Cancro, oncogeni e trasposizioni genomiche

Corneo, GianMarco

Atti della Accademia nazionale dei Lincei. Rendiconti della Classe di scienze fisiche, matematiche e naturali, Série 8, Tome 72 (1982) no. 2, pp. 77-85

Résumé

Transposable elements are nucleotide sequences, often middle repeated DNAs, which can move from one point to another of the eukaryote genome. They are thought to be involved in the control of development, differentiation and growth processes. Proviruses seem to be comparable in many aspects to transposable elements. There are two types of oncogenic retroviruses: the first one determines transformation rapidly, contains oncogenes and is defective, the second one induces transformation slowly, does not contain oncogenes and is not defective. Oncogenes are normal constituents of cellular genomes which can be induced to increase their expression by tumoral promoters. Retrovirus genomes have at their ends long terminal repeats, which might act as promoters of oncogene expression. Genomic transpositions, like chromosomal translocations, might induce neoplastic transformation by insertion of oncogenes in transcriptionally active sections of the genome. Studies are being carried out in several laboratories to identify oncogenes and products of their functional activity in human cancer cells.