DOC-2 HDAB2, A CANDIDATE TUMOR-SUPPRESSOR GENE INVOLVED IN THE DEVELOPMENT OF GESTATIONAL TROPHOBLASTIC DISEASES/

Gestational trophoblastic diseases comprise a spectrum of interrelated diseases including partial mole, complete mole and gestational chorio carcinoma, Using reverse transcriptase PCR (RT-PCR) analysis, we ident ified higher levels of DOC-2/hDab2 expression in the normal trophoblas t cells in culture than in choriocarcinoma cell lines. Subsequent stud y using immunohistochemistry showed high levels of DOC-2/hDab2 protein expression in normal trophoblast tissues but significantly lower leve ls of expression in gestational trophoblastic disease tissues, particu larly in complete mole and choriocarcinoma. When DOC-2/hDab2 was trans fected into the choriocarcinoma cell lines, Jar, JEG and BeWo, the sta ble transfectants showed significantly reduced growth rate in culture. These data suggest that down regulation of DOC-2/hDab2 may play an im portant role in the development of gestational trophoblastic diseases.