Abstract
Colon cancer is the third most common cancer worldwide. Many miRNAs have been reported to be involved in colon cancer progression. However, there are only a few studies on the role of miR-219a-1 in colon cancer, and the molecular mechanisms involved remain unclear. The aim of this study was to investigate the miR-219a-1 level in patients with colon cancer and to explore both the effects and regulatory mechanisms of miR-219a-1 in the malignancy of colon cancer cells. Real-time PCR and western blot analysis were used to analyze the expression levels of miR-219a-1 and mediator of ErbB2-driven cell motility 1. Cell Counting Kit-8, transwell and wound-healing assays were performed to investigate the malignant ability of colon cancer cells. A luciferase assay was performed to explore whether miR-219a-1 could directly bind to 3'-UTR region of MEMO1. miR-219a-1 was found to be downregulated in colon cancer cell lines and in patients with colon cancer. Additionally, miR-219a-1 could inhibit colon cancer cell proliferation, invasion and migration. We identified MEMO1 as a novel potential target gene of miR-219a-1. Luciferase assays showed that miR-219a-1 could directly bind to 3'-UTR of MEMO1. Overexpression of miR-219a-1 in colon cancer cells could inhibit the expression of MEMO1. Furthermore, MEMO1 was upregulated in patients with colon cancer, which was inversely correlated with miR-219a-1 levels. In conclusion, our study revealed that miR-219a-1 exerts anti-tumor effects and regulates colon cancer cell proliferation, invasion and migration by targeting MEMO1, suggesting that miR-219a-1 could act as a therapeutic target in colon cancer.