Decreased expression of miR-874 and its tumor suppressive function in human colorectal cancer

Dysregulation of miRNAs is associated with cancer development and progression. For example, aberrant expression of miR-874 has been found in some types of cancer. However, miR-874 expression and its clinical significance in colorectal cancer (CRC) have not yet been explored. The aim of the current study was to explore the effects of miR-874 in CRC tumorigenesis and development. Quantitative reverse-transcription PCR was performed to evaluate miR-874 levels in CRC cell lines and in 135 pairs of primary human CRC specimens and adjacent noncancerous tissues. The association of miR-874 expression with clinicopathological factors and prognosis was also analyzed. Furthermore, the effects of miR-874 on the biological behavior of CRC cells in vitro were investigated. Our results revealed that miR-874 expression was significantly downregulated in CRC cancer tissues and cell lines. Decreased miR-874 expression was significantly associated with larger tumor size, deeper invasion depth, and advanced TNM stage in vivo. Additionally, low miR-874 expression in CRC was an independent predictor of poor survival. Moreover, overexpression of miR-874 inhibited cell proliferation, invasion, and migration, and promoted cell apoptosis of the SW620 CRC cell line in vitro. Taken together, these findings indicate that miR-874 may act as a tumor suppressor in CRC, and may serve as a novel therapeutic target for miR-based therapy.