Published online Jun 21, 2016. doi: 10.3748/wjg.v22.i23.5317
Peer-review started: March 25, 2016
First decision: April 14, 2016
Revised: April 23, 2016
Accepted: May 4, 2016
Article in press: May 4, 2016
Published online: June 21, 2016
Colorectal carcinoma (CRC) is one of the most common types of cancer worldwide and the prognosis for CRC patients with recurrence or metastasis is extremely poor. Although chemotherapy and radiation therapy can improve survival, there are still numerous efforts to be performed. Immunotherapy is frequently used, either alone or in combination with other therapies, for the treatment of CRC and is a safe and feasible way to improve CRC treatment. Furthermore, the significance of the immune system in the biology of CRC has been demonstrated by retrospective assessments of immune infiltrates in resected CRC tumors. MicroRNAs (miRNAs) are short, non-coding RNAs that can regulate multiple target genes at the post-transcriptional level and play critical roles in cell proliferation, differentiation and apoptosis. MiRNAs are required for normal immune system development and function. Nevertheless, aberrant expression of miRNAs is often observed in various tumor types and leads to immune disorders or immune evasion. The immunomodulatory function of miRNAs indicates that miRNAs may ultimately be part of the portfolio of anti-cancer targets. Herein, we will review the potential roles of miRNAs in the regulation of the immune response in CRC and then move on to discuss how to utilize different miRNA targets to treat CRC. We also provide an overview of the major limitations and challenges of using miRNAs as immunotherapeutic targets.
Core tip: Colorectal carcinoma (CRC) is one of the most common tumor types worldwide. Immunotherapy has been used to treat advanced CRC and has the potential to eradicate the disease by activating immune responses. MicroRNAs play critical roles in regulating anti-tumor immune responses. There is a need to summarize the current understanding of the diverse roles of microRNAs in the regulation of immune responses and their clinical applications for CRC immunotherapy.