Molecular cloning of the canine telomerase reverse transcriptase gene and its expression in neoplastic and non-neoplastic cells.
OBJECTIVE
To perform molecular cloning of the canine telomerase reverse transcriptase (TERT) gene and determine its expression in neoplastic and non-neoplastic cells.


METHODS
9 canine tumor cell lines derived from various neoplasms, 16 primary canine tumors, and tissues from 15 normal canine organs.


METHODS
Tumor cell lines were derived from canine tumors that included osteosarcoma, mammary gland adenocarcinoma, melanoma, acute lymphoblastic leukemia, lymphoma, and mastocytoma and a canine primary fibroblast culture. Canine TERT complementary DNA (cDNA) was amplified by use of polymerase chain reaction (PCR) and sequenced. Expression of TERT mRNA was examined by reverse transcription (RT)-PCR assay. Telomerase activity was measured by use of the telomeric repeat amplification protocol assay.


RESULTS
The canine TERT cDNA clone was 237 base pairs in length and contained a central region encoding the reverse transcriptase motif 2. Expression of TERT mRNA was detected in canine tumor cell lines that had telomerase activity but not in telomerase-negative canine primary fibroblasts. The TERT mRNA was detected in 13 of 16 canine tumor tissues and several normal tissues such as liver, ovary, lymph node, and thymus. A significant correlation between TERT expression level and telomerase activity was noted.


CONCLUSIONS
Expression of TERT mRNA was closely associated with telomerase activity in neoplastic cells as well as some non-neoplastic cells from dogs. In addition to telomerase activity, expression of TERT mRNA can be used as a marker of tumor cells.
Yazawa
Mitsuhiro
M
Department of Veterinary Internal Medicine, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan.
Okuda
Masaru
M
Kanaya
Noriko
N
Hong
Sung-Hyeok
SH
Takahashi
Tomoko
T
Ohashi
Emi
E
Nakagawa
Takayuki
T
Nishimura
Ryohei
R
Sasaki
Nobuo
N
Masuda
Kenichi
K
Ohno
Koichi
K
Tsujimoto
Hajime
H
D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins; D004283:Dog Diseases / Q000201:enzymology* / Q000235:genetics; D004285:Dogs / Q000378:metabolism*; D004587:Electrophoresis, Agar Gel; D005347:Fibroblasts / Q000201:enzymology; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D008969:Molecular Sequence Data; D009369:Neoplasms / Q000201:enzymology / Q000235:genetics / Q000662:veterinary*; D012333:RNA, Messenger / Q000235:genetics; D012016:Reference Values; D019098:Telomerase / Q000235:genetics*; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D019098:Telomerase