Abstract
microRNAs play key roles during various crucial cell processes such as proliferation, migration, invasion and apoptosis. Also, microRNAs have been shown to possess oncogenic and tumor-suppressive functions in human cancers. Here, we describe the regulation and function of miR-149 in colorectal cancer cell lines. miR-149 expression patterns were detected in human colorectal cell lines and tissue samples, and then focused on its role in regulation of cell growth, migration, invasion, and its target gene identification. Furthermore, the function of the target gene of miR-149 was analyzed in vitro and in vivo. miR-149 expression was downregulated in human colorectal cancer HCT116 and SW620 cell lines compared to the normal colon epithelial NCM460 cell line using quantitative real-time polymerase chain reaction methods. Further studies indicated that introduction of miR-149 was able to suppress cell migration and invasion. Then, EphB3 was identified as a direct target gene of miR-149 in colorectal cancer cells. Moreover, experiments in vitro showed that knockdown expression of EphB3 could suppress cell proliferation and invasion, and ectopic expression of EphB3 restored the phenotypes of CRC cell lines transfected with miR149. In addition, silencing of EphB3 significantly affected cycle progression distribution and increased apoptosis in CRC cell lines. Finally, in vivo results demonstrated that knockdown of EphB3 by siRNA inhibited tumor growth. In conclusion,the important role of miR-149 in colorectal cancer progression suggesting that miR-149 may serve as a therapeutic target for colorectal cancer treatment.