Telomerase activity and the subunit of telomerase in hydatidiform mole and their relationship with the development of postmolar tumor

Objectives: To investigate the pattern of telomerase activity and the subunit of telomerase in normal placentae and GTD, and to determine the prognostic significance of telomerase activity and the subunit of telomerase in GTD. Methods: Telomerase activity human telomerase (hTERT) and human telomerase (hTR) expression were analyzed in the initial uterine evacuation specimen of 63 hydatidiform moles (HMs), 42 normal human placental tissues, 17 malignant gestational trophoblastic tumors, primary cultures of normal villi and JAR cell lines by use of the polymerase chain reaction-based telomeric repeat amplification protocol (TRAP) assay and reverse transcription-polymerase chain reaction (RT-PCR) methods. Results: Telomerase activity was 100% in primary cultures of normal villi and JAR cell lines and in less than 60-day early placental villi, while only 9.1% in greater than 60-day placental villi, 27% in HMs and 58% in malignant trophoblastic tumors. High levels of hTR could be found in all groups. hTR expression was detected in all cases of < 60-day placental villi, in 72.7% > 60-day placental villi, in 87.3% in HMs and 100% in malignant trophoblastic tumors. Telomerase activity and hTERT expression had significant differences among the groups. Telomerase activity was associated with serum hCG levels but not related to other clinical risk factors. Conclusions: Telomerase activity may be correlated with the development of trophoblastic tumors, and hTERT may be a useful diagnostic marker for detecting the existence of malignant trophoblastic cells.