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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2003-8-13
pubmed:abstractText
A tumor-specific targeting system for cancer gene therapy was studied using the human telomerase reverse transcriptase (hTERT) promoter. Telomerase activity is increased in most tumors but not detected in most normal cells. We developed the recombinant adenovirus, carrying human herpes simplex virus thymidine kinase gene under the control of the hTERT promoter (AdhTERTtk) to obtain restricted expression of a suicide gene only in tumor cells. We found that transcriptional activity of hTERT was 2- to 9-fold higher in undifferentiated thyroid carcinoma cell lines than that of the Simian virus 40 promoter in transient transfection assay. Undifferentiated thyroid carcinoma cell lines were infected with AdhTERTtk, and sensitivity to ganciclovir (GCV) was analyzed. Cell viability was decreased in a GCV dose-dependent manner after treatment with AdhTERTtk/GCV. The cell-killing ability of AdhTERTtk in all thyroid or nonthyroid carcinoma cell lines tested was similar to AdCMVtk, which carries herpes simplex virus thymidine kinase gene driven by the cytomegalovirus promoter. However, normal cell lines were largely unaffected by AdhTERTtk/GCV, whereas these cells were also sensitive to GCV after infection with AdCMVtk. A xenograft model was established by transplanting human differentiated or undifferentiated thyroid carcinoma cells into Balb-C nude mice. The injections of AdhTERTtk into tumors and ip administration of GCV showed significant inhibition of tumor growth, similar to AdCMVtk/GCV treatment. Systemic administrations of adenovirus and GCV to normal rats demonstrated remarkable increase of serum liver transaminase levels and severe hepatic damages in pathological examinations in AdCMVtk-injected rats but not in the AdhTERTtk group. These results indicate that the AdhTERTtk/GCV system is a promising therapy for undifferentiated thyroid carcinoma, which is one of the most malignant tumors, without damage to normal tissues.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-972X
pubmed:author
pubmed:issnType
Print
pubmed:volume
88
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3531-8
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Tumor-specific gene therapy for undifferentiated thyroid carcinoma utilizing the telomerase reverse transcriptase promoter.
pubmed:affiliation
Department of Aging Medicine and Geriatrics, Shinshu University, Graduate School, Matsumoto, Nagano 390-8621, Japan. teiji@hsp.md.shinshu-u.ac.jp
pubmed:publicationType
Journal Article