[Disruption of genomic imprinting in human carcinogenesis]

Several lines of evidence have suggested that the accumulation of specific gene alterations such as the activation of proto-oncogenes and the silencing of suppressor genes is indispensable for tumorigenesis. In addition, recent molecular studies demonstrated that epigenetic alteration also have an important role in the initiation and progression of human cancers. In particular, the parent-of-origin specific gene modification, named genomic imprinting, has been demonstrated to play a causative roles in several human cancers including renal tumors of childhood. Although the precise mechanisms of genomic imprinting have not been clarified yet, it is obvious that the DNA methylation could be one of the key machinery to regulate differential expression of genes. In near future, the rapid advance in molecular genetics of human cancer will be expected in terms of epigenetic modification of cancer-associated genes.