MicroRNAs: Novel immunotherapeutic targets in colorectal carcinoma

Figure 1 MicroRNAs control colorectal carcinoma progression through modulating anti-tumor immune responses in tumor microenvironment. MiRNAs play important roles in colorectal carcinoma (CRC) biology, including tumor proliferation, invasion/metastasis and immune responses. For example, miR-20b and miR-130b repress the expression of PTEN and increase the activity of PI3K, leading to the increased viability of CRC cells. MiR-21 promotes CRC invasion and metastasis by directly targeting PDCD4. Furthermore, miR-34a enhances CD8+ T cells cytotoxicity by repressing the expression of PD-L1, contributing to the elimination of CRC cells by CTLs.