Abstract
In this study we investigated the biological role and mechanism of miR-198 in colorectal carcinoma (CRC). MiR-198 expression was shown to exhibit a strongly negative correlation with lymph node invasion, distant metastasis and patient survival in examinations of colorectal cancer tissues and paired normal colorectal mucosa tissues. fucosyl transferase 8 (FUT8) was identified as a potential target of miR-198 in bioinformatics analysis and luciferase reporter assays. Overexpression of miR-198 in CRC cell lines decreased FUT8 levels as shown by immunofluorescence analysis, and inhibited cell proliferation, migration, and invasion. These anti-tumor phenotypes were rescued by reconstitution of FUT8 expression. Furthermore, miR-198 was shown to target the 3'UTR of FUT8 directly to downregulate FUT8 expression at both mRNA and protein levels in qRT-PCR and Western blot analyses, respectively. In vivo, restoration of miR-198 significantly inhibited xenograft growth and invasion of CRC tumors in nude mice. Therefore, it could be concluded that miR-198 suppresses the proliferation and invasion of CRC by directly targeting FUT8.