The Regulation of miRNAs in Inflammation-Related Carcinogenesis

Chronic inflammation plays important roles in the initiation and development of various cancers, particularly gastrointestinal cancer. Cancer is characterized by stepwise accumulation of genetic and epigenetic alterations of genes. As a high risk factor for cancer, chronic inflammatory response produces great amount of mediators, including cytokines, reactive oxygen and nitrogen species, proteinases, which can induce genetic and epigenetic changes of cancer-associated genes and pathways. Furthermore, inflammation also modulates the expression of miRNAs that not only regulate the expression of tumor-related proteins but also enhance the tumor-promoting inflammatory process. In the current review, we summarize the mechanisms by which inflammatory mediators and signaling regulate the biosynthesis of miRNAs, as well as the involvement of miRNAs in the feedback loops promoting inflammation-associated carcinogenesis.