MicroRNA‐6869‐5p acts as a tumor suppressor via targeting TLR4/NF‐κB signaling pathway in colorectal cancer

Many studies have implicated that microRNAs (miRNAs), as non‐coding RNAs, play important roles in the development and progression of colorectal cancer (CRC). However, little is known about the role of a newly identified miRNA, miR‐6869‐5p, in CRC. We aim to investigate the modifying effects and underlying mechanisms of miR‐6869‐5 in colorectal carcinogenesis and progression. Significantly reduced levels of miR‐6869‐5p were observed in both serum exosomes tumor tissue samples from patients with CRC. The prediction of targets of miR‐6869‐5p in databases of targetscan, microRNA. ORG and miRDBA revealed that toll‐like receptor 4 (TLR4) is a potential target for this miRNA. MiR‐6869‐5p could inhibit cell proliferation and the production of inflammatory cytokines (TNF‐α and IL‐6) in CRC cells via directly targeting TLR4. The protective effect of miR‐6869‐5p from colorectal carcinogenesis was dependent on TLR4/NF‐κB signaling pathway. In addition, the 3‐year survival was poor among CRC patients with decreased levels of miR‐6869‐5p in serum exosomes. Thus, miR‐6869‐5p may serve as a tumor suppressor in CRC, and serum exosomal miR‐6869‐5p is a promising circulating biomarker for the prediction of CRC prognosis. MiR‐6869‐5p may serve as a tumor suppressor in CRC via TLR4/ NF‐κB signaling pathway, and serum exosomal miR‐6869‐5p is a promising circulating biomarker for the prediction of CRC prognosis.