ALTERED IMPRINTING OF THE H19 AND INSULIN-LIKE GROWTH-FACTOR-II GENESIN TESTICULAR-TUMORS

Purpose: H19 and insulin-like growth factor II (IGF2) genes are imprin ted in normal human tissues. Recent reports have described loss of imp rinting (LOI) for these genes in some malignancies. We therefore exami ned the allele-specific expression of the H19 and IGF2 genes in testic ular tumors. Materials and Methods: Restriction fragment length polymo rphisms were examined in 17 testicular germ cell tumors and 2 testicul ar malignant lymphomas. Results: All 4 informative testicular germ cel l tumors showed LOI for the H19 gene. Five of 9 informative germ cell tumors showed LOI for the IGF2 gene, while testicular lymphomas did no t show biallelic expression of the H19 or IGF2 gene. Conclusion: Loss of imprinting for the H19 and IGF2 genes in testicular seminomatous ge rm cell tumors may be involved in oncogenesis.