Expression of human telomerase reverse transcriptase and correlation with telomerase activity in placentas with and without intrauterine growth retardation.
BACKGROUND
Human telomerase reverse transcriptase has been found in telomerase-positive tumor tissues, but not in telomerase-negative nonmalignant somatic cells.


METHODS
Thirty-two first-trimester chorionic villi specimens (Group A), 33 second- and third-trimester placenta specimens without asymmetric intrauterine growth retardation (Group B) and 13 specimens of placenta tissue from cases with intrauterine growth retardation (Group C) were examined for telomerase activity and expression of human telomerase reverse transcriptase by reverse transcription polymerase chain reaction and quantitative reverse transcription polymerase chain reaction.


RESULTS
Telomerase activity was detected in 29 of the 32 specimens (90.6%) in Group A, in 20 of the 33 specimens (60.6%) in Group B and none of the 13 specimens (0.0%) in Group C. Human telomerase reverse transcriptase was identified in all 32 specimens of Group A (100%), all 33 specimens of Group B (100%) and 2 of the 13 specimens in Group C (15.4%) by nested reverse transcription polymerase chain reaction. Copy numbers of human telomerase reverse transcriptase were 202.3 +/- 73.0 (n=32), 8.8 +/- 2.9 (n=33) and 0 (n=13) in Groups A, B, and C, respectively. Significant differences were observed between Groups A and B, Groups A and C, and Groups B and C (p <0.01, p < 0.01, and p < 0.01, respectively).


CONCLUSIONS
Our findings indicate that human telomerase reverse transcriptase expression is the rate-limiting determinant of telomerase activity in chorionic villi during the first trimester. Telomerase activity was not detected in placentas with intrauterine growth retardation, whereas human telomerase reverse transcriptase was expressed in some placentas with intrauterine growth retardation.
Izutsu
Toshihiko
T
Department of Obstetrics and Gynecology, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate 020-8505, Japan. tizutsu@iwate-med.ac.jp
Izutsu
Naoko
N
Iwane
Ayako
A
Takada
Anna
A
Nagasawa
Takayuki
T
Kanasugi
Tomonobu
T
Sugiyama
Toru
T
D015193:Chorionic Villi Sampling; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005260:Female; D005317:Fetal Growth Retardation / Q000378:metabolism*; D006801:Humans; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019098:Telomerase / Q000378:metabolism*
D004268:DNA-Binding Proteins; D019098:Telomerase