Genomic imprinting in testicular germ cell tumours

Genomic imprinting refers to the parental origin-specific functional difference between the paternally and maternally-derived mammalian haploid genome. Normal embryogenesis depends on the presence of both a paternal and a maternal copy of particular chromosomal regions, containing the so-called imprinted genes. Genomic imprinting is established somewhere in the maturation from a primordial germ cell to a mature gamete, either spermatid or oocyte. We discuss the value of testicular cancers, especially those derived from the germ cell lineage, as a model to study erasement of the biparental pattern of genomic imprinting as present in the zygote and establishment of the paternal pattern during spermatogenesis. In addition, we will present data on the presence of X-inactivation in these cancers.