Localization of telomerase hTERT protein and survivin in placenta: relation to placental development and hydatidiform mole

OBJECTIVE: To find if a difference in telomerase or survivin expression exists between non-neoplastic tissues and hydatidiform moles, and explore expression of those proteins in normal placental development, post-term gestation, and preeclampsia. METHODS: Formalin-fixed placental tissues were selected from collections of the Department of Pathology at the University of Colorado. Five specimens of each trimester, five each of preeclamptic and post-term placentas, and 23 molar pregnancies were selected. The telomerase catalytic protein hTERT was localized in placental tissues using the catalyzed signal amplification system, and survivin was localized by conventional immunoperoxidase method. Staining was graded on a scale of zero to 4. RESULTS: hTERT staining was detected in sections of 42 of 48 specimens (23 of 23 hydatidiform moles, 19 of 25 non-neoplastic placental tissues). The intensity of staining for hTERT was higher in hydatidiform moles (mean 3.3, median 3) compared with levels in non-neoplastic placental tissues (mean 0.92, median 1) (P <.001). Survivin was detected in 39 of 48 specimens (22 of 23 hydatidiform moles, 17 of 25 non-neoplastic placental tissues). Compared with non-neoplastic tissues (mean 0.88, median 1), survivin levels were elevated in hydatidiform moles (mean 1.35, median 1) (P =.031). CONCLUSION: Survivin and telomerase were increased in hydatidiform moles, suggesting that regulation of apoptosis and stabilization of telomere length might be involved in neoplastic transformation of the placenta. The patterns of expression observed for survivin and telomerase in non-neoplastic placental tissues suggest that the control of apoptosis and stabilization of telomeric DNA might also be involved in normal gestational development.