MicroRNA-141 Regulates Smad Interacting Protein 1 (SIP1) and Inhibits Migration and Invasion of Colorectal Cancer Cells

Colorectal cancer (CRC) is the third most common cancer in the world. Despite recent advances in diagnostics and treatment, prognosis for patients with advanced disease is still poor. microRNAs (miRNAs) are a class of endogenous, small noncoding RNA molecules which are crucial regulators of gene expression at the posttranscriptional level. miRNAs participate in many biological events and play an important role in various human diseases, including CRC. This study is to identify the role of miR-141 in migration and invasion of CRC cells. Expression of miR-141 and Smad interacting protein 1 (SIP1) were detected by real-time reverse-transcription polymerase chain reaction (RT-PCR) and Western blotting. The effect of miR-141 on migration and invasion of CRC cells was investigated using wound healing assay and Matrigel invasion assay in vitro. The regulation effect of miR-141 on SIP1 was evaluated by dual-luciferase reporter assay. We demonstrated that miR-141 levels correlate inversely with SIP1 protein levels as well as cell migration and invasion of CRC cells. SIP1 was identified as a functional target of miR-141. miR-141 regulates SIP1 to inhibit migration and invasion of CRC cells. miR-141 and SIP1 might be candidate therapeutic targets in CRC.