Telomerase reverse transcriptase (TERT) expression in canine mammary tissues: a specific marker for malignancy?
BACKGROUND
Telomerase reverse transcriptase (TERT), the catalytic subunit of the enzyme telomerase, is expressed in virtually all human tumors. Telomerase activity has also been reported in the majority of canine tumors and dogTERT also correlates with the enzyme activity.


METHODS
DogTERT expression in normal and malignant mammary tissues was investigated by immunohistochemistry and RT-PCR.


RESULTS
Using a highly specific TERT antibody in canins for the first time, immunoreactivity was identified in 46/50 malignant tumors, 26/50 adjacent to the tumor mammary tissues and 0/4 healthy mammary tissues. Two patterns of immunostaining were observed: cytoplasmic and concomitant nuclear and cytoplasmic. DogTERT mRNA was detected in 48/50 malignant tissues, 44/50 adjacent mammary tissues and in 2/4 healthy mammary tissues.


CONCLUSIONS
The observation that normal canine mammary epithelium expresses TERT challenges the conventional view that this gene is repressed in somatic and activated in malignant cells and supports the notion that dogTERT may not be a useful marker for canine mammary cancer.
Zavlaris
Michael
M
Laboratory of Pathology, School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Angelopoulou
Katerina
K
Vlemmas
Ioannis
I
Papaioannou
Nikolaos
N