Genomic imprinting: a proposed explanation for the different behaviours of testicular and ovarian germ cell tumors.
Gonadal germ cell tumors in males are malignant in greater than 98% of cases while their ovarian counterparts are benign in 97% of cases. It has recently become clear that the maternal and paternal genomic contributions to the fertilized egg, provided by the haploid germ cells, have different and, to some extent, complementary effects on the developing embryo. This phenomenon, termed genomic imprinting, is a result of epigenetic modification of the genomes of male and female germ cells that has occurred in a sex-specific way during gametogenesis. There is a balance between the paternal and maternal effects in a normal embryo; results to date suggest that the paternal imprint promotes growth while the maternal imprint acts to limit potentially harmful overgrowth. It is proposed that differences in clinical behaviour between ovarian and testicular germ cell tumors can be explained by differences in the normal pattern of genomic imprinting of female and male germ cells.
Porter
S
S
Department of Pathology, University Hospital, University of British Columbia, Vancouver, Canada.
Gilks
C B
CB
D002872:Chromosome Deletion; D005260:Female; D018237:Germinoma / Q000235:genetics*; D006801:Humans; D008297:Male; D008957:Models, Genetic; D010051:Ovarian Neoplasms / Q000235:genetics*; D013736:Testicular Neoplasms / Q000235:genetics*