Abstract: As an internal environment of tumor occurrence, tumor microenvironment is composed of a variety of cells and extracellular matrix, and plays a crucial role in tumor formation, transfer and resistance to drugs. The regulation of tumor microenvironment will be a potential target to control the cancer. MicroRNAs (miRNAs) are a kind of 21 to 25 nucleotides single-stranded RNA, and are mainly involved in regulating gene expression. Recently, with the suggestion of cellular autonomous tumor inhibition mechanism, the regulation of tumor microenvironment by miRNAs has received great attention. This review summarizes recent findings on the non-cell-autonomous mechanisms of miRNAs-mediated regulation of tumor micro⁃ environments, which provides foundations and perspective on the design of therapeutic interventions.

Key words: microRNAs, tumor, microenvironment, non-cell-autonomous function, gene expression regulation, immunity, cellular, review