Characteristics of binding sites of intergenic, intronic and exonic miRNAs with mRNAs of oncogenes coding intronic miRNAs

International audience; The interaction of 784 intergenic (ig-miRNA), 686 intronic (in-miRNA) and 49 exonic miRNAs (ex-miRNA) with mRNAs of 51 oncogenes coding in-miRNAs was investigated. Out of the studied genes, 44 were targets for 94 ig-miRNAs, 29 were targets for 44 in-miRNAs and 7 were targets for 7 ex-miRNAs. The density of miRNA binding sites was higher in 5'-untranslated regions than it was in coding sequences and 3'-untranslated regions. Three types of miRNA interaction with mRNA were revealed: 5'-dominant canonical, 3'-compensatory and complementary types. In-miRNAs do not interact with mRNAs of host genes (where in-miRNA is encoded). Linkage between some mRNAs of genes encodes in-miRNAs via other in-miRNAs was revealed. These data promote the understanding of interaction mechanism of miRNA with mRNA genes participating in gastrointestinal and breast cancers.; L'interaction de miRNAs avec des mRNAs de 51 incogènes a été étudiée, Trois types d'interaction ont été mis en évidence. Ces données améliorent la compréhension du mécanisme d'interaction des miRNAs avec des gènes mRNAs impliqués dans des cancers de l'intestin ou du sein.