MicroRNAs as Regulators, Biomarkers and Therapeutic Targets in the Drug Resistance of Colorectal Cancer.

Chemotherapy and targeted therapy are the main options for andvanced colorectal cancer (CRC). However, resistance to these therapies is a major challenge in the clinic. Understanding molecular mechanisms and developing effective strategies against the drug resistance are highly desired. Increasing evidence has revealed that microRNAs (miRNAs) are closely linked to drug resistance in CRC. The explosion of knowledge in this field has brought forward new predictive and therapeutic opportunities. In this review, we systemically summarize the roles of miRNAs as regulators, tissue or circulating biomarkers, and therapeutics in the CRC resistance to 5-fluorouracil (5-FU), oxaliplatin and anti-EGFR therapy. We also discuss the potential unsettled issues and future directions concerning these processes.