
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:umu:diva-7761DOI: 10.1002/ijc.21020PubMedID: 15818616OAI: oai:DiVA.org:umu-7761DiVA: diva2:147432