Human imprinted genes as oncodevelopmental markers.

Imprinted genes mediate unique maternal or paternal genetic roles and their function is essential in prenatal development. The reciprocally imprinted human insulin-like growth factor 2 (IGF2) and H19 genes are expressed during embryonal life, also in the placenta, and are downregulated postnatally. They reexpress in pediatric tumors (e.g. Wilms' tumor) and in inborn developmental syndromes predisposing to such tumors (e.g., Beckwith-Wiedemann syndrome). H19 (RNA transcripts) and IGF2 are manifested in Wilms' tumor, rhabdomyosarcoma, immature ovarian teratoma and gestational trophoblastic diseases. We have found that in the placenta and in urothelial carcinoma, H19 expression reflects the degree of invasiveness. These genes, displaying a tissue-specific oncofetal pattern of expression, are, therefore, tumor markers.